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Sample records for crystallization rate factor

  1. Measurements of Protein Crystal Face Growth Rates

    Science.gov (United States)

    Gorti, S.

    2014-01-01

    Protein crystal growth rates will be determined for several hyperthermophile proteins.; The growth rates will be assessed using available theoretical models, including kinetic roughening.; If/when kinetic roughening supersaturations are established, determinations of protein crystal quality over a range of supersaturations will also be assessed.; The results of our ground based effort may well address the existence of a correlation between fundamental growth mechanisms and protein crystal quality.

  2. Crystal modifications and dissolution rate of piroxicam.

    Science.gov (United States)

    Lyn, Lim Yee; Sze, Huan Wen; Rajendran, Adhiyaman; Adinarayana, Gorajana; Dua, Kamal; Garg, Sanjay

    2011-12-01

    Piroxicam is a nonsteroidal anti-inflammatory drug with low aqueous solubility which exhibits polymorphism. The present study was carried out to develop polymorphs of piroxicam with enhanced solubility and dissolution rate by the crystal modification technique using different solvent mixtures prepared with PEG 4000 and PVP K30. Physicochemical characteristics of the modified crystal forms of piroxicam were investigated by X-ray powder diffractometry, FT-IR spectrophotometry and differential scanning calorimetry. Dissolution and solubility profiles of each modified crystal form were studied and compared with pure piroxicam. Solvent evaporation method (method I) produced both needle and cubic shaped crystals. Slow crystallization from ethanol with addition of PEG 4000 or PVP K30 at room temperature (method II) produced cubic crystal forms. Needle forms produced by method I improved dissolution but not solubility. Cubic crystals produced by method I had a dissolution profile similar to that of untreated piroxicam but showed better solubility than untreated piroxicam. Cubic shaped crystals produced by method II showed improved dissolution, without a significant change in solubility. Based on the XRPD results, modified piroxicam crystals obtained by method I from acetone/benzene were cube shaped, which correlates well with the FTIR spectrum; modified needle forms obtained from ethanol/methanol and ethanol/acetone showed a slight shift of FTIR peak that may be attributed to differences in the internal structure or conformation.

  3. Crystallized Rate Regions for MIMO Transmission

    Directory of Open Access Journals (Sweden)

    Debbah Merouane

    2010-01-01

    Full Text Available When considering the multiuser SISO interference channel, the allowable rate region is not convex and the maximization of the aggregated rate of all the users by the means of transmission power control becomes inefficient. Hence, a concept of the crystallized rate regions has been proposed, where the time-sharing approach is considered to maximize the sumrate.In this paper, we extend the concept of crystallized rate regions from the simple SISO interference channel case to the MIMO/OFDM interference channel. As a first step, we extend the time-sharing convex hull from the SISO to the MIMO channel case. We provide a non-cooperative game-theoretical approach to study the achievable rate regions, and consider the Vickrey-Clarke-Groves (VCG mechanism design with a novel cost function. Within this analysis, we also investigate the case of OFDM channels, which can be treated as the special case of MIMO channels when the channel transfer matrices are diagonal. In the second step, we adopt the concept of correlated equilibrium into the case of two-user MIMO/OFDM, and we introduce a regret-matching learning algorithm for the system to converge to the equilibrium state. Moreover, we formulate the linear programming problem to find the aggregated rate of all users and solve it using the Simplex method. Finally, numerical results are provided to confirm our theoretical claims and show the improvement provided by this approach.

  4. Role of Solvents in Improvement of Dissolution Rate of Drugs: Crystal Habit and Crystal Agglomeration

    Directory of Open Access Journals (Sweden)

    Maryam Maghsoodi

    2015-03-01

    Full Text Available Crystallization is often used for manufacturing drug substances. Advances of crystallization have achieved control over drug identity and purity, but control over the physical form remains poor. This review discusses the influence of solvents used in crystallization process on crystal habit and agglomeration of crystals with potential implication for dissolution. According to literature it has been known that habit modification of crystals by use of proper solvents may enhance the dissolution properties by changing the size, number and the nature of crystal faces exposed to the dissolution medium. Also, the faster dissolution rate of drug from the agglomerates of crystals compared with the single crystals may be related to porous structure of the agglomerates and consequently their better wettability. It is concluded from this review that in-depth understanding of role of the solvents in crystallization process can be applied to engineering of crystal habit or crystal agglomeration, and predictably dissolution improvement in poorly soluble drugs.

  5. Computing the crystal growth rate by the interface pinning method

    DEFF Research Database (Denmark)

    Pedersen, Ulf Rørbæk; Hummel, Felix; Dellago, Christoph

    2015-01-01

    -phase configurations are stabilized by adding a spring-like bias field coupling to an order-parameter that discriminates between the two phases. Crystal growth is a Smoluchowski process and the crystal growth rate can, therefore, be computed from the terminal exponential relaxation of the order parameter. The approach...... from first principles. A generalized version of the method may be used for computing the rates of crystal nucleation or other rare events....

  6. Correlating dynamic amino acid properties with success rate of crystallization of proteins from Bacteroides vulgatus

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Shaomin [State Key Laboratory of Non-food Biomass Enzyme Technology, National Engineering Research Center for Non-food Biorefinery, Guangxi Key Laboratory of Biorefinery, Guangxi Academy of Sciences, 98 Daling Road, Nanning, Guangxi, 530007 (China); Wu, Guang [State Key Laboratory of Non-food Biomass Enzyme Technology, National Engineering Research Center for Non-food Biorefinery, Guangxi Key Laboratory of Biorefinery, Guangxi Academy of Sciences, 98 Daling Road, Nanning, Guangxi, 530007 (China); DreamSciTech Consulting, 301, Building 12, Nanyou A-zone, Jiannan Road, Shenzhen, Guangdong, 518054 (China)

    2012-05-15

    To enhance the success rate of protein crystallization, many studies were conducted to determine the relationship between amino acid properties and the success rate of protein crystallization. Although those were successful, new efforts should be made to search for the new factors, which affect protein crystallization. In this study, two dynamic amino acid properties were used to correlate with the success rate of crystallization of proteins from Bacteroides vulgatus, because the amino acid properties used in previous studies were steady. As previously done, logistic regression and neural network were used to model that relationship, and the results were compared against those obtained from each of 532 amino acid properties, which severed as benchmark. The results demonstrated that dynamic amino acid properties should be taken into consideration of protein crystallization. (copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  7. Calcite crystal growth rate inhibition by polycarboxylic acids

    Science.gov (United States)

    Reddy, M.M.; Hoch, A.R.

    2001-01-01

    Calcite crystal growth rates measured in the presence of several polycarboxyclic acids show that tetrahydrofurantetracarboxylic acid (THFTCA) and cyclopentanetetracarboxylic acid (CPTCA) are effective growth rate inhibitors at low solution concentrations (0.01 to 1 mg/L). In contrast, linear polycarbocylic acids (citric acid and tricarballylic acid) had no inhibiting effect on calcite growth rates at concentrations up to 10 mg/L. Calcite crystal growth rate inhibition by cyclic polycarboxyclic acids appears to involve blockage of crystal growth sites on the mineral surface by several carboxylate groups. Growth morphology varied for growth in the absence and in the presence of both THFTCA and CPTCA. More effective growth rate reduction by CPTCA relative to THFTCA suggests that inhibitor carboxylate stereochemical orientation controls calcite surface interaction with carboxylate inhibitors. ?? 20O1 Academic Press.

  8. On growth rate hysteresis and catastrophic crystal growth

    Science.gov (United States)

    Ferreira, Cecília; Rocha, Fernando A.; Damas, Ana M.; Martins, Pedro M.

    2013-04-01

    Different crystal growth rates as supersaturation is increasing or decreasing in impure media is a phenomenon called growth rate hysteresis (GRH) that has been observed in varied systems and applications, such as protein crystallization or during biomineralization. We have recently shown that the transient adsorption of impurities onto newly formed active sites for growth (or kinks) is sensitive to the direction and rate of supersaturation variation, thus providing a possible explanation for GRH [6]. In the present contribution, we expand on this concept by deriving the analytical expressions for transient crystal growth based on the energetics of growth hillock formation and kink occupation by impurities. Two types of GRH results are described according to the variation of kink density with supersaturation: for nearly constant density, decreasing or increasing supersaturation induce, respectively, growth promoting or inhibiting effects relative to equilibrium conditions. This is the type of GRH measured by us during the crystallization of egg-white lysozyme. For variable kink density, slight changes in the supersaturation level may induce abrupt variations in the crystal growth rate. Different literature examples of this so-called 'catastrophic' crystal growth are discussed in terms of their fundamental consequences.

  9. GROWTH RATE DISTRIBUTION OF BORAX SINGLE CRYSTALS ON THE (001 FACE UNDER VARIOUS FLOW RATES

    Directory of Open Access Journals (Sweden)

    Suharso Suharso

    2010-06-01

    Full Text Available The growth rates of borax single crystals from aqueous solutions at various flow rates in the (001 direction were measured using in situ cell method. From the growth rate data obtained, the growth rate distribution of borax crystals was investigated using Minitab Software and SPSS Software at relative supersaturation of 0807 and temperature of 25 °C. The result shows that normal, gamma, and log-normal distribution give a reasonably good fit to GRD. However, there is no correlation between growth rate distribution and flow rate of solution.   Keywords: growth rate dispersion (GRD, borax, flow rate

  10. Effect of cooling rate on crystallization in an aluminophosphosilicate melt

    DEFF Research Database (Denmark)

    Liu, S. J.; Zhang, Yanfei; Yue, Yuanzheng

    2011-01-01

    The effect of cooling rate on spontaneous crystallization behavior of an alumino-phospho-silicate melt is studied by means of differential scanning calorimetry, X-ray diffraction, scanning electron microscopy and viscometry. The cooling rates of 160, 2100 and 12000 K/s are attained by subjecting...

  11. Effect of cooling rate on crystallization in an aluminophosphosilicate melt

    DEFF Research Database (Denmark)

    Liu, S. J.; Zhang, Yanfei; Yue, Yuanzheng

    2011-01-01

    The effect of cooling rate on spontaneous crystallization behavior of an alumino-phospho-silicate melt is studied by means of differential scanning calorimetry, X-ray diffraction, scanning electron microscopy and viscometry. The cooling rates of 160, 2100 and 12000 K/s are attained by subjecting...

  12. Polarization factor measurements of flat crystals using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Wohrer, K.; Touati, A.; Chetioui, A.; Rozet, J.P.; Chevallier, P.; Wang, J.X.; Bouisset, P.

    1989-01-01

    A method for measuring polarization factors of flat crystals, using a highly polarized beam source provided by synchrotron radiation, is presented. Application to the test of a graphite mosaic crystal, performed at the LURE-DCI facility in Orsay (France), is reported. Results concerning polarization factors at different energies are discussed in connection with measured crystal reflectivities.

  13. Single crystal plasticity by modeling dislocation density rate behavior

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Benjamin L [Los Alamos National Laboratory; Bronkhorst, Curt [Los Alamos National Laboratory; Beyerlein, Irene [Los Alamos National Laboratory; Cerreta, E. K. [Los Alamos National Laboratory; Dennis-Koller, Darcie [Los Alamos National Laboratory

    2010-12-23

    The goal of this work is to formulate a constitutive model for the deformation of metals over a wide range of strain rates. Damage and failure of materials frequently occurs at a variety of deformation rates within the same sample. The present state of the art in single crystal constitutive models relies on thermally-activated models which are believed to become less reliable for problems exceeding strain rates of 10{sup 4} s{sup -1}. This talk presents work in which we extend the applicability of the single crystal model to the strain rate region where dislocation drag is believed to dominate. The elastic model includes effects from volumetric change and pressure sensitive moduli. The plastic model transitions from the low-rate thermally-activated regime to the high-rate drag dominated regime. The direct use of dislocation density as a state parameter gives a measurable physical mechanism to strain hardening. Dislocation densities are separated according to type and given a systematic set of interactions rates adaptable by type. The form of the constitutive model is motivated by previously published dislocation dynamics work which articulated important behaviors unique to high-rate response in fcc systems. The proposed material model incorporates thermal coupling. The hardening model tracks the varying dislocation population with respect to each slip plane and computes the slip resistance based on those values. Comparisons can be made between the responses of single crystals and polycrystals at a variety of strain rates. The material model is fit to copper.

  14. Crystallization of Al-Zr alloys at high cooling rates

    Energy Technology Data Exchange (ETDEWEB)

    Toropova, L.S.; Kamardinkin, A.N.

    1989-01-01

    The nonequilibrium crystallization of Al-Zr alloys containing up to 5 mass pct Zr is investigated by light and electron microscopy and on the basis of lattice spacing and electrical conductivity measurements. A phase diagram of the system is presented. The dependence of the dendritic parameters of Al-Zr alloys on the cooling rate is demonstrated. 10 references.

  15. Rate of Homogeneous Crystal Nucleation in molten NaCl

    CERN Document Server

    Valeriani, C; Frenkel, D; 10.1063/1.1896348

    2009-01-01

    We report a numerical simulation of the rate of crystal nucleation of sodium chloride from its melt at moderate supercooling. In this regime nucleation is too slow to be studied with "brute-force" Molecular Dynamics simulations. The melting temperature of ("Tosi-Fumi") NaCl is $\\sim 1060$K. We studied crystal nucleation at $T$=800K and 825K. We observe that the critical nucleus formed during the nucleation process has the crystal structure of bulk NaCl. Interestingly, the critical nucleus is clearly faceted: the nuclei have a cubical shape. We have computed the crystal-nucleation rate using two completely different approaches, one based on an estimate of the rate of diffusive crossing of the nucleation barrier, the other based on the Forward Flux Sampling and Transition Interface Sampling (FFS-TIS) methods. We find that the two methods yield the same result to within an order of magnitude. However, when we compare the extrapolated simulation data with the only available experimental results for NaCl nucleatio...

  16. Factor Model Forecasts of Exchange Rates

    OpenAIRE

    Charles Engel; Nelson C. Mark; Kenneth D. West

    2012-01-01

    We construct factors from a cross section of exchange rates and use the idiosyncratic deviations from the factors to forecast. In a stylized data generating process, we show that such forecasts can be effective even if there is essentially no serial correlation in the univariate exchange rate processes. We apply the technique to a panel of bilateral U.S. dollar rates against 17 OECD countries. We forecast using factors, and using factors combined with any of fundamentals suggested by Taylor r...

  17. Controlling protein crystal growth rate by means of temperature

    Energy Technology Data Exchange (ETDEWEB)

    SantamarIa-Holek, I; Gadomski, A [Institute of Mathematics and Physics, University of Technology and Life Sciences, PL-85796 Bydgoszcz (Poland); RubI, J M, E-mail: isholek.fc@gmail.com, E-mail: agad@utp.edu.pl, E-mail: mrubi@ub.edu [Departament de Fisica Fonamental, University of Barcelona, Av. Diagonal 647, E-08028 Barcelona (Spain)

    2011-06-15

    We have proposed a model to analyze the growth kinetics of lysozyme crystals/aggregates under non-isothermal conditions. The model was formulated through an analysis of the entropy production of the growth process which was obtained by taking into account the explicit dependence of the free energy on the temperature. We found that the growth process is coupled with temperature variations, resulting in a novel Soret-type effect. We identified the surface entropy of the crystal/aggregate as a decisive ingredient controlling the behavior of the average growth rate as a function of temperature. The behavior of the Gibbs free energy as a function of temperature is also analyzed. The agreement between theory and experiments is very good in the range of temperatures considered.

  18. Controlling protein crystal growth rate by means of temperature.

    Science.gov (United States)

    Sanamaría-Holek, I; Gadomski, A; Rubí, J M

    2011-06-15

    We have proposed a model to analyze the growth kinetics of lysozyme crystals/aggregates under non-isothermal conditions. The model was formulated through an analysis of the entropy production of the growth process which was obtained by taking into account the explicit dependence of the free energy on the temperature. We found that the growth process is coupled with temperature variations, resulting in a novel Soret-type effect. We identified the surface entropy of the crystal/aggregate as a decisive ingredient controlling the behavior of the average growth rate as a function of temperature. The behavior of the Gibbs free energy as a function of temperature is also analyzed. The agreement between theory and experiments is very good in the range of temperatures considered.

  19. Heart rate variability and heart rate recovery as prognostic factors

    OpenAIRE

    GRAD, COSMIN

    2015-01-01

    Background and aim Heart rate (HR) can appear static and regular at rest, during exercise or recovery after exercise. However, HR is constantly adjusted due to factors such as breathing, blood pressure control, thermoregulation and the renin-angiotensin system, leading to a more dynamic response that can be quantified using HRV (heart rate variability). HRV is defined as the deviation in time between successive normal heart beat and is a noninvasive method to measure the total variation in a ...

  20. In situ investigation of growth rates and growth rate dispersion of α-lactose monohydrate crystals

    Science.gov (United States)

    Dincer, T. D.; Ogden, M. I.; Parkinson, G. M.

    2009-02-01

    The growth rates and growth rate dispersion (GRD) of four different faces of α-lactose monohydrate crystal were measured at 30, 40 and 50 °C in the relative supersaturation range 0.55-2.33 in aqueous solutions. The overall growth rate of the crystal is around 50-60% of the (0 1 0) face of the crystal. The power law was applied to the growth rates of the four faces and the activation energies were calculated to be between 9.5 and 13.7 kcal/mol. This indicates a diffusion-controlled growth, but the exponents calculated are between 2.5 and 3.1 which are higher than unity. Introduction of critical supersaturation decreased the exponents to between 1.8 and 2.4. The variance of GRD for the (0 1 0) face is twice the variance of the GRD of the (1 1 0) and (1 0 0) faces and 10 times higher than the (1 1¯ 1¯) face at the same supersaturations and temperatures. The GRD of the four faces were similar when expressed as a function of growth rate. However, the (0 1 1) face displayed lower GRD than the other faces at the same temperatures and supersaturations.

  1. Extraction of the beta-factor for single quantum dots coupled to a photonic crystal waveguide

    DEFF Research Database (Denmark)

    Nielsen, Henri Thyrrestrup; Sapienza, Luca; Lodahl, Peter

    2010-01-01

    wavelength of single quantum dots is temperature tuned across the band edge of a photonic crystal waveguide and the spontaneous emission rate is recorded. Decay rates up to 5.7 ns−1, corresponding to a Purcell factor of 5.2, are measured and β-factors up to 85% are extracted. These results prove......We present measurements of the β-factor, describing the coupling efficiency of light emitted by single InAs/GaAs semiconductor quantum dots into a photonic crystal waveguide mode. The β-factor is evaluated by means of time resolved frequency-dependent photoluminescence spectroscopy. The emission...... the potential of photonic crystal waveguides in the realization of on-chip single-photon sources....

  2. Model of apparent crystal growth rate and kinetics of seeded precipitation from sodium aluminate solution

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-bin; LIU Zhi-jian; XU Xiao-hui; ZHOU Qiu-sheng; PENG Zhi-hong; LIU Gui-hua

    2005-01-01

    Based on the population balance equation in a batch crystallizer characteristic of seeded precipitation, a model to calculate the rate of apparent crystal growth of aluminum hydroxide from the size distribution was deve-loped. The simulation results indicate that the rate of apparent crystal growth during seeded precipitation exhibits a manifest dependence on the crystal size. In general, there is an obvious increase in the apparent crystal growth rate with the augment in crystal size. The apparent activation energy increases with the increase of characteristic crystal size, which indicates that the growth of small crystals is controlled by surface chemical reaction; it is gradually controlled by both the surface reaction and diffusion with the augment in crystal size.

  3. Controlling the Spontaneous Emission Rate of Monolayer MoS$_2$ in a Photonic Crystal Nanocavity

    CERN Document Server

    Gan, Xuetao; Mak, Kin Fai; Yao, Xinwen; Shiue, Ren-Jye; van der Zande, Arend; Trusheim, Matthew; Hatami, Fariba; Heinz, Tony F; Hone, James; Englund, Dirk

    2013-01-01

    We report on controlling the spontaneous emission (SE) rate of a molybdenum disulfide (MoS$_2$) monolayer coupled with a planar photonic crystal (PPC) nanocavity. Spatially resolved photoluminescence (PL) mapping shows strong variations of emission when the MoS$_2$ monolayer is on the PPC cavity, on the PPC lattice, on the air gap, and on the unpatterned gallium phosphide substrate. Polarization dependences of the cavity-coupled MoS$_2$ emission show a more than 5 times stronger extracted PL intensity than the un-coupled emission, which indicates an underlying cavity mode Purcell enhancement of MoS$_2$ SE rate exceeding a factor of 70.

  4. The Effect of Solution Parameters on Lysozyme Nucleation Rates and Crystal Quality

    Science.gov (United States)

    Judge, R. A.; Snell, E. H.

    1998-01-01

    In the pursuit of strongly diffracting high quality macromolecule crystals of suitable volume, this study investigates how the formation of macromolecules in solution and their growth characteristics effect crystal volume and diffracting quality. We systematically investigated the effect of solution conditions on lysozyme nucleation rates and the volume of crystals produced. Batch crystallization plates were used in combination with a video microscope system to measure nucleation rates and crystal volume. As expected from classical nucleation theory, crystal numbers were found to increase with increases in temperature and supersaturation. Small changes in solution pH, at constant supersaturation values were found, however, to dramatically effect the number of crystals nucleated in the wells varying from 1000s to 10s in the pH range 4.0 to 5.2. Having optimized the conditions required to produce an appropriate number of crystals of a suitable volume for X-ray analysis, a large number of uniform crystals were produced under exactly the same conditions. In the X-ray analysis of more than 50 such crystals there was found a wide variation in crystal lattice parameters and data quality. The variation in X-ray quality crystal samples is thought to be related to the growth rate variation caused by growth rate dispersion seen in lysozyme crystal growth experiments.

  5. Main Factors for Affecting Photonic Bandgap of Photonic Crystals

    Institute of Scientific and Technical Information of China (English)

    LI Xia; XUE Wei; JIANG Yu-rong; YU Zhi-nong; WANG Hua-qing

    2007-01-01

    The factors affecting one dimensional (1D) and two dimensional (2D) photonic crystals (PhCs) are systemically analyzed in this paper by numerical simulation.Transfer matrix method (TMM) is employed for 1D PCs, both finite difference time domain method (FDTD) and plane wave expansion method (PWE) are employed for 2D PCs.The result shows that the photonic bandgaps (PBG) are directly affected by crystal type, crystal lattice constant, modulation of refractive index and periodicity, and it is should be useful for design of different type photonic crystals with the required PBG and functional devices.Finally, as an example, a near-IR 1D PCs narrow filter was designed.

  6. Porphyroblast crystallization kinetics: the role of the nutrient production rate

    DEFF Research Database (Denmark)

    Schwarz, Jens-Oliver; Engi, Martin; Berger, Alfons

    2011-01-01

    , such as grain size distributions. In turn, data on porphyroblast textures for natural samples are used to infer which mechanism dominated during their formation. Whereas previous models assume that the rate-limiting step for a porphyroblast producing reaction is either transport or growth, the model advanced...... in this study considers the production of nutrients for porphyroblasts as a potentially rate-limiting factor. This production reflects the breakdown of (metastable) reactants, which at a specific pressure (P) and temperature (T) depends on the bulk composition of the sample. The production of nutrients...... that potentially contribute to the formation of porphyroblasts is computed based on thermodynamic models. The conceptual model assumes that these nutrients feed into some intergranular medium, and products form by nutrient consumption from that medium, with rates depending on reaction affinity. For any sequence...

  7. EFFECT OF SODIUM DODECYLBENZENESULFONIC ACID (SDBS ON THE GROWTH RATE AND MORPHOLOGY OF BORAX CRYSTAL

    Directory of Open Access Journals (Sweden)

    Suharso Suharso

    2010-06-01

    Full Text Available An investigation of the effect of sodium dodecylbenzenesulfonic acid (SDBS on both growth rate and morphology of borax crystal has been carried out.  This experiment was carried out at temperature of 25 °C and relative supersaturation of 0.21 and 0.74 under in situ cell optical microscopy method.  The result shows that SDBS inhibits the growth rate and changes the morphology of borax crystal.   Keywords: Borax; growth rate; crystallization, SDBS

  8. EFFECT OF SODIUM DODECYLBENZENESULFONIC ACID (SDBS) ON THE GROWTH RATE AND MORPHOLOGY OF BORAX CRYSTAL

    OpenAIRE

    Suharso, Suharso

    2010-01-01

    An investigation of the effect of sodium dodecylbenzenesulfonic acid (SDBS) on both growth rate and morphology of borax crystal has been carried out.  This experiment was carried out at temperature of 25 °C and relative supersaturation of 0.21 and 0.74 under in situ cell optical microscopy method.  The result shows that SDBS inhibits the growth rate and changes the morphology of borax crystal.   Keywords: Borax; growth rate; crystallization, SDBS

  9. Effect of heating rate and kinetic model selection on activation energy of nonisothermal crystallization of amorphous felodipine.

    Science.gov (United States)

    Chattoraj, Sayantan; Bhugra, Chandan; Li, Zheng Jane; Sun, Changquan Calvin

    2014-12-01

    The nonisothermal crystallization kinetics of amorphous materials is routinely analyzed by statistically fitting the crystallization data to kinetic models. In this work, we systematically evaluate how the model-dependent crystallization kinetics is impacted by variations in the heating rate and the selection of the kinetic model, two key factors that can lead to significant differences in the crystallization activation energy (Ea ) of an amorphous material. Using amorphous felodipine, we show that the Ea decreases with increase in the heating rate, irrespective of the kinetic model evaluated in this work. The model that best describes the crystallization phenomenon cannot be identified readily through the statistical fitting approach because several kinetic models yield comparable R(2) . Here, we propose an alternate paired model-fitting model-free (PMFMF) approach for identifying the most suitable kinetic model, where Ea obtained from model-dependent kinetics is compared with those obtained from model-free kinetics. The most suitable kinetic model is identified as the one that yields Ea values comparable with the model-free kinetics. Through this PMFMF approach, nucleation and growth is identified as the main mechanism that controls the crystallization kinetics of felodipine. Using this PMFMF approach, we further demonstrate that crystallization mechanism from amorphous phase varies with heating rate. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  10. In-Situ Crystallization of a Lithium Disilicate Glass--Effect of Pressure on Crystal Growth Rate

    Science.gov (United States)

    Fuss, T.; Ray, C. S.; Lesher, C. E.; Day, D. E.

    2006-01-01

    Crystallization of a Li2O.2SiO2 (LS2) glass subjected to a uniform hydrostatic pressure of 4.5 GPa and 6 GPa was investigated up to a temperature of 750 C. The density of the compressed glass is about 2% greater at 4.5 GPa than at 1 atm and, depending upon the processing temperature, up to 10% greater at 6 GPa. Crystal growth rates investigated as a function of temperature and pressure show that lithium disilicate crystal growth is an order of magnitude slower at 4.5 GPa than 1 atm resulting in a shift of +45 C (plus or minus 10 C) in the growth rate curve at high pressure compared to 1 atm condition. At 6 GPa lithium disilicate crystallization is suppressed entirely, while a new high pressure lithium metasilicate crystallizes at temperatures 95 C (plus or minus 10 C) higher than those reported for lithium disilicate crystallization at 1 atm. The decrease in crystal growth rate with increasing pressure for lithium disilicate glass up to 750 C is related to an increase in viscosity with pressure associated with fundamental changes in glass structure accommodating densification.

  11. Shielding factors of ions in rock-salt crystals

    Science.gov (United States)

    Michihiro, Y.; Mahan, G. D.

    1997-11-01

    The calculation of the quadrupole shielding factor of closed-shell ions in crystalline solids with rock-salt structure is done based on the self-consistent-field local-density approximation, modified Sternheimer equation, and spherical solid model. A significant reduction of the values of the quadrupole shielding factor is found for the anions, and the amount of the reduction is different in different crystals.

  12. Heart rate variability and heart rate recovery as prognostic factors.

    Science.gov (United States)

    Grad, Cosmin

    2015-01-01

    Heart rate (HR) can appear static and regular at rest, during exercise or recovery after exercise. However, HR is constantly adjusted due to factors such as breathing, blood pressure control, thermoregulation and the renin-angiotensin system, leading to a more dynamic response that can be quantified using HRV (heart rate variability). HRV is defined as the deviation in time between successive normal heart beat and is a noninvasive method to measure the total variation in a number of HR interval. HRV can serve as measure of autonomic activity of sino-atrial node. The aim of the study was to determine the influence of certain clinical and paraclinical parameters on heart rate recovery after exercise in patients with ischemic heart disease and the relation with HRV using 24 h Holter monitoring. The study included 46 patients who were submitted to cardiovascular exercise stress test and also to 24 h Holter EKG monitoring. Subjects had a mean age of 56.2±11.2 years, with a minimum of 25 and a maximum of 79 years. The study included 22 (47.8%) men and 24 (52.2%) women. Statistical analysis was performed using MedCalc software version 14.8.1. Multivariate analysis consisted of the construction of several multiple linear regression models. A p value of 0.05 was considered statistically significant. The HRV values (time domain) were all lower in the IHD compared with the group without coronary heart disease, even if the difference is not statistically significant. Also rest and maximal HR values were similar but during the test varies in the sense that those with IHD had higher values of rest and maximal HR and lower HRR, but not statistically significant. HRV is a very easy and safe method if there is an available device and it is used for evaluation of the autonomic nervous system in many cardiovascular diseases, but also in other pathologies. In uncomplicated ischemic heart disease HRV is depressed, but not significant. HRR, which is also considered an indicator of the

  13. In situ measurement and dynamic control of the evaporation rate in vapor diffusion crystallization of proteins

    Science.gov (United States)

    Shu, Zhan-Yong; Gong, Hai-Yun; Bi, Ru-Chang

    1998-08-01

    A special device with a weight-sensitive facility was designed for monitoring and controlling the water evaporation in vapor diffusion protein crystallization. The device made it possible to measure the weight of the drop in real time while the crystallization experiment was going on normally. The precise water equilibration curves under different crystallization conditions could be obtained automatically. By monitoring and controlling the evaporation rate, the crystallization of hen egg-white lysozyme and trichosanthin, a plant protein from Chinese herb, was optimized by regulating the reservoir solution dynamically. The experimental results of these two proteins indicate both the feasibility of the device and the usefulness of dynamic control technique. Compared with traditional crystallization experiments, dynamically controlled crystallization can reduce the number of nuclei, increase the crystal size and save experimental time effectively.

  14. Microscopic Rate Constants of Crystal Growth from Molecular Dynamic Simulations Combined with Metadynamics

    Directory of Open Access Journals (Sweden)

    Dániel Kozma

    2012-01-01

    Full Text Available Atomistic simulation of crystal growth can be decomposed into two steps: the determination of the microscopic rate constants and a mesoscopic kinetic Monte Carlo simulation. We proposed a method to determine kinetic rate constants of crystal growth. We performed classical molecular dynamics on the equilibrium liquid/crystal interface of argon. Metadynamics was used to explore the free energy surface of crystal growth. A crystalline atom was selected at the interface, and it was displaced to the liquid phase by adding repulsive Gaussian potentials. The activation free energy of this process was calculated as the maximal potential energy density of the Gaussian potentials. We calculated the rate constants at different interfacial structures using the transition state theory. In order to mimic real crystallization, we applied a temperature difference in the calculations of the two opposite rate constants, and they were applied in kinetic Monte Carlo simulation. The novelty of our technique is that it can be used for slow crystallization processes, while the simple following of trajectories can be applied only for fast reactions. Our method is a possibility for determination of elementary rate constants of crystal growth that seems to be necessary for the long-time goal of computer-aided crystal design.

  15. GROWTH RATE DISPERSION (GRD OF THE (010 FACE OF BORAX CRYSTALS IN FLOWING SOLUTION

    Directory of Open Access Journals (Sweden)

    Suharso Suharso

    2010-06-01

    Full Text Available The growth rates of borax crystals from aqueous solutions in the (010 direction at various flow rates were measured. The observed variations of the growth rate can be represented by a normal distribution.  It was found that there is no correlation between growth rate distribution and solution flow under these experimental conditions.   Keywords: Growth rate dispersion (GRD, borax, flow rate

  16. Crystal Structure of the Pseudomonas aeruginosa Virulence Factor Regulator

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, Timothy J.; Worzalla, Gregory A.; Ginster, Aaron M.; Forest, Katrina T. (UW)

    2012-09-07

    Virulence factor regulator (Vfr) enhances Pseudomonas aeruginosa pathogenicity through its role as a global transcriptional regulator. The crystal structure of Vfr shows that it is a winged-helix DNA-binding protein like its homologue cyclic AMP receptor protein (CRP). In addition to an expected primary cyclic AMP-binding site, a second ligand-binding site is nestled between the N-terminal domain and the C-terminal helix-turn-helix domain. Unlike CRP, Vfr is a symmetric dimer in the absence of DNA. Removal of seven disordered N-terminal residues of Vfr prvents the growth of P. aeruginosa.

  17. [Factors that influence student ratings of instruction].

    Science.gov (United States)

    Chae, Su Jin; Choung, Yun Hoon; Chung, Yoon Sok

    2015-03-01

    The purpose of this study was to examine the validity of student ratings of instruction by analyzing their relationships with several variables, including gender, academic rank, specialty, teaching time, and teaching method, at a medical school. This study analyzed the student ratings of 297 courses at Ajou University School of Medicine in 2013. SPSS version 12.0 was used to analyze the data and statistics by t-test, analysis of variance, and Scheffe test. There were no statistically significant differences in student ratings between gender, rank, and specialty. However, student ratings were significantly influenced by teaching times and methods (pStudent ratings were high for teaching times of 10 hours or more and small-group learning, compared with lectures. There was relatively mean differences in students ratings by teaching times, specialty and rank, although the difference in ratings was not statistically significant. Student ratings can be classified by teaching time and method for summative purposes. To apply student ratings to the evaluation of the performance of faculty, further studies are needed to analyze the variables that influence student ratings.

  18. Oscillations of the crystal-melt interface caused by harmonic oscillations of the pulling rate for the cylindrical phase of crystal growth

    Science.gov (United States)

    Vasil'ev, M. G.

    2017-02-01

    A technique for measuring the crystal cross-sectional area with a weight sensor based on the difference between its readings at the extreme rod positions in the stepwise and continuous modes of modulation of the pulling rate is proposed for the low-thermal gradient Czochralski method. A change in the crystallization rate at harmonic oscillations of the pulling rate is estimated with the aim of conserving the quality of the growing crystal for this measurement method.

  19. Ultraviolet optomechanical crystal cavities with ultrasmall modal mass and high optomechanical coupling rate

    Science.gov (United States)

    Zhou, Wen; Yu, Zejie; Ma, Jingwen; Zhu, Bingqing; Tsang, Hon Ki; Sun, Xiankai

    2016-11-01

    Optomechanical crystal (OMC) cavities which exploit the simultaneous photonic and phononic bandgaps in periodic nanostructures have been utilized to colocalize, couple, and transduce optical and mechanical resonances for nonlinear interactions and precision measurements. The development of near-infrared OMC cavities has difficulty in maintaining a high optomechanical coupling rate when scaling to smaller mechanical modal mass because of the reduction of the spatial overlap between the optical and mechanical modes. Here, we explore OMC nanobeam cavities in gallium nitride operating at the ultraviolet wavelengths to overcome this problem. With a novel optimization strategy, we have successfully designed an OMC cavity, with a size of 3.83 × 0.17 × 0.13 μm3 and the mechanical modal mass of 22.83 fg, which possesses an optical mode resonating at the wavelength of 393.03 nm and the fundamental mechanical mode vibrating at 14.97 GHz. The radiation-limited optical Q factor, mechanical Q factor, and optomechanical coupling rate are 2.26 × 107, 1.30 × 104, and 1.26 MHz, respectively. Our design and optimization approach can also serve as the general guidelines for future development of OMC cavities with improved device performance.

  20. ON PLASTIC ANISOTROPY OF CONSTITUTIVE MODEL FOR RATE-DEPENDENT SINGLE CRYSTAL

    Institute of Scientific and Technical Information of China (English)

    张光; 张克实; 冯露

    2005-01-01

    An algorithm for single crystals was developed and implemented to simulate plastic anisotropy using a rate-dependent slip model. The proposed procedure was a slightly modified form of single crystal constitutive model of Sarma and Zacharia. Modified Euler method, together with Newton-Raphson method was used to integrate this equation which was stable and efficient. The model together with the developed algorithm was used to study three problems. First, plastic anisotropy was examined by simulating the crystal deformation in tension and plane strain compression, respectively. Secondly, the orientation effect of some material parameters in the model and applied strain rate on plastic anisotropy for single crystal also is investigated. Thirdly, the influence of loading direction on the active slip system was discussed.

  1. Sublimation rate of molecular crystals - role of internal degrees of freedom

    Energy Technology Data Exchange (ETDEWEB)

    Maiti, A; Zepeda-Ruiz, L A; Gee, R H; Burnham, A

    2007-01-19

    It is a common practice to estimate site desorption rate from crystal surfaces with an Arrhenius expression of the form v{sub eff} exp(-{Delta}E/k{sub B}T), where {Delta}E is an activation barrier to desorb and v{sub eff} is an effective vibrational frequency {approx} 10{sup 12} sec{sup -1}. However, such a formula can lead to several to many orders of magnitude underestimation of sublimation rates in molecular crystals due to internal degrees of freedom. We carry out a quantitative comparison of two energetic molecular crystals with crystals of smaller entities like ice and Argon (solid) and uncover the errors involved as a function of molecule size. In the process, we also develop a formal definition of v{sub eff} and an accurate working expression for equilibrium vapor pressure.

  2. Chalcopyrite leaching: The rate controlling factors

    Science.gov (United States)

    Li, J.; Kawashima, N.; Kaplun, K.; Absolon, V. J.; Gerson, A. R.

    2010-05-01

    The processes that determine the rate of chalcopyrite leaching are central to understanding how chalcopyrite (CuFeS 2) behaves under the environmentally adverse conditions of acid rock drainage. To this end the effect of the acid anion on chalcopyrite leach rates using a variety of acidic media (H 2SO 4, HClO 4, HCl and H 2SO 4 with 0.25 M NaCl) under carefully controlled solution conditions (pH 1 and 2, Eh 750 mV (SHE) and 75 °C) has been examined. These conditions have been chosen to enable sufficient leach rates for accurate experimental determination and to compare to the previous mechanistic analysis carried out by Harmer et al. (2006). Extensive surface analysis of leach residues demonstrated that variations in the surface speciation could not be responsible for the observed variations in leach rate. The rate of Cu release, however, was found to be first order with respect to Fe 3+ activity and inversely proportional with respect to H + activity to the power of 0.7: {1}/{S}{dC}/{dt}=(2.0±0.2){a}/{aH0.7} where S is the relative surface area, C is concentration of Cu in the solution (M), t is the time (h), 2.0 is the rate constant (M 0.7 h -1) and a and a are Fe 3+ and H + activities, respectively (M). The rate model was further validated against additional leaches carried out in H 2SO 4 media with the initial addition of Fe 3+ (8 mM as Fe 2(SO 4) 3) at 75 °C under various pH and Eh regimes. The only condition under which this rate model was found not to hold was at simultaneously low a and high a, that is at pH 1 and a<5×10-5M, where the concentration of dissolved O 2 may be leach rate determining.

  3. A High-Rate, Single-Crystal Model including Phase Transformations, Plastic Slip, and Twinning

    Energy Technology Data Exchange (ETDEWEB)

    Addessio, Francis L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Bronkhorst, Curt Allan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Bolme, Cynthia Anne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Explosive Science and Shock Physics Division; Brown, Donald William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Cerreta, Ellen Kathleen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Lebensohn, Ricardo A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Lookman, Turab [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Luscher, Darby Jon [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Mayeur, Jason Rhea [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Theoretical Division; Morrow, Benjamin M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division; Rigg, Paulo A. [Washington State Univ., Pullman, WA (United States). Dept. of Physics. Inst. for Shock Physics

    2016-08-09

    An anisotropic, rate-­dependent, single-­crystal approach for modeling materials under the conditions of high strain rates and pressures is provided. The model includes the effects of large deformations, nonlinear elasticity, phase transformations, and plastic slip and twinning. It is envisioned that the model may be used to examine these coupled effects on the local deformation of materials that are subjected to ballistic impact or explosive loading. The model is formulated using a multiplicative decomposition of the deformation gradient. A plate impact experiment on a multi-­crystal sample of titanium was conducted. The particle velocities at the back surface of three crystal orientations relative to the direction of impact were measured. Molecular dynamics simulations were conducted to investigate the details of the high-­rate deformation and pursue issues related to the phase transformation for titanium. Simulations using the single crystal model were conducted and compared to the high-­rate experimental data for the impact loaded single crystals. The model was found to capture the features of the experiments.

  4. SOME MISUNDERSTANDINGS ON ROTATION OF CRYSTALS AND REASONABLE PLASTIC STRAIN RATE

    Institute of Scientific and Technical Information of China (English)

    赵祖武

    2001-01-01

    It is pointed out that crystals are discrete but not continuous materials. Hence the rotation R in decomposition F = RU and spin W in F F-1 are not correct. Errors will arise in plastic deformation rate if it is directly expressed with amounts of velocity of slips in glide systems such as γv n . The geometrical figure of crystal lattices does not change after slips and based on this idea a simple way in mechanics of continuous media to get the plastic deformations rate induced by slips is proposed. Constitutive equations are recommended.

  5. Simulation of V/G During Φ450 mm Czochralski Grown Silicon Single Crystal Growth Under the Different Crystal and Crucible Rotation Rates

    Directory of Open Access Journals (Sweden)

    Guan X J

    2016-01-01

    Full Text Available For discovering the principle of processing parameter combination for the stable growth and better wafer quality of Φ450 mm Czochralski grown silicon single crystal (shortly called Cz silicon crystal, the effects of crystal rotation rate and crucible one on the V/G ratio were simulated by using CGSim software. The results show that their effect laws on the V/G ratio for Φ450 mm Cz silicon crystal growth are some different from that for Φ200 mm Cz silicon one, and the effects of crucible rotation rate are relatively smaller than that of crystal one and its increasing only makes the demarcation point between two regions with different V/G ratio variations outward move along radial direction, and it promotes the wafer quality to weaken crystal rotation rate and strengthen crucible one.

  6. Crystallized Rates Region of the Interference Channel via Correlated Equilibrium with Interference as Noise

    CERN Document Server

    Charafeddine, Mohamad; Paulraj, Arogyaswami; Cioffi, John

    2010-01-01

    Treating the interference as noise in the n-user interference channel, the paper describes a novel approach to the rates region, composed by the time-sharing convex hull of 2^n-1 corner points achieved through On/Off binary power control. The resulting rates region is denoted crystallized rates region. By treating the interference as noise, the n-user rates region frontiers has been found in the literature to be the convex hull of n hyper-surfaces. The rates region bounded by these hyper-surfaces is not necessarily convex, and thereby a convex hull operation is imposed through the strategy of time-sharing. This paper simplifies this rates region in the n-dimensional space by having only an On/Off binary power control. This consequently leads to 2^n-1 corner points situated within the rates region. A time-sharing convex hull is imposed onto those corner points, forming the crystallized rates region. The paper focuses on game theoretic concepts to achieve that crystallized convex hull via correlated equilibrium...

  7. Economic Factors for Televison Programme Rating in Slovenia

    OpenAIRE

    Matjaz Dodic; Bojan Nastav

    2011-01-01

    Factors that influence televison programme rating can be divided into environment, outer factors and internal factors of televison programmes. In this paper we apply the regression analysis to study the influence of the number of unemployed, inflation rate, average salary, consumers’ trust, households’ financial status in the past 12 months and the economic state in Slovenia on rating of national, commercial and other televison programmes in Slovenia in the 2000–2009 period. The results show ...

  8. Cooling rates and crystallization dynamics of shallow level pegmatite-aplite dikes, San Diego County, California

    Science.gov (United States)

    Webber, Karen L.; Simmons, William B.; Falster, Alexander U.; Foord, Eugene E.

    1999-01-01

    Pegmatites of the Pala and Mesa Grande Pegmatite Districts, San Diego County, California are typically thin, sheet-like composite pegmatite-aplite dikes. Aplitic portions of many dikes display pronounced mineralogical layering referred to as "line rock," characterized by fine-grained, garnet-rich bands alternating with albite- and quartz-rich bands. Thermal modeling was performed for four dikes in San Diego County including the 1 m thick Himalaya dike, the 2 m thick Mission dike, the 8 m thick George Ashley dike, and the 25 m thick Stewart dike. Calculations were based on conductive cooling equations accounting for latent heat of crystallization, a melt emplacement temperature of 650 °C into 150 °C fractured, gabbroic country rock at a depth of 5 km, and an estimated 3 wt% initial H2O content in the melt. Cooling to -5 cm/s. Crystal size distribution (CSD) studies of garnet from layered aplites suggest growth rates of about 10-6 cm/s. These results indicate that the dikes cooled and crystallized rapidly, with variable nucleation rates but high overall crystal-growth rates. Initial high nucleation rates coincident with emplacement and strong undercooling can account for the millimeter-size aplite grains. Lower nucleation rates coupled with high growth rates can explain the decimeter-size minerals in the hanging walls, cores, and miarolitic cavities of the pegmatites. The presence of tourmaline and/or lepidolite throughout these dikes suggests that although the melts were initially H2O-undersaturated, high melt concentrations of incompatible (or fluxing) components such as B, F, and Li (±H2O), aided in the development of large pegmatitic crystals that grew rapidly in the short times suggested by the conductive cooling models.

  9. Determining factors for implant referral rates.

    Science.gov (United States)

    Levin, Roger P

    2002-01-01

    The research findings indicate that the field of implant dentistry will only grow at a moderately low level unless certain changes are made. Findings indicated that the effort by the implant companies has been nothing short of dramatic, and yet almost 60% of restorative doctors do not participate annually in any implant case. There was no clear indication that younger restorative doctors will significantly increase the number of implant referrals, as their overall implant education has not dramatically differed from those dentists who graduated in earlier years. Once the research was completed, it became obvious to Levin Group that the driving force behind implant referral growth will be implant surgeons, because of their one-to-one relationship with restorative doctors. The Levin Group Implant Management and Marketing Consulting Program is based on approaching restorative doctors in several different levels, starting with awareness all the way through to case facilitation and long-term tracking and communication. Finally, a continuing marketing/education effort needs to be consistently in place with effective materials, not only to create a high level of awareness, but also to motivate restorative doctors to refer cases and then work through the case with the implant surgeon to a satisfactory completion for the restorative doctor, implant surgeon, and patient. While the surgical insertion of implants may seem to carry a high-profit margin relative to the restoration of implants, the truth is that the restoration of implants usually provides a 40% higher profit margin for the restorative doctor than traditional dental services. One of the key issues is that referring doctors have not necessarily learned how to set fees and present cases with regard to implant dentistry. The key factor here is to ensure that the patient understands that implant services involve higher fees than traditional services, because of the necessarily higher levels of experience, education

  10. Crystallization of a stringent response factor from Aquifex aeolicus

    DEFF Research Database (Denmark)

    Kristensen, Ole; Laurberg, Martin; Gajhede, Michael

    2002-01-01

    The crystallization of a key enzyme from Aquifex aeolicus with suggested bifunctional activity, acting as an exopolyphosphatase and a guanosine pentaphosphate phosphohydrolase, is reported. Native data were collected to below 2 A resolution from an orthorhombic crystal with unit-cell parameters...... a = 50.8, b = 70.3, c = 90.9 A. Methionine residues were introduced by mutation and deliberate oxidation of the protein allowed us to produce additional crystal forms with reproducible diffraction ability and increased phasing potential. This is the first report on the crystallization of a member...

  11. Dependence of calcite growth rate and Sr partitioning on solution stoichiometry: Non-Kossel crystal growth

    NARCIS (Netherlands)

    Nehrke, G.; Reichart, G.-J.; Van Cappellen, P.; Meile, C.; Bijma, J.

    2007-01-01

    Seeded calcite growth experiments were conducted at fixed pH (10.2) and two degrees of supersaturation (Ω = 5, 16), while varying the Ca2+ to CO3 2- solution ratio over several orders of magnitude. The calcite growth rate and the incorporation of Sr in the growing crystals strongly depended on

  12. Automatic Stand Modeling of Casting Rate Influence on Solid Phase Growth of Round Ingot inside Crystallizer

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2006-01-01

    Full Text Available The method of calculation and results of computer dynamics modeling of solid ingot skin in a crystallizer are presented in the paper. The paper shows influence of ingot drawing rate on dynamics of solid ingot skin growth in the continuous casting machine at steel grades used at Republic Unitary Enterprise «Belarussian Metallurgical Works» (BMZ.

  13. Pseudo-steady rates of crystal nucleation in suspensions of charged colloidal particles

    CERN Document Server

    Dixit, N M

    2003-01-01

    We develop an analytical model to describe crystal nucleation in suspensions of charged colloidal particles. The particles are assumed to interact with a repulsive hard-core Yukawa potential. The thermodynamic properties of the suspensions are determined by mapping onto an effective hard-sphere system using perturbation theory. Hydrodynamic effects are calculated by approximating particle interactions with the excluded shell potential. The rates of particle aggregation and dissociation from cluster surfaces in supersaturated suspensions are determined by solving the diffusion and Smoluchowski equations, respectively, which allow the calculation of pseudo-steady rates of crystal nucleation. By decoupling thermodynamic and hydrodynamic effects, we find intriguing non-monotonic dependencies of the nucleation rate on the strength and the range of particle repulsions. In particular, we find that the rate at any effective hard-sphere volume fraction can be lower than that of the hard-sphere system at that volume fr...

  14. Multiscale simulations of damage of perfect crystal Cu at high strain rates

    Indian Academy of Sciences (India)

    S Rawat; M Warrier; S Chaturvedi; V R Ikkurthi

    2014-08-01

    We use the molecular dynamics code, large-scale atomic/molecular massively parallel simulator (LAMMPS), to simulate high strain rate triaxial deformation of crystal copper to understand void nucleation and growth (NAG) within the framework of an experimentally fitted macroscopic NAG model for polycrystals (also known as DFRACT model). It is seen that void NAG at the atomistic scales for crystal copper (Cu) has the same qualitative behaviour as the DFRACT model, albeit with a different set of parameters. The effect of material temperature on the nucleation and growth of voids is studied. As the temperature increases, there is a steady decrease in the void NAG thresholds and close to the melting point of Cu, a double-dip in the pressure–time profile is observed. Analysis of this double-dip shows disappearance of the long-range order due to the creation of stacking faults and the system no longer has a face centred cubic (fcc) structure. Molecular dynamics simulation of shock in crystal Cu at strain rates high enough to cause spallation of crystal Cu are then carried out to validate the void NAG parameters. We show that the pre-history of the material affects the void nucleation threshold of the material. We also simulate high-strain-rate triaxial deformation of crystal Cu with defects and obtain void NAG parameters. The parameters are then used in a macroscale hydrodynamic simulation to obtain spallation threshold of realistic crystal Cu. It is seen that our results match experimental results within the limit of 20% error.

  15. Quasi-static crack tip fields in rate-sensitive FCC single crystals

    Indian Academy of Sciences (India)

    P Biswas; R Narasimhan

    2012-02-01

    In this work, the effects of loading rate, material rate sensitivity and constraint level on quasi-static crack tip fields in a FCC single crystal are studied. Finite element simulations are performed within a mode I, plane strain modified boundary layer framework by prescribing the two term $(K −T)$ elastic crack tip field as remote boundary conditions. The material is assumed to obey a rate-dependent crystal plasticity theory. The orientation of the single crystal is chosen so that the crack surface coincides with the crystallographic (010) plane and the crack front lies along $[10\\bar{1}]$ direction. Solutions corresponding to different stress intensity rates $\\dot{K}$, -stress values and strain rate exponents are obtained. The results show that the stress levels ahead of the crack tip increase with $\\dot{K}$ which is accompanied by gradual shrinking of the plastic zone size. However, the nature of the shear band patterns around the crack tip is not affected by the loading rate. Further, it is found that while positive -stress enhances the opening and hydrostatic stress levels ahead of crack tip, they are considerably reduced with imposition of negative -stress. Also, negative -stress promotes formation of shear bands in the forward sector ahead of the crack tip and suppresses them behind the tip.

  16. Influence of solvent evaporation rate on crystallization of poly(vinylidene fluoride) thin films

    Indian Academy of Sciences (India)

    K Pramod; R B Gangineni

    2015-08-01

    The processes for obtaining crystalline and smooth poly(vinylidene fluoride) (PVDF) thin films using 2-butanone solvent are explored. The in-situ substrate temperature has been systematically controlled to observe the crystallization process. The in-situ substrate temperature is manipulated to control the rate of evaporation of 2-butanone solvent and is found to have played a vital role in the crystallization of PVDF thin films. Further, X-ray diffraction and Raman microscope were utilized to understand the crystalline phase of PDVF thin films, while atomic force microscopy and scanning electron microscopy have been utilized to investigate the surface morphology and surface roughness of the films.

  17. SPHERICAL CRYSTALLIZATION OF ZALTOPROFEN FOR ENHANCEMENT OF MICROMERITIC PROPERTIES AND DISSOLUTION RATE

    Directory of Open Access Journals (Sweden)

    E. Hari Krishna*, V. Ram Mohan Gupta and S. Jyothi

    2012-07-01

    Full Text Available The present work deals with the spherical crystallization process by Spherical agglomeration method applied to Zaltoprofen, a novel NSAID drug. The object of present study was to prepare and characterize the spherical agglomeration of water insoluble non-steroidal anti-inflammatory drug. Zaltoprofen spherical agglomerates prepared with poly ethylene glycol, which is hydrophilic polymer by using simple spherical agglomeration technique for enhancing micromeritic properties and dissolution rate. The prepared zaltoprofen spherical agglomerates were examined in terms of flow properties, particle size analysis, compression and dissolution behavior. Physical characters of the crystals were studied for the morphology of crystals using scanning electron microscope (SEM, identification of polymorphism done by x-ray powder diffraction (XPRD and for thermo dynamic properties using differential scanning colorimetry (DSC. The prepared agglomerates were improved the micromeritic properties, packability, wettability, solubility and compaction behavior, as well as dissolution behavior in comparison to pure Zaltoprofen drug.

  18. The effect factors of potassium dihydrogen phosphate crystallization in aqueous solution

    Science.gov (United States)

    Zhou, Cun; Sun, Fei; Liu, Xuzhao

    2017-01-01

    The effects of cooling rate and pH on the potassium dihydrogen phosphate crystallization process were studied by means of batch crystallization process. The experiment shows that with the increase of cooling rate, the metastable zone width increase and the induction period decrease. When the pH is 3.0, the metastable zone width and induction period are both the minimum, while the crystallization rate is the highest. The crystallization products were characterized by scanning election microscope. Potassium Dihydrogen Phosphate (KDP) is a kind of excellent nonlinear optical materials, and belongs to tetragonal system, and ideal shape is aggregate of tetragonal prism and tetragonal dipyramid, the (100) cone is alternating accumulation by double positive ions and double negative ions [1-4]. The crystals of aqueous solution method to grow have large electro-optical nonlinear coefficient and high loser-damaged threshold, and it is the only nonlinear optical crystal could be used in inertial confinement fusion (ICF), KDP crystals are the ideal system to study the native defects of complex oxide insulating material [5-7]. With the development of photovoltaic technology, KDP crystals growth and performance have become a research focus worldwide [8, 9]. The merits of the crystallization process directly affect the quality of KDP products, so the study of the effect of crystallization conditions has an important significance on industrial production. This paper studied the change rule of metastable zone width, induction period, crystallization rate and particle size distribution in crystal process, and discussed the technical condition of KDP crystallization.

  19. Effect of high-intensity ultrasound and cooling rate on the crystallization behavior of beeswax in edible oils.

    Science.gov (United States)

    Jana, Sarbojeet; Martini, Silvana

    2014-10-15

    The objective of this study was to evaluate the effect of wax concentration (0.5 and 1%), cooling rate (0.1, 1, and 10 °C/min), and high-intensity ultrasound (HIU) on the crystallization behavior of beeswax (BW) in six different edible oils. Samples were crystallized at 25 °C with and without HIU. Crystal sizes and morphologies and melting profiles were measured by microscopy and differential scanning calorimetry, respectively, after 7 days of incubation. Higher wax concentrations resulted in faster crystallization and more turbidity. Phase separation was observed due to crystals' sedimentation when samples were crystallized at slow cooling rates. Results showed that HIU induced the crystallization of 0.5% BW samples and delayed phase separation in sunflower, olive, soybean, and corn oils. Similar effects were observed in 1% samples where HIU delayed phase separation in canola, soybean, olive, and safflower oils.

  20. MORPHOLOGICAL STUDIES OF PET FILMS WITH DIFFERENT CRYSTALLIZATION RATE IN DRAWING PROCESSES

    Institute of Scientific and Technical Information of China (English)

    XU Mao; ZHU Lilan; GUAN Jiayu

    1984-01-01

    Morphological changes during stretching of two PET samples (S and T) with different crystallization rate have been studied by means of SALS, solvent etching and polarizing microscope techniques. Results show that under the same drawing conditions larger and more perfect rod-like and spherulitic superstructures were formed more easily in the sample with higher crystallization rate (sample S). The amount of less compact regions which may be easily attacked by the vapor of allyl amine decreases more rapidly in sample S than in sample T during stretching, and these regions are more randomly distributed in sample T especially at low elongations. The difference of the two samples in morphological changes is coincident with their difference in tensile behavior.

  1. Crystal Structure of Human Factor VIII: Implications for the Formation of the Factor IXa-Factor VIIIa Complex

    Energy Technology Data Exchange (ETDEWEB)

    Ngo, J.C.; Huang, M.; Roth, D.A.; Furie, B.C.; Furie, B. (Wyeth); (MBL)

    2008-06-03

    Factor VIII is a procofactor that plays a critical role in blood coagulation, and is missing or defective in hemophilia A. We determined the X-ray crystal structure of B domain-deleted human factor VIII. This protein is composed of five globular domains and contains one Ca{sup 2+} and two Cu{sup 2+} ions. The three homologous A domains form a triangular heterotrimer where the A1 and A3 domains serve as the base and interact with the C2 and C1 domains, respectively. The structurally homologous C1 and C2 domains reveal membrane binding features. Based on biochemical studies, a model of the factor IXa-factor VIIIa complex was constructed by in silico docking. Factor IXa wraps across the side of factor VIII, and an extended interface spans the factor VIII heavy and light chains. This model provides insight into the activation of factor VIII and the interaction of factor VIIIa with factor IXa on the membrane surface.

  2. Crystal Structure of Human Factor VIII: Implications for the Formation of the Factor IXa-Factor VIIIa Complex

    Energy Technology Data Exchange (ETDEWEB)

    Chi Ki Ngo,J.; Huang, M.; Roth, D.; Furie, B.; Furie, B.

    2008-01-01

    Factor VIII is a procofactor that plays a critical role in blood coagulation, and is missing or defective in hemophilia A. We determined the X-ray crystal structure of B domain-deleted human factor VIII. This protein is composed of five globular domains and contains one Ca(2+) and two Cu(2+) ions. The three homologous A domains form a triangular heterotrimer where the A1 and A3 domains serve as the base and interact with the C2 and C1 domains, respectively. The structurally homologous C1 and C2 domains reveal membrane binding features. Based on biochemical studies, a model of the factor IXa-factor VIIIa complex was constructed by in silico docking. Factor IXa wraps across the side of factor VIII, and an extended interface spans the factor VIII heavy and light chains. This model provides insight into the activation of factor VIII and the interaction of factor VIIIa with factor IXa on the membrane surface.

  3. Probing polymer crystallization at processing-relevant cooling rates with synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Cavallo, Dario, E-mail: Dario.cavallo@unige.it [University of Genoa, Dept. of Chemistry and Industrial Chemistry, Via Dodecaneso 31, 16146 Genoa (Italy); Portale, Giuseppe [ESRF, Dubble CRG, Netherlands Organization of Scientific Research (NWO), 38043 Grenoble (France); Androsch, René [Martin-Luther-University Halle-Wittenberg, Center of Engineering Sciences, D-06099 Halle/S. (Germany)

    2015-12-17

    Processing of polymeric materials to produce any kind of goods, from films to complex objects, involves application of flow fields on the polymer melt, accompanied or followed by its rapid cooling. Typically, polymers solidify at cooling rates which span over a wide range, from a few to hundreds of °C/s. A novel method to probe polymer crystallization at processing-relevant cooling rates is proposed. Using a custom-built quenching device, thin polymer films are ballistically cooled from the melt at rates between approximately 10 and 200 °C/s. Thanks to highly brilliant synchrotron radiation and to state-of-the-art X-ray detectors, the crystallization process is followed in real-time, recording about 20 wide angle X-ray diffraction patterns per second while monitoring the instantaneous sample temperature. The method is applied to a series of industrially relevant polymers, such as isotactic polypropylene, its copolymers and virgin and nucleated polyamide-6. Their crystallization behaviour during rapid cooling is discussed, with particular attention to the occurrence of polymorphism, which deeply impact material’s properties.

  4. Numerical implementation of a crystal plasticity model with dislocation transport for high strain rate applications

    Science.gov (United States)

    Mayeur, Jason R.; Mourad, Hashem M.; Luscher, Darby J.; Hunter, Abigail; Kenamond, Mark A.

    2016-05-01

    This paper details a numerical implementation of a single crystal plasticity model with dislocation transport for high strain rate applications. Our primary motivation for developing the model is to study the influence of dislocation transport and conservation on the mesoscale response of metallic crystals under extreme thermo-mechanical loading conditions (e.g. shocks). To this end we have developed a single crystal plasticity theory (Luscher et al (2015)) that incorporates finite deformation kinematics, internal stress fields caused by the presence of geometrically necessary dislocation gradients, advection equations to model dislocation density transport and conservation, and constitutive equations appropriate for shock loading (equation of state, drag-limited dislocation velocity, etc). In the following, we outline a coupled finite element-finite volume framework for implementing the model physics, and demonstrate its capabilities in simulating the response of a [1 0 0] copper single crystal during a plate impact test. Additionally, we explore the effect of varying certain model parameters (e.g. mesh density, finite volume update scheme) on the simulation results. Our results demonstrate that the model performs as intended and establishes a baseline of understanding that can be leveraged as we extend the model to incorporate additional and/or refined physics and move toward a multi-dimensional implementation.

  5. What Factors Predict Student Self-Rated Physical Health?

    Science.gov (United States)

    Vingilis, Evelyn; Wade, Terrance J.; Adlaf, Edward

    1998-01-01

    Data from a randomly selected sample of 840 Ontario students were used to examine factors that affect self-rated physical health. Analyses focused on demographics, family structure, financial situation, child-parent relationship, school achievement, self-esteem, alcohol, tobacco, and cannabis use as factors which directly and indirectly influence…

  6. Factors Affecting the Plasticity of Sodium Chloride, Lithium Fluoride, and Magnesium Oxide Single Crystals. 1

    Science.gov (United States)

    Stearns, Carl A.; Pack, Ann E.; Lad, Robert A.

    1959-01-01

    A study was made of the relative magnitude of the effects of various factors on the ductility of single crystals of sodium chloride (NaCl), lithium fluoride (LiF), and magnesium oxide (MgO). Specimen treatments included water-polishing, varying cleavage rate, annealing, quenching, X-irradiation, surface coating, aging, and combinations of some of these treatments. The mechanical behavior of the crystals was studied in flexure and in compression, the latter study being performed at both constant strain rate and constant load. Etch-pit studies were carried out to provide some pertinent information on the results of pretreatment on the dislocation concentration and distribution in the vicinity of the surface. The load deformation curves for these ionic single crystals show an initial region of very low slope which proved to be due to anelastic deformation. The extent of initial anelastic deformation is modified by specimen pretreatment in a way that suggests that this deformation is the result of expansion of cleaved-in dislocation loops, which can contract on the removal of the stress. The effects of the various pretreatments on the load and deflection at fracture are in accord with the prediction one might make with regard to their effect on the nucleation of fatal surface cracks. For NaCl, increases in ductility are always accompanied by increases in strength. The creep constants for NaCl are a function of treatments which affect the bulk structure but are not a function of treatments which only affect the surface.

  7. Vapor diffusion, nucleation rates and the reservoir to crystallization volume ratio.

    Science.gov (United States)

    Forsythe, Elizabeth L; Maxwell, Daniel L; Pusey, Marc

    2002-10-01

    In a classical vapor diffusion crystallization, the protein solution is mixed in a 1:1 ratio with the reservoir solution, containing one or more precipitant species, after which the two are placed in an enclosed chamber. As the vapor pressure is lower for the reservoir solution, due to its higher solute concentration, there is a net transfer of water through the vapor phase from the protein droplet to the reservoir. In theory, the initial conditions in the droplet are such that the protein is in either a metastable or undersaturated state with respect to crystal nucleation. The loss of water serves to both concentrate the protein and the precipitant concentrations within the drop, bringing the protein past the metastable point to nucleation. The equilibration rate is a function of the precipitant(s) used, their concentration, the temperature, the distance between the two surfaces, and the droplet to reservoir volume ratio. For a given reservoir volume smaller droplets equilibrate faster, the rate being inversely linear with the droplet volume. In attempts to maximize the number of crystallization trials, and as crystals in the 100 - 200 micro m size range are sufficient, it has currently become standard practice to use starting droplet volumes of 2 - 4 micro l, with reservoir volumes typically in the 200 to 500 micro l range. The equilibration rates are maximized, and for most common salt concentrations and higher concentrations of polyethylene glycol (PEG) and 2-methyl-2,4-pentanediol (MPD) one can reasonably estimate that equilibration has occurred within 3 to 6 days at room temperature. Crystals appearing after this time are essentially grown under batch conditions. We experimentally find that altering the reservoir to droplet volume ratio, by changing the reservoir volume, from 50:1 (high ratio) to 5:1 (low ratio), on average increases the equilibration time by approximately 50 % when tested with solutions of 50% MPD, 1.5 M NaCl, or 30 % PEG 400. However

  8. High-Rate Growth and Nitrogen Distribution in Homoepitaxial Chemical Vapour Deposited Single-crystal Diamond

    Institute of Scientific and Technical Information of China (English)

    LI Hong-Dong; ZOU Guang-Tian; WANG Qi-Liang; CHENG Shao-Heng; LI Bo; L(U) Jian-Nan; L(U) Xian-Yi; JIN Zeng-Sun

    2008-01-01

    High rate (> 50 μm/h) growth of homoepitaxial single-crystal diamond (SCD) is carried out by microwave plasma chemical vapour deposition (MPCVD) with added nitrogen in the reactant gases of methane and hydrogen,using a polycrystalline-CVD-diamond-film-made seed holder. Photoluminescence results indicate that the nitrogen concentration is spatially inhomogeneous in a large scale,either on the top surface or in the bulk of those as-grown SCDs.The presence of N-distribution is attributed to the facts: (I) a difference in N-incorporation efficiency and (ii) N-diffusion,resulting from the local growth temperatures changed during the high-rate deposition process.In addition,the formed nitrogen-vacancy centres play a crucial role in N-diffusion through the growing crystal.Based on the N-distribution observed in the as-grown crystals,we propose a simple method to distinguish natural diamonds and man-made CVD SCDs.Finally,the disappearance of void defect on the top surface of SCDs is discussed to be related to a filling-in mechanism.

  9. Application of a conversion factor to estimate the adenoma detection rate from the polyp detection rate.

    LENUS (Irish Health Repository)

    Francis, Dawn L

    2011-03-01

    The adenoma detection rate (ADR) is a quality benchmark for colonoscopy. Many practices find it difficult to determine the ADR because it requires a combination of endoscopic and histologic findings. It may be possible to apply a conversion factor to estimate the ADR from the polyp detection rate (PDR).

  10. Crystallization and preliminary crystallographic data for a ternary complex between tissue factor, factor VIIa and a BPTI-derived inhibitor

    Science.gov (United States)

    Stura, Enrico A.; Ruf, Wolfram; Wilson, Ian A.

    1996-10-01

    The binding of tissue factor (TF) with the serine protease coagulation factor VIIa (VIIa) is the initial trigger for activation of the coagulation protease cascades. In complex with TF, VIIa has profoundly enhanced function in the limited proteolytic activation of the natural substrate factors X and IX. Here we report the screening and identification of crystallization conditions to produce diffraction quality crystals of the complex between TF · VIIa and a potent inhibitor (5L 15) derived from mutagenesis of the bovine pancreatic trypsin inhibitor (BPTI) sequence. The complex crystals were obtained from the soluble extracellular domain of tissue factor, expressed in Escherichia coli as a fusion protein, VIIa expressed in mammalian cells and recombinant 5L15. Because only 1.5 mg of complex were available for this work, a reverse screening based strategy was used in the search and optimization of the crystallization conditions. Two different crystal forms were obtained from polyethylene glycol 4000 and monomethyl polyethylene glycol 2000 with cacodylate buffer at pH 6.5 in the presence of sodium and calcium ions. The addition of magnesium and zinc have profound effects on the crystallization. Both crystal forms are trigonal with cell parameters a = b = 129.3 Å, c = 110.8 Å and a = b = 67.2 Å, c = 314.8 Å diffracting to 7 and 3.2 Å resolution, respectively, each with one molecule in the asymmetric unit. Complete data sets have been collected from each of these forms to the resolution to which the crystals diffract. A structural understanding of the interaction of VIIa with its cofactor TF to form a binary enzyme, and its inhibition by 5L15 will provide a basis for the development of antithrombotic strategies.

  11. Constraints on the Rates of Replenishment, Magma Mixing, and Crystal Recycling at Santorini Volcano, Greece

    Science.gov (United States)

    Martin, V. M.; Davidson, J. P.; Morgan, D. J.; Jerram, D. A.

    2007-12-01

    Santorini is a young, active volcano, which preserves abundant evidence for open-system processes such as magma replenishment and crystal recycling, and thus represents an ideal system in which to study magma chamber dynamics. Santorini is the largest volcanic centre in the Aegean arc, with an eruptive history spanning more than 250,000 years over two eruptive cycles. The cycles are dominated by extended periods of effusive shield-building activity with occasional large-magnitude explosive eruptions, the Minoan eruption of ~3600 years ago being the most recent. Current activity consists of a phase of post-caldera reconstruction, focused recently on the intra-caldera Kameni islands. Microsampling to measure 87Sr/86Sr ratios of plagioclase cores indicates the presence of a complex plumbing system beneath Santorini. Large rhyodacitic deposits typically contain a mafic component, interpreted as the eruption trigger. In some cases, the mafic magma groundmass and phenocrysts are isotopically similar to their rhyodacite host; other deposits show the opposite, implying the coexistence of isotopically distinct magma batches. To add further complexity, plagioclase phenocrysts are in some cases in equilibrium with their groundmass while others show the reverse, implying modification due to crystal recycling or shallow mixing processes prior to eruption. Mafic enclaves in the recent Kameni lavas, again interpreted as the probable eruption trigger, provide some constraints on the rates of these recycling, mixing, and triggering processes. Glomerocrysts and xenocrysts of recycled gabbroic cumulate material are present in a number of Kameni enclaves. Isotopic and chemical disequilibrium between the cumulate crystals and the host indicate that these fragments are derived from pre- existing crystal mush piles pervaded by the replenishing melts as they migrated to shallow levels, creating disequilibrium between the cumulate mineral cores and the replenishing melts. 87Sr/86Sr isotope

  12. Sustainability and Counteracting Factors to Profit Rate Decline

    DEFF Research Database (Denmark)

    Ougaard, Morten

    2014-01-01

    This paper discusses sustainability implications of barriers to growth as specified in the theory of the long-term falling rate of profit but focusing on the counteracting factors (CFs) specified by Marx. These depend much on political processes and are important in state theory for understanding...... policies of national and international institutions. Fourteen partly overlapping factors are identified and grouped in five categories: increased pressure on labor, geographical expansion, resource efficiency, technological progress, and destruction or devaluation of capital. It is suggested...... which implies a destruction of capital that will counteract the falling rate of profit. This will require sustained political intervention....

  13. Factors Influencing the Success Rate of Cardiopulmonary Resuscitation

    Directory of Open Access Journals (Sweden)

    Aisyah Amanda Hanif

    2015-12-01

    Full Text Available Background: Cardiopulmonary resuscitation (CPR is a series of actions performed on cardiac arrest patients. Not all patients receiving CPR can survive. The outcome of CPR is influenced by several factors. This study was conducted to determine the success rate of CPR and the factors influencing it in Dr. Hasan Sadikin General Hospital in 2013. Methods: This study was conducted by using 168 patient medical records who underwent CPR and met the inclusion criteria in the Resuscitation Room of Dr. Hasan Sadikin General Hospital from January to December 2013. The collected data consisted of age, gender, pre-arrest diagnosis, initial rhythm, response time and clinical outcome of CPR. The results were expressed in frequencies and percentage. The data were analyzed using the chi-square test. Results: The Success rate of CPR was 15.5%. The success rate was higher in patients with cardiac prearrest diagnoses (8.33%, p=0.024. The most common initial rhythm was unshockable rhythms (83.92%, yet patients with shockable heart rhythms had higher success rates (40.74%, p<0.001. All of the surviving patients had response time within the first minute from cardiac arrest. Conclusions: Success rate of CPR in the resuscitation room of Dr. Hasan Sadikin General Hospital during 2013 is still low. The factors influencing the survival rate are the pre-arrest diagnosis and initial heart rhythm.

  14. The Effect of Selected Principal Demographic Factors and Student Academic Factors on Overall School Accountability Ratings

    Science.gov (United States)

    Roberts, Karen Collette

    2013-01-01

    This study was designed to examine the relationship and predictability of selected principal demographic factors and academic factors on overall school accountability ratings. Specifically, the effect of principals' age, gender and years of experience and TAKS reading and TAKS mathematics score on overall accountability ratings. The population for…

  15. Factors Affecting the Changes of Ice Crystal Form in Ice Cream

    Science.gov (United States)

    Wang, Xin; Watanabe, Manabu; Suzuki, Toru

    In this study, the shape of ice crystals in ice cream was quantitatively evaluated by introducing fractal analysis. A small droplet of commercial ice cream mix was quickly cooled to about -30°C on the cold stage of microscope. Subsequently, it was heated to -5°C or -10°C and then held for various holding time. Based on the captured images at each holding time, the cross-sectional area and the length of circumference for each ice crystal were measured to calculate fractal dimension using image analysis software. The results showed that the ice crystals were categorized into two groups, e.g. simple-shape and complicated-shape, according to their fractal dimensions. The fractal dimension of ice crystals became lower with increasing holding time and holding temperature. It was also indicated that the growing rate of complicated-shape ice crystals was relatively higher because of aggregation.

  16. Macro factors and the Term Structure of Interest Rates

    NARCIS (Netherlands)

    H.D.R. Dewachter (Hans); M. Lyrio (Marco)

    2003-01-01

    textabstractThis paper presents an essentially affine model of the term structure of interest rates making use of macroeconomic factors and their long-run expectations. The model extends the approach pioneered by Kozicki and Tinsley (2001) by modeling consistently long-run inflation expectations

  17. Isotopic incorporation rates and discrimination factors in mantis shrimp crustaceans.

    Science.gov (United States)

    deVries, Maya S; Del Rio, Carlos Martínez; Tunstall, Tate S; Dawson, Todd E

    2015-01-01

    Stable isotope analysis has provided insights into the trophic ecology of a wide diversity of animals. Knowledge about isotopic incorporation rates and isotopic discrimination between the consumer and its diet for different tissue types is essential for interpreting stable isotope data, but these parameters remain understudied in many animal taxa and particularly in aquatic invertebrates. We performed a 292-day diet shift experiment on 92 individuals of the predatory mantis shrimp, Neogonodactylus bredini, to quantify carbon and nitrogen incorporation rates and isotope discrimination factors in muscle and hemolymph tissues. Average isotopic discrimination factors between mantis shrimp muscle and the new diet were 3.0 ± 0.6 ‰ and 0.9 ± 0.3 ‰ for carbon and nitrogen, respectively, which is contrary to what is seen in many other animals (e.g. C and N discrimination is generally 0-1 ‰ and 3-4 ‰, respectively). Surprisingly, the average residence time of nitrogen in hemolymph (28.9 ± 8.3 days) was over 8 times longer than that of carbon (3.4 ± 1.4 days). In muscle, the average residence times of carbon and nitrogen were of the same magnitude (89.3 ± 44.4 and 72.8 ± 18.8 days, respectively). We compared the mantis shrimps' incorporation rates, along with rates from four other invertebrate taxa from the literature, to those predicted by an allometric equation relating carbon incorporation rate to body mass that was developed for teleost fishes and sharks. The rate of carbon incorporation into muscle was consistent with rates predicted by this equation. Our findings provide new insight into isotopic discrimination factors and incorporation rates in invertebrates with the former showing a different trend than what is commonly observed in other animals.

  18. Isotopic incorporation rates and discrimination factors in mantis shrimp crustaceans.

    Directory of Open Access Journals (Sweden)

    Maya S deVries

    Full Text Available Stable isotope analysis has provided insights into the trophic ecology of a wide diversity of animals. Knowledge about isotopic incorporation rates and isotopic discrimination between the consumer and its diet for different tissue types is essential for interpreting stable isotope data, but these parameters remain understudied in many animal taxa and particularly in aquatic invertebrates. We performed a 292-day diet shift experiment on 92 individuals of the predatory mantis shrimp, Neogonodactylus bredini, to quantify carbon and nitrogen incorporation rates and isotope discrimination factors in muscle and hemolymph tissues. Average isotopic discrimination factors between mantis shrimp muscle and the new diet were 3.0 ± 0.6 ‰ and 0.9 ± 0.3 ‰ for carbon and nitrogen, respectively, which is contrary to what is seen in many other animals (e.g. C and N discrimination is generally 0-1 ‰ and 3-4 ‰, respectively. Surprisingly, the average residence time of nitrogen in hemolymph (28.9 ± 8.3 days was over 8 times longer than that of carbon (3.4 ± 1.4 days. In muscle, the average residence times of carbon and nitrogen were of the same magnitude (89.3 ± 44.4 and 72.8 ± 18.8 days, respectively. We compared the mantis shrimps' incorporation rates, along with rates from four other invertebrate taxa from the literature, to those predicted by an allometric equation relating carbon incorporation rate to body mass that was developed for teleost fishes and sharks. The rate of carbon incorporation into muscle was consistent with rates predicted by this equation. Our findings provide new insight into isotopic discrimination factors and incorporation rates in invertebrates with the former showing a different trend than what is commonly observed in other animals.

  19. Factors Controlling Sediment Denitrification Rates in Grassland and Forest Streams

    Directory of Open Access Journals (Sweden)

    Haryun Kim

    2014-01-01

    Full Text Available Sediment denitrification is an important nitrate (NO3- removal process from agricultural streams. The direct and indirect factors that control denitrification rates in tributary sediments can vary depending on the types of agricultural activities and vegetation. Our research investigated (1 tributary sediment denitrification rates in a grassland stream affected by pasture ecosystems and a forest stream affected by N fertilization; and (2 the environmental factors that determine denitrification rates in tributary sediments. The denitrification enzyme activity (DEA in grassland stream sediments is positively correlated with precipitation likely due to the increased nutrient exchange rates between stream water and sediments, and was higher than in forest stream sediments, leading to a decrease in NO3- concentration ([NO3-] in stream sediments. The DEA in riparian sediments was regulated by carbon concentrations and did not contribute to NO3- removal from the riparian sediment in grassland and forest streams. Thus, environmental factors affected by different types of agricultural activities and vegetation might regulate denitrification rates and [NO3-] in agricultural stream ecosystems.

  20. Nonsurgical factors of digital replantation and survival rate A metaanalysis

    Directory of Open Access Journals (Sweden)

    Huawei Yu

    2015-01-01

    Full Text Available The aim of this metaanalysis was to evaluate the association between nonsurgical factors and survival rate of digital replantation. A computer search of MEDLINE, OVID, EMBASE and CNKI databases was conducted to identify literatures for digital replantation, with the keywords of "digit," "finger" and "replantation" from their inception to June 10, 2014. Based on the inclusion and exclusion criteria, data were extracted independently by two authors using piloted forms. Review Manager 5.2 software was used for data analysis. The effect of some nonsurgical factors (gender, age, amputated finger, injury mechanisms, ischemia time and the way of preservation on the survival rate of digital replantation was assessed. The metaanalysis result suggested that gender and ischemia time had no significant influence on the survival rate of amputation replantation. However, the survival rate of digital replantation of adults was significantly higher than that of children. The guillotine injury of a finger was easier to replant successfully than the crush and avulsion. The little finger was more difficult for replantation than thumb. Survival rate of fingers stored in low temperature was higher than that in common temperature. The present metaanalysis suggested that age, injury mechanism, amputated finger and the way of preservation were significantly associated with the survival rate of digital replantation.

  1. Extraction of the beta-factor for single quantum dots coupled to a photonic crystal waveguide

    DEFF Research Database (Denmark)

    Nielsen, Henri Thyrrestrup; Sapienza, Luca; Lodahl, Peter

    2010-01-01

    We present measurements of the β-factor, describing the coupling efficiency of light emitted by single InAs/GaAs semiconductor quantum dots into a photonic crystal waveguide mode. The β-factor is evaluated by means of time resolved frequency-dependent photoluminescence spectroscopy. The emission...

  2. Broadly wavelength- and pulse width-tunable high-repetition rate light pulses from soliton self-frequency shifting photonic crystal fiber integrated with a frequency doubling crystal.

    Science.gov (United States)

    Lanin, Aleksandr A; Fedotov, Andrei B; Zheltikov, Aleksei M

    2012-09-01

    Soliton self-frequency shift (SSFS) in a photonic crystal fiber (PCF) pumped by a long-cavity mode-locked Cr:forsterite laser is integrated with second harmonic generation (SHG) in a nonlinear crystal to generate ultrashort light pulses tunable within the range of wavelengths from 680 to 1800 nm at a repetition rate of 20 MHz. The pulse width of the second harmonic output is tuned from 70 to 600 fs by varying the thickness of the nonlinear crystal, beam-focusing geometry, and the wavelength of the soliton PCF output. Wavelength-tunable pulses generated through a combination of SSFS and SHG are ideally suited for coherent Raman microspectroscopy at high repetition rates, as verified by experiments on synthetic diamond and polystyrene films.

  3. Solutions of two-factor models with variable interest rates

    Science.gov (United States)

    Li, Jinglu; Clemons, C. B.; Young, G. W.; Zhu, J.

    2008-12-01

    The focus of this work is on numerical solutions to two-factor option pricing partial differential equations with variable interest rates. Two interest rate models, the Vasicek model and the Cox-Ingersoll-Ross model (CIR), are considered. Emphasis is placed on the definition and implementation of boundary conditions for different portfolio models, and on appropriate truncation of the computational domain. An exact solution to the Vasicek model and an exact solution for the price of bonds convertible to stock at expiration under a stochastic interest rate are derived. The exact solutions are used to evaluate the accuracy of the numerical simulation schemes. For the numerical simulations the pricing solution is analyzed as the market completeness decreases from the ideal complete level to one with higher volatility of the interest rate and a slower mean-reverting environment. Simulations indicate that the CIR model yields more reasonable results than the Vasicek model in a less complete market.

  4. Factors affecting production rates of cosmogenic nuclides in extraterrestrial matter

    Energy Technology Data Exchange (ETDEWEB)

    Reedy, R.C., E-mail: reedy@psi.edu

    2015-10-15

    Good production rates are needed for cosmic-ray-produced nuclides to interpret their measurements. Rates depend on many factors, especially the pre-atmospheric object’s size, the location of the sample in that object (such as near surface or deep inside), and the object’s bulk composition. The bulk composition affects rates, especially in objects with very low and very high iron contents. Extraterrestrial materials with high iron contents usually have higher rates for making nuclides made by reactions with energetic particles and lower rates for the capture of thermal neutrons. In small objects and near the surface of objects, the cascade of secondary neutrons is being developed as primary particles are being removed. Deep in large objects, that secondary cascade is fully developed and the fluxes of primary particles are low. Recent work shows that even the shape of an object in space has a small but measureable effect. Work has been done and continues to be done on better understanding those and other factors. More good sets of measurements in meteorites with known exposure geometries in space are needed. With the use of modern Monte Carlo codes for the production and transport of particles, the nature of these effects have been and is being studied. Work needs to be done to improve the results of these calculations, especially the cross sections for making spallogenic nuclides.

  5. Polarizabilities and Shielding Factors of Ions in Cesium Halide Crystals with the Cesium Chloride Structure

    Science.gov (United States)

    Mahbubar, Rahman; Michihiro, Yoshitaka; Nakamura, Koichi; Kanashiro, Tatsuo

    2001-08-01

    The calculated results of the polarizabilities and the quadrupole shielding factor of the ions in cesium halide crystals with the cesium chloride structure are presented. The calculation is done on the basis of the self-consistent field local density approximation and the modified Sternheimer equation. The crystalline potential is treated by the spherical solid model. The size effect is seen in the values of the polarizabilities and the quadrupole shielding factor. The values of the polarizabilities and the quadrupole shielding factor of cesium ion show only slight change in different crystals. The values of chlorine ion show significant reduction and the amount of the reduction is different in the different crystals. The effect of the crystalline environment on the electron states is discussed.

  6. Dynamic increase and decrease of photonic crystal nanocavity Q factors for optical pulse control.

    Science.gov (United States)

    Upham, Jeremy; Tanaka, Yoshinori; Asano, Takashi; Noda, Susumu

    2008-12-22

    We introduce recent advances in dynamic control over the Q factor of a photonic crystal nanocavity system. By carefully timing a rapid increase of the Q factor from 3800 to 22,000, we succeed in capturing a 4ps signal pulse within the nanocavity with a photon lifetime of 18ps. By performing an additional transition of the Q factor within the photon lifetime, the held light is once again ejected from of the system on demand.

  7. High interest rate policy in Turkey and factors influencing interest rate spreads

    Directory of Open Access Journals (Sweden)

    Funda Yurdakul

    2009-01-01

    Full Text Available The main purpose of this paper is to examine what factors explain the difference between effective interest rates of Turkey and USA. The paper considers seven variables explaining interest rate spread such as general prices, Gross Domestic Product (GDP, exchange rate, credibility index, level of international reserves, foreign trade deficit, and budget deficit. Four distinct periods were selected to explore the influences of the above mentioned variables on on interest rate spreads in these different time periods. The period covering 1994.1-2006:12 was splitted into three sub-periods: the sub-period covering 1994:1-1998:12, crisis period covering 1999:1-2001:.12, and post-crisis period covering 2002:1-2006.12. Employing the data for Turkey and applying Engle and Granger two-step procedure, this paper concludes that the only variable reducing interest rate spreads in all periods is GDP. The other variables generally increase the interest rate spreads.Engle and Granger estimation procedure, unit-root test, interest rate spreads, interest rate.

  8. High interest rate policy in Turkey and factors influencing interest rate spreads

    Directory of Open Access Journals (Sweden)

    Funda Yurdakul

    2009-01-01

    Full Text Available The main purpose of this paper is to examine what factors explain the difference between effective interest rates of Turkey and USA. The paper considers seven variables explaining interest rate spread such as general prices, Gross Domestic Product (GDP, exchange rate, credibility index, level of international reserves, foreign trade deficit, and budget deficit. Four distinct periods were selected to explore the influences of the above mentioned variables on on interest rate spreads in these different time periods. The period covering 1994.1-2006:12 was splitted into three sub-periods: the sub-period covering 1994:1-1998:12, crisis period covering 1999:1-2001:.12, and post-crisis period covering 2002:1-2006.12.                            Employing the data for Turkey and applying Engle and Granger two-step procedure, this paper concludes that the only variable reducing interest rate spreads in all periods is GDP. The other variables generally increase the interest rate spreads.Engle and Granger estimation procedure, unit-root test, interest rate spreads, interest rate.    

  9. Transcription factor control of growth rate dependent genes in Saccharomyces cerevisiae: A three factor design

    DEFF Research Database (Denmark)

    Fazio, Alessandro; Jewett, Michael Christopher; Daran-Lapujade, Pascale;

    2008-01-01

    Background: Characterization of cellular growth is central to understanding living systems. Here, we applied a three-factor design to study the relationship between specific growth rate and genome-wide gene expression in 36 steady-state chemostat cultures of Saccharomyces cerevisiae. The three...... factors we considered were specific growth rate, nutrient limitation, and oxygen availability. Results: We identified 268 growth rate dependent genes, independent of nutrient limitation and oxygen availability. The transcriptional response was used to identify key areas in metabolism around which m...... transcription factor target sets, transcription factors that coordinate balanced growth were also identified. Our analysis shows that FhII, Rap1, and Sfp1, regulating protein biosynthesis, have significantly enriched target sets for genes up-regulated with increasing growth rate. Cell cycle regulators...

  10. Cerebrovascular accidents in sickle cell disease: rates and risk factors.

    Science.gov (United States)

    Ohene-Frempong, K; Weiner, S J; Sleeper, L A; Miller, S T; Embury, S; Moohr, J W; Wethers, D L; Pegelow, C H; Gill, F M

    1998-01-01

    Cerebrovascular accident (CVA) is a major complication of sickle cell disease. The incidence and mortality of and risk factors for CVA in sickle cell disease patients in the United States have been reported only in small patient samples. The Cooperative Study of Sickle Cell Disease collected clinical data on 4,082 sickle cell disease patients enrolled from 1978 to 1988. Patients were followed for an average of 5.2 +/- 2.0 years. Age-specific prevalence and incidence rates of CVA in patients with the common genotypes of sickle cell disease were determined, and the effects of hematologic and clinical events on the risk of CVA were analyzed. The highest rates of prevalence of CVA (4.01%) and incidence (0.61 per 100 patient-years) were in sickle cell anemia (SS) patients, but CVA occurred in all common genotypes. The incidence of infarctive CVA was lowest in SS patients 20 to 29 years of age and higher in children and older patients. Conversely, the incidence of hemorrhagic stroke in SS patients was highest among patients aged 20 to 29 years. Across all ages the mortality rate was 26% in the 2 weeks after hemorrhagic stroke. No deaths occurred after infarctive stroke. Risk factors for infarctive stroke included prior transient ischemic attack, low steady-state hemoglobin concentration and rate of and recent episode of acute chest syndrome, and elevated systolic blood pressure. Hemorrhagic stroke was associated with low steady-state hemoglobin and high leukocyte count.

  11. Quartz dissolution. I - Negative crystal experiments and a rate law. II - Theory of rough and smooth surfaces

    Science.gov (United States)

    Gratz, Andrew J.; Bird, Peter

    1993-01-01

    The range of the measured quartz dissolution rates, as a function of temperature and pOH, extent of saturation, and ionic strength, is extended to cover a wider range of solution chemistries, using the negative crystal methodology of Gratz et al. (1990) to measure the dissolution rate. A simple rate law describing the quartz dissolution kinetics above the point of zero charge of quartz is derived for ionic strengths above 0.003 m. Measurements were performed on some defective crystals, and the mathematics of step motion was developed for quartz dissolution and was compared with rough-face behavior using two different models.

  12. Microparticle Formation and Crystallization Rate of HMX with Supercritical CO2 Antisolvent Recrystallization

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Microparticle formation and crystallization rate of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) in acetone solution using supercritical carbon dioxide antisolvent (GAS) recrystallization were studied. Scanning electronic microscopy, X-ray diffraction and infrared radiation were used to examine particle size, crystallinity and chemical structure. The results show that β-HMX microparticle in different average size (2-9.5μm) and with narrow size distribution were obtained by controlling the expansibility, expansion speed, initial concentration and temperature during recrystallization of HMX. The formation of nuclei may be a main cause of consumption of solute when the solution is expanded rapidly enough and the equilibrium concentration is lower, in which almost monodisperse microparticle can be obtained.

  13. Microparticle Formation and Crystallization Rate of HMX with Supercritical CO2 Antisolvent Recrystallization

    Institute of Scientific and Technical Information of China (English)

    蔡建国; 周展云; 邓修

    2001-01-01

    Microparticle formation and crystallization rate of 1,3,5,7-tetranitro-l,3,5,7-tetraazacyclooctane (HMX) in acetone solution using supercritical carbon dioxide antisolvent (GAS) recrystallization were studied. Scanning electronic microscopy, X-ray diffraction and infrared radiation were used to examine particle size, crystallinity and chemical structure. The results show that β-HMX microparticle in different average size (2--9.5μm) and with narrow size distribution were obtained by controlling the expansibility, expansion speed, initial concentration and temperature during recrystallization of HMX. The formation of nuclei may be a main cause of consumption of solute when the solution is expanded rapidly enough and the equilibrium concentration is lower, in which almost monodisperse microparticle can be obtained.

  14. A Rate-Dependent Crystal Plasticity Analysis of Orientation Stability in Biaxial Tension of Magnesium

    Institute of Scientific and Technical Information of China (English)

    Donghong Zhang; Saiyi Li

    2011-01-01

    The development of texture during plastic deformation plays an important role in determining the stretch formability of magnesium alloy sheets. In this study, the orientation stability during equibiaxial tension of magnesium was analyzed based on three dimensional lattice rotations calculated by using a rate-dependent crystal plasticity model and assuming five different combinations of slip modes. The results show that no orientations can satisfy the stability criteria with both zero rotation velocity and convergent orientation flow in all dimensions. However, relatively stable orientations with zero rotation velocity and an overall convergence are found. They are featured by characteristic alignments of specific crystallographic directions in the macroscopic axis of contraction, depending on the slip modes involved in the deformation. It is also shown that the orientation stability varies significantly with the deviation of deformation mode from equibiaxial tension. The simulation results are briefly discussed in comparison with pre-existing experiments.

  15. Estimation of the Dose and Dose Rate Effectiveness Factor

    Science.gov (United States)

    Chappell, L.; Cucinotta, F. A.

    2013-01-01

    Current models to estimate radiation risk use the Life Span Study (LSS) cohort that received high doses and high dose rates of radiation. Transferring risks from these high dose rates to the low doses and dose rates received by astronauts in space is a source of uncertainty in our risk calculations. The solid cancer models recommended by BEIR VII [1], UNSCEAR [2], and Preston et al [3] is fitted adequately by a linear dose response model, which implies that low doses and dose rates would be estimated the same as high doses and dose rates. However animal and cell experiments imply there should be curvature in the dose response curve for tumor induction. Furthermore animal experiments that directly compare acute to chronic exposures show lower increases in tumor induction than acute exposures. A dose and dose rate effectiveness factor (DDREF) has been estimated and applied to transfer risks from the high doses and dose rates of the LSS cohort to low doses and dose rates such as from missions in space. The BEIR VII committee [1] combined DDREF estimates using the LSS cohort and animal experiments using Bayesian methods for their recommendation for a DDREF value of 1.5 with uncertainty. We reexamined the animal data considered by BEIR VII and included more animal data and human chromosome aberration data to improve the estimate for DDREF. Several experiments chosen by BEIR VII were deemed inappropriate for application to human risk models of solid cancer risk. Animal tumor experiments performed by Ullrich et al [4], Alpen et al [5], and Grahn et al [6] were analyzed to estimate the DDREF. Human chromosome aberration experiments performed on a sample of astronauts within NASA were also available to estimate the DDREF. The LSS cohort results reported by BEIR VII were combined with the new radiobiology results using Bayesian methods.

  16. Effective bichromatic potential for ultra-high Q-factor photonic crystal slab cavities

    Energy Technology Data Exchange (ETDEWEB)

    Alpeggiani, Filippo, E-mail: filippo.alpeggiani01@ateneopv.it; Andreani, Lucio Claudio; Gerace, Dario [Department of Physics and CNISM, University of Pavia, Via Bassi 6, 27100 Pavia (Italy)

    2015-12-28

    We introduce a confinement mechanism in photonic crystal slab cavities, which relies on the superposition of two incommensurate one-dimensional lattices in a line-defect waveguide. It is shown that the resulting photonic profile realizes an effective quasi-periodic bichromatic potential for the electromagnetic field confinement yielding extremely high quality (Q) factor nanocavities, while simultaneously keeping the mode volume close to the diffraction limit. We apply these concepts to pillar- and hole-based photonic crystal slab cavities, respectively, and a Q-factor improvement by over an order of magnitude is shown over existing designs, especially in pillar-based structures. Thanks to the generality and easy adaptation of such confinement mechanism to a broad class of cavity designs and photonic lattices, this work opens interesting routes for applications where enhanced light–matter interaction in photonic crystal structures is required.

  17. Polymer-Ion Interaction Weakens the Strain-Rate Dependence of Extension-Induced Crystallization for Poly(ethylene oxide).

    Science.gov (United States)

    Hu, Tingting; Tian, Nan; Ali, Sarmad; Wang, Zhen; Chang, Jiarui; Huang, Ningdong; Li, Liangbin

    2016-03-01

    The crystallization of poly(ethylene oxide) (PEO)-sodium iodine (NaI) composites is investigated by differential scanning calorimetry (DSC), extensional rheology, and in situ small-angle X-ray scattering (SAXS) with the aim of demonstrating versatile roles played by polymer-ion interactions. In the isothermal quiescent crystallization process, a decrease in the crystal growth rate is observed for PEO-NaI and is attributed to slow chain movement caused by the coordination between cations and polymer. In situ SAXS on extensional flow-induced crystallization (FIC) exhibits enhanced kinetics and orientation for both PEO and PEO-NaI with increasing strain rate. However, an overall weaker strain-rate dependence of FIC is observed for PEO-NaI, which can be interpreted as a synergistic consequence of promoted nucleation under flow and impeded crystal growth by polymer-ion interaction. A possible microscopic mechanism is proposed to account for the experimental observation based on the formation of transient cross-linking points in PEO-NaI and their influence on the entanglement network of polymer under various flow fields. The disclosed strain-rate dependence and various ion effects on the behavior of PEO-salt composites contribute to a comprehensive understanding of polymer-ion solid polyelectrolytes.

  18. Comparison of Five Computational Methods for Computing Q Factors in Photonic Crystal Membrane Cavities

    DEFF Research Database (Denmark)

    Novitsky, Andrey; de Lasson, Jakob Rosenkrantz; Frandsen, Lars Hagedorn

    2017-01-01

    Five state-of-the-art computational methods are benchmarked by computing quality factors and resonance wavelengths in photonic crystal membrane L5 and L9 line defect cavities. The convergence of the methods with respect to resolution, degrees of freedom and number of modes is investigated. Specia...

  19. Light propagation in optical crystal powders: effects of particle size and volume filling factor

    Energy Technology Data Exchange (ETDEWEB)

    GarcIa-Ramiro, B [Departamento de Fisica Aplicada I, Escuela Tecnica Superior de IngenierIa, Universidad del PaIs Vasco, Alameda Urquijo s/n, 48013 Bilbao (Spain); Illarramendi, M A [Departamento de Fisica Aplicada I, Escuela Tecnica Superior de IngenierIa, Universidad del PaIs Vasco, Alameda Urquijo s/n, 48013 Bilbao (Spain); Aramburu, I [Departamento de Fisica Aplicada I, Escuela Tecnica Superior de IngenierIa, Universidad del PaIs Vasco, Alameda Urquijo s/n, 48013 Bilbao (Spain); Fernandez, J [Departamento de Fisica Aplicada I, Escuela Tecnica Superior de IngenierIa, Universidad del PaIs Vasco, Alameda Urquijo s/n, 48013 Bilbao (Spain); Balda, R [Departamento de Fisica Aplicada I, Escuela Tecnica Superior de IngenierIa, Universidad del PaIs Vasco, Alameda Urquijo s/n, 48013 Bilbao (Spain); Al-Saleh, M [Departamento de Fisica Aplicada I, Escuela Tecnica Superior de IngenierIa, Universidad del PaIs Vasco, Alameda Urquijo s/n, 48013 Bilbao (Spain)

    2007-11-14

    In this work, we analyse the light propagation in some laser and nonlinear crystal powders. In particular, we study the dependence of the diffusive absorption lengths and the transport lengths on particle size and volume filling factor. The theoretical calculations have been made by assuming a diffusive propagation of light in these materials.

  20. Fabricating centimeter-scale high quality factor two-dimensional periodic photonic crystal slabs.

    Science.gov (United States)

    Lee, Jeongwon; Zhen, Bo; Chua, Song-Liang; Shapira, Ofer; Soljačić, Marin

    2014-02-10

    We present a fabrication route for centimeter-scale two-dimensional defect-free photonic crystal slabs with quality factors bigger than 10,000 in the visible, together with a unique way to quantify their quality factors. We fabricate Si(3)N(4) photonic crystal slabs, and perform an angle-resolved reflection measurement. This measurement data is used to retrieve the quality factors of the slabs by fitting it to a model based on temporal coupled-mode theory. The macroscopic nature of the structure and the high quality factors of their resonances could open up new opportunities for realizing efficient macroscale optoelectronic devices such as sensors, lasers, and energy harvesting systems.

  1. Copper and silver selenide crystal growth rate measurements as a method for determination of ionic conductivity

    Science.gov (United States)

    Vučić, Zlatko; Lovrić, Davorin; Gladić, Jadranko; Etlinger, Božidar

    2004-03-01

    The motivation behind this work is the discrepancy between the measured and calculated growth rates of copper selenide spherical single crystals between 740 and 800 K. The growth of cylindrical polycrystalline samples of copper selenide at high temperatures was monitored in experiments that enabled full control of the geometry of growth. Together with the calculations based on Yokota's transport equation, these measurements eliminated ionic conductivity data as a possible reason behind too high values of the calculated growth rates. The equivalent growth experiments on polycrystalline silver selenide samples were performed as a test of the method, yielding excellent agreement with the results obtained by extrapolation of existing data. On the basis of these measurements and associated analysis, this method is proposed as a method for determination of ionic conductivity of mixed superionic conductors on temperatures up to the temperatures of melting, i.e. in the range in which other methods of ionic conductivity measurements either do not work or are not accurate enough.

  2. Large area crystallization of amorphous Si with overlapping high repetition rate laser pulses

    KAUST Repository

    Ryu, Sang-Gil

    2012-09-01

    This paper presents a pulsed laser crystallization technique, enabling large area crystallization of amorphous Si to produce grains having well-defined size and orientation. The method is developed by first determining the parameters influencing crystallization induced by single laser pulses of circular cross-sectional profile. In a second step, crystallization by overlapping round spots is examined. The experiments reveal three zones characterized by distinctly different crystallized morphologies following the laser irradiation. One of these zones corresponds to the regime of lateral crystal growth, wherein grains are driven towards the center of the spot by the radial temperature gradient. These findings are then applied to processing via line beam profiles that facilitate large area crystallization upon rapid translation of the specimen. Crystallization of extended areas hinges on the determination of the crystal growth length for a single spot. The pitch between successive pulses is then set on the basis of this information. It is shown that the pulse energy has only a weak effect on the crystal growth length. © 2012 Elsevier B.V.

  3. Factors influencing crime rates: an econometric analysis approach

    Science.gov (United States)

    Bothos, John M. A.; Thomopoulos, Stelios C. A.

    2016-05-01

    The scope of the present study is to research the dynamics that determine the commission of crimes in the US society. Our study is part of a model we are developing to understand urban crime dynamics and to enhance citizens' "perception of security" in large urban environments. The main targets of our research are to highlight dependence of crime rates on certain social and economic factors and basic elements of state anticrime policies. In conducting our research, we use as guides previous relevant studies on crime dependence, that have been performed with similar quantitative analyses in mind, regarding the dependence of crime on certain social and economic factors using statistics and econometric modelling. Our first approach consists of conceptual state space dynamic cross-sectional econometric models that incorporate a feedback loop that describes crime as a feedback process. In order to define dynamically the model variables, we use statistical analysis on crime records and on records about social and economic conditions and policing characteristics (like police force and policing results - crime arrests), to determine their influence as independent variables on crime, as the dependent variable of our model. The econometric models we apply in this first approach are an exponential log linear model and a logit model. In a second approach, we try to study the evolvement of violent crime through time in the US, independently as an autonomous social phenomenon, using autoregressive and moving average time-series econometric models. Our findings show that there are certain social and economic characteristics that affect the formation of crime rates in the US, either positively or negatively. Furthermore, the results of our time-series econometric modelling show that violent crime, viewed solely and independently as a social phenomenon, correlates with previous years crime rates and depends on the social and economic environment's conditions during previous years.

  4. Identification of factors affecting birth rate in Czech Republic

    Science.gov (United States)

    Zámková, Martina; Blašková, Veronika

    2013-10-01

    This article is concerned with identifying economic factors primarily that affect birth rates in Czech Republic. To find the relationship between the magnitudes, we used the multivariate regression analysis and for modeling, we used a time series of annual values (1994-2011) both economic indicators and indicators related to demographics. Due to potential problems with apparent dependence we first cleansed all series obtained from the Czech Statistical Office using first differences. It is clear from the final model that meets all assumptions that there is a positive correlation between birth rates and the financial situation of households. We described the financial situation of households by GDP per capita, gross wages and consumer price index. As expected a positive correlation was proved for GDP per capita and gross wages and negative dependence was proved for the consumer price index. In addition to these economic variables in the model there were used also demographic characteristics of the workforce and the number of employed people. It can be stated that if the Czech Republic wants to support an increase in the birth rate, it is necessary to consider the financial support for households with small children.

  5. Factors affecting decomposition rates of chironomid (Diptera pupal exuviae

    Directory of Open Access Journals (Sweden)

    Rathi G. Kavanaugh

    2014-12-01

    Full Text Available Collections of floating chironomid pupal exuviae are used to monitor water quality and assess ecological conditions. Factors controlling exuviae sinking rates are not well known, although they should have an effect on conclusions that can be drawn from collections. The current study was conducted to determine the rate of sinking under controlled laboratory conditions using water from three streams with different nutrient levels. Sinking rates ranged from less than a day to seven days, depending on microbial activity, nutrient concentrations, temperature and turbulence. Results also varied by genus, with pupal exuviae of Chironomus riparius, Diamesa nivoriunda, Orthocladius (Euorthocladius thienemanni and Eukiefferiella sp. used in experiments. Four species of bacteria and eight genera of fungi colonized and metabolized exuviae, with bacteria dominant early and fungi dominant later in the decomposition process. Decomposition was faster in lightly chitinized abdominal conjunctive areas, which resulted in exuviae breaking apart and sinking. Examination of untreated, dewaxed and dewaxed-deproteinized exuviae indicated that untreated exuviae sank faster. Waxes appeared important for colonization and initial microbial metabolization was delayed when waxes were removed. Results confirm the importance of biological degradation of exuviae in determining floatation times. We predict that streams and other waterbodies with high dissolved nutrients will result in rapidly sinking exuviae, while exuviae in low nutrient waterbodies will float longer.Article submitted 1. October 2014, accepted 18. November 2014, published 22. December 2014.

  6. Effects of Saponification Rate on Electrooptical Properties and Morphology of Poly(vinyl alcohol)/Liquid Crystal Composite Films

    Science.gov (United States)

    Ono, Hiroshi; Kawatsuki, Nobuhiro

    1995-03-01

    The relationship between the saponification rate of poly(vinyl alcohol) (PVA), and the electrooptical properties and morphology of the PVA/liquid crystal (LC) composite films was investigated. Light transmission clazing and the LC droplet size were varied by changing the saponification rate or the blend ratio of two kinds of PVA with different saponification rates because the refractive index and surface tension could be controlled by the saponification rate of PVA. The threshold voltage decreased with increasing saponification rate though the extrapolation length was decreased. It was suggested that the electrooptical properties were strongly dependent on the droplet size.

  7. Final LDRD report : enhanced spontaneous emission rate in visible III-nitride LEDs using 3D photonic crystal cavities.

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Arthur Joseph; Subramania, Ganapathi S.; Coley, Anthony J.; Lee, Yun-Ju; Li, Qiming; Wang, George T.; Luk, Ting Shan; Koleske, Daniel David; Fullmer, Kristine Wanta

    2009-09-01

    The fundamental spontaneous emission rate for a photon source can be modified by placing the emitter inside a periodic dielectric structure allowing the emission to be dramatically enhanced or suppressed depending on the intended application. We have investigated the relatively unexplored realm of interaction between semiconductor emitters and three dimensional photonic crystals in the visible spectrum. Although this interaction has been investigated at longer wavelengths, very little work has been done in the visible spectrum. During the course of this LDRD, we have fabricated TiO{sub 2} logpile photonic crystal structures with the shortest wavelength band gap ever demonstrated. A variety of different emitters with emission between 365 nm and 700 nm were incorporated into photonic crystal structures. Time-integrated and time-resolved photoluminescence measurements were performed to measure changes to the spontaneous emission rate. Both enhanced and suppressed emission were demonstrated and attributed to changes to the photonic density of states.

  8. The effects of temperature and strain rate on the yielding behavior of the single crystal superalloy PWA 1480

    Science.gov (United States)

    Milligan, Walter W.; Antolovich, Stephen D.

    1988-01-01

    Interrupted tensile tests were conducted on (001) oriented single crystals at temperatures from 20 to 1093 C. Two strain rates were used, 0.5 and 50 percent/min. After the tests, the deformation substructures were characterized by transmission electron microscopy. Results of these tests are given.

  9. Impurity microsegregation due to periodic changes in the temperature and pulling rate of crystal grown by the Stepanov method

    Energy Technology Data Exchange (ETDEWEB)

    Zhdanov, A.V.; Nikolaeva, L.P.; Red`kin, B.S. [Institute of Solid-State Physics, Chernogolovka (Russian Federation)

    1995-12-01

    A mathematical model is proposed to describe the behavior of a doping impurity concentration in a crystal grown by the Stepanov method from a melt and subjected to periodic changes in its pulling rate and temperature of the thermal node. Various modes of these effects are discussed. The results obtained are given by graphs that characterize their influence on concentration distribution.

  10. Correlation of Heating Rates, Crystal Structures, and Microwave Dielectric Properties of Li2ZnTi3O8 Ceramics

    Science.gov (United States)

    Lu, Xuepeng; Zheng, Yong; Huang, Qi; Xiong, Weihao

    2015-11-01

    The correlation of heating rates, crystal structures, and microwave dielectric properties of Li2ZnTi3O8 ceramics was thoroughly investigated. Ionic polarizability, atomic packing fractions, bond strengths, and octahedral distortion of Li2ZnTi3O8 ceramics were calculated on the basis of structure refinement data. The "black core" phenomenon resulting from reduction of Ti4+ ions was observed for Li2ZnTi3O8 ceramic sintered at 1°/min; reduction of Ti4+ ions could be limited by heating more rapidly. For heating rates from 1 to 7°/min, the dielectric constants ( ɛ r) of Li2ZnTi3O8 ceramics were mainly determined by ionic polarizability. The temperature coefficient of the resonant frequency ( τ f ) of Li2ZnTi3O8 ceramics was determined by bond strengths. Li2ZnTi3O8 ceramic sintered at 1°/min had the lowest quality factor ( Q × f); this was related to the high dielectric loss as a result of oxygen vacancies formed by reduction of Ti4+ ions. Q × f values of Li2ZnTi3O8 ceramics also decreased with increasing heating rate from 3 to 7°/min, owing to reduced packing fractions and average grain sizes. Li2ZnTi3O8 ceramic sintered at 3°/min had the optimum microwave dielectric properties of ɛ r = 26.6, Q × f = 83,563 GHz, and τ f = -12.4 ppm/°C.

  11. Physical limitations and fundamental factors affecting performance of liquid crystal tunable lenses with concentric electrode rings.

    Science.gov (United States)

    Li, Liwei; Bryant, Doug; van Heugten, Tony; Bos, Philip J

    2013-03-20

    A comprehensive analysis of fundamental factors and their effects on the performance of liquid crystal (LC)-based lenses is given. The analysis adopts numerical LC director and electric field simulation, as well as scalar diffraction theory for calculating the lens performance considering different variable factors. A high-efficiency LC lens with concentric electrode rings is fabricated for verifying and enriching the analysis. The measurement results are in close agreement with the analysis, and a summary of key factors is given with their quantitative contributions to the efficiency.

  12. Injury rates and risk factors in competitive professional boxing.

    Science.gov (United States)

    Zazryn, Tsharni R; McCrory, Paul R; Cameron, Peter A

    2009-01-01

    To determine injury rates and risk factors for injury in a cohort of professional boxers. Retrospective cohort design reporting on data collected for a fight statistics database maintained by the Professional Boxing and Combat Sports Board of Victoria, Australia. Data were extracted for the years January 1997 through June 2005. Victoria, Australia. 545 professional boxers (age, 18 to 43 years) who participated in a total of 907 fights over the study period. Independent variables under investigation included age, gender, weight, bout exposure, and location of the bout (within or outside of the State of Victoria). Physician-reported acute boxing injuries occurring during bouts of any region or nature. 214 injuries were sustained over the 8.5 years, corresponding to an injury rate of 23.6 per 100 professional fights. The majority of these injuries were lacerations to the head and face. An increasing age and an increasing number of fights were both significant predictors of injury. Injury reduction strategies for professional boxing might include restrictions of eligibility to fight based on age and boxing bout exposure. Future research using prospective cohort designs and standardized injury definitions are needed to confirm these results. Greater mechanistic detail and more complete data entry are necessary to ensure that optimal injury prevention strategies can be developed and implemented. Upon confirmation of the results of this study, the Professional Boxing and Combat Sports Board of Victoria may consider different criteria upon which to sanction a fight.

  13. Effect of cooling rate on the crystallization behavior of perovskite in high titanium-bearing blast furnace slag

    Institute of Scientific and Technical Information of China (English)

    Lu Liu; Mei-long Hu; Chen-guang Bai; Xue-weiLü; Yu-zhou Xu; Qing-yu Deng

    2014-01-01

    The effect of cooling rate on the crystallization of perovskite in high Ti-bearing blast furnace (BF) slag was studied using confocal scanning laser microscopy (CSLM). Results showed that perovskite was the primary phase formed during the cooling of slag. On the slag surface, the growth of perovskite proceeded via the successive production of quasi-particles along straight lines, which further extended in certain directions. The morphology and structure of perovskite was found to vary as a function of cooling rate. At cooling rates of 10 and 30 K/min, the dendritic arms of perovskite crossed obliquely, while they were orthogonal at a cooling rate of 20 K/min and hexagonal at cooling rates of 40 and 50 K/min. These three crystal morphologies thus obtained at different cooling rates respectively corresponded to the ortho-rhombic, cubic and hexagonal crystal structures of perovskite. The observed change in the structure of perovskite could probably be attrib-uted to the deficiency of O2-,when Ti2O3 was involved in the formation of perovskite.

  14. Factors affecting high resting pulse rate in military pilots

    Directory of Open Access Journals (Sweden)

    Minarma Siagian

    2014-02-01

    Full Text Available AbstrakLatar belakang: Pilot terpajan pada keadaan yang memerlukan kewaspadaan yang meningkatkan kegiatan sistem saraf simpatis. Hal ini dapat berdampak pada sistem kardiovaskular manusia, yang antara lain tercermin pada peningkatan frekuensi denyut jantung. Penelitian bertujuan untuk mengetahui pengaruh beberapa faktor yang meningkatkan frekuensi denyut jantung pada pilot. Metode:Penelitian nested case-control yang dilakukan pada pilot militer yang melakukan pemeriksaan fisik tahunan di Lembaga Kesehatan Penerbangan dan Ruang Angkasa (LAKESPRA Saryanto dari tahun 2003 sampai 2008. Data yang diperoleh dari rekam medik berupa umur, pangkat, jumlah jam terbang, rata-rata jam terbang per tahun, dan jenis pesawat. Hasil: Dari 539 pilot, terdapat 155 pilot dengan frekuensi nadi istirahat tinggi. Dibandingkan dengan pilot berumur 23-29 tahun, pilot berumur 30-39 tahun mempunyai risiko 66% lebih banyak untuk frekuensi nadi istirahat tinggi [rasio odds suaian (ORa = 1,66; 95% interval kepercayaan (CI = 1,17-2,35, P = 0,004], sedangkan yang berumur 40-49 tahun berisiko 2,4 kali (ORa = 2,40; P = 0,000]. Dibandingkan pilot pesawat transport, pilot pesawat tempur berisiko 59% lebih banyak dengan frekuensi nadi istirahat tinggi (ORa = 1,59; P = 0,002. Kesimpulan:Umur pilot yang semakin tua dan jenis pesawat tempur meningkatkan risiko frekuensi nadi istirahat pada pilot. (Health Science Indones 2013;2:51-4Kata kunci:umur, jenis pesawat terbang, frekuensi nadi istirahat, pilotAbstractBackground:Pilots are almost constantly exposed to emergency situations which increase sympathetic activity. This will affect the cardiovascular system, which among others will be reflected by increased resting pulse rate. The aim of this study was to investigate factors that increase resting pulse rate in pilots. Methods:A nested case-control study was conducted on Indonesian Air Force military pilots doing annual medical check-ups at the Saryanto Institute for Medical and Health

  15. Effect of sucrose polyesters on crystallization rate of vegetable ghee: solid fat content study

    Directory of Open Access Journals (Sweden)

    Ibrahim Nasir, Mohammad

    2003-12-01

    Full Text Available Crystallization rate of partial hydrogenated blend of soybean oil and cottonseed oil used for making vegetable ghee (vanaspati was investigated, by solid fat content (SFC using pulsed nuclear magnetic resonance (p-NMR. The effects of adding sucrose fatty acid esters or sucrose polyesters (SPE on the crystallization rate of the blend fat were studied. Sucrose tetrastearate DK ester F-10 (stearate 70% - palmitate 30% was added to the fat at different concentration, namely 0.5% and 1.0%. Blank sample and sample containing 0.5% and 1.0% DK ester F-10 / (DK F-10 were chosen to measure the change in SFC at constant temperature of 15ºC for a period of 25 hr. Five determinations of SFC were taken to the fat samples during the 25 hr i.e. 2,5,9,13 and 25th hr. SFC vs. time of crystallization of the three samples showed continuous increasing in SFC in all samples during the 25 hr, with sharp increasing at the first two hours. Samples containing 0.0% and 0.5% DK F-10, showed no significant difference in SFC during the first thirteen hours, while sample containing 1.0% DK F-10, showed higher SFC than the other two samples, through out the period. The amount of SFC for 1.0% DK F-10 sample at the 13th hour is equal to the SFC of the blank (0.0% sample at the 25th hour. Melting point of the same samples increased with the increasing DK F-10 concentration in the fat samples. The results of SFC make it sure that the addition of 1.0% DK F- 10 will shorten the time required for the crystallization of vegetable ghee while the addition of 0.5% will not have significant effect.Se ha investigado, mediante el contenido en grasa sólida (SFC por resonancia magnética nuclear pulsada (p-NMR, la velocidad de cristalización de mezcla de aceite de la soja y aceite de semilla del algodón parcialmente hidrogenada utilizada en la elaboración de ghee vegetal (vanaspati. Se han estudiado los efectos de añadir ésteres de sacarosa de ácidos grasos o poliésteres de

  16. High quality factor nanophotonic resonators in bulk rare-earth doped crystals

    CERN Document Server

    Zhong, Tian; Kindem, Jonathan M; Miyazono, Evan; Faraon, Andrei

    2015-01-01

    Numerous bulk crystalline materials exhibit attractive nonlinear and luminescent properties for classical and quantum optical applications. A chip-scale platform for high quality factor optical nanocavities in these materials will enable new optoelectronic devices and quantum light-matter interfaces. In this article, photonic crystal nanobeam resonators fabricated using focused ion beam milling in bulk insulators, such as rare-earth doped yttrium orthosilicate and yttrium vanadate, are demonstrated. Operation in the visible, near infrared, and telecom wavelengths with quality factors up to 27,000 and optical mode volumes close to one cubic wavelength is measured. These devices enable new nanolasers, on-chip quantum optical memories, single photon sources, and non-linear devices at low photon numbers based on rare-earth ions. The techniques are also applicable to other luminescent centers and crystals.

  17. Crystallization field and rate study for the formation of single phase sodium-potassium and potassium clinoptilolite

    Energy Technology Data Exchange (ETDEWEB)

    Guevenir, Oe.; Kalipcilar, H.; Culfaz, A. [Middle East Technical University, Department of Chemical Engineering, 06531 Ankara (Turkey)

    2011-04-15

    Reproducible synthesis of clinoptilolite as the single crystalline phase was achieved in the narrow crystallization field at or around the nominal batch composition of 2.1(Na{sub 2}O+K{sub 2}O):Al{sub 2}O{sub 3}:10SiO{sub 2}:110H{sub 2}O at 140 C. Clinoptilolites of high purity were crystallized in the pure sodium or mixed sodium-potassium cation systems. Partial replacement of hydroxyl anions with the salts of carbonates or chlorides also yielded clinoptilolite as the single crystalline phase although at lower crystallization rates. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  18. Dissolution rates and surface chemistry of feldspar glass and crystal. Final technical report, June 15, 1995 - August 14, 2001

    Energy Technology Data Exchange (ETDEWEB)

    Brantley, S.; Pantano, C.

    2002-06-11

    Final report summarizing the completed work of the project entitled 'Dissolution of Feldspar in the Field and Laboratory.' One of the highly debated questions today in low-temperature geochemical kinetics centers upon the rate and mechanism of dissolution of feldspar, the most common mineral in the crust. In this project, the mechanisms of feldspar dissolution were investigated by emphasizing experiments with feldspar glass and crystal while comparing surface and solution chemistry. Specifically, laboratory work focused on the structure of altered surface layers on feldspars, the rate of dissolution of feldspar crystal and glass, and the presence of porosity and surface coatings on feldspars. In a complementary field project, the use of Sr concentrations and isotopic ratios were used to calculate feldspar dissolution rates.

  19. Gambling disorder: estimated prevalence rates and risk factors in Macao.

    Science.gov (United States)

    Wu, Anise M S; Lai, Mark H C; Tong, Kwok-Kit

    2014-12-01

    An excessive, problematic gambling pattern has been regarded as a mental disorder in the Diagnostic and Statistical Manual for Mental Disorders (DSM) for more than 3 decades (American Psychiatric Association [APA], 1980). In this study, its latest prevalence in Macao (one of very few cities with legalized gambling in China and the Far East) was estimated with 2 major changes in the diagnostic criteria, suggested by the 5th edition of DSM (APA, 2013): (a) removing the "Illegal Act" criterion, and (b) lowering the threshold for diagnosis. A random, representative sample of 1,018 Macao residents was surveyed with a phone poll design in January 2013. After the 2 changes were adopted, the present study showed that the estimated prevalence rate of gambling disorder was 2.1% of the Macao adult population. Moreover, the present findings also provided empirical support to the application of these 2 recommended changes when assessing symptoms of gambling disorder among Chinese community adults. Personal risk factors of gambling disorder, namely being male, having low education, a preference for casino gambling, as well as high materialism, were identified.

  20. Self-citation rate and impact factor in ophthalmology.

    Science.gov (United States)

    Mimouni, Michael; Segal, Ori

    2014-01-01

    To analyze the self-citation rate (SCR) of ophthalmology journals, determine its possible effect on a journal's impact factor (IF) and compare the SCR of subspecialty journals versus general ophthalmology journals. A retrospective consecutive study of ophthalmology journals listed in the Journal Citations Report (JCR) 2013. We retrieved these parameters from each journal's report: IF, total citations, self-citations, SCR and IF without self-citations (corrected IF). A significant correlation was detected between the number of self-citations and publications (R(2) = 86.3, p = 0.000). Subspecialty journals had a significantly higher SCR than general journals (p = 0.017). No significant difference was found in terms of IF and corrected IF between general and subspecialty journals (p = 0.260 and p = 0.108, respectively). No significant correlation between IF and SCR was detected (p = 0.099). The corrected IF was inversely correlated with SCR (R(2) = -32.6, p = 0.013). An inverse correlation was detected between SCR and IF in the 29 ophthalmology journals with the lowest IF (R(2) = -57.3, p = 0.001). Unlike other fields of medicine, the IF of an ophthalmology journal does not correlate with its SCR. Self-citation is found more often in journals with a low corrected IF and is inversely correlated with IF in the bottom half. © 2014 S. Karger AG, Basel.

  1. Structural and phase transformations in iron-based alloy obtained in conditions of high cooling rate crystallization

    Science.gov (United States)

    Kovalevskaya, Zh. G.; Khimich, M. A.

    2016-11-01

    The production of parts by selective electron beam melting (SEBM) is accompanied by the formation of nonequilibrium structures. This is caused by the crystallization of alloys with high cooling rates. To evaluate the influence of cooling rate on the process of structural and phase transformations in the Fe-8Si-5Al-2C alloy, the electron beam melting of plasma coating was carried out. The dendritic structure was formed in the molten pool. The distance between dendritic branches of the second order was 2-5 µm. This corresponds to the cooling rate of about 103 K/s. The electron microscopy has shown that dendrites were formed by α-phase, while γ-phase was localized between α-phase crystals in form of intercalations. The secondary phases (intermetallic, aluminum and iron carbosilicides, aluminates and iron carboaluminates) are of sub-micron size and located in the α- and γ-phase boundary intersections or within the grains of the main phase. The microhardness of the alloy increases twofold. This suggests that complex hardening by solid-solution and dispersed hardening by the secondary phase particles occurs during crystallization with the above-mentioned cooling rate.

  2. Modification of spontaneous emission rate of micrometer-sized light sources using hollow-core photonic crystal fibers

    Institute of Scientific and Technical Information of China (English)

    Lu Jiao-Hua; Meng Zi-Ming; Liu Hai-Ying; Feng Tian-Hua; Dai Qiao-Feng; Wu Li-Jun; Gun Qi; Hu Wei; Lan Sheng

    2009-01-01

    We investigate numerically and experimentally the modification of the spontaneous emission rate for micrometer. sized light sources embedded in a hollow-core photonic crystal fiber(HCPCF). The diameter of the light source is deliberately chosen such that they could be easily introduced into the central hole of the hollow-core photonic crystal fiber by canillary force. The photoluminescence from the microparticles is measured by using an inverted microscope in combination with a spectrometer. The modification of the spontaneous emission rate is observed in a wavelength region where there is no band gap. The experimental observations are consistent with the simulation results obtained by the plane wave expansion and finite-difference time-domain techniques.

  3. Dual mode cobaloxime crystals: Acceleration of trans-cis photochromic reaction rate by photoisomerization

    Science.gov (United States)

    Sekine, Akiko

    2016-08-01

    Our recent results on the photochromic reactions in dual mode cobaloxime crystals containing azobenzene derivatives are briefly reviewed. This work represents the first step toward the design of functional materials which can be controlled by two independent external stimuli, one by visible light and the other by UV radiation.

  4. Steady-State Crack Growth in Rate-Sensitive Single Crystals

    DEFF Research Database (Denmark)

    Juul, Kristian Jørgensen; Nielsen, Kim Lau; Niordson, Christian Frithiof

    2016-01-01

    The characteristics of the active plastic zone surrounding a crack growingin a single crystal (FCC, BCC, and HCP) at constant velocity is investigated for ModeI loading under plane strain assumptions. The framework builds upon a steady-state relation bringing the desired solution out in a frame...

  5. Strong optomechanical coupling in a slotted photonic crystal nanobeam cavity with an ultrahigh quality factor-to-mode volume ratio

    CERN Document Server

    Schneider, Katharina

    2016-01-01

    We describe the design, fabrication, and characterization of a one-dimensional silicon photonic crystal cavity in which a central slot is used to enhance the overlap between highly localized optical and mechanical modes. The optical mode has an extremely small mode volume of 0.017 $(\\lambda_{vac}/n)^3$, and an optomechanical vacuum coupling rate of 310 kHz is measured. With optical quality factors up to $1.2 \\cdot 10^5$, fabricated devices are in the resolved-sideband regime. The electric field has its maximum at the slot wall and couples to the in-plane breathing motion of the slot. The optomechanical coupling is thus dominated by the moving-boundary effect, which we simulate to be six times greater than the photoelastic effect, in contrast to most structures, where the photoelastic effect is often the primary coupling mechanism.

  6. Modification of the Ti40Cu36Zr10Pd14 BMG Crystallization Mechanism with Heating Rates 10-140 K/min

    Science.gov (United States)

    Czeppe, T.; Sypien, A.; Wierzbicka-Miernik, A.

    2016-12-01

    The article presents investigations of Ti40Cu36Zr10Pd14 bulk metallic glass crystallization process heated with the rates of 10, 60, 100 and 140 K/min. High heating rates experiments were performed in a new type of differential scanning calorimeter equipped with a fast responding thermal sensor. Phase composition and microstructure were studied with x-ray diffraction and transmission electron microscopy. The observed crystallization proceeded in two separate steps. Applied high rates of heating/cooling resulted in the crystallization of only one CuTi phase, replacing typical multi-phase crystallization. The microstructure after crystallization was polycrystalline with some amount of amorphous phase retained. Kinetic parameters were determined with the use of the Kissinger and Friedman iso-conversional analysis and Matusita-Sakka iso-kinetic model. The kinetic analysis supplies results concerning autocatalytically activated mechanism of primary crystallization with decreasing activation energy and small density of quenched-in nuclei, in good agreement with previous structural investigations. The mechanism of secondary crystallization required dense nuclei site, increasing activation energy and large nucleation frequency. The amorphous phase of Ti40Cu36Zr10Pd14 BMG revealed high thermal stability against crystallization. Application of high heating rates in DSC experiments might be useful for the determination of mechanism and kinetic parameters in investigations of metallic glasses crystallization, giving reasonable results.

  7. Crystal structure of elongation factor 4 bound to a clockwise ratcheted ribosome

    Energy Technology Data Exchange (ETDEWEB)

    Gagnon, M. G.; Lin, J.; Bulkley, D.; Steitz, T. A.

    2014-08-08

    Elongation factor 4 (EF4/LepA) is a highly conserved guanosine triphosphatase translation factor. It was shown to promote back-translocation of tRNAs on posttranslocational ribosome complexes and to compete with elongation factor G for interaction with pretranslocational ribosomes, inhibiting the elongation phase of protein synthesis. Here, we report a crystal structure of EF4–guanosine diphosphate bound to the Thermus thermophilus ribosome with a P-site tRNA at 2.9 angstroms resolution. The C-terminal domain of EF4 reaches into the peptidyl transferase center and interacts with the acceptor stem of the peptidyl-tRNA in the P site. The ribosome is in an unusual state of ratcheting with the 30S subunit rotated clockwise relative to the 50S subunit, resulting in a remodeled decoding center. The structure is consistent with EF4 functioning either as a back-translocase or a ribosome sequester.

  8. Influence of Dielectric Loss on Quality Factors of Photonic Crystal Microcavity Modes

    Institute of Scientific and Technical Information of China (English)

    XIONG Zhi-Gang; LI Zhi-Yuan; ZHANG Dao-Zhong

    2008-01-01

    We numerically investigate the quMity factors of two-dimensionM (2D) photonic crystal (PC) microcavities using an auxiliary differential equations (ADE) technique in the context of finite-difference time-domain (FDTD)method. The microcavities are formed by point defects in the air hole lattice hexagonedly patterned in ZnO (zinc oxide) matrix. The quality factors of these microcavities are limited primarily by the absorption of the background dielectric. We show that the ratio between the quality factors of microcavities in lossy and lossless background dielectric depends on the overlap between the field of cavity modes and the absorbing background dielectric in addition to the magnitude of absorption. These results will be helpful when designing and optimizing photonie erystal microcavities formed in lossy medium.

  9. Effect of Age and Other Factors on Maximal Heart Rate.

    Science.gov (United States)

    Londeree, Ben R.; Moeschberger, Melvin L.

    1982-01-01

    To reduce confusion regarding reported effects of age on maximal exercise heart rate, a comprehensive review of the relevant English literature was conducted. Data on maximal heart rate after exercising with a bicycle, a treadmill, and after swimming were analyzed with regard to physical fitness and to age, sex, and racial differences. (Authors/PP)

  10. Crystal Structure of the Fab Fragment of an Anti-factor IX Antibody 10C12

    Institute of Scientific and Technical Information of China (English)

    SHI Xiao-Li; ZENG Tu; HUANG Ming-Dong

    2008-01-01

    10C12 is an anticoagulant antibody identified from a phage display single-chain Fv human antibody library. It can be directed at the calcium-stabilized Gla domain of Factor-IX, an important coagulation factor in intrinsic pathway of blood coagulation cascade, and interfere with membrane anchoring of Factor IX, thus inhibiting blood coagulation function. 10C12 has been demonstrated as an effective anti-coagulant in attenuating thrombosis in several different animal models. Here, we report the crystal structure of the Fab fragment of 10C12. The crystal contains two Fab molecules in the asymmetric unit with identical conformation, forming a lattice with large cavities. In addition, comparison of this free Fab with the antigen-bound structure of 10C12 shows no change in CDR conformations and the relative disposition of the variable subunits of H and L chains, suggesting the rigid conformation of this 10C12 Fab and a lock-and-key mechanism of antibody-antigen recognition for 10C 12.

  11. Shear dependent nonlinear vibration in a high quality factor single crystal silicon micromechanical resonator

    Science.gov (United States)

    Zhu, H.; Shan, G. C.; Shek, C. H.; Lee, J. E.-Y.

    2012-07-01

    The frequency response of a single crystal silicon resonator under nonlinear vibration is investigated and related to the shear property of the material. The shear stress-strain relation of bulk silicon is studied using a first-principles approach. By incorporating the calculated shear property into a device-level model, our simulation closely predicts the frequency response of the device obtained by experiments and further captures the nonlinear features. These results indicate that the observed nonlinearity stems from the material's mechanical property. Given the high quality factor (Q) of the device reported here (˜2 × 106), this makes it highly susceptible to such mechanical nonlinear effects.

  12. Oscillations and accelerations of ice crystal growth rates in microgravity in presence of antifreeze glycoprotein impurity in supercooled water

    Science.gov (United States)

    Furukawa, Yoshinori; Nagashima, Ken; Nakatsubo, Shun-ichi; Yoshizaki, Izumi; Tamaru, Haruka; Shimaoka, Taro; Sone, Takehiko; Yokoyama, Etsuro; Zepeda, Salvador; Terasawa, Takanori; Asakawa, Harutoshi; Murata, Ken-ichiro; Sazaki, Gen

    2017-01-01

    The free growth of ice crystals in supercooled bulk water containing an impurity of glycoprotein, a bio-macromolecule that functions as ‘antifreeze’ in living organisms in a subzero environment, was observed under microgravity conditions on the International Space Station. We observed the acceleration and oscillation of the normal growth rates as a result of the interfacial adsorption of these protein molecules, which is a newly discovered impurity effect for crystal growth. As the convection caused by gravity may mitigate or modify this effect, secure observations of this effect were first made possible by continuous measurements of normal growth rates under long-term microgravity condition realized only in the spacecraft. Our findings will lead to a better understanding of a novel kinetic process for growth oscillation in relation to growth promotion due to the adsorption of protein molecules and will shed light on the role that crystal growth kinetics has in the onset of the mysterious antifreeze effect in living organisms, namely, how this protein may prevent fish freezing. PMID:28262787

  13. Guiding synchrotron X-ray diffraction by multimodal video-rate protein crystal imaging

    OpenAIRE

    Newman, Justin A.; ZHANG, Shijie; Sullivan, Shane Z.; Dow, Ximeng Y.; Becker, Michael; Sheedlo, Michael J.; Stepanov, Sergey; Carlsen, Mark S.; Everly, R. Michael; Das, Chittaranjan; Fischetti, Robert F.; Simpson, Garth J.

    2016-01-01

    Synchronous digitization, in which an optical sensor is probed synchronously with the firing of an ultrafast laser, was integrated into an optical imaging station for macromolecular crystal positioning prior to synchrotron X-ray diffraction. Using the synchronous digitization instrument, second-harmonic generation, two-photon-excited fluorescence, one-photon-excited fluorescence, two-photon-excited ultraviolet fluorescence and bright field by laser transmittance were all acquired with perfect...

  14. Factors affecting conception rates in cattle following embryo transfer

    African Journals Online (AJOL)

    ACSS

    ... such as lack of trained personnel and equipment for ovulation and packaging ... Temperatures range from 10 to 270 C, .... conception rates are within the range of ... efficiency of heat detection, early .... Faculty of Veterinary Medicine, Debre.

  15. Improvement of the quality factor of single crystal diamond mechanical resonators

    Science.gov (United States)

    Liao, Meiyong; Toda, Masaya; Sang, Liwen; Teraji, Tokuyuki; Imura, Masataka; Koide, Yasuo

    2017-02-01

    Single-crystal diamond (SCD) has the potential to boost microelectromechanical system (MEMS) with unprecedented performance in terms of its intrinsic mechanical, chemical, and electronic properties, especially in the applications under extreme conditions. On the basis of the analysis of the energy dissipation in diamond mechanical resonators, the authors report on the marked improvement of the quality factor of SCD-MEMS resonators. Ion implantation assisted lift-off technique (IAL) is utilized to fabricate the SCD resonators. The quality factor of the resonator fabricated from the ion-damaged SCD layer alone is as low as 100-300 owing to the bulk or surface defects. The growth of homoepitaxial layers on the ion-implanted SCD substrates significantly improves the quality factor by more than 100 times. Cantilevers made of SCD epilayers of different thicknesses are examined. It is found that the quality factor increases with increasing the epilayer thickness. The maximum quality factor of the SCD cantilevers fabricated by the IAL technique reaches 3.9 × 104. A bilayer model is proposed to describe the variation of the quality factor.

  16. Factors affecting patients' ratings of health-care satisfaction

    DEFF Research Database (Denmark)

    Thygesen, Marianne K; Fuglsang, Marie; Miiller, Max Mølgaard

    2015-01-01

    INTRODUCTION: Surveys that include rating scales are commonly used to collect data about patients' experiences. We studied how patients associated their ratings with their experiences of care. METHODS: A survey and a qualitative study were conducted at a Danish hospital. Initially, 19 female...... themes, e.g. a "very good" experience required that clinical service was provided at the expected level, at the very least, and that it was provided with recognition and respect. CONCLUSIONS: The female patients associated their experiences with their ratings, and two types of relation seemed...... Ethical Committees deemed it unnecessary to be involved in this project. TRIAL REGISTRATION: The Danish Data Protection Agency number of this study is 2008-58-0035....

  17. Confirmatory Factor Analysis of the Behavioral and Emotional Rating Scale-2 (BERS-2) Parent and Youth Rating Scales

    Science.gov (United States)

    Buckley, Jacquelyn A.; Ryser, Gail; Reid, Robert; Epstein, Michael H.

    2006-01-01

    We confirmed the factor structure of the Behavioral and Emotional Rating Scale-2nd Edition (BERS-2) with a normative parent and youth sample. The BERS-2, based on the Behavioral and Emotional Rating Scale (BERS), is a standardized instrument that assesses children's emotional and behavioral strengths. The original BERS was renormed to create a…

  18. Design of slotted high quality factor photonic-crystal nanocavities embedded in electro-optic polymers

    Science.gov (United States)

    Nakadai, Masahiro; Konoike, Ryotaro; Tanaka, Yoshinori; Asano, Takashi; Noda, Susumu

    2017-09-01

    We improve design quality factors of slotted photonic crystal nanocavities embedded in electro-optic polymers (EOPs), which enables control of resonant wavelengths without the use of light-absorbing free carriers. We form nanocavities by modifying single- and double-slotted line-defect waveguides with lattice-constant modulations analytically determined based on dispersions of the waveguides. A double-slotted nanocavity achieves a fourfold increase in Q factor (36 million) compared to a single-slotted nanocavity with similar modulation of lattice constants. Both structures can realize large concentration of light in the EOP region (50%), and resonant wavelength modulations of ∼0.01% are expected with applied voltage of 2 V.

  19. Sternheimer Factors and Electric-Field-Gradient Hyperpolarisabilities for Ions in Crystals

    Science.gov (United States)

    Fowler, P. W.; Kelly, H. M.

    1994-02-01

    Analytic coupled Hartree-Fock calculations of the electric field gradient response properties y (the Sternheimer shielding factor) and e (the dipole-dipole-electric field gradient hyperpolarisability) have been carried out on anions in clusters that simulate that crystal environment. The systems studied are F- in LiF and NaF, Cl- in LiCl and NaCl, O2-in MgO, S2- in MgS, and H- in LiH. Both properties show large reductions from free-ion values and significant variation with lattice parameter, and the results indicate that damped values of anion Sternheimer factors will be necessary in accurate simulation of N Q R data or modelling of properties of ion-pairs.

  20. P270: Factors associated with fall rate in psychogeriatric residents

    NARCIS (Netherlands)

    Kosse, N.M.; de Groot, Maartje H; Hortobágyi, T.; Lamoth, C.J.C.

    2014-01-01

    Introduction: Falls in psychogeriatric residents represent a costly but unresolved safety issue. Identifying fall risk factors and their inter-relationship may help to individualize prevention programs and increase the effectiveness. Therefore, we aimed to examine the relationship between patient ch

  1. Reproduction rate as a factor in meat production

    African Journals Online (AJOL)

    The need to optimize rather than maximize rates of reproduction has been ..... The prin- cipal component of this management is believed to be the .... milk production were most efficient in retail product/ME. Contrary ... period. Returning finally to the concept of genotype-environmental ... Life cycle efficiency of beef production:.

  2. [Studies on expression, purification, crystal growth and optimization of putative transcription factor LytR from Streptococcus pneumoniae].

    Science.gov (United States)

    Min, Xun; Zhong, Wen; Zhao, Shasha; Dong, Jie; Dong, Shanshan; Zhou, Aie; Yan, Wenjuan; Wang, Deqiang

    2013-08-01

    The aim of the present study was to obtain the crystal of transcription factor LytR of streptococcus pneumoniae for X-ray crystal structure and function analysis. The LytR gene of D39 strains from Streptococcus pneumoniae (S. pn) was cloned into the prokaryotic expression vector pET32a(+), then overexpression was obtained in the E. coli BL21 (DE3) through transformation of the recombinant plasmid that had been verified by colony PCR and sequencing. Soluble fusion protein with His-tag highly expressed by the induction of 0.5 mmol/L IPTG and was purified by a three step procedure, the purity of the purified LytR recombinant protein was over 90%. Preliminary screening of crystallization conditions was performed using the hanging-drop vapour-diffusing method with Hampton Crystal screen and PEG screen kits. The protein crystals X-ray diffraction data were collected from a single crystal and more stick crystals whose X-ray diffraction reached 4.0 A were obtained. These works laid the foundation for further research on the 3D structure of putative transcription factor LytR and its biological aspects.

  3. In-situ, variable thickness, liquid crystal film target formation at moderate repetition rate for intense laser applications

    CERN Document Server

    Poole, P L; Cochran, G E; Hanna, R J; Andereck, C D; Schumacher, D W

    2015-01-01

    Liquid crystal films have recently been demonstrated as variable thickness, planar targets for ultra-intense laser matter experiments and applications such as ion acceleration. By controlling the parameters of film formation, including liquid crystal temperature and volume, their thickness can be varied on-demand from 10 $nm$ to above 10 $\\mu m$. This thickness range enables for the first time real-time selection and optimization of various ion acceleration mechanisms using low cost, high quality targets. Our previous work employed these targets in single shot configuration, requiring chamber cycling after the pre-made films were expended. Presented here is a film formation device capable of drawing films from a bulk liquid crystal source volume to any thickness in the aforementioned range. This device will form films under vacuum within 2 $\\mu m$ of the same location each time, well within the Rayleigh range of even tight $F/ \\#$ systems. The repetition rate of the device exceeds 0.1 $Hz$ for sub-100 $nm$ fi...

  4. Factors affecting patients' ratings of health-care satisfaction

    DEFF Research Database (Denmark)

    Thygesen, Marianne K; Fuglsang, Marie; Miiller, Max Mølgaard

    2015-01-01

    INTRODUCTION: Surveys that include rating scales are commonly used to collect data about patients' experiences. We studied how patients associated their ratings with their experiences of care. METHODS: A survey and a qualitative study were conducted at a Danish hospital. Initially, 19 female...... patients completed a questionnaire using the response categories from very good to very bad; and subsequently they participated in a semi-structured interview held within two days after they completed the questionnaire. Additionally, 44 female patients participated in an interview within six weeks...... of completing a questionnaire. A phenomenological-hermeneutical approach was used in the analysis and interpretation. RESULTS: Two major themes emerged: experienced versus expected clinical quality and health-care professional attitude. Patients responded to each question by combining their experiences of both...

  5. Optimized ion acceleration using high repetition rate, variable thickness liquid crystal targets

    Science.gov (United States)

    Poole, Patrick; Willis, Christopher; Cochran, Ginevra; Andereck, C. David; Schumacher, Douglass

    2015-11-01

    Laser-based ion acceleration is a widely studied plasma physics topic for its applications to secondary radiation sources, advanced imaging, and cancer therapy. Recent work has centered on investigating new acceleration mechanisms that promise improved ion energy and spectrum. While the physics of these mechanisms is not yet fully understood, it has been observed to dominate for certain ranges of target thickness, where the optimum thickness depends on laser conditions including energy, pulse width, and contrast. The study of these phenomena is uniquely facilitated by the use of variable-thickness liquid crystal films, first introduced in P. L. Poole et al. PoP21, 063109 (2014). Control of the formation parameters of these freely suspended films such as volume, temperature, and draw speed allows on-demand thickness variability between 10 nanometers and several 10s of microns, fully encompassing the currently studied thickness regimes with a single target material. The low vapor pressure of liquid crystal enables in-situ film formation and unlimited vacuum use of these targets. Details on the selection and optimization of ion acceleration mechanism with target thickness will be presented, including recent experiments on the Scarlet laser facility and others. This work was performed with support from the DARPA PULSE program through a grant from AMRDEC and by the NNSA under contract DE-NA0001976.

  6. Urological complications after radical hysterectomy: Incidence rates and predisposing factors

    Directory of Open Access Journals (Sweden)

    Likić-Lađević Ivana

    2007-01-01

    Full Text Available Bacground/Aim. Radical hysterectomy is a surgical approach for stage Ib and IIa of cervical cancer. The incidence of intraoperative injuries of the bladder during radical hysterectomy ranges from 0.4-3.7%. The ureter can be crushed, caught in sutures, transsected, obstructed by angulation, or ischemic by the stippling or periureteric fascia. Vesicovaginal and ureterovaginal fistuls are reported to develop in 0.9-2% of patients after radical abdominal hysterectomy. Fistulas usually become manifested or visible at speculum examination within 14 days following the surgery. The aim of this study was to establish the incidence and predisposing factor of urological complications after radical hysterectomy. Methods. The study included a total of 536 patients with invasive stage Ib to IIb cancer of the cervix uteri who had underwent radical hysterectomy. The special elements considered were: the patient’s age; the International Federation of Ginecology and Obstetrics (FIGO stage after pathohistology; duration of operation; the result of preoperative laboratory tests for diabetes, anemia, hypoproteinemia, or disorders of liver or kidney function; ASA status; postoperative surgical infection. Results. The average age of the patients with complications was 48.68 years. All patients with intraoperative ureteric and bladder injuries had statisticaly significant higher stage of disease and operation lasted more than in others without injury. We noticed 1.3% ureteral injuries and 1.49% bladder injuries, more than 50% of the patients with a previously mentioned injuries were operated on more than 3 hours. We found 2.61% vesicovaginal and 2.43% ureterovaginal fistuls. A total of 50% of the patients with bladder injury and vesicovaginal fistuls and 70% of the patients with ureterovaginal fistuls had diabetes mellitus. Postoperative infection of surgical site is a very important factor for the development of fistule. Half of the patients with vesicovaginal

  7. Factors contributing to suboptimal rates of childhood vaccinations in Vermont.

    Science.gov (United States)

    Kelley, Catherine A; Velazco, Cristine S; Delaney, Thomas V; Bensimhon, Adam; Huang, Kuang-Ning; Jarvis, Paul R; Jolin, Jonathan S; Schaberg, Kurt B; Burke, Marianne; Finley, Christine; Carney, Jan K

    2015-12-01

    Childhood immunizations are invaluable in preventing contagious diseases. Nonetheless, vaccines have become increasingly controversial with growing numbers of caregivers refusing to vaccinate their children. The percentage of fully vaccinated children in Vermont is one of the lowest nationally. This study set out to determine Vermont caregivers' attitudes toward immunizations to better explain why the percentage of fully vaccinated children has fallen in Vermont. A survey regarding caregivers' health care knowledge about children, their vaccination concerns, and their children's vaccination status was sent to participants in the Vermont Women, Infants and Children's Program from two districts. In total, 83% (n = 379) of respondents reported their children received all recommended vaccinations for their age. Respondents who considered themselves highly knowledgeable regarding their children's health care and confident about the safety of vaccinations were significantly associated with reporting their children as being current on vaccinations and with their intent to continue vaccinations. Respondents indicated highest concern regarding the safety and number of vaccinations administered during one visit. Primary care providers were indicated as important resources for addressing concerns about vaccinations and health care knowledge of children. The results help to understand low vaccination rates in Vermont and can be used for targeting health campaigns to improve vaccination rates. © The Author(s) 2014.

  8. Modeling the Crystallization of Amorphous Silicon Thin Films Using a High Repetition Rate Scanning Laser

    Directory of Open Access Journals (Sweden)

    R. Černý

    2000-01-01

    Full Text Available An optimum design of experimental setup for the preparation of polycrystalline silicon (pc-Si films from amorphous layers applicable in the solar cell production is analyzed in the paper. In the computational simulations, the influence of basic characteristic parameters of the experimental procedure on the mechanisms of pc-Si lateral growth is studied. Among these parameters, the energy density of the applied laser and the thickness of the amorphous silicon (a-Si layer are identified as the most significant. As an optimum solution, the mechanism of pc-Si growth consisting in repeated melting of a part of already crystallized pc-Si layer by the scanning laser is proposed.

  9. Cellular Oxygen Sensing: Crystal Structure of Hypoxia-Inducible Factor Prolyl Hydroxylase (PHD2)

    Energy Technology Data Exchange (ETDEWEB)

    McDonough,M.; Li, V.; Flashman, E.; Chowdhury, R.; Mohr, C.; Lienard, B.; Zondlo, J.; Oldham, N.; Clifton, I.; et al.

    2006-01-01

    Cellular and physiological responses to changes in dioxygen levels in metazoans are mediated via the posttranslational oxidation of hypoxia-inducible transcription factor (HIF). Hydroxylation of conserved prolyl residues in the HIF-{alpha} subunit, catalyzed by HIF prolyl-hydroxylases (PHDs), signals for its proteasomal degradation. The requirement of the PHDs for dioxygen links changes in dioxygen levels with the transcriptional regulation of the gene array that enables the cellular response to chronic hypoxia; the PHDs thus act as an oxygen-sensing component of the HIF system, and their inhibition mimics the hypoxic response. We describe crystal structures of the catalytic domain of human PHD2, an important prolyl-4-hydroxylase in the human hypoxic response in normal cells, in complex with Fe(II) and an inhibitor to 1.7 Angstroms resolution. PHD2 crystallizes as a homotrimer and contains a double-stranded {beta}-helix core fold common to the Fe(II) and 2-oxoglutarate-dependant dioxygenase family, the residues of which are well conserved in the three human PHD enzymes (PHD 1-3). The structure provides insights into the hypoxic response, helps to rationalize a clinically observed mutation leading to familial erythrocytosis, and will aid in the design of PHD selective inhibitors for the treatment of anemia and ischemic disease.

  10. RATES OF HYDROUS FERRIC OXIDE CRYSTALLIZATION AND THE INFLUENCE ON COPRECIPITATED ARSENATE

    Science.gov (United States)

    Arsenate coprecipitated with hydrous ferric oxide (HFO) was stabilized against dissolution during transformation of HFO to more crystalline iron (hydr)oxides. The rate of arsenate stabilization approximately coincided with the rate of HFO transformation at pH 6 and 40 ?C. Compa...

  11. EFFECT OF GAS FLOW RATE ON CRYSTAL STRUCTURES OF ELECTROSPUN AND GAS-JET/ELECTROSPUN POLY(VINYLIDENE FLUORIDE) FIBERS

    Institute of Scientific and Technical Information of China (English)

    Yi Lin; Yong-yi Yao; Xiao-zhan Yang; Li-ming Shen; Rui-xia Li; Da-cheng Wu

    2009-01-01

    The effect of gas flow rate on crystal structures of electrospun and gas-jet/electrospun poly(vinylidene fluoride) (PVDF) fibers was investigated. PVDF fibers were prepared by electrospinning and gas-jet/electrospinning of its N,N-dimethylformamide (DMF) solutions. The morphology of the PVDF fibers was investigated by scanning electron microscopy (SEM). With an increase of the gas flow rate, the average diameters of PVDF fibers were decreased.The crystal structures and thermal properties of the PVDF fibers were investigated by attenuated Fourier transform infrared spectroscopy (AT-FTIR), wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). It was found that electrospinning and gas-jet/electrospinning of PVDF from its DMF solutions promoted the formation of β phase. Moreover, gas-jet/electrospun PVDF fibers exhibited higher crystallinity and β phase content than electrospun fibers did. Similar with electrostatic force, the drawing force of gas jet may induce the conformational change to all-trans (TTTT) planar zigzag conformation, and then promote the formation of the β phase.

  12. Spin Dephasing as a Probe of Mode Temperature, Motional State Distributions, and Heating Rates in a 2D Ion Crystal

    CERN Document Server

    Sawyer, Brian C; Bollinger, John J

    2014-01-01

    We employ spin-dependent optical dipole forces to characterize the transverse center-of-mass (COM) motional mode of a two-dimensional Wigner crystal of hundreds of $^9$Be$^+$. By comparing the measured spin dephasing produced by the spin-dependent force with the predictions of a semiclassical dephasing model, we obtain absolute mode temperatures in excellent agreement with both the Doppler laser cooling limit and measurements obtained from a previously published technique (B. C. Sawyer et al. Phys. Rev. Lett. \\textbf{108}, 213003 (2012)). Furthermore, the structure of the dephasing histograms allows for discrimination between initial thermal and coherent states of motion. We also apply the techniques discussed here to measure, for the first time, the ambient heating rate of the COM mode of a 2D Coulomb crystal in a Penning trap. This measurement places an upper limit on the anomalous single-ion heating rate due to electric field noise from the trap electrode surfaces of $\\frac{d\\bar{n}}{dt}\\sim 5$ s$^{-1}$ fo...

  13. The Study of Dissolution Kinetics of K2SO4 Crystal in Aqueous Ethanol Solutions with a Statistical Rate Theory

    Institute of Scientific and Technical Information of China (English)

    刘畅; 冯新; 吉晓燕; 陈栋梁; 魏涛; 陆小华

    2004-01-01

    Dissolution kinetics of K2SO4 crystal in aqueous ethanol solutions was studied on-line with ion selective electrode. The concentration of K2SO4 was calculated from the determined electromotive force in which the activity coefficient of components in the liquid phase was calculated with the Pitzer equation. Dissolution kinetic parameters in the modified statistical rate theory were regressed. The correlation results show that dissolution rate of K2SO4 is slower in aqueous ethanol solutions than that in aqueous solutions. The two most important reasons are as follows: (1) The solubility of K2SO4 in aqueous ethanol solutions is lower than that in aqueous solutions, which causes a decrease of the driving force of mass transfer. (2) The process of surface reaction of K2SO4 became slower due to the addition of ethanol, so that the whole process is mainly dominated by the surface reaction instead of mass transfer.

  14. High quality factor two dimensional GaN photonic crystal cavity membranes grown on silicon substrate

    Science.gov (United States)

    Vico Triviño, N.; Rossbach, G.; Dharanipathy, U.; Levrat, J.; Castiglia, A.; Carlin, J.-F.; Atlasov, K. A.; Butté, R.; Houdré, R.; Grandjean, N.

    2012-02-01

    We report on the achievement of freestanding GaN photonic crystal L7 nanocavities with embedded InGaN/GaN quantum wells grown by metal organic vapor phase epitaxy on Si (111). GaN was patterned by e-beam lithography, using a SiO2 layer as a hard mask, and usual dry etching techniques. The membrane was released by underetching the Si (111) substrate. Micro-photoluminescence measurements performed at low temperature exhibit a quality factor as high as 5200 at ˜420 nm, a value suitable to expand cavity quantum electrodynamics to the near UV and the visible range and to develop nanophotonic platforms for biofluorescence spectroscopy.

  15. Ultrahigh power factor and thermoelectric performance in hole-doped single-crystal SnSe.

    Science.gov (United States)

    Zhao, Li-Dong; Tan, Gangjian; Hao, Shiqiang; He, Jiaqing; Pei, Yanling; Chi, Hang; Wang, Heng; Gong, Shengkai; Xu, Huibin; Dravid, Vinayak P; Uher, Ctirad; Snyder, G Jeffrey; Wolverton, Chris; Kanatzidis, Mercouri G

    2016-01-01

    Thermoelectric technology, harvesting electric power directly from heat, is a promising environmentally friendly means of energy savings and power generation. The thermoelectric efficiency is determined by the device dimensionless figure of merit ZT(dev), and optimizing this efficiency requires maximizing ZT values over a broad temperature range. Here, we report a record high ZT(dev) ∼1.34, with ZT ranging from 0.7 to 2.0 at 300 to 773 kelvin, realized in hole-doped tin selenide (SnSe) crystals. The exceptional performance arises from the ultrahigh power factor, which comes from a high electrical conductivity and a strongly enhanced Seebeck coefficient enabled by the contribution of multiple electronic valence bands present in SnSe. SnSe is a robust thermoelectric candidate for energy conversion applications in the low and moderate temperature range.

  16. Ekonomski dejavniki gledanosti televizijskih programov v Sloveniji = Economic Factors for Televison Programme Rating in Slovenia

    OpenAIRE

    Matjaž Dodič; Bojan Nastav

    2011-01-01

    Factors that influence televison programme rating can be divided intoenvironment, outer factors and internal factors of televison programmes.In this paper we apply the regression analysis to study the influence ofthe number of unemployed, inflation rate, average salary, consumers’trust, households’ financial status in the past 12 months and the economicstate in Slovenia on rating of national, commercial and othertelevison programmes in Slovenia in the 2000–2009 period. The resultsshow that in...

  17. 7 CFR 52.777 - Ascertaining the rating for the factors which are scored.

    Science.gov (United States)

    2010-01-01

    ... THEREOF, AND CERTAIN OTHER PROCESSED FOOD PRODUCTS 1 United States Standards for Grades of Canned Red Tart Pitted Cherries 1 Factors of Quality § 52.777 Ascertaining the rating for the factors which are...

  18. A numerical method for determining the strain rate intensity factor under plane strain conditions

    Science.gov (United States)

    Alexandrov, S.; Kuo, C.-Y.; Jeng, Y.-R.

    2016-07-01

    Using the classical model of rigid perfectly plastic solids, the strain rate intensity factor has been previously introduced as the coefficient of the leading singular term in a series expansion of the equivalent strain rate in the vicinity of maximum friction surfaces. Since then, many strain rate intensity factors have been determined by means of analytical and semi-analytical solutions. However, no attempt has been made to develop a numerical method for calculating the strain rate intensity factor. This paper presents such a method for planar flow. The method is based on the theory of characteristics. First, the strain rate intensity factor is derived in characteristic coordinates. Then, a standard numerical slip-line technique is supplemented with a procedure to calculate the strain rate intensity factor. The distribution of the strain rate intensity factor along the friction surface in compression of a layer between two parallel plates is determined. A high accuracy of this numerical solution for the strain rate intensity factor is confirmed by comparison with an analytic solution. It is shown that the distribution of the strain rate intensity factor is in general discontinuous.

  19. Factors affecting ice crystal purity during freeze concentration process for urine treatment

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Freeze concentration has great potential in treating wastewaters containing soluble pollutions. It is important for freeze concentration process to produce ice crystals with large size and high purity. In this work raw urines of 4660-7914 mg/L in COD,512.71-872.41 mg/L in NH3-N and 22600-28800μs/cm in e lectric conductivity were studied. Urines were frozen by a digital refrigerated circulator bath. Ice crystals were purified by ice-water steep and vacuum filtration. The COD,NH3-N,and electric conductivity levels of the melted ices were measured to reflect ice crystal purity. Effects of coolant temperature, ice crystal shape, initial solution temperature, solution concentration, ice seeding, re-crystallization process and crystallization time on ice crystal purity were analyzed. The results show that an appropriate coolant temperature, suspended ice crystals,an initial solution temperature of about 6 C, introduction of seed ice, addition of re-crystallization process. And crystallization time of less than 30 min are in favor of producing ice crystals with hith purity.Under such conditions, more than 99 percent of inorganic salts, COD and NH3-N sources in raw urine could be removed.

  20. Crystals in crystals

    DEFF Research Database (Denmark)

    Christensen, Claus H.; Schmidt, I.; Carlsson, A.;

    2005-01-01

    A major factor governing the performance of catalytically active particles supported on a zeolite carrier is the degree of dispersion. It is shown that the introduction of noncrystallographic mesopores into zeolite single crystals (silicalite-1, ZSM-5) may increase the degree of particle dispersion...... of the zeolite particles, particularly after thermal treatment. When using mesoporous zeolites, the particles were evenly distributed throughout the mesopore system of the zeolitic support, even after calcination, leading to nanocrystals within mesoporous zeolite single crystals....

  1. Crystallization and preliminary X-ray diffraction analysis of the mitochondrial transcription factor sc-mtTFB from Saccharomyces cerevisiae.

    Science.gov (United States)

    Schubot, F D; Chen, C J; Rose, J P; Wang, B C

    2000-07-01

    Eukaryotic mitochondria contain a distinct mini-chromosome. In yeast, transcription of the mitochondrial genome is mediated by a nuclear-encoded RNA polymerase consisting of a single polypeptide core enzyme and a specificity factor termed sc-mtTFB which bears some similarity to bacterial sigma-factors. sc-mtTFB from Saccharomyces cerevisiae has been cloned, expressed, purified and crystallized. The crystals belong to the monoclinic space group C2, with unit-cell parameters a = 89.7, b = 44.6, c = 98.9 A, beta = 110 degrees. Based on one molecule per asymmetric unit, the solvent content is estimated to be 48%. Small crystals of dimensions 0.01 x 0.05 x 0.13 mm diffract to at least 2.7 A resolution on a rotating-anode X-ray source.

  2. Purification, crystallization and preliminary X-ray diffraction analysis of Cif, a virulence factor secreted by Pseudomonas aeruginosa.

    Science.gov (United States)

    Bahl, Christopher D; MacEachran, Daniel P; O'Toole, George A; Madden, Dean R

    2010-01-01

    The opportunistic pathogen Pseudomonas aeruginosa secretes a protein that triggers the accelerated degradation of the cystic fibrosis transmembrane conductance regulator (CFTR) in airway epithelial cells. This protein, which is known as the CFTR inhibitory factor (Cif), acts as a virulence factor and may facilitate airway colonization by P. aeruginosa. Based on sequence similarity Cif appears to be an epoxide hydrolase (EH), but it lacks several of the conserved features found in the active sites of canonical members of the EH family. Here, the crystallization of purified recombinant Cif by vapor diffusion is reported. The crystals formed in space group C2, with unit-cell parameters a = 167.4, b = 83.6, c = 88.3 A, beta = 100.6 degrees . The crystals diffracted to 2.39 A resolution on a rotating-anode source. Based on the calculated Matthews coefficient (2.2 A(3) Da(-1)), it appears that the asymmetric unit contains four molecules.

  3. The effect of substrate temperature and growth rate on the doping efficiency of single crystal boron doped diamond

    Energy Technology Data Exchange (ETDEWEB)

    Demlow, SN; Rechenberg, R; Grotjohn, T

    2014-10-01

    The substrate growth temperature dependence of the plasma gas-phase to solid-phase doping efficiency in single crystal, boron doped diamond (BDD) deposition is investigated. Single crystal diamond (SCD) is grown by microwave plasma assisted chemical vapor deposition (MPACVD) on high pressure, high temperature (HPHT) type Ib substrates. Samples are grown at substrate temperatures of 850-950 degrees C for each of five doping concentration levels, to determine the effect of the growth temperature on the doping efficiency and defect morphology. The substrate temperature during growth is shown to have a significant effect on the grown sample defect morphology, and a temperature dependence of the doping efficiency is also shown. The effect of the growth rate on the doping efficiency is discussed, and the ratio of the boron concentration in the gas phase to the flux of carbon incorporated into the solid diamond phase is shown to be a more predictive measure of the resulting boron concentration than the gas phase boron to carbon ratio that is more commonly reported. (C) 2014 Elsevier B.V. All rights reserved.

  4. Crystal structure of a macrophage migration inhibitory factor from Giardia lamblia

    Energy Technology Data Exchange (ETDEWEB)

    Buchko, Garry W.; Abendroth, Jan; Robinson, Howard; Zhang, Yanfeng; Hewitt, Stephen N.; Edwards, Tom E.; Van Voorhis, Wesley C.; Myler, Peter J.

    2013-06-15

    Macrophage migration inhibitory factor (MIF) is a eukaryotic cytokine that affects a broad spectrum of immune responses and its activation/inactivation is associated with numerous diseases. During protozoan infections MIF is not only expressed by the host, but, has also been observed to be expressed by some parasites and released into the host. To better understand the biological role of parasitic MIF proteins, the crystal structure of the MIF protein from Giardia lamblia (Gl-MIF), the etiological agent responsible for giardiasis, has been determined at 2.30 Å resolution. The 114-residue protein adopts an α/β fold consisting of a four-stranded β-sheet with two anti-parallel α-helices packed against a face of the β-sheet. An additional short β-strand aligns anti-parallel to β4 of the β-sheet in the adjacent protein unit to help stabilize a trimer, the biologically relevant unit observed in all solved MIF crystal structures to date, and form a discontinuous β-barrel. The structure of Gl-MIF is compared to the MIF structures from humans (Hs-MIF) and three Plasmodium species (falciparum, berghei, and yoelii). The structure of all five MIF proteins are generally similar with the exception of a channel that runs through the center of each trimer complex. Relative to Hs-MIF, there are differences in solvent accessibility and electrostatic potential distribution in the channel of Gl-MIF and the Plasmodium-MIFs due primarily to two “gate-keeper” residues in the parasitic MIFs. For the Plasmodium MIFs the gate-keeper residues are at positions 44 (Y==>R) and 100 (V==>D) and for Gl-MIF it is at position 100 (V==>R). If these gate-keeper residues have a biological function and contribute to the progression of parasitemia they may also form the basis for structure-based drug design targeting parasitic MIF proteins.

  5. Dose-rate conversion factors for external exposure to photons and electrons

    Energy Technology Data Exchange (ETDEWEB)

    Kocher, D.C.

    1981-08-01

    Dose-rate conversion factors for external exposure to photons and electrons have been calculated for approximately 500 radionuclides of potential importance in environmental radiological assessments. The dose-rate factors were obtained using the DOSFACTER computer code. The results given in this report incorporate calculation of electron dose-rate factors for radiosensitive tissues of the skin, improved estimates of organ dose-rate factors for photons, based on organ doses for monoenergetic sources at the body surface of an exposed individual, and the spectra of scattered photons in air from monoenergetic sources in an infinite, uniformly contaminated atmospheric cloud, calculation of dose-rate factors for other radionuclides in addition to those of interest in the nuclear fuel cycle, and incorporation of updated radioactive decay data for all radionuclides. Dose-rate factors are calculated for three exposure modes - immersion in contaminated air, immersion in contaminated water, and exposure at a height of 1 m above a contaminated ground surface. The report presents the equations used to calculate the external dose-rate factors for photons and electrons, documentation of the revised DOSFACTER computer code, and a complete tabulation of the calculated dose-rate factors. 30 refs., 12 figs.

  6. Crystal structure of catalytic domain of the initiation factor 2B epsilon subunit

    DEFF Research Database (Denmark)

    Boesen, Thomas; Mohammad, Sarah S.; Pavitt, Graham D.;

    this motif is involved in binding to the N-terminal part of the eIF2β subunit The aliphatic residues in the AA box motifs are involved in specific contacts in the hydrophobic core of the C-terminal helices important for maintaining the overall structure, whereas acidic residues in the motifs form a clustered......-terminal two helices contain the catalytic part of the domain, whereas the C-terminal six helices harbor the two Aromatic Acidic (AA) box motifs. This motif is also found in initiation factor 5, the GTPase activator protein of eIF2, and furthermore in mammalian initiation factor 4G. In eIF2B and eIF5......, surface exposed acidic patch which might interact with the lysine boxes of eIF2β. Interestingly, Tryptophan 699 was found to be solvent exposed and involved in crystal packing. This residue could possibly be important for the specific interaction with eIF2β. Furthermore, the structure shows the location...

  7. Jamin-interferometer-setup for the determination of concentration and temperature dependent face-specific crystal growth rates from a single experiment

    Science.gov (United States)

    Eder, Cornelia; Choscz, Carsten; Müller, Vesna; Briesen, Heiko

    2015-09-01

    An interference technique that permits the investigation of the crystal growth from a temperature controlled solution is presented. Contrary to Mach-Zehnder- or Michelson-type interferometers, the Jamin-interferometer applied in this work is characterized by improved thermal and long-time stability. In consequence a single experiment may comprise several temperature steps leading to significant changes in the bulk concentration. A procedure for the automated analysis of the acquired sequence of interference patterns is presented. Within this evaluation procedure the position of the selected crystal face, the bulk concentration and the vertical concentration distribution above the crystal are determined simultaneously. Long-term single crystal growth experiments in the range from 20 to 60 °C with sucrose and lactose crystals are used to test the method. The exact bulk concentration is determined by the interferometer. The obtained results for the growth rate of sucrose are consistent with values given in the literature. The vertical concentration distribution above the two saccharide crystals differs clearly indicating that the diffusion strongly limits the sucrose growth but not the growth of the lactose crystal. The major benefit of the described setup is that the data of a single experiment are sufficient to deduce the parameters of the model equation for the growth rate as a function of temperature and supersaturation.

  8. An Investigation of the Factor Structure and Convergent and Discriminant Validity of the Five-Factor Model Rating Form

    Science.gov (United States)

    Samuel, Douglas B.; Mullins-Sweatt, Stephanie N.; Widiger, Thomas A.

    2013-01-01

    The Five-Factor Model Rating Form (FFMRF) is a one-page measure designed to provide an efficient assessment of the higher order domains of the Five Factor Model (FFM) as well as the more specific, lower order facets proposed by McCrae and Costa. Although previous research has suggested that the FFMRF's assessment of the lower order facets converge…

  9. Comparison of four computational methods for computing Q factors and resonance wavelengths in photonic crystal membrane cavities

    DEFF Research Database (Denmark)

    de Lasson, Jakob Rosenkrantz; Frandsen, Lars Hagedorn; Burger, Sven

    2016-01-01

    We benchmark four state-of-the-art computational methods by computing quality factors and resonance wavelengths in photonic crystal membrane L5 and L9 line defect cavities.The convergence of the methods with respect to resolution, degrees of freedom and number ofmodes is investigated. Special att...

  10. Crystal Thermoelasticity at Extreme Loading Rates and Pressures: Analysis of Higher-Order Energy Potentials

    Science.gov (United States)

    2015-07-01

    Solids II, Springer, New York, 1996. [2] R.A. Regueiro, D.J. Bammann, E.B. Marin, G.C. Johnson, Finite defor- mation elastoplasticity for rate and...Impact Eng. 73 (2014) 56–65. [17] K.N. Solanki, D.J. Bammann, A thermodynamic framework for a gradient theory of continuum damage , Acta Mech. 213 (2010) 27...Clayton, D.L. McDowell, A multiscale multiplicative decompo- sition for elastoplasticity of polycrystals, Int. J. Plast. 19 (2003) 1401–1444. [35] J.D

  11. Multiplicity factor and diffraction geometry factor for single crystal X-ray diffraction analysis and measurement of phase content in cubic GaN/GaAs(001) epilayers

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    On the basis of integrated intensity of rocking curves, the multiplicity factor and the diffraction geometry factor for single crystal X-ray diffraction (XRD) analysis were proposed and a general formula for calculating the content of mixed phases was obtained. With a multifunction four-circle X-ray double-crystal diffractometer, pole figures of cubic (002), {111} and hexagonal {1010} and reciprocal space mapping were measured to investigate the distributive character of mixed phases and to obtain their multiplicity factors and diffraction geometry factors. The contents of cubic twins and hexagonal inclusions were calculated by the integrated intensities of rocking curves of cubic (002), cubic twin {111}, hexagonal {1010} and {1011}.

  12. A comparison of the abilities of natural rubber (NR) and synthetic polyisoprene cis-1,4 rubber (IR) to crystallize under strain at high strain rates.

    Science.gov (United States)

    Candau, Nicolas; Chazeau, Laurent; Chenal, Jean-Marc; Gauthier, Catherine; Munch, Etienne

    2016-02-07

    Strain induced crystallization (SIC) of a natural rubber (NR) and a synthetic rubber (IR) with a high amount of cis-1,4 units (98.6%) is studied, thanks to in situ wide angle X-ray (WAXS) experiments at room temperature performed in a large range of strain rates. During stretching at a low strain rate (4.2 × 10(-3) s(-1)), SIC in IR occurs at a larger stretching ratio than in NR. As a result, the crystallinity index at a given stretching ratio is lower in IR than in NR, in spite of the similar crosslink densities of the chains involved in the crystallization in both materials. This lower ability for crystallization in IR is attributed to the presence of branching along its backbone and its lower stereoregularity. Conversely, dynamic experiments performed at high strain rates (10(1)/10(2) s(-1)) show for both materials a similar ability to crystallize. This unexpected result is confirmed by monotonic tensile tests performed in a large range of strain rates. The reason is thermodynamic: the chain extension plays a predominant role compared to the role of the microstructure defects when the strain rate is high, i.e. when the kinetics of the crystallite nucleation forces the crystallization to occur at a large stretching ratio. A thermodynamic model enables qualitative reproduction of the experimental results.

  13. Experimental and theoretical analysis of the rate of solvent equilibration in the hanging drop method of protein crystal growth

    Science.gov (United States)

    Fowlis, William W.; Delucas, Lawrence J.; Twigg, Pamela J.; Howard, Sandra B.; Meehan, Edward J.

    1988-01-01

    The principles of the hanging-drop method of crystal growth are discussed, and the rate of water evaporation in a water droplet (containing protein, buffer, and a precipitating agent) suspended above a well containing a double concentration of precipitating agent is investigated theoretically. It is shown that, on earth, the rate of evaporation may be determined from diffusion theory and the colligative properties of solutions. The parameters affecting the rate of evaporation include the temperature, the vapor pressure of water, the ionization constant of the salt, the volume of the drop, the contact angle between the droplet and the coverslip, the number of moles of salt in the droplet, the number of moles of water and salt in the well, the molar volumes of water and salt, the distance from the droplet to the well, and the coefficient of diffusion of water vapor through air. To test the theoretical equations, hanging-drop experiments were conducted using various reagent concentrations in 25-microliter droplets and measuring the evaporation times at 4 C and 25 C. The results showed good agreement with the theory.

  14. A novel technique for measuring stress-corrosion crack-growth rates in single-crystal experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lichter, B.D. [Vanderbilt Univ., Nashville, TN (United States)]|[Delft Univ. of Technology (Netherlands); Flanagan, W.F. [Vanderbilt Univ., Nashville, TN (United States)

    1994-12-31

    Crack-growth occurs discontinuously in oriented copper-gold single-crystals during slow-strain rate experiments performed under anodic polarization in aqueous NaCl solutions. Crack advance between major crack arrests is accompanied by load-drops and current-transients which can be quantitatively related to the length of the advance as well as yielding the average instantaneous rate of advance. Two independent but self-consistent methods are used: (1) mechanical analysis of the load-drops, taking into account the elastic displacement of the load-train and of the specimen, due to both the load and the crack advance, and (2) analysis of the current-transients in which it is argued that the current is proportional to the rate of new surface production. Results show that the crack velocity is on the order of 50--400{mu}/s, depending on the environment and potential, too slow to be explained by a running brittle crack, and too fast to be explained by Faradaic dissolution.

  15. Crystallization in lactose refining-a review.

    Science.gov (United States)

    Wong, Shin Yee; Hartel, Richard W

    2014-03-01

    In the dairy industry, crystallization is an important separation process used in the refining of lactose from whey solutions. In the refining operation, lactose crystals are separated from the whey solution through nucleation, growth, and/or aggregation. The rate of crystallization is determined by the combined effect of crystallizer design, processing parameters, and impurities on the kinetics of the process. This review summarizes studies on lactose crystallization, including the mechanism, theory of crystallization, and the impact of various factors affecting the crystallization kinetics. In addition, an overview of the industrial crystallization operation highlights the problems faced by the lactose manufacturer. The approaches that are beneficial to the lactose manufacturer for process optimization or improvement are summarized in this review. Over the years, much knowledge has been acquired through extensive research. However, the industrial crystallization process is still far from optimized. Therefore, future effort should focus on transferring the new knowledge and technology to the dairy industry.

  16. Electrical and thermal tuning of quality factor and free spectral range of optical resonance of nematic liquid crystal microdroplets

    Science.gov (United States)

    Sofi, Junaid Ahmad; Mohiddon, M. A.; Dutta, N.; Dhara, Surajit

    2017-08-01

    We experimentally study the effect of temperature and electric field on the quality (Q ) factor and free spectral range (FSR) of whispering-gallery-mode optical resonance of dye-doped nematic liquid crystal microdroplets. Both the Q factor and the FSR are highly sensitive to the temperature and electric field and are tunable. The Q factor decreases, whereas the FSR increases substantially, with increasing temperature and electric field. The variation of the Q factor and FSR is understood based on the change in the effective refractive index and the dynamic size of the microdroplets.

  17. Ekonomski dejavniki gledanosti televizijskih programov v Sloveniji = Economic Factors for Televison Programme Rating in Slovenia

    Directory of Open Access Journals (Sweden)

    Matjaž Dodič

    2011-09-01

    Full Text Available Factors that influence televison programme rating can be divided intoenvironment, outer factors and internal factors of televison programmes.In this paper we apply the regression analysis to study the influence ofthe number of unemployed, inflation rate, average salary, consumers’trust, households’ financial status in the past 12 months and the economicstate in Slovenia on rating of national, commercial and othertelevison programmes in Slovenia in the 2000–2009 period. The resultsshow that inflation, unemployment, average salary and economicstate have a positive effect, whereas consumers’ trust and households’financial status in the past 12 months have a negative impact on rating.The e xplanatory power of the models is relatively low. In orderto study the topic further research, focusing (also on factors not includedin the analysis (e. g. culture and internal factors of televisonprogrammes, is needed.

  18. Does ovarian hyperstimulation in intrauterine insemination for cervical factor subfertility improve pregnancy rates?

    Science.gov (United States)

    Steures, Pieternel; van der Steeg, Jan Willem; Verhoeve, Harold R; van Dop, Peter A; Hompes, Peter G A; Bossuyt, Patrick M M; van der Veen, Fulco; Habbema, J Dik F; Eijkemans, Marinus J C; Mol, Ben W J

    2004-10-01

    Intrauterine insemination (IUI) can be performed with or without controlled ovarian hyperstimulation (COH). Studies in which the additional benefit of COH on IUI for cervical factor subfertility is assessed are lacking. We assessed whether COH in IUI improved pregnancy rates in cervical factor subfertility. We performed a historical cohort study among couples with cervical factor subfertility, treated with IUI. A cervical factor was diagnosed by a well-timed, non-progressive post-coital test with normal semen parameters. We compared ongoing pregnancy rate per cycle in groups treated with IUI with or without COH. We tabulated ongoing pregnancy rates per cycle number and compared the effectiveness of COH by stratified univariable analysis. We included 181 couples who underwent 330 cycles without COH and 417 cycles with COH. Ongoing pregnancy rates in IUI cycles without and with COH were 9.7% and 12.7%, respectively (odds ratio 1.4; 95% confidence interval 0.85-2.2). The pregnancy rates in IUI without COH in cycles 1, 2, 3 and 4 were 14%, 11%, 6% and 15%, respectively. For IUI with COH, these rates were 17%, 15%, 14% and 16%, respectively. Although our data indicate that COH improves the pregnancy rate over IUI without COH, IUI without COH generates acceptable pregnancy rates in couples with cervical factor subfertility. Since IUI without COH bears no increased risk for multiple pregnancy, this treatment should be seriously considered in couples with cervical factor subfertility.

  19. On the Lower Limit of Chondrule Cooling Rates: The Significance of Iron Loss in Dynamic Crystallization Experiments

    Science.gov (United States)

    Paque, Julie M.; Connolly, Harold C., Jr.; Lofgren, Gary E.

    1998-01-01

    It is unlikely that the presence of chondrules, and thus their formation, within the protoplanetary nebula would be predicted if it were not for their ubiquitous presence in most chondritic meteorites. The study of these enigmatic, igneous objects has a direct influence on how meteoritic and solar system researchers model the processes operating and the materials present within our protoplanetary nebula. Key to understanding chondrule formation is a determination of constraints on their thermal histories. The three important variables in this history are their peak melting temperatures, the duration of their melting at peak temperatures, and the rate at which these object cool. Although these three variables are interdependent, it is cooling rate that provides the most powerful constraint. Cooling rate has a direct affect on the development of both crystal morphology and the elemental distributions within these grains. To date, experiments have indicated that chondrule cooling rates are in the range of 10's to 100's of degrees per hour for porphyritic chondrules (the most abundant type). The cooling rate for radial and barred chondrules is thought to be more rapid. To generate these cooling rates (rapid relative to the cooling of the nebula as a whole, but slow compared to simple black body radiation) the environment of chondrule formation must have been localized, and the abundance of solid materials must have been greatly enhanced above a gas of solar composition. Thus accurate determinations of chondrule cooling rates is critical in understanding both their formation and the nebular environment in which they formed. In a quest to more accurately determine the lower limit on cooling rates and to determine in more detail the effects of Fe loss from a molten sample to Pt wire loops, Weinbruch et al. have explored this issue experimentally and reevaluated the findings of Radomsky and Hewins in light of their new results. The basic conclusions of their paper are an

  20. Crystal structure of enterococcus faecalis sly A-like transcriptional factor.

    Energy Technology Data Exchange (ETDEWEB)

    Wu, R.; Zhang, R.; Zagnitko, O.; Dementieva, I.; Maltsev, N.; Watson, J. D.; Laskowski, R.; Gornicki, P.; Joachimiak, A.; Univ. of Chicago; European Bioinformatics Inst.

    2003-05-30

    The crystal structure of a SlyA transcriptional regulator at 1.6 {angstrom} resolution is presented, and structural relationships between members of the MarR/SlyA family are discussed. The SlyA family, which includes SlyA, Rap, Hor, and RovA proteins, is widely distributed in bacterial and archaeal genomes. Current evidence suggests that SlyA-like factors act as repressors, activators, and modulators of gene transcription. These proteins have been shown to up-regulate the expression of molecular chaperones, acid-resistance proteins, and cytolysin, and down-regulate several biosynthetic enzymes. The structure of SlyA from Enterococcus faecalis, determined as a part of an ongoing structural genomics initiative (www.mcsg.anl.gov), revealed the same winged helix DNA-binding motif that was recently found in the MarR repressor from Escherichia coli and the MexR repressor from Pseudomonas aeruginosa, a sequence homologue of MarR. Phylogenetic analysis of the MarR/SlyA family suggests that Sly is placed between the SlyA and MarR subfamilies and shows significant sequence similarity to members of both subfamilies.

  1. Crystal Structure of Bovine Mitochondrial Factor B at 0.96-Angstrom Resolution

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J.K.; Belogrudov, G.I.; Stroud, R.M.

    2009-05-20

    Coupling factor B (FB) is a mitochondrial inner membrane polypeptide that facilitates the energy-driven catalysis of ATP synthesis in animal mitochondria by blocking a proton leak across the membrane. Here, we report the crystal structure of the bovine mitochondrial FB mutant with Gly-3-Glu substitution determined at a resolution of 0.96 {angstrom} and that of the WT polypeptide at a resolution of 2.9 {angstrom}. The structure reveals an oblong, oval-shaped molecule with a unique globular N-terminal domain that is proposed to be the membrane anchor domain and the capping region to the C-terminal leucine-rich repeats domain. A short N-terminal {alpha}-helix, which extends away from the molecule's body, is suggestive of functioning as an anchor for FB to the matrix side of the mitochondrial inner membrane. Identification of a bound Mg{sup 2+} ion reveals that FB is a metalloprotein. We also report the cocrystal structures of FB bound with phenylarsine oxide and Cd{sup 2+}, two known inhibitors of the FB coupling activity.

  2. Solute Distribution in Columnar Crystal Zone and Influences of Correlative Factors for Continuous Casting Slabs

    Institute of Scientific and Technical Information of China (English)

    CHEN Shu-ying; CHANG Guo-wei; YUE Xu-dong; WU Chun-jing

    2008-01-01

    The expression of the solute distribution in columnar crystal zone was deduced when the solid-liquid interface bended periodically,and the quantitative calculations of macrosegregation were also made in the process of the continuous casting.The solute distribution along the thickness direction of the slabs was obtained,which verified the theoretical calculation.The effect of the bulge size,solidification speed,and solidification shrinkage speed on macrosegregation of the slabs was calculated.It can be concluded that normal segregation and negative segregation alternatively appear as a result of the bulge.The normal segregation exponentially depends on the bulge size,and the negative segregation linearly depends on the bulge size.The extent of the normal segregation is greater than that of the negative segregation when the bulge size is the same.The macrosegregation of the same position along the thickness direction of the slabs changes in a sine wave with increasing the solidification rate,and the amplitude is larger at the casting blank center.The normal segregation linearly decreases with increasing the solidification shrinkage speed,and when the solidification shrinkage speed exceeds a critical value,the segregation appears negatively and increases linearly.

  3. Non-negative matrix factorization and term structure of interest rates

    Science.gov (United States)

    Takada, Hellinton H.; Stern, Julio M.

    2015-01-01

    Non-Negative Matrix Factorization (NNMF) is a technique for dimensionality reduction with a wide variety of applications from text mining to identification of concentrations in chemistry. NNMF deals with non-negative data and results in non-negative factors and factor loadings. Consequently, it is a natural choice when studying the term structure of interest rates. In this paper, NNMF is applied to obtain factors from the term structure of interest rates and the procedure is compared with other very popular techniques: principal component analysis and Nelson-Siegel model. The NNMF approximation for the term structure of interest rates is better in terms of fitting. From a practitioner point of view, the NNMF factors and factor loadings obtained possess straightforward financial interpretations due to their non-negativeness.

  4. Common factors and the exchange rate: results from the Brazilian case

    Directory of Open Access Journals (Sweden)

    Wilson Rafael de Oliveira Felício

    2014-03-01

    Full Text Available This paper studies the usefulness of factor models in explaining the dynamics of the exchange rate Real / Dollar from January 1999 to August 2011. The paper verifies that the inclusion of factors embedded on the common movements of exchange rates of a set of countries significantly improves the in-sample and out-of-sample predictive power of the models comprising only macroeconomic fundamentals commonly used in the literature to forecast the exchange rate. The paper also links the information contained in the factors to global shocks like the demand for dollars - a "dollar effect", volatility and liquidity of global financial markets.

  5. Crystal structure of the DNA-binding domain of Myelin-gene Regulatory Factor.

    Science.gov (United States)

    Zhen, Xiangkai; Li, Bowen; Hu, Fen; Yan, Shufeng; Meloni, Gabriele; Li, Huiliang; Shi, Ning

    2017-06-16

    Myelin-gene Regulatory Factor (MyRF) is one of the master transcription factors controlling myelin formation and development in oligodendrocytes which is crucial for the powerful brain functions. The N-terminal of MyRF, which contains a proline-rich region and a DNA binding domain (DBD), is auto-cleaved from the ER membrane, and then enters the nucleus to participate in transcription regulation of the myelin genes. Here we report the crystal structure of MyRF DBD. It shows an Ig-fold like architecture which consists of two antiparallel β-sheets with 7 main strands, packing against each other, forming a β-sandwich. Compared to its homolog, Ndt80, MyRF has a smaller and less complex DBD lacking the helices and the big loops outside the core. Structural alignment reveals that MyRF DBD possess less interaction sites with DNA than Ndt80 and may bind only at the major groove of DNA. Moreover, the structure reveals a trimeric assembly, agreeing with the previous report that MyRF DBD functions as a trimer. The mutant that we designed based on the structure disturbed trimer formation, but didn't affect the auto-cleavage reaction. It demonstrates that the activation of self-cleavage reaction of MyRF is independent of the presence of its N-terminal DBD homotrimer. The structure reported here will help to understand the molecular mechanism underlying the important roles of MyRF in myelin formation and development.

  6. Gallium nitride L3 photonic crystal cavities with an average quality factor of 16 900 in the near infrared

    Energy Technology Data Exchange (ETDEWEB)

    Vico Triviño, Noelia; Carlin, Jean-François; Butté, Raphaël; Grandjean, Nicolas [Institute of Condensed Matter Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Minkov, Momchil, E-mail: momchil.minkov@epfl.ch; Savona, Vincenzo [Laboratory of Theoretical Physics of Nanosystems, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne (Switzerland); Urbinati, Giulia; Galli, Matteo [Dipartimento di Fisica, Università di Pavia, via Bassi 6, 27100 Pavia (Italy)

    2014-12-08

    Photonic crystal point-defect cavities were fabricated in a GaN free-standing photonic crystal slab. The cavities are based on the popular L3 design, which was optimized using an automated process based on a genetic algorithm, in order to maximize the quality factor. Optical characterization of several individual cavity replicas resulted in an average unloaded quality factor Q = 16 900 at the resonant wavelength λ∼1.3 μm, with a maximal measured Q value of 22 500. The statistics of both the quality factor and the resonant wavelength are well explained by first-principles simulations including fabrication disorder and background optical absorption.

  7. Gallium nitride L3 photonic crystal cavities with an average quality factor of 16,900 in the near infrared

    CERN Document Server

    Triviño, Noelia Vico; Urbinati, Giulia; Galli, Matteo; Carlin, Jean-François; Butté, Raphaël; Savona, Vincenzo; Grandjean, Nicolas

    2014-01-01

    Photonic crystal point-defect cavities were fabricated in a GaN free-standing photonic crystal slab. The cavities are based on the popular L3 design, which was optimized using an automated process based on a genetic algorithm, in order to maximize the quality factor. Optical characterization of several individual cavity replicas resulted in an average unloaded quality factor Q = 16,900 at the resonant wavelength {\\lambda} $\\sim 1.3$ {\\mu}m, with a maximal measured Q value of 22,500. The statistics of both the quality factor and the resonant wavelength are well explained by first-principles simulations including fabrication disorder and background optical absorption.

  8. High thermoelectric power factor in two-dimensional crystals of Mo S2

    Science.gov (United States)

    Hippalgaonkar, Kedar; Wang, Ying; Ye, Yu; Qiu, Diana Y.; Zhu, Hanyu; Wang, Yuan; Moore, Joel; Louie, Steven G.; Zhang, Xiang

    2017-03-01

    The quest for high-efficiency heat-to-electricity conversion has been one of the major driving forces toward renewable energy production for the future. Efficient thermoelectric devices require high voltage generation from a temperature gradient and a large electrical conductivity while maintaining a low thermal conductivity. For a given thermal conductivity and temperature, the thermoelectric power factor is determined by the electronic structure of the material. Low dimensionality (1D and 2D) opens new routes to a high power factor due to the unique density of states (DOS) of confined electrons and holes. The 2D transition metal dichalcogenide (TMDC) semiconductors represent a new class of thermoelectric materials not only due to such confinement effects but especially due to their large effective masses and valley degeneracies. Here, we report a power factor of Mo S2 as large as 8.5 mW m-1K-2 at room temperature, which is among the highest measured in traditional, gapped thermoelectric materials. To obtain these high power factors, we perform thermoelectric measurements on few-layer Mo S2 in the metallic regime, which allows us to access the 2D DOS near the conduction band edge and exploit the effect of 2D confinement on electron scattering rates, resulting in a large Seebeck coefficient. The demonstrated high, electronically modulated power factor in 2D TMDCs holds promise for efficient thermoelectric energy conversion.

  9. Crystal structure of norcoclaurine-6-O-methyltransferase, a key rate-limiting step in the synthesis of benzylisoquinoline alkaloids.

    Science.gov (United States)

    Robin, Adeline Y; Giustini, Cécile; Graindorge, Matthieu; Matringe, Michel; Dumas, Renaud

    2016-09-01

    Growing pharmaceutical interest in benzylisoquinoline alkaloids (BIA) coupled with their chemical complexity make metabolic engineering of microbes to create alternative platforms of production an increasingly attractive proposition. However, precise knowledge of rate-limiting enzymes and negative feedback inhibition by end-products of BIA metabolism is of paramount importance for this emerging field of synthetic biology. In this work we report the structural characterization of (S)-norcoclaurine-6-O-methyltransferase (6OMT), a key rate-limiting step enzyme involved in the synthesis of reticuline, the final intermediate to be shared between the different end-products of BIA metabolism, such as morphine, papaverine, berberine and sanguinarine. Four different crystal structures of the enzyme from Thalictrum flavum (Tf 6OMT) were solved: the apoenzyme, the complex with S-adenosyl-l-homocysteine (SAH), the complexe with SAH and the substrate and the complex with SAH and a feedback inhibitor, sanguinarine. The Tf 6OMT structural study provides a molecular understanding of its substrate specificity, active site structure and reaction mechanism. This study also clarifies the inhibition of Tf 6OMT by previously suggested feedback inhibitors. It reveals its high and time-dependent sensitivity toward sanguinarine.

  10. Experimental study on the relationship between average isotopic fractionation factor and evaporation rate

    Directory of Open Access Journals (Sweden)

    Tao WANG

    2010-12-01

    Full Text Available Isotopic fractionation is the foundation of tracing water cycle using hydrogen and oxygen isotopes. Isotopic fractionation factors in evaporation from free water body are mainly affected by temperature and relative humidity, and greatly vary with these atmospheric factors in a day. Evaporation rate can properly reveal the effects of atmospheric factors. Therefore, there should be a certain function relationship existing in isotopic fractionation factors and evaporation rate. An average isotopic fractionation factor was defined to describe isotopic differences between vapor and liquid phases in evaporation with time interval of hours or days. The relationship of average isotopic fractionation factor and evaporation based on isotopic mass balance was investigated through an evaporation pan experiment with no inflow. The experimental results showed that the isotopic compositions of residual water became more enrichment with time; the average isotopic fractionation factor was affected by air temperature, relative humidity and other atmospheric factors, and had a good functional relation with evaporation rate. The values of average isotopic fractionation factor could be easily calculated with the known of evaporation rate, the initial volume of water in pan and isotopic compositions of residual water.

  11. External dose-rate conversion factors for calculation of dose to the public

    Energy Technology Data Exchange (ETDEWEB)

    1988-07-01

    This report presents a tabulation of dose-rate conversion factors for external exposure to photons and electrons emitted by radionuclides in the environment. This report was prepared in conjunction with criteria for limiting dose equivalents to members of the public from operations of the US Department of Energy (DOE). The dose-rate conversion factors are provided for use by the DOE and its contractors in performing calculations of external dose equivalents to members of the public. The dose-rate conversion factors for external exposure to photons and electrons presented in this report are based on a methodology developed at Oak Ridge National Laboratory. However, some adjustments of the previously documented methodology have been made in obtaining the dose-rate conversion factors in this report. 42 refs., 1 fig., 4 tabs.

  12. Consequences of the Fermat's anisotropic uniaxial principle on the reflexion and transmission factors for one-dimensional uniaxial crystal slabs

    CERN Document Server

    LeDez, Vital

    2010-01-01

    A coherent definition of the reflection and transmission factors at a plane interface separating two uniaxial crystals is proposed, from the photons impulsion-energy 4-vectors conservation. This definition, different from the classical electromagnetic one, is compatible with the completely resolved extended Fermat's principle of the geometric optics for extraordinary luminous rays inside uniaxial media, and allows the exact calculation of the transmission factors at the plane interface for any practical configuration, combining all possible optical axes and anisotropy factors variations. Furthermore, this particular technique points out the existence of quasi-particles strongly associated to the photons, whose behaviour is highly correlated to the photons transmission/reflection possibilities.

  13. From Rate Measurements to Mechanistic Data for Condensed Matter Reactions: A Case Study Using the Crystallization of [Zn(OH26][ZnCl4

    Directory of Open Access Journals (Sweden)

    Berkley G. Hillis

    2016-12-01

    Full Text Available The kinetics of crystallization of the R = 3 hydrate of zinc chloride, [Zn(OH26][ZnCl4], is measured by time-resolved synchrotron x-ray diffraction, time-resolved neutron diffraction, and by differential scanning calorimetry. It is shown that analysis of the rate data using the classic Kolmogorov, Johnson, Mehl, Avrami (KJMA kinetic model affords radically different rate constants for equivalent reaction conditions. Reintroducing the amount of sample measured by each method into the kinetic model, using our recently developed modified-KJMA model (M-KJMA, it is shown that each of these diverse rate measurement techniques can give the intrinsic, material specific rate constant, the velocity of the phase boundary, vpb. These data are then compared to the velocity of the crystallization front directly measured optically. The time-resolved diffraction methods uniquely monitor the loss of the liquid reactant and formation of the crystalline product demonstrating that the crystallization of this hydrate phase proceeds through no intermediate phases. The temperature dependent vpb data are then well fit to transition zone theory to extract activation parameters. These demonstrate that the rate-limiting component to this crystallization reaction is the ordering of the waters (or protons of hydration into restricted positions of the crystalline lattice resulting in large negative entropy of activation.

  14. Focused beam reflectance measurement as a tool for in situ monitoring of the lactose crystallization process

    National Research Council Canada - National Science Library

    Pandalaneni, K; Amamcharla, J K

    2016-01-01

    .... Production of lactose is usually carried out by a process called crystallization. Several factors including rate of cooling, presence of impurities, and mixing speed influence the crystal size characteristics...

  15. Driving factors behind O/N interbank interest rates – the Hungarian experiences

    OpenAIRE

    Szilárd Erhart

    2005-01-01

    This study examines overnight (O/N) interest rates which constitute the short end of the yield curve and the factors which have an impact on such rates. The MNB, unlike several other central banks, does not have a direct overnight interest rate target; it does, however, limit the divergence of O/N interest rates from its policy rate with the settings of its operational framework. First, the MNB’s regulations on compulsory reserves allow banks to apply averaging in the reserve maintenance peri...

  16. High rates and the risk factors for emergency room visits and hospitalization in Parkinson's disease

    NARCIS (Netherlands)

    Hassan, A.; Wu, S.S.; Schmidt, P.; Dai, Y.; Simuni, T.; Giladi, N.; Bloem, B.R.; Malaty, I.A.; Okun, M.S.; Investigators, N.-Q.

    2013-01-01

    BACKGROUND: Parkinson's disease (PD) patients are hospitalized more frequently than their peers as a result of falls, psychosis, infections and other medical complications. However, patient-specific risk factors for hospitalization are unclear. OBJECTIVE: To identify rates and risk factors for hospi

  17. Evaluating Iowa Community College Student Demographics, Characteristics, Enrollment Factors, and Educational Goals Influence on Retention Rates

    Science.gov (United States)

    Mitchley-McAvoy, Joan A.

    2012-01-01

    This study examined the influence that previously researched and affirmed persistence and early withdrawal factors such as student demographics, enrollment status factors, student characteristics, and student educational goals had on Iowa community college retention rates for the 2005, 2007, and 2009 academic years. It is the researcher's…

  18. Factors contributing to the differences in work related injury rates between Danish and Swedish construction workers

    DEFF Research Database (Denmark)

    Spangenberg, S.; Baarts, C.; Dyreborg, J.;

    2002-01-01

    of injury risk factors at group and individual level for Danish and Swedish workers. LTI-rates and injury risk factors were compared for Danish and Swedish workers during the construction of the combined rail and road link across the 16-km wide sound, Oresund, between Denmark and Sweden. The comparison...

  19. Looking beyond credit ratings : Factors investors consider In pricing European asset-backed securities

    NARCIS (Netherlands)

    Fabozzi, F.; Vink, D.

    2012-01-01

    In this paper, we empirically investigate what credit factors investors rely upon when pricing the spread at issue for European asset-backed securities. More specifically, we investigate how credit factors affect new issuance spreads after taking into account credit rating. We do so by investigating

  20. Looking beyond credit ratings : Factors investors consider In pricing European asset-backed securities

    NARCIS (Netherlands)

    Fabozzi, F.; Vink, D.

    2012-01-01

    In this paper, we empirically investigate what credit factors investors rely upon when pricing the spread at issue for European asset-backed securities. More specifically, we investigate how credit factors affect new issuance spreads after taking into account credit rating. We do so by investigating

  1. An assessment system for rating scientific journals in the field of ergonomics and human factors

    NARCIS (Netherlands)

    J. Dul (Jan); W. Karwowski

    2003-01-01

    textabstractA method for selecting and rating scientific and professional journals representing the discipline of ergonomics and human factors is proposed. The method is based upon the journal list, impact factors and citations provided by the Institute of Scientific Information (ISI), and the

  2. Factor Structure of the Rorschach Prognostic Rating Scale and Its Relation to Therapeutic Outcome

    Science.gov (United States)

    Auerbach, Stephen M.; Edinger, Jack D.

    1976-01-01

    This study evaluated the factor structure of the Rorschach Prognostic Rating Scale (RPRS) in order to: (a) test the assumption that the RPRS represents a unitary response system and (b) determine the efficacy of employing population specific factor scores as predictors of therapy outcome. (Author/NG)

  3. A note on the long rate in factor models of the term structure

    NARCIS (Netherlands)

    de Kort, Jan

    2017-01-01

    In this paper, we consider factor models of the term structure based on a Brownian filtration. We show that the existence of a nondeterministic long rate in a factor model of the term structure implies, as a consequence of the Dybvig–Ingersoll–Ross theorem, that the model has an equivalent

  4. Factors Influencing Middle and High Schools' Active Parental Consent Return Rates

    Science.gov (United States)

    Ji, Peter Y.; Pokorny, Steven B.; Jason, Leonard A.

    2004-01-01

    The authors examined factors influencing the return rates for attempting to collect active parental consent forms from 21,123 students in the 7th through 10th grades in 41 middle and high schools. Overall return rates from middle schools were higher than from high schools. Schools that offered high levels of staff support for collecting consent…

  5. Socioeconomic factors affecting marriage, divorce and birth rates in a Japanese population.

    Science.gov (United States)

    Uchida, E; Araki, S; Murata, K

    1993-10-01

    The effects of low income, urbanisation and young age population on age-adjusted rates of first marriage, divorce and live birth among the Japanese population in 46 prefectures were analysed by stepwise regression for 1970 and for 1975. During this period, Japanese society experienced a drastic change from long-lasting economic growth to serious recession in 1973. In both 1970 and 1975, the first marriage rate for females was inversely related to low income and the divorce rates for both males and females were positively related to low income. The live birth rate was significantly related to low income, urbanisation and young age population only in 1975. The first marriage rate for females and the divorce rates for both sexes increased significantly but the first marriage rate for males and live birth rate significantly decreased between 1970 and 1975. These findings suggest that low income was the essential factor affecting first marriage for females and divorce for males and females.

  6. An assessment system for rating scientific journals in the field of ergonomics and human factors

    OpenAIRE

    Dul, Jan; Karwowski, W.

    2003-01-01

    textabstractA method for selecting and rating scientific and professional journals representing the discipline of ergonomics and human factors is proposed. The method is based upon the journal list, impact factors and citations provided by the Institute of Scientific Information (ISI), and the journal list published in the Ergonomics Abstracts. Three groups of journals were distinguished. The "ergonomics journals" focus exclusively on ergonomics or human factors. The "related journals" focus ...

  7. Low-repetition rate femtosecond laser writing of optical waveguides in KTP crystals: analysis of anisotropic refractive index changes.

    Science.gov (United States)

    Butt, Muhammad Ali; Nguyen, Huu-Dat; Ródenas, Airán; Romero, Carolina; Moreno, Pablo; Vázquez de Aldana, Javier R; Aguiló, Magdalena; Solé, Rosa Maria; Pujol, Maria Cinta; Díaz, Francesc

    2015-06-15

    We report on the direct low-repetition rate femtosecond pulse laser microfabrication of optical waveguides in KTP crystals and the characterization of refractive index changes after the thermal annealing of the sample, with the focus on studying the potential for direct laser fabricating Mach-Zehnder optical modulators. We have fabricated square cladding waveguides by means of stacking damage tracks, and found that the refractive index decrease is large for vertically polarized light (c-axis; TM polarized) but rather weak for horizontally polarized light (a-axis; TE polarized), this leading to good near-infrared light confinement for TM modes but poor for TE modes. However, after performing a sample thermal annealing we have found that the thermal process enables a refractive index increment of around 1.5x10(-3) for TE polarized light, while maintaining the negative index change of around -1x10(-2) for TM polarized light. In order to evaluate the local refractive index changes we have followed a multistep procedure: We have first characterized the waveguide cross-sections by means of Raman micro-mapping to access the lattice micro-modifications and their spatial extent. Secondly we have modeled the waveguides following the modified region sizes obtained by micro-Raman with finite element method software to obtain a best match between the experimental propagation modes and the simulated ones. Furthermore we also report the fabrication of Mach-Zehnder structures and the evaluation of propagation losses.

  8. Exploratory Factor Analysis of SRS-2 Teacher Ratings for Youth with ASD.

    Science.gov (United States)

    Nelson, Andrew T; Lopata, Christopher; Volker, Martin A; Thomeer, Marcus L; Toomey, Jennifer A; Dua, Elissa

    2016-09-01

    This study examined the factor structure and internal consistency of special education teaching staff ratings on the Social Responsiveness Scale-2 (SRS-2; Constantino and Gruber 2012), as well as the percentage of ratings falling above pre-established cut scores, for a sample of lower-functioning youth with autism spectrum disorder (ASD; n = 264). Results of the exploratory factor analysis yielded a four-factor correlated solution. The individual factors and total score demonstrated satisfactory internal consistency reliability for screening purposes. When applying the lowest pre-established cut score (T ≥ 60; minimum indication of clinically significant symptoms/impairments), 85 % of the sample had ratings in that range or higher (more severe). Implications for assessment and future research are provided.

  9. The crystal zero degree detector at BESIII as a realistic high rate environment for evaluating PANDA data acquisition modules

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Marcel

    2015-03-15

    The BESIII experiment located in Beijing, China, is investigating physics in the energy region of the charm-quark via electron positron annihilation reactions. A small detector to be placed in the very forward/backward region around θ=0 at BESIII is foreseen to measure photons from the initial state. This is especially interesting, because it opens the door for various physics measurements over a wide range of energies, even below the experiment's designated energy threshold, which is fixed by the accelerator. This thesis is investigating the capabilities of a crystal zero degree detector (cZDD) consisting of PbWO{sub 4} crystals placed in that region of BESIII. Detailed Geant4-based simulations have been performed, and the energy resolution of the detector has been determined to be σ/μ=0.06+0.025/√(E[GeV]). The determination of the center-of-mass energy √(s){sub isr} after the emission of the photon is of great importance for the study of such events. Preliminary simulations estimated the resolution of the reconstructed √(s){sub isr} using the cZDD information to be significantly better than 10 % for appropriate photon impacts on the detector. Such events can only be investigated, when data from the cZDD and other detectors of BESIII can be correlated. A fast and powerful Data Acquisition (DAQ) capable of performing event correlation in real time is needed. DAQ modules capable of performing real time event correlation are being developed for the PANDA experiment at the future FAIR facility in Darmstadt, Germany. Investigating these modules in a realistic high-rate environment such as provided at BESIII, offers a great opportunity to gain experience in real time event correlation before the start of PANDA. Developments for the cZDD's DAQ using prototype PANDA DAQ modules have been done and successfully tested in experiments with radioactive sources and a beamtest with 210 MeV electrons at the Mainz Microtron.

  10. The Role of Infertility Etiology in Success Rate of Intrauterine Insemination Cycles: An Evaluation of Predictive Factors for Pregnancy Rate

    Science.gov (United States)

    Ashrafi, Mahnaz; Rashidi, Mandana; Ghasemi, Afsaneh; Arabipoor, Arezoo; Daghighi, Sara; Pourasghari, Parisa; Zolfaghari, Zahra

    2013-01-01

    Background: The objective of this study was to identify the prognostic factors that influence the outcome of ovarian stimulation with intrauterine insemination (IUI) cycles in couples with different infertility etiology. Materials and Methods: This retrospective study was performed in data of 1348 IUI cycles with ovarian stimulation by clomiphene citrate (CC) and/or gonadotropins in 632 women with five different infertility etiology subgroups at Akbarabbadi Hospital, Tehran, Iran. Results: The pregnancy rate (PR)/ cycle was highest (19.9%) among couples with unexplained infertility and lowest (10.6%) in couples with multiple factors infertility. In cases of unexplained infertility, the best PRs were seen after CC plus gonadotropins stimulation (26.3%) and with inseminated motile sperm count>30×106 (21.9%), but the tendency didn’t reach statistical significant. In the ovarian factor group, the best PRs were observed in women aged between 30 and 34 years (20.8%), with 2-3 preovulatory follicles (37.8%) and infertility duration between 1and 3 years (20.8%), while only infertility duration (p=0.03) and number of preovulatory follicles (p=0.01) were statistically significant. Multiple logistic regression analysis determined that number of preovulatory follicles (p=0.02), duration of infertility (p=0.015), age (p=0.019), infertility etiology (p=0.05) and stimulation regimen (p=0.01) were significant independent factors in order to predict overall clinical PR. Conclusion: The etiology of infertility is important to achieve remarkable IUI success. It is worth mentioning that within different etiologies of infertility, the demographic and cycles characteristics of couples did not show the same effect. Favorable variables for treatment success are as follows: age infertility ≤5 years and a cause of infertility except of multiple factors. PMID:24520471

  11. Crystal structure of the catalytic domain of the initiation factor 2B epsilon subunit from saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Boesen, Thomas; Pavitt, Graham D.; Andersen, Gregers Rom

    -terminal domain harbors the two aa-box motifs involved in binding to the N-terminal part of the initiation factor 2 β subunit. Aliphatic residues in the aa-box motifs are involved in specific contacts in the hydrophobic core of the C-terminal bundle important for maintaining the overall structure, whereas, acidic...... residues in the motifs form a surface exposed acidic patch which might interact with the lysine boxes of initiation factor 2 β. Interestingly, tryptophan 699 was found to be solvent exposed and involved in crystal packing. This residue could possibly be important for the specific interaction...

  12. Control of effect on the nucleation rate for hen egg white lysozyme crystals under application of an external ac electric field.

    Science.gov (United States)

    Koizumi, H; Uda, S; Fujiwara, K; Nozawa, J

    2011-07-05

    The effect of an external ac electric field on the nucleation rate of hen egg white lysozyme crystals increased with an increase in the concentration of the precipitant used, which enabled the design of an electric double layer (EDL) formed at the inner surface of the drop in the oil. This is attributed to the thickness of the EDL controlled by the ionic strength of the precipitant used. Control of the EDL formed at the interface between the two phases is important to establishing this novel technique for the crystallization of proteins under the application of an external ac electric field. © 2011 American Chemical Society

  13. A meta-analysis of the factors influencing development rate variation in Aedes aegypti (Diptera: Culicidae)

    Science.gov (United States)

    2014-01-01

    Background Development rates of Aedes aegypti are known to vary with respect to many abiotic and biotic factors including temperature, resource availability, and intraspecific competition. The relative importance of these factors and their interactions are not well established across populations. We performed meta-analysis on a dataset of development rate estimates from 49 studies. Results Meta-analytic results indicated that the environmental factor of temperature is sufficient to explain development rate variability in Ae. aegypti. While diet and density may greatly impact other developmental phenotypes, these results suggest that for development rate these factors should never be considered to the exclusion of temperature. The effect of temperature on development rate is not homogenous or constant. The sources of heterogeneity of the effect of temperature are difficult to analyze due to lack of consistent reporting of larval rearing methods. Conclusions Temperature is the most important ecological determinant of development rate in Ae. aegypti, but its effect is heterogeneous. Ignoring this heterogeneity is problematic for models of vector population and vector-borne disease transmission. PMID:24495345

  14. Clinical pearls: factors affecting reported contraceptive efficacy rates in clinical studies.

    Science.gov (United States)

    Burkman, Ronald T

    2002-01-01

    Current combination oral contraceptives (OCs) are among the most popular, safe, and effective methods of reversible contraception. There are, however, many factors that can affect contraceptive failure rates as reported in clinical trials, including subject characteristics, factors related to study methodology and data analysis, and publication biases. The variability of these factors among clinical trials makes meaningful comparisons of contraceptive efficacy data across studies difficult, if not misleading or erroneous. It is even more difficult to reconcile the differences between clinical trial efficacy rates and everyday use rates; for instance, the National Survey of Family Growth reported that the rate of OC failure is close to 8% in the United States, which is higher than rates reported in clinical trials. Thus, it is important for the clinician to consider the many factors that can influence reporting of contraceptive failure rates in clinical trials and be aware of the limitations in differentiating OCs on the basis of contraceptive efficacy derived from clinical trial data. Furthermore, clinical trial data may not accurately predict contraceptive efficacy in everyday use.

  15. Risk Factors Influencing Conception Rate in Holstein Heifers before Artificial Insemination or Embryo Transfer

    Directory of Open Access Journals (Sweden)

    M. Yusuf

    2016-12-01

    Full Text Available The objective of this study was to show the risk factors affecting the conception rate in Holstein heifers after synchronization of estrus. A total of 275 Holstein heifers housed in a free barn were used for the experiment. The herd was visited regularly at four week intervals for synchronization of estrus using Heatsynch and CIDR-Heatsynch protocols. A group of four to 14 animals, depending on the availability, were referred to the experiment at each visit. Estrus induction rates in the two protocols were 93.9% and 94.9%, respectively. There was no difference in the conception rate between the two protocols. Conception rate after artificial insemination (AI or embryo transfer (ET were 46.3% and 51.4%, respectively. The risk factors affecting conception rate in heifers were daily weight gain (odds ratio [OR]= 4.673; P= 0.036 and body condition score (BCS (OR= 3.642; P= 0.018. Furthermore, estrus synchronization protocol (OR= 1.774; P= 0.083 and the absence of corpus luteum (CL at the initiation of treatment (OR= 0.512; P= 0.061 had a tendency to affect the conception rate, while age (OR= 0.715; P= 0.008 was a protective factor to conception rate.  In conclusion, positive daily weight gain before AI or ET, higher BCS, younger age, and the presence of CL at the initiation of estrus synchronization in dairy heifers increased the likelihood to conceive.

  16. Exchange rate prediction with multilayer perceptron neural network using gold price as external factor

    Directory of Open Access Journals (Sweden)

    Mohammad Fathian

    2012-04-01

    Full Text Available In this paper, the problem of predicting the exchange rate time series in the foreign exchange rate market is going to be solved using a time-delayed multilayer perceptron neural network with gold price as external factor. The input for the learning phase of the artificial neural network are the exchange rate data of the last five days plus the gold price in two different currencies of the exchange rate as the external factor for helping the artificial neural network improving its forecast accuracy. The five-day delay has been chosen because of the weekly cyclic behavior of the exchange rate time series with the consideration of two holidays in a week. The result of forecasts are then compared with using the multilayer peceptron neural network without gold price external factor by two most important evaluation techniques in the literature of exchange rate prediction. For the experimental analysis phase, the data of three important exchange rates of EUR/USD, GBP/USD, and USD/JPY are used.

  17. Purification, Crystallization and Preliminary X-ray Diffraction Analysis of Cif, a Virulence Factor Secreted by Pseudomonas aeruginosa

    Energy Technology Data Exchange (ETDEWEB)

    Bahl, C.; MacEachran, D; O& apos; Toole, G; Madden, D

    2010-01-01

    The opportunistic pathogen Pseudomonas aeruginosa secretes a protein that triggers the accelerated degradation of the cystic fibrosis transmembrane conductance regulator (CFTR) in airway epithelial cells. This protein, which is known as the CFTR inhibitory factor (Cif), acts as a virulence factor and may facilitate airway colonization by P. aeruginosa. Based on sequence similarity Cif appears to be an epoxide hydrolase (EH), but it lacks several of the conserved features found in the active sites of canonical members of the EH family. Here, the crystallization of purified recombinant Cif by vapor diffusion is reported. The crystals formed in space group C2, with unit-cell parameters a = 167.4, b = 83.6, c = 88.3 {angstrom}, {beta} = 100.6{sup o}. The crystals diffracted to 2.39 {angstrom} resolution on a rotating-anode source. Based on the calculated Matthews coefficient (2.2 {angstrom}{sup 3} Da{sup -1}), it appears that the asymmetric unit contains four molecules.

  18. Incidence rates of asthma, rhinitis and eczema symptoms and influential factors in young children in Sweden

    DEFF Research Database (Denmark)

    Larsson, M.; Hagerhed-Engman, L.; Sigsgaard, T.

    2008-01-01

    period of breast-feeding. Allergic symptoms in parents were also a strong risk factor for incident asthma, as well as for rhinitis and eczema. Conclusion: When comparing incident rates of asthma between different studies it is important to realize that different definitions of the healthy baseline......Aim: To estimate the incidence rates for asthma, rhinitis and eczema symptoms and to investigate the importance of different influential factors for the incidence of these symptoms. Methods: The Dampness in Building and Health study commenced in the year 2000 in Varmland, Sweden with a parental...... study. Results: The 5-year incidence of doctor-diagnosed asthma was 4.9% (95% CI 4.3-5.3), rhinitis was 5.7% (5.0-6.4) and eczema was 13.4% (12.3-14.5). However, incidence rates strongly depend on the health status of the baseline population. Risk factors for incident asthma were male gender and short...

  19. Effects of loss factors on zero permeability and zero permittivity gaps in 1D photonic crystal containing DNG materials

    CERN Document Server

    Aghajamali, Alireza; Barati, Mahmood

    2014-01-01

    The effects of electric and magnetic loss factors on zero-mu and zero-epsilon gaps in a one-dimensional lossy photonic crystal composed of double-negative and double-positive materials are theoretically investigated by employing the characteristic matrix method. This study contradicts the previous reports as it indicates that by applying the inevitable factors of electric and magnetic losses to the double-negative material, the zero-mu and zero-epsilon gaps appear simultaneously in the transmission spectrum, being independent of the incidence angle and polarizations. Moreover, the results show that these gaps appear not only for an oblique incidence but also in the case of normal incidence, and their appearance at the normal incidence is directly related to the magnetic and electric loss factors. Besides, the results indicate that as the loss factors and angle of incidence increase, the width of both gaps also increases.

  20. Composition and crystal structure of N doped TiO2 film deposited at different O2 flow rate by direct current sputtering.

    Science.gov (United States)

    Ding, Wanyu; Ju, Dongying; Chai, Weiping

    2011-06-01

    N doped Ti02 films were deposited by direct current pulse magnetron sputtering system at room temperature. The influence of 02 flow rate on the crystal structure of deposited films was studied by Stylus profilometer, X-ray photoelectron spectroscopy, and X-ray diffractometer. The results indicate that the 02 flow rate strongly controls the growth behavior and crystal structure of N doped Ti02 film. It is found that N element mainly exists as substitutional doped state and the chemical stiochiometry is near to TiO1.68±0.06N0.11±0.01 for all film samples. N doped Ti02 film deposited with 2 sccm (standard-state cubic centimeter per minute) 02 flow rate is amorphous structure with high growth rate, which contains both anatase phase and rutile phase crystal nucleuses. In this case, the film displays the mix-phase of anatase and rutile after annealing treatment. While N doped Ti02 film deposited with 12 cm(3)/min 02 flow rate displays anatase phase before and after annealing treatment. And it should be noticed that no TiN phase appears for all samples before and after annealing treatment.

  1. Surveys of Health Professions Trainees: Prevalence, Response Rates, and Predictive Factors to Guide Researchers.

    Science.gov (United States)

    Phillips, Andrew W; Friedman, Benjamin T; Utrankar, Amol; Ta, Andrew Q; Reddy, Shalini T; Durning, Steven J

    2017-02-01

    To establish a baseline overall response rate for surveys of health professions trainees, determine strategies associated with improved response rates, and evaluate for the presence of nonresponse bias. The authors performed a comprehensive analysis of all articles published in Academic Medicine, Medical Education, and Advances in Health Sciences Education in 2013, recording response rates. Additionally, they reviewed nonresponse bias analyses and factors suggested in other fields to affect response rate including survey delivery method, prenotification, and incentives. The search yielded 732 total articles; of these, 356 were research articles, and of these, 185 (52.0%) used at least one survey. Of these, 66 articles (35.6%) met inclusion criteria and yielded 73 unique surveys. Of the 73 surveys used, investigators reported a response rate for 63.0% of them; response rates ranged from 26.6% to 100%, mean (standard deviation) 71.3% (19.5%). Investigators reported using incentives for only 16.4% of the 73 surveys. The only survey methodology factor significantly associated with response rate was single- vs. multi-institutional surveys (respectively, 74.6% [21.2%] vs. 62.0% [12.8%], P = .022). Notably, statistical power for all analyses was limited. No articles evaluated for nonresponse bias. Approximately half of the articles evaluated used a survey as part of their methods. Limited data are available to establish a baseline response rate among health professions trainees and inform researchers which strategies are associated with higher response rates. Journals publishing survey-based health professions education research should improve reporting of response rate, nonresponse bias, and other survey factors.

  2. Central bank forecasts of liquidity factors and the control of short term interest rates

    Directory of Open Access Journals (Sweden)

    Ulrich Bindseil

    2002-03-01

    Full Text Available A simple model of the interaction between central bank liquidity management and the inter-bank overnight rate is suggested, which allows analysing the publication offorecasts of liquidity factors by the European Central Bank adopted in June 2000. The paper argues that the main practical advantage of the publication of theseforecasts is that it makes the signal extraction problem with regard to the centralbank's intentions trivial and hence allows establishing a superior behavioural equilibrium between the central bank and the money market participants. In this equilibrium, the central bank can achieve a better steering of overnight rates than under private autonomous factor forecasts, depending of course also on the quality of liquidity forecasts. It is furthermore shown that the publication of an average of autonomous factors, such as adopted by the ECB, is, at least within the model presented, superior to the separate publication of autonomous factors for each single day.

  3. What factors drive interest rate spread of commercial banks? Empirical evidence from Kenya

    Directory of Open Access Journals (Sweden)

    Maureen Were

    2014-12-01

    Full Text Available The paper empirically investigates the determinants of interest rate spread in Kenya's banking sector based on panel data analysis. The findings show that bank-specific factors play a significant role in the determination of interest rate spreads. These include bank size, credit risk as measured by non-performing loans to total loans ratio, return on average assets and operating costs, all of which positively influence interest rate spreads. On the other hand, higher bank liquidity ratio has a negative effect on the spreads. On average, big banks have higher spreads compared to small banks. The impact of macroeconomic factors such as real economic growth is insignificant. The effect of the monetary policy rate is positive but not highly significant. The results largely reflect the structure of the banking industry, in which a few big banks control a significant share of the market.

  4. Impurity scattering rate and coherence factor in vortex core of sign-reversing s -wave superconductors

    Science.gov (United States)

    Nagai, Yuki; Kato, Yusuke

    2010-11-01

    We investigate the impurity scattering rates for quasiparticles in vortex cores of sign-reversing s -wave superconductors as a probe to detect the internal phase difference of the order parameters among different Fermi surfaces. The impurity scattering rates and coherence factors are related to quasiparticle interference effect by the scanning tunneling microscopy and spectroscopy technique. With use of the Born and Kramer-Pesch approximations for the Andreev bound states, we show that the sign-reversed forward scatterings are dominant in vortex cores. Owing to the coherence factor in vortex cores of ±s -wave superconductors, the impurity scattering rate of the Andreev bound states has a characteristic distribution on the Fermi surfaces. For comparison, the impurity scattering rates in vortex cores of s -wave and d -wave superconductors are also discussed.

  5. Relationship between the crystallization rates of amorphous nifedipine, phenobarbital, and flopropione, and their molecular mobility as measured by their enthalpy relaxation and (1)H NMR relaxation times.

    Science.gov (United States)

    Aso, Y; Yoshioka, S; Kojima, S

    2000-03-01

    Isothermal crystallization of amorphous nifedipine, phenobarbital, and flopropione was studied at temperatures above and below their glass transition temperatures (T(g)). A sharp decrease in the crystallization rate with decreasing temperature was observed for phenobarbital and flopropione, such that no crystallization was observed at temperatures 20-30 degrees C lower than their T(g) within ordinary experimental time periods. In contrast, the crystallization rate of nifedipine decreased moderately with decreasing temperature, and considerable crystallization was observed at 40 degrees C below its T(g) within 4 months. The molecular mobility of these amorphous drugs was assessed by enthalpy relaxation and (1)H-NMR relaxation measurements. The enthalpy relaxation time of nifedipine was smaller than that of phenobarbital or flopropinone at the same T - T(g) values, suggesting higher molecular mobility of nifedipine. The spin-lattice relaxation time in the rotating frame (T(1rho)) decreased markedly at temperature above T(g). The slope of the Arrhenius type plot of the T(1rho) for nifedipine protons changed at about 10 degrees C below the T(g), whereas the slope for phenobarbital protons became discontinuous at about 10 degrees C above the T(g). Even at temperatures below its T(g), the spin-spin relaxation process of nifedipine could be described by the sum of its Gaussian relaxation, which is characteristic of solid protons, and its Lorentzian relaxation, which is characteristic of protons with higher mobility. In contrast, no Lorentzian relaxation was observed for phenobarbital or flopropione at temperatures below their T(g). These results also suggest that nifedipine has higher molecular mobility than phenobarbital and flopropione at temperatures below T(g). The faster crystallization of nifedipine than that of phenobarbital or flopropione observed at temperatures below its T(g) may be partly ascribed to its higher molecular mobility at these temperatures.

  6. Dose and Dose-Rate Effectiveness Factor (DDREF); Der Dosis- und Dosisleistungs-Effektivitaetsfaktor (DDREF)

    Energy Technology Data Exchange (ETDEWEB)

    Breckow, Joachim [Fachhochschule Giessen-Friedberg, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz

    2016-08-01

    For practical radiation protection purposes it is supposed that stochastic radiation effects a determined by a proportional dose relation (LNT). Radiobiological and radiation epidemiological studies indicated that in the low dose range a dependence on dose rates might exist. This would trigger an overestimation of radiation risks based on the LNT model. OCRP had recommended a concept to combine all effects in a single factor DDREF (dose and dose-Rate effectiveness factor). There is still too low information on cellular mechanisms of low dose irradiation including possible repair and other processes. The Strahlenschutzkommission cannot identify a sufficient scientific justification for DDREF and recommends an adaption to the actual state of science.

  7. Effects of Environmental Factors on Death Rate of Pigs in South Korea

    OpenAIRE

    Lee, Seung-Joo; Oh, Taek-Kuen; Kim, Suk; Min, Won-Gi; Gutierrez, Winson-Montanez; Chang, Hong-Hee; Chikushi, Jiro

    2012-01-01

    Reducing the mortality rate among pigs for a swine industry is very important. In this study, environmental factors such as average air temperature, average daily temperature rage and average relative humidity were determined on its effects of on mortality rate of pigs and its optimum ranges to influence pigs health that were correlated with the pigs periodic growth. Data were collected from 10 pig farms in South Korea during the Summer, Fall and Winter seasons. Correlation and regression equ...

  8. Risk Factors Influencing Conception Rate in Holstein Heifers before Artificial Insemination or Embryo Transfer

    OpenAIRE

    2016-01-01

    The objective of this study was to show the risk factors affecting the conception rate in Holstein heifers after synchronization of estrus. A total of 275 Holstein heifers housed in a free barn were used for the experiment. The herd was visited regularly at four week intervals for synchronization of estrus using Heatsynch and CIDR-Heatsynch protocols. A group of four to 14 animals, depending on the availability, were referred to the experiment at each visit. Estrus induction rates in the two ...

  9. The Crystal Structure of Cobra Venom Factor, a Cofactor for C3- and C5-Convertase CVFBb

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Vengadesan; Ponnuraj, Karthe; Xu, Yuanyuan; Macon, Kevin; Volanakis, John E.; Narayana, Sthanam V.L.; (Madras); (UAB)

    2009-05-26

    Cobra venom factor (CVF) is a functional analog of human complement component C3b, the active fragment of C3. Similar to C3b, in human and mammalian serum, CVF binds factor B, which is then cleaved by factor D, giving rise to the CVFBb complex that targets the same scissile bond in C3 as the authentic complement convertases C4bC2a and C3bBb. Unlike the latter, CVFBb is a stable complex and an efficient C5 convertase. We solved the crystal structure of CVF, isolated from Naja naja kouthia venom, at 2.6 {angstrom} resolution. The CVF crystal structure, an intermediate between C3b and C3c, lacks the TED domain and has the CUB domain in an identical position to that seen in C3b. The similarly positioned CUB and slightly displaced C345c domains of CVF could play a vital role in the formation of C3 convertases by providing important primary binding sites for factor B.

  10. Protein Crystallization

    Science.gov (United States)

    Chernov, Alexander A.

    2005-01-01

    Nucleation, growth and perfection of protein crystals will be overviewed along with crystal mechanical properties. The knowledge is based on experiments using optical and force crystals behave similar to inorganic crystals, though with a difference in orders of magnitude in growing parameters. For example, the low incorporation rate of large biomolecules requires up to 100 times larger supersaturation to grow protein, rather than inorganic crystals. Nucleation is often poorly reproducible, partly because of turbulence accompanying the mixing of precipitant with protein solution. Light scattering reveals fluctuations of molecular cluster size, its growth, surface energies and increased clustering as protein ages. Growth most often occurs layer-by-layer resulting in faceted crystals. New molecular layer on crystal face is terminated by a step where molecular incorporation occurs. Quantitative data on the incorporation rate will be discussed. Rounded crystals with molecularly disordered interfaces will be explained. Defects in crystals compromise the x-ray diffraction resolution crucially needed to find the 3D atomic structure of biomolecules. The defects are immobile so that birth defects stay forever. All lattice defects known for inorganics are revealed in protein crystals. Contribution of molecular conformations to lattice disorder is important, but not studied. This contribution may be enhanced by stress field from other defects. Homologous impurities (e.g., dimers, acetylated molecules) are trapped more willingly by a growing crystal than foreign protein impurities. The trapped impurities induce internal stress eliminated in crystals exceeding a critical size (part of mni for ferritin, lysozyme). Lesser impurities are trapped from stagnant, as compared to the flowing, solution. Freezing may induce much more defects unless quickly amorphysizing intracrystalline water.

  11. Parent and teacher ratings of attention-deficit/hyperactivity disorder symptoms: Factor structure and normative data.

    Science.gov (United States)

    DuPaul, George J; Reid, Robert; Anastopoulos, Arthur D; Lambert, Matthew C; Watkins, Marley W; Power, Thomas J

    2016-02-01

    Comprehensive assessment of attention-deficit/hyperactivity disorder (ADHD) symptoms includes parent and teacher questionnaires. The ADHD Rating Scale-5 was developed to incorporate changes for the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association, 2013). This study examined the fit of a correlated, 2-factor structure of ADHD (i.e., DSM-5 conceptual model) and alternative models; determined whether ADHD symptom ratings varied across teacher and child demographic characteristics; and presented normative data. Two samples were included: (a) 2,079 parents and guardians (1,131 female, 948 male) completed ADHD symptom ratings for children (N = 2,079; 1,037 males, 1,042 females) between 5 and 17 years old (M = 10.68; SD = 3.75) and (b) 1,070 teachers (766 female, 304 male) completed ADHD symptom ratings for students (N = 2,140; 1,070 males, 1,070 females) between 5 and 17 years old (M = 11.53; SD = 3.54) who attended kindergarten through 12th grade. The 2-factor structure was confirmed for both parent and teacher ratings and was invariant across child gender, age, informant, informant gender, and language. In general, boys were higher in symptom frequency than girls; older children were rated lower than younger children, especially for hyperactivity-impulsivity; and non-Hispanic children were rated higher than Hispanic children. Teachers also rated non-Hispanic African American children higher than non-Hispanic White, Asian, and Hispanic children. Non-Hispanic White teachers provided lower hyperactivity-impulsivity ratings than non-Hispanic, African American, and Hispanic teachers. Normative data are reported separately for parent and teacher ratings by child gender and age. The merits of using the ADHD Rating Scale-5 in a multimodal assessment protocol are discussed. (PsycINFO Database Record

  12. Evaluation of effective factors in success rate of intervention on CTO.

    Science.gov (United States)

    Namazi, Mohammadhasan; Safi, Morteza; Vakili, Hosein; Saadat, Habibollah; Alipour, Saeed; Mahjoob, Parsa; Taherkhani, Maryam; Pedari, Shamseddin; Taherion, Mehrdad; Rajabi Moghaddam, Hasan; Alhazifi, Abdolkarim; Vatanparast, Masoume; Khaligh, Saeed

    2015-01-01

    Chronic total occlusion (CTO) intervention is still a challenging problem. The aim of this study is to determine factors that affect PCI results. The study was conducted on 72 patients in two centers. CTO angioplasty was done by the antegrade approach from the femoral and/or radial approach. The role of age, gender, anatomical variations such as calcification, length of the lesion, proximal bending, retrograde filling and occluded coronary artery (LAD, CCK or RCA), and wires were assessed. The success rate was 79.6%, and presence of calcification was an important factor in CTO PCI. Operator's experience, use of appropriate equipment and calcification are important factors in predicting a successful PCI.

  13. Time scales of magma recharge and crystal growth rate determined from Mg and Ti zoning in plagioclase phenocrysts from the Upper Toluca Pumice, Mexico

    Science.gov (United States)

    Dohmen, Ralf; Smith, Victoria C.; Arce, Jose Luis; Blundy, Jonathan D.

    2010-05-01

    Major and trace element zoning in plagioclase phenocrysts has the potential to stores information on the temporal evolution of the chemical environment during crystal growth, i.e. the surrounding melt composition as well as the intensive parameters temperature (T) and pressure (P), provided that equilibrium partitioning accompanies growth. However, the problem is complicated by the fact that diffusion of mobile elements changes their initial concentrations due to re-equilibration with the surrounding melt at later stages, making estimation of the pre-diffusive element profiles fraught with uncertainty. Here we present a new approach that combines the information from immobile (e.g., Ca, Ti) and mobile (e.g., Mg) elements in plagioclase to unravel the growth history and time scales of magma recharge events from the 10.5 ka Upper Toluca plinian eruption of Nevado de Toluca volcano, Mexico. Since trace elements are less sensitive to intensive parameters their variations in plagioclase phenocrysts have been used to identify open-system processes in silicic systems [1]. These phenocrysts preserve complex element patterns, such as oscillatory zoning and overgrowths, indicating multiple magma recharging events. Based on available diffusion data major elements and, for example, the trace element Ba, are effectively unchanged since crystallization, but the mobility of Mg [2] is large enough to alter the initial concentration at later growth stages. We made attempts to model the Mg zoning using two endmember cases for the growth history of the plagioclase. In the model the growth rate can either be constant until the final crystal diameter is reached or involve various short growth stages with diffusion relaxation breaks in-between. The corresponding moving boundary problem of the diffusion equation was solved numerically using the method of finite differences and a front-tracking method [3]. A particular challenge of the modelling is to estimate the initial Mg concentration

  14. Factors influencing success rate of IVF/ET:analysis of 770 treatment cycles

    Institute of Scientific and Technical Information of China (English)

    叶碧绿; 林金菊; 周颖; 黄学峰; 赵军招; 郑菊芬; 林文琴

    2002-01-01

    Objective: To evaluate the factors influencing success ra te of in vitro fertilization /embryo transfer(IVF/ET).Methods: A retrospective study of 770 consecutive cycles under gone IVF/ET or intracytoplasmic sperm injection (ICSI) from March 1999 to June 2 001.Estradiol and progesterone concentrations on the day of hCG administration w ere measured. Factors effecting embryo transfer on the effects of clinical pregn ancy rate were evaluated.Results: The overall clinical pregnancy rate in 770 cycles was 40.8%. Take home baby rate was 31%. No significantly differences rate were obse rved between groups with different estradiol levels.If the progesterone concentr ation on the day of hCG administration was >6.36 nmol/L, the implantation and cl inical pregnancy rate was lower(P<0.003). The lowest clinical pregnancy rat e was observed when the duration of infertility was ≥10 years. The average numb er of embryos transferred was 2.23±0.83.Conclusion: This study demonstrated that the most important fac tor on clinical pregnancy rate was low progesterone concentration on the day of hCG administration. The other two important variables influencing success rate o f IVF/ET were the duration of infertility, the number of high-grade embryos tra nsferred.

  15. Analysis of Factors Influencing Pregnancy Rate in Frozen-thawed Embryo Transfer

    Institute of Scientific and Technical Information of China (English)

    Lu LI; Xiao-xi SUN; Jun-ling CHEN; Xiao-hong GAO; Yong-wei WANG; Jie-wei TAO; Li-nan CHENG

    2004-01-01

    Objective To analyse factors influencing the outcome of frozen-thawed embryo transfer (FET)Method A retrospective analysis was performed in our center on 129 thawing cycles from March 2001 to April 2003. The related parameters were compared between conceived and non-conceived cycles.Results There were totally 129 clinical pregnancies in these transfers (pregnancy rate: 27.1%). Frozen-thawed embryos were transferred to natural cycles and CC cycling and hormone replacement treatment had equal success. Groups of IVF and ICSI did not differ significantly in pregnancy rates (P>0. 05). The pregnancy rates for one, two, three and four pre-embryos transfer were 0, 20.0%,44.1% and 75.0%,respectively (P<0. 05). There were statistical differences between pregnancy group or non- pregnancy group in the endometrial thickness, CES, CES/No. Of embryo. A higher pregnancy rate was observed in embryo transfers which had at least one 4-cell grade I embryo (d 2)(P<0.01). Conclusions The most important factors influencing the implantation rate and pregnancy rate of frozen-thawed embryo transfer are age, endometrium thickness, and the number, morphology and growth rate of transferred frozen embryos of women participants.

  16. Risk factor selection in rate making: EM adaptive LASSO for zero-inflated poisson regression models.

    Science.gov (United States)

    Tang, Yanlin; Xiang, Liya; Zhu, Zhongyi

    2014-06-01

    Risk factor selection is very important in the insurance industry, which helps precise rate making and studying the features of high-quality insureds. Zero-inflated data are common in insurance, such as the claim frequency data, and zero-inflation makes the selection of risk factors quite difficult. In this article, we propose a new risk factor selection approach, EM adaptive LASSO, for a zero-inflated Poisson regression model, which combines the EM algorithm and adaptive LASSO penalty. Under some regularity conditions, we show that, with probability approaching 1, important factors are selected and the redundant factors are excluded. We investigate the finite sample performance of the proposed method through a simulation study and the analysis of car insurance data from SAS Enterprise Miner database.

  17. The Evolution and Influence of Direct and Indirect Factors on the Economic Rate of Return

    Directory of Open Access Journals (Sweden)

    Mihaela Loredana ECOBICI

    2016-12-01

    Full Text Available The evolution and progress of activity of any company depend mostly on the efficiency with which materials, human and financial resources are employed. Thus the efficiency of the use of material and financial resources may result through the rate of return. This captures in a certain degree the effectiveness of material and financial means allocated to the company's activity. The purpose of this article is to present a synthetic summary of the analysis models of the economic rate of return, models on which we create a diagnostic analysis of factorial type, which establishes the direct and indirect factors acting on this rate. The finality of this article will result in a number of issues highlighting the importance of the economic rate of return and of the evolution and implications of the economic rate of return.

  18. Regional analysis of big five personality factors and suicide rates in Russia.

    Science.gov (United States)

    Voracek, Martin

    2013-08-01

    Extending cross-national and intranational studies on possible aggregate-level associations between personality dimensions and suicide prevalence, this study examined the associations of the Big Five personality factors and suicide rates across 32 regions of the Russian Federation. Failing to replicate one key finding of similar geographic studies, namely, a correspondence of higher suicide rates with lower Agreeableness and Conscientiousness (i.e., higher Psychoticism) scores, higher suicide rates corresponded to higher Agreeableness scores. This effect was obtained with one available data source (regional-level Big Five ratings based on the National Character Survey), but not with another (based on the NEO-PI-R measure). All in all, regional suicide rates across Russia were dissociated from regional variation in personality dimensions.

  19. Risk of solid cancer in low dose-rate radiation epidemiological studies and the dose-rate effectiveness factor.

    Science.gov (United States)

    Shore, Roy; Walsh, Linda; Azizova, Tamara; Rühm, Werner

    2017-10-01

    Estimated radiation risks used for radiation protection purposes have been based primarily on the Life Span Study (LSS) of atomic bomb survivors who received brief exposures at high dose rates, many with high doses. Information is needed regarding radiation risks from low dose-rate (LDR) exposures to low linear-energy-transfer (low-LET) radiation. We conducted a meta-analysis of LDR epidemiologic studies that provide dose-response estimates of total solid cancer risk in adulthood in comparison to corresponding LSS risks, in order to estimate a dose rate effectiveness factor (DREF). We identified 22 LDR studies with dose-response risk estimates for solid cancer after minimizing information overlap. For each study, a parallel risk estimate was derived from the LSS risk model using matching values for sex, mean ages at first exposure and attained age, targeted cancer types, and accounting for type of dosimetric assessment. For each LDR study, a ratio of the excess relative risk per Gy (ERR Gy(-1)) to the matching LSS ERR risk estimate (LDR/LSS) was calculated, and a meta-analysis of the risk ratios was conducted. The reciprocal of the resultant risk ratio provided an estimate of the DREF. The meta-analysis showed a LDR/LSS risk ratio of 0.36 (95% confidence interval [CI] 0.14, 0.57) for the 19 studies of solid cancer mortality and 0.33 (95% CI 0.13, 0.54) when three cohorts with only incidence data also were added, implying a DREF with values around 3, but statistically compatible with 2. However, the analyses were highly dominated by the Mayak worker study. When the Mayak study was excluded the LDR/LSS risk ratios increased: 1.12 (95% CI 0.40, 1.84) for mortality and 0.54 (95% CI 0.09, 0.99) for mortality + incidence, implying a lower DREF in the range of 1-2. Meta-analyses that included only cohorts in which the mean dose was radiation exposure. The LDR data provide direct evidence regarding risk from exposures at low dose rates as an important complement to the

  20. DSM-5 posttraumatic stress disorder: factor structure and rates of diagnosis.

    Science.gov (United States)

    Gentes, Emily L; Dennis, Paul A; Kimbrel, Nathan A; Rissling, Michelle B; Beckham, Jean C; Calhoun, Patrick S

    2014-12-01

    Posttraumatic stress disorder (PTSD) is a significant problem among Iraq/Afghanistan-era veterans. To date, however, there has been only limited research on how the recent changes in DSM-5 influence the prevalence and factor structure of PTSD. To address this key issue, the present research used a modified version of a gold-standard clinical interview to assess PTSD among a large sample of Iraq/Afghanistan-era veterans (N = 414). Thirty-seven percent of the sample met DSM-5 criteria for PTSD compared to a rate of 38% when DSM-IV diagnostic criteria were used. Differences in rates of diagnosis between DSM-IV and DSM-5 were primarily attributable to changes to Criterion A and the separation of the "avoidance" and "numbing" symptoms into separate clusters. Confirmatory factor analysis (CFA) was used to compare the fit of the previous 3-factor DSM-IV model of PTSD to the 4-factor model specified in DSM-5, a 4-factor "dysphoria" model, and a 5-factor model. CFA demonstrated that the 5-factor model (re-experiencing, active avoidance, emotional numbing, dysphoric arousal, anxious arousal) provided the best overall fit to the data, although substantial support was also found for the 4-factor DSM-5 model. Low factor loadings were noted for two of the symptoms in the DSM-5 model (psychogenic amnesia and reckless/self-destructive behavior), raising questions regarding the adequacy of fit between these symptoms and the other core features of PTSD. Overall, findings suggest the DSM-5 model of PTSD is an improvement over the previous DSM-IV model of PTSD, but still may not represent the true underlying factor structure of PTSD.

  1. Gaming in risk-adjusted mortality rates: effect of misclassification of risk factors in the benchmarking of cardiac surgery risk-adjusted mortality rates

    NARCIS (Netherlands)

    Siregar, S.; Groenwold, R.H.; Versteegh, M.I.; Noyez, L.; Burg, W.J.P.P. ter; Bots, M.L.; Graaf, Y. van der; Herwerden, L.A. van

    2013-01-01

    OBJECTIVE: Upcoding or undercoding of risk factors could affect the benchmarking of risk-adjusted mortality rates. The aim was to investigate the effect of misclassification of risk factors on the benchmarking of mortality rates after cardiac surgery. METHODS: A prospective cohort was used comprisin

  2. Does ovarian hyperstimulation in intrauterine insemination for cervical factor subfertility improve pregnancy rates?

    NARCIS (Netherlands)

    Steures, P; van der Steeg, JW; Verhoeve, HR; van Dop, PA; Hompes, PGA; Bossuyt, PMM; van der Veen, F; Habbema, JDF; Eijkemans, MJC; Mol, BWJ

    2004-01-01

    BACKGROUND: Intrauterine insemination (IUI) can be performed with or without controlled ovarian hyperstimulation (COH). Studies in which the additional benefit of COH on IUI for cervical factor subfertility is assessed are lacking. We assessed whether COH in IUI improved pregnancy rates in cervical

  3. Factor-Based Student Rating in Academic Performance in Southern Province of Rwanda

    Science.gov (United States)

    Rulinda, Ephrard; Role, Elizabeth; Makewa, Lazarus Ndiku

    2013-01-01

    This study examined students' perception on academic performance using five-factor ratings namely, principal's instructional leadership, school climate, school facilities, teachers' effectiveness and family support. Data for this study were collected from selected Parent's Private Seventh-Day Adventist Secondary Schools (PPSDASS) in Southern…

  4. Does ovarian hyperstimulation in intrauterine insemination for cervical factor subfertility improve pregnancy rates?

    NARCIS (Netherlands)

    Steures, P; van der Steeg, JW; Verhoeve, HR; van Dop, PA; Hompes, PGA; Bossuyt, PMM; van der Veen, F; Habbema, JDF; Eijkemans, MJC; Mol, BWJ

    2004-01-01

    BACKGROUND: Intrauterine insemination (IUI) can be performed with or without controlled ovarian hyperstimulation (COH). Studies in which the additional benefit of COH on IUI for cervical factor subfertility is assessed are lacking. We assessed whether COH in IUI improved pregnancy rates in cervical

  5. Retention in Higher Education: Faculty and Student Perceptions of Retention Programs and Factors Impacting Attrition Rates

    Science.gov (United States)

    Mansfield, Malinda; O'Leary, Erin; Webb, Shekeita

    2011-01-01

    The purpose of this study was to examine faculty and student perceptions of what factors are contributing to drop-out rates in a Northern Indiana higher educational facility and to study whether or not the drop-out prevention programs that are in place are effective. Survey links were sent out to all adjuncts and some full-time faculty at a local…

  6. Does ovarian hyperstimulation in intrauterine insemination for cervical factor subfertility improve pregnancy rates?

    NARCIS (Netherlands)

    P. Steures (Pieternel); J.W. van der Steeg (Jan Willem); H.R. Verhoeve (Harold); P.A. van Dop; P.G. Hompes (Peter); P.M.M. Bossuyt (Patrick); F. Veen (Fulco); J.D.F. Habbema (Dik); M.J.C. Eijkemans (René); B.W.J. Mol (Ben)

    2004-01-01

    textabstractBackground: Intrauterine insemination (IUI) can be performed with or without controlled ovarian hyperstimulation (COH). Studies in which the additional benefit of COH on IUI for cervical factor subfertility is assessed are lacking. We assessed whether COH in IUI improved pregnancy rates

  7. Impact of ideal health behaviors and health factors on the detection rate of the carotid plaques

    Institute of Scientific and Technical Information of China (English)

    高竞生

    2013-01-01

    Objective To explore the impact of ideal health behaviors and health factors on the detection rate of the carotid plaques. Methods Subjects with previous stroke,TIA,myocardial infarction were excluded from the study.A total of 5 852 employees(active and retired employers

  8. Analyzing the Factors that Influence Persistence Rates in STEM Field, Majors: Introduction to the Symposium

    Science.gov (United States)

    Ehrenberg, Ronald G.

    2010-01-01

    To improve our understanding of the factors that influence persistence rates in STEM field majors, the Alfred P. Sloan Foundation provided a grant to the Cornell Higher Education Research Institute in 2007 to study the question. The five papers in the symposium represent the output of the project. This introduction explains the motivation for…

  9. Turnover and vacancy rates for registered nurses: do local labor market factors matter?

    Science.gov (United States)

    Rondeau, Kent V; Williams, Eric S; Wagar, Terry H

    2008-01-01

    Turnover of nursing staff is a significant issue affecting health care cost, quality, and access. In recent years, a worldwide shortage of skilled nurses has resulted in sharply higher vacancy rates for registered nurses in many health care organizations. Much research has focused on the individual, group, and organizational determinants of turnover. Labor market factors have also been suggested as important contributors to turnover and vacancy rates but have received limited attention by scholars. This study proposes and tests a conceptual model showing the relationships of organization-market fit and three local labor market factors with organizational turnover and vacancy rates. The model is tested using ordinary least squares regression with data collected from 713 Canadian hospitals and nursing homes. Results suggest that, although modest in their impact, labor market and the organization-market fit factors do make significant yet differential contributions to turnover and vacancy rates for registered nurses. Knowledge of labor market factors can substantially shape an effective campaign to recruit and retain nurses. This is particularly true for employers who are perceived to be "employers-of-choice."

  10. Effect of physicochemical factors on the microplasticity of the surface layer of molybdenum single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Savenko, V.I.; Kuchumova, V.M.; Kochanova, L.A.; Shchukin, E.D.

    1984-07-01

    The microplastic properties of the surface layer of molybdenum single crystals produced by electron-beam zone melting have been investigated experimentaly using ultramicrosclerometry and microindentation techniques. It is found that the 111 plane has the highest susceptibility to plastic damage, while the 100 plane is the hardest. An analysis of the stressed state of the material under an indenter shows that the dislocation density along the loading paths, which characterizes the microplasticity of the material, is largely determined by the crystallography of the lattice, i.e., by the arrangement and the number of effective slip systems in specimens of different orientations. The effect of a monolayer octadecylamine film on the microplastic behavior of molybdenum single crystals is discussed.

  11. Studies decode crystal structure of a neurotrophic factor and the p75 neurotrophin receptor complex

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ CAS biophysicists have made new discoveries about the p75 neurotrophin receptor (p75NTR).Under the guidance of Prof.JIANG Tao of the CAS Institute of Biophysics (IBP),Dr.GONG Yong and Dr.CAO Peng revealed crystal structure of a symmetrical complex of the neurotrophin-3 and p75NTR,bringing to light the mode of their interaction and their structural basis.The work was published by the ioumal Nature on 7 August.

  12. Controlling factors for the brittle-to-ductile transition in tungsten single crystals

    Science.gov (United States)

    Gumbsch; Riedle; Hartmaier; Fischmeister

    1998-11-13

    Materials performance in structural applications is often restricted by a transition from ductile response to brittle fracture with decreasing temperature. This transition is currently viewed as being controlled either by dislocation mobility or by the nucleation of dislocations. Fracture experiments on tungsten single crystals reported here provide evidence for the importance of dislocation nucleation for the fracture toughness in the semibrittle regime. However, it is shown that the transition itself, in general, is controlled by dislocation mobility rather than by nucleation.

  13. Rates and risk factors for Coccidioidomycosis among prison inmates, California, USA, 2011.

    Science.gov (United States)

    Wheeler, Charlotte; Lucas, Kimberley D; Mohle-Boetani, Janet C

    2015-01-01

    In California, coccidioidomycosis is a disease acquired by inhaling spores of Coccidioides immitis, a fungus found in certain arid regions, including the San Joaquin Valley, California, USA, where 8 state prisons are located. During 2011, we reviewed coccidioidomycosis rates at 2 of the prisons that consistently report >80% of California's inmate cases and determined inmate risk factors for primary, severe (defined as pulmonary coccidioidomycosis requiring >10 hospital days), and disseminated coccidioidomycosis (defined by hospital discharge International Classification of Disease, Ninth Revision code). Inmates of African American ethnicity who were >40 years of age were at significantly higher risk for primary coccidioidomycosis than their white counterparts (odds ratio = 2.0, 95% CI 1.5-2.8). Diabetes was a risk factor for severe pulmonary coccidioidomycosis, and black race a risk factor for disseminated disease. These findings contributed to a court decision mandating exclusion of black inmates and inmates with diabetes from the 2 California prisons with the highest rates of coccidioidomycosis.

  14. Scale Factor Determination of Micro-Machined Angular Rate Sensors Without a Turntable

    Institute of Scientific and Technical Information of China (English)

    Gaisser Alexander; GAO Zhongyu; ZHOU Bin; ZHANG Rong; CHEN Zhiyong

    2006-01-01

    This paper presents a digital readout system to detect small capacitive signals of a micro-machined angular rate sensor. The flexible parameter adjustment ability and the computation speed of the digital signal processor were used to develop a new calibration procedure to determine the scale factor of a gyroscope without a turntable. The force of gravity was used to deflect the movable masses in the sensor, which resulted in a corresponding angular rate input. The gyroscope scale factor was then measured without a turntable. Test results show a maximum deviation of about 1.2% with respect to the scale factor determined on a turntable with the accuracy independent of the manufacturing process and property variations. The calibration method in combination with the improved readout electronics can minimize the calibration procedure and, thus, reduce the manufacturing costs.

  15. A Tri-Factor Model for Integrating Ratings Across Multiple Informants

    Science.gov (United States)

    Bauer, Daniel J.; Howard, Andrea L.; Baldasaro, Ruth E.; Curran, Patrick J.; Hussong, Andrea M.; Chassin, Laurie; Zucker, Robert A.

    2014-01-01

    Psychologists often obtain ratings for target individuals from multiple informants such as parents or peers. In this paper we propose a tri-factor model for multiple informant data that separates target-level variability from informant-level variability and item-level variability. By leveraging item-level data, the tri-factor model allows for examination of a single trait rated on a single target. In contrast to many psychometric models developed for multitrait-multimethod data, the tri-factor model is predominantly a measurement model. It is used to evaluate item quality in scale development, test hypotheses about sources of target variability (e.g., sources of trait differences) versus informant variability (e.g., sources of rater bias), and generate integrative scores that are purged of the subjective biases of single informants. PMID:24079932

  16. Crystallization of hepatocyte nuclear factor 4α (HNF4α) in complex with the HNF1α promoter element

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Peng; Liu, Jianguo; Melikishvili, Manana; Fried, Michael G.; Chi, Young-In, E-mail: ychi@uky.edu [Department of Molecular and Cellular Biochemistry and Center for Structural Biology, University of Kentucky, Lexington, KY 40536 (United States)

    2008-04-01

    Sample preparation, characterization, crystallization and preliminary X-ray analysis are reported for the HNF4α–DNA binary complex. Hepatocyte nuclear factor 4α (HNF4α) is a member of the nuclear receptor superfamily that plays a central role in organ development and metabolic functions. Mutations on HNF4α cause maturity-onset diabetes of the young (MODY), a dominant monogenic cause of diabetes. In order to understand the molecular mechanism of promoter recognition and the molecular basis of disease-causing mutations, the recombinant HNF4α DNA-binding domain was prepared and used in a study of its binding properties and in crystallization with a 21-mer DNA fragment that contains the promoter element of another MODY gene, HNF1α. The HNF4α protein displays a cooperative and specific DNA-binding activity towards its target gene-recognition elements. Crystals of the complex diffract to 2.0 Å using a synchrotron-radiation source under cryogenic (100 K) conditions and belong to space group C2, with unit-cell parameters a = 121.63, b = 35.43, c = 70.99 Å, β = 119.36°. A molecular-replacement solution has been obtained and structure refinement is in progress. This structure and the binding studies will provide the groundwork for detailed functional and biochemical studies of the MODY mutants.

  17. Influence of elliptical shaped holes on the sensitivity and Q factor in 2D photonic crystals sensor

    Science.gov (United States)

    Benmerkhi, A.; Bouchemat, M.; Bouchemat, T.

    2016-07-01

    We theoretically investigate the refractive index sensor based on L2 photonic crystal cavity where neighboring holes are locally infiltrated with polymers. The photonic crystal is composed of periodic triangular hole array patterned perpendicularly to an InP-based confining heterostructure. The number of the holes surrounding a L2 cavity and their shape were modified in order to optimize the sensitivity and quality factor. From this study we have selected two structures that have good results. The first one is called locally which has a very high Q factor and a good sensitivity. Their values are 6.03 × 106 and 163 nm/RIU, respectively. The second optimized structure is called design B, which has a high sensitivity toward 227.78 nm/RIU with a Q factor of 5 × 105. The calculated detect limit for the two designs are lower than 1.59 × 10-6 and 1.4 × 10-5 RIU, respectively.

  18. Position specific variation in the rate of evolution intranscription factor binding sites

    Energy Technology Data Exchange (ETDEWEB)

    Moses, Alan M.; Chiang, Derek Y.; Kellis, Manolis; Lander, EricS.; Eisen, Michael B.

    2003-08-28

    The binding sites of sequence specific transcription factors are an important and relatively well-understood class of functional non-coding DNAs. Although a wide variety of experimental and computational methods have been developed to characterize transcription factor binding sites, they remain difficult to identify. Comparison of non-coding DNA from related species has shown considerable promise in identifying these functional non-coding sequences, even though relatively little is known about their evolution. Here we analyze the genome sequences of the budding yeasts Saccharomyces cerevisiae, S. bayanus, S. paradoxus and S. mikataeto study the evolution of transcription factor binding sites. As expected, we find that both experimentally characterized and computationally predicted binding sites evolve slower than surrounding sequence, consistent with the hypothesis that they are under purifying selection. We also observe position-specific variation in the rate of evolution within binding sites. We find that the position-specific rate of evolution is positively correlated with degeneracy among binding sites within S. cerevisiae. We test theoretical predictions for the rate of evolution at positions where the base frequencies deviate from background due to purifying selection and find reasonable agreement with the observed rates of evolution. Finally, we show how the evolutionary characteristics of real binding motifs can be used to distinguish them from artifacts of computational motif finding algorithms. As has been observed for protein sequences, the rate of evolution in transcription factor binding sites varies with position, suggesting that some regions are under stronger functional constraint than others. This variation likely reflects the varying importance of different positions in the formation of the protein-DNA complex. The characterization of the pattern of evolution in known binding sites will likely contribute to the effective use of comparative

  19. Crystal shape controlled H2 storage rate in nanoporous carbon composite with ultra-fine Pt nanoparticle

    Science.gov (United States)

    Chen, Tsan-Yao; Zhang, Yanhui; Hsu, Liang-Ching; Hu, Alice; Zhuang, Yu; Fan, Chia-Ming; Wang, Cheng-Yu; Chung, Tsui-Yun; Tsao, Cheng-Si; Chuang, Haw-Yeu

    2017-02-01

    This study demonstrates that the hydrogen storage rate (HSR) of nanoporous carbon supported platinum nanocatalysts (NC) is determined by their heterojunction and geometric configurations. The present NC is synthesized in an average particle size of ~1.5 nm by incipient wetness impregnation of Pt4+ at carbon support followed by annealing in H2 ambient at 102–105 °C. Among the steps in hydrogen storage, decomposition of H2 molecule into 2 H atoms on Pt NC surface is the deciding factor in HSR that is controlled by the thickness of Pt NC. For the best condition, HSR of Pt NC in 1~2 atomic layers thick (4.7 μg/g min) is 2.6 times faster than that (1.3 μg/g min) of Pt NC with higher than 3 atomic layers thick.

  20. Measurement of deposition rate and ion energy distribution in a pulsed dc magnetron sputtering system using a retarding field analyzer with embedded quartz crystal microbalance

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Shailesh, E-mail: shailesh.sharma6@mail.dcu.ie [Dublin City University, Glasnevin, Dublin 9 (Ireland); Impedans Limited, Chase House, City Junction Business Park, Northern Cross, D17 AK63, Dublin 17 (Ireland); Gahan, David, E-mail: david.gahan@impedans.com; Scullin, Paul; Doyle, James; Lennon, Jj; Hopkins, M. B. [Impedans Limited, Chase House, City Junction Business Park, Northern Cross, D17 AK63, Dublin 17 (Ireland); Vijayaraghavan, Rajani K.; Daniels, Stephen [Dublin City University, Glasnevin, Dublin 9 (Ireland)

    2016-04-15

    A compact retarding field analyzer with embedded quartz crystal microbalance has been developed to measure deposition rate, ionized flux fraction, and ion energy distribution arriving at the substrate location. The sensor can be placed on grounded, electrically floating, or radio frequency (rf) biased electrodes. A calibration method is presented to compensate for temperature effects in the quartz crystal. The metal deposition rate, metal ionization fraction, and energy distribution of the ions arriving at the substrate location are investigated in an asymmetric bipolar pulsed dc magnetron sputtering reactor under grounded, floating, and rf biased conditions. The diagnostic presented in this research work does not suffer from complications caused by water cooling arrangements to maintain constant temperature and is an attractive technique for characterizing a thin film deposition system.

  1. Measurement of deposition rate and ion energy distribution in a pulsed dc magnetron sputtering system using a retarding field analyzer with embedded quartz crystal microbalance.

    Science.gov (United States)

    Sharma, Shailesh; Gahan, David; Scullin, Paul; Doyle, James; Lennon, Jj; Vijayaraghavan, Rajani K; Daniels, Stephen; Hopkins, M B

    2016-04-01

    A compact retarding field analyzer with embedded quartz crystal microbalance has been developed to measure deposition rate, ionized flux fraction, and ion energy distribution arriving at the substrate location. The sensor can be placed on grounded, electrically floating, or radio frequency (rf) biased electrodes. A calibration method is presented to compensate for temperature effects in the quartz crystal. The metal deposition rate, metal ionization fraction, and energy distribution of the ions arriving at the substrate location are investigated in an asymmetric bipolar pulsed dc magnetron sputtering reactor under grounded, floating, and rf biased conditions. The diagnostic presented in this research work does not suffer from complications caused by water cooling arrangements to maintain constant temperature and is an attractive technique for characterizing a thin film deposition system.

  2. An I-integral method for crack-tip intensity factor variation due to domain switching in ferroelectric single-crystals

    Science.gov (United States)

    Yu, Hongjun; Wang, Jie; Shimada, Takahiro; Wu, Huaping; Wu, Linzhi; Kuna, Meinhard; Kitamura, Takayuki

    2016-09-01

    In the present study, an I-integral method is established for solving the crack-tip intensity factors of ferroelectric single-crystals. The I-integral combined with the phase field model is successfully used to investigate crack-tip intensity factor variations due to domain switching in ferroelectricity subjected to electromechanical loadings, which exhibits several advantages over previous methods based on small-scale switching. First, the shape of the switching zone around a crack tip is predicted by the time-dependent Ginzburg-Landau equation, which does not require preset energy-based switching criterion. Second, the I-integral can directly solve the crack-tip intensity factors and decouple the crack-tip intensity factors of different modes based on superimposing an auxiliary state onto an actual state. Third, the I-integral is area-independent, namely, the I-integral is not affected by the integral area size, the polarization distributions, or domain walls. This makes the I-integral applicable to large-scale domain switching. To this end, the electro-elastic field intensity factors of an impermeable crack in PbTiO3 ferroelectric single crystals are evaluated under electrical, mechanical, and combined loading. The intensity factors obtained by the I-integral agree well with those obtained by the extrapolation technique. From numerical results, the following conclusions can be drawn with respect to fracture behavior of ferroelectrics under large-scale switching. Under displacement controlled mechanical loading, the stress intensity factors (SIFs) decrease monotonically due to the domain switching process, which means a crack tip shielding or effective switching-induced toughening occurs. If an external electric field is applied, the electric displacement intensity factor (EDIF) increases in all cases, i.e., the formed domain patterns enhance the electric crack tip loading. The energy release rate, expressed by the crack-tip J-integral, is reduced by the domain

  3. Growth and high rate reactive ion etching of epitaxially grown barium hexaferrite films on single crystal silicon carbide substrates

    Science.gov (United States)

    Chen, Zhaohui

    Ferrites are an invaluable group of insulating magnetic materials used for high frequency microwave applications in such passive electronic devices as isolators, phase shifters, and circulators. Because of their high permeability, non-reciprocal electromagnetic properties, and low eddy current losses, there are no other materials that serve such a broad range of applications. Until recently, they have been widely employed in bulk form, with little success in thin film-based applications in commercial or military microwave technologies. In today's technology, emerging electronic systems, such as high frequency, high power wireless and satellite communications (GPS, Bluetooth, WLAN, commercial radar, etc) thin film materials are in high demand. It is widely recognized that as high frequency devices shift to microwave frequencies the integration of passive devices with semiconductor electronics holds significant advantages in the realization of miniaturization, broader bandwidths, higher performance, speed, power and lower production costs. Thus, the primary objective of this thesis is to explore the integration of ferrite films with wide band gap semiconductor substrates for the realization of monolithic integrated circuits (MICs). This thesis focuses on two key steps for the integration of barium hexaferrite (Ba M-type or BaM) devices on semiconductor substrates. First, the development of high crystal quality ferrite film growth via pulsed laser deposition on wide band gap silicon carbide semiconductor substrates, and second, the effective patterning of BaM films using dry etching techniques. To address part one, BaM films were deposited on 6H silicon carbide (0001) substrates by Pulsed Laser Deposition. X-ray diffraction showed strong crystallographic alignment while pole figures exhibited reflections consistent with epitaxial growth. After optimized annealing, BaM films have a perpendicular magnetic anisotropy field of 16,900 Oe, magnetization (4piMs) of 4.4 k

  4. Cardiovascular risk factors in primary care: methods and baseline prevalence rates--the DETECT program.

    Science.gov (United States)

    Wittchen, H-U; Glaesmer, H; März, W; Stalla, G; Lehnert, H; Zeiher, A M; Silber, S; Koch, U; Böhler, S; Pittrow, D; Ruf, G

    2005-04-01

    DETECT is an epidemiological study in primary care to examine (a) the prevalence rates and comorbidity of diabetes mellitus, hypertension, hyperlipidaemia and coronary heart disease (CHD), and associated conditions; (b) the frequency of behavioural and clinical risk factors for onset and progression; (c) the 12-month course and outcome; and (d) the met and unmet needs for these patients. Three-stage, cross-sectional clinical-epidemiological study with a prospective-longitudinal component in a nationally representative sample of N = 3795 primary care settings [response rate (RR): 60.2%] and N = 55518 patients (RR: 95.5%). Patients completed a standardized assessment, including questionnaires for patients and the physician and diagnostic screening measures (i.e. blood pressure, heart rate, body mass index and waist circumference assessments). A subsample of patients (N = 7519) also completed a standardized laboratory screening program and was followed-up after 12 months. Data were weighted to adjust for non-response, regional distribution and attrition. (1) Doctors and patients sample can be regarded as representative for primary care settings in Germany. (2) The clinician-rated point prevalence of hypertension is highest (35.5%), followed by hyperlipidaemia (29.1%), diabetes (14.1%) and CHD (12.1%); prevalence rates of each disorder as well as their co-incidence rates increase markedly with age. (3) The vast majority (78%) of all patients revealed multiple (3+) behavioural and clinical risk factors. The findings of DETECT underline the considerable burden for primary care doctors in managing a highly morbid patient population, with predominantly complex risk factor constellations, in routine care. Our data provide, in unprecedented detail, a basis for calculating age-, gender- and risk-group-adjusted risk-factor profiles in routine care.

  5. Tumor Volume Reduction Rate After Preoperative Chemoradiotherapy as a Prognostic Factor in Locally Advanced Rectal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Yeo, Seung-Gu [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Department of Radiation Oncology, Soonchunhyang University College of Medicine, Cheonan (Korea, Republic of); Kim, Dae Yong, E-mail: radiopiakim@hanmail.net [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of); Park, Ji Won; Oh, Jae Hwan; Kim, Sun Young; Chang, Hee Jin; Kim, Tae Hyun; Kim, Byung Chang; Sohn, Dae Kyung; Kim, Min Ju [Center for Colorectal Cancer, Research Institute and Hospital, National Cancer Center, Goyang (Korea, Republic of)

    2012-02-01

    Purpose: To investigate the prognostic significance of tumor volume reduction rate (TVRR) after preoperative chemoradiotherapy (CRT) in locally advanced rectal cancer (LARC). Methods and Materials: In total, 430 primary LARC (cT3-4) patients who were treated with preoperative CRT and curative radical surgery between May 2002 and March 2008 were analyzed retrospectively. Pre- and post-CRT tumor volumes were measured using three-dimensional region-of-interest MR volumetry. Tumor volume reduction rate was determined using the equation TVRR (%) = (pre-CRT tumor volume - post-CRT tumor volume) Multiplication-Sign 100/pre-CRT tumor volume. The median follow-up period was 64 months (range, 27-99 months) for survivors. Endpoints were disease-free survival (DFS) and overall survival (OS). Results: The median TVRR was 70.2% (mean, 64.7% {+-} 22.6%; range, 0-100%). Downstaging (ypT0-2N0M0) occurred in 183 patients (42.6%). The 5-year DFS and OS rates were 77.7% and 86.3%, respectively. In the analysis that included pre-CRT and post-CRT tumor volumes and TVRR as continuous variables, only TVRR was an independent prognostic factor. Tumor volume reduction rate was categorized according to a cutoff value of 45% and included with clinicopathologic factors in the multivariate analysis; ypN status, circumferential resection margin, and TVRR were significant prognostic factors for both DFS and OS. Conclusions: Tumor volume reduction rate was a significant prognostic factor in LARC patients receiving preoperative CRT. Tumor volume reduction rate data may be useful for tailoring surgery and postoperative adjuvant therapy after preoperative CRT.

  6. Terahertz gas sensing based on a simple one-dimensional photonic crystal cavity with high-quality factors

    DEFF Research Database (Denmark)

    Chen, T.; Han, Z. H.; Liu, J. J.

    2014-01-01

    exhibits high-quality factors, facilitating the realization of high sensitivity in the gas refractive index sensing. In our experiment, 6% of the change of hydrogen concentration in air, which corresponds to a refractive index change of 1.4 x 10(-5), can be steadily detected, and different gas samples can......We report in this paper terahertz gas sensing using a simple 1D photonic crystal cavity. The resonant frequencies of the cavity depend linearly on the refractive index of the ambient gas, which can then be measured by monitoring the resonance shift. Although quite easy to manufacture, this cavity...

  7. High-sensitivity and high-Q-factor glass photonic crystal cavity and its applications as sensors.

    Science.gov (United States)

    Siraji, Ashfaqul Anwar; Zhao, Yang

    2015-04-01

    We investigate the properties of a planar photonic crystal cavity on glass and its applications as sensors. An airbridged twofold defect cavity on Schott glass background and Gorilla glass substrate has been designed for high Q-factor up to 4459. The average sensitivity of the cavity resonance to background refractive index is 388 nm/Refractive Index Unit. The resonant wavelength is sensitive to background temperature by 18.5 pm/°C. The designed sensors show much higher sensitivity than those based on waveguide interferometers or photonic bandgap structures without cavity resonance. The results are also useful for experimental studies of glass photonic devices.

  8. Crystal Structure of Hypusine-Containing Translation Factor eIF5A Bound to a Rotated Eukaryotic Ribosome.

    Science.gov (United States)

    Melnikov, Sergey; Mailliot, Justine; Shin, Byung-Sik; Rigger, Lukas; Yusupova, Gulnara; Micura, Ronald; Dever, Thomas E; Yusupov, Marat

    2016-09-11

    Eukaryotic translation initiation factor eIF5A promotes protein synthesis by resolving polyproline-induced ribosomal stalling. Here, we report a 3.25-Å resolution crystal structure of eIF5A bound to the yeast 80S ribosome. The structure reveals a previously unseen conformation of an eIF5A-ribosome complex and highlights a possible functional link between conformational changes of the ribosome during protein synthesis and the eIF5A-ribosome association.

  9. Risk Factors for Reduced Salivary Flow Rate in a Japanese Population: The Hisayama Study

    Directory of Open Access Journals (Sweden)

    Kenji Takeuchi

    2015-01-01

    Full Text Available The purpose of this study was to determine distinct risk factors causing reduced salivary flow rate in a community-dwelling population using a prospective cohort study design. This was a 5-year follow-up survey of 1,377 community-dwelling Japanese individuals aged ≥40 years. The salivary flow rate was evaluated at baseline and follow-up by collecting stimulated saliva. Data on demographic characteristics, use of medication, and general and oral health status were obtained at baseline. The relationship between reduced salivary flow rate during the follow-up period and its predictors was evaluated after adjustment for confounding factors. In a multivariate logistic regression model, higher age and plaque score and lower serum albumin levels were significantly associated with greater odds of an obvious reduction in salivary flow rate (age per decade, odds ratio [OR] = 1.25, 95% confidence interval [CI] = 1.03–1.51; serum albumin levels <4 g/dL, OR = 1.60, 95% CI = 1.04–2.46; plaque score ≥1, OR = 1.53, 95% CI = 1.04–2.24. In a multivariate linear regression model, age and plaque score remained independently associated with the increased rate of reduced salivary flow. These results suggest that aging and plaque score are important predictors of reduced salivary flow rate in Japanese adults.

  10. Crystallization and preliminary X-ray diffraction analysis of BipD, a virulence factor from Burkholderia pseudomallei

    Energy Technology Data Exchange (ETDEWEB)

    Knight, M. J.; Ruaux, A.; Mikolajek, H.; Erskine, P. T.; Gill, R.; Wood, S. P. [School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX (United Kingdom); Wood, M. [Institute of Animal Health, Division of Environmental Microbiology, Institute for Animal Health, Compton Laboratory, Berkshire RG20 7NN (United Kingdom); Cooper, J. B., E-mail: j.b.cooper@soton.ac.uk [School of Biological Sciences, University of Southampton, Bassett Crescent East, Southampton SO16 7PX (United Kingdom)

    2006-08-01

    BipD is likely to be a component of a type-III protein secretion system (TTSS) in B. pseudomallei. Native and selenomethionyl-BipD proteins have been expressed and crystals have been obtained which diffract to 2.1 Å. Burkholderia pseudomallei, the causative agent of melioidosis, possesses a protein-secretion apparatus that is similar to those found in Salmonella and Shigella. A major function of these secretion systems is to secrete virulence-associated proteins into target cells of the host organism. The BipD gene of B. pseudomallei encodes a secreted virulence factor that is similar in sequence and most likely functionally analogous to IpaD from Shigella and SipD from Salmonella. Thus, the BipD protein is likely to be a component of a type III protein-secretion system (TTSS) in B. pseudomallei. Proteins in the same class as BipD, such as IpaD and SipD, are thought to act as extracellular chaperones to help the hydrophobic translocator proteins enter the target cell membrane, where they form a pore and might even link the translocon pore with the secretion needle. There is evidence that the translocator proteins also bind an integrin which stimulates actin-mediated insertion of the bacterium into the host-cell membrane. Native BipD has been crystallized in a monoclinic crystal form that diffracts X-rays to 2.5 Å resolution. BipD protein which incorporates selenomethionine (SeMet-BipD) has also been expressed and forms crystals which diffract to a higher resolution of 2.1 Å.

  11. Self-citation rate and impact factor in the field of plastic and reconstructive surgery.

    Science.gov (United States)

    Miyamoto, Shimpei

    2017-05-09

    Journal ranking based on the impact factor (IF) can be distorted by self-citation. The aim of this study is to investigate the present status of self-citation in the plastic surgery journals and its effect on the journals' IFs. IF, IF without self-citations (corrected IF), self-cited rate, and self-citing rate for 11 plastic surgery journals were investigated from 2009-2015, by reviewing the Journal Citation Report(®). The correlations of the IF with the self-cited rate and the self-citing rate were statistically assessed. In addition, Plastic and Reconstructive Surgery was compared with 15 top journals from other surgical specialties in 2015. IF was significantly correlated with the self-cited rate (R: 0.594, p = 0.001) and the self-citing rate (R: 0.824, p journals from other surgical specialties. The IFs of Microsurgery and Journal of Cranio-Maxillo-Facial Surgery increased greatly in recent years, but they were inflated by high self-cited and self-citing rates. The self-citation rate positively affects the IF in plastic surgery journals. A high concentration of self-citation of some journals could distort the ranking among plastic surgery journals in general.

  12. Determination of crystal growth rates during rapid solidification of polycrystalline aluminum by nano-scale spatio-temporal resolution in situ transmission electron microscopy

    Science.gov (United States)

    Zweiacker, K.; McKeown, J. T.; Liu, C.; LaGrange, T.; Reed, B. W.; Campbell, G. H.; Wiezorek, J. M. K.

    2016-08-01

    In situ investigations of rapid solidification in polycrystalline Al thin films were conducted using nano-scale spatio-temporal resolution dynamic transmission electron microscopy. Differences in crystal growth rates and asymmetries in melt pool development were observed as the heat extraction geometry was varied by controlling the proximity of the laser-pulse irradiation and the associated induced melt pools to the edge of the transmission electron microscopy support grid, which acts as a large heat sink. Experimental parameters have been established to maximize the reproducibility of the material response to the laser-pulse-related heating and to ensure that observations of the dynamical behavior of the metal are free from artifacts, leading to accurate interpretations and quantifiable measurements with improved precision. Interface migration rate measurements revealed solidification velocities that increased consistently from ˜1.3 m s-1 to ˜2.5 m s-1 during the rapid solidification process of the Al thin films. Under the influence of an additional large heat sink, increased crystal growth rates as high as 3.3 m s-1 have been measured. The in situ experiments also provided evidence for development of a partially melted, two-phase region prior to the onset of rapid solidification facilitated crystal growth. Using the experimental observations and associated measurements as benchmarks, finite-element modeling based calculations of the melt pool evolution after pulsed laser irradiation have been performed to obtain estimates of the temperature evolution in the thin films.

  13. Compact High-Repetition-Rate Monochromatic Terahertz Source Based on Difference Frequency Generation from a Dual-Wavelength Nd:YAG Laser and DAST Crystal

    Science.gov (United States)

    Zhong, Kai; Mei, Jialin; Wang, Maorong; Liu, Pengxiang; Xu, Degang; Wang, Yuye; Shi, Wei; Yao, Jianquan; Teng, Bing; Xiao, Yong

    2017-01-01

    Although high-repetition-rate dual-wavelength Nd:YAG lasers at 1319 and 1338 nm have been realized for quite a long time, we have employed it in generating monochromatic terahertz (THz) wave in this paper for the first time. The dual-wavelength laser was LD-end-pumped and acousto-optically (AO) Q-switched with the output power of watt level operating at different repetition rates from 5.5 to 30 kHz. Using a 0.6-mm-thick organic nonlinear crystal DAST for difference frequency generation (DFG), a compact terahertz source was achieved at 3.28 THz. The maximum average output power was about 0.58 μW obtained at a repetition rate of 5.5 kHz, corresponding to the conversion efficiency of about 6.4 × 10-7. The output power scaling is still feasible with higher pump power and a longer nonlinear DFG crystal. Owing to the compactness of the dual-wavelength laser and the nonlinear crystal, a palm-top terahertz source is expected for portable applications such as imaging and so on.

  14. Factor Structure of Scores from the Conners’ Rating Scales–Revised Among Nepali Children

    Science.gov (United States)

    Pendergast, Laura L.; Vandiver, Beverly J.; Schaefer, Barbara A.; Cole, Pamela M.; Murray-Kolb, Laura M.; Christian, Parul

    2014-01-01

    This study used exploratory and confirmatory factor analyses to examine the structures of scores from the Conners’ Teacher and Parent Rating Scales–Revised (CTRS-R and CPRS-R, respectively; Conners, 1997). The scales were administered to 1,835 parents and 1,387 teachers of children in Nepal's Sarlahi district – a region where no other measures of child psychopathology have been studied. With a Nepali sample, the findings indicate that reduced two factor models for the Conners’ scales are superior to the models identified in the scale development research. The hyperactivity and inattention factors were comparable to what has been identified in prior research, while other factors (e.g., social problems) differed substantially. Implications for use of the Conners’ scales in Nepal and cross cultural issues in the assessment of ADHD symptoms are discussed. PMID:25574454

  15. Parent Ratings of the Strengths and Difficulties Questionnaire: What Is the Optimum Factor Model?

    Science.gov (United States)

    Gomez, Rapson; Stavropoulos, Vasilis

    2017-07-01

    To date, at least 12 different models have been suggested for the Strengths and Difficulties Questionnaire (SDQ). The current study used confirmatory factor analysis to examine the relative support for these models. In all, 1,407 Malaysian parents completed SDQ ratings of their children (age range = 5-13 years). Although the findings showed some degree of support for all 12 models, there was most support for an oblique six-factor model that included the five SDQ domains (emotional problems, conduct problems, hyperactivity, peer problems, and low prosocial behavior) and a positive construal factor comprising all the 10 SDQ positive worded items. The original proposed five-factor oblique model also showed good fit. The implications of the findings for understanding the results of past studies of the structural models of the parent version of the SDQ, and for clinical and research practice involving the SDQ are discussed.

  16. Organ Donation in Switzerland - An Analysis of Factors Associated with Consent Rate

    Science.gov (United States)

    Keel, Isabelle; Immer, Franz F.; Jüni, Peter

    2014-01-01

    Background and Aim Switzerland has a low post mortem organ donation rate. Here we examine variables that are associated with the consent of the deceased’s next of kin (NOK) for organ donation, which is a prerequisite for donation in Switzerland. Methods and Analysis During one year, we registered information from NOK of all deceased patients in Swiss intensive care units, who were approached for consent to organ donation. We collected data on patient demographics, characteristics of NOK, factors related to the request process and to the clinical setting. We analyzed the association of collected predictors with consent rate using univariable logistic regression models; predictors with p-values donation, and respecting personal values and cultural differences, could be of importance for increasing donation rates. Additional measures are needed to address the pronounced differences in consent rates between language regions. PMID:25208215

  17. Models of Anaylzing the Influence of Factors on Forming Profit Rate

    Directory of Open Access Journals (Sweden)

    Klara S. Jakovčević

    2014-04-01

    Full Text Available The analysis in this paper is focused on identifying the impact of individual factors on the elements of the profit rate. The primary aim of this work is a methodological overview of solutions for understanding the full content of the profit rate as a cause of economic quality as well as indicators of the results of reproduction. Application of model analysis of profit rate factors was performed in an enterprise from Serbia that manufactures construction materials from baked clay. The aim is of application is to test the range in determining elements and factors of economic success of the enterprise, and quantification of changes in its assumptions. The results are useful guideline for the management to take organizational measures to increase the economic success of the enterprise. This means eliminating the negative, emphasizing the positive impact of objectively, and organizational factors to make higher economic success. Based on empirical research, it could be concluded that the proposed quantitative models of analyzing the dynamics of enterprise business quality could be applied in practice.

  18. Trend of Stillbirth Rates and the Associated Risk Factors in Babol, Northern Iran

    Directory of Open Access Journals (Sweden)

    Karimollah Hajian-Tilaki

    2014-01-01

    Full Text Available Objectives: Stillbirth is an important public health concern and its rate indicates the sanitary development of society. The purpose of this study is to determine the trend of stillbirth rates and its risk factors in Babol. Methods: A retrospective study was conducted based on the data of hospital charts of two major Gynecological wards in Shahid Yahyanejat and Babol clinic hospitals in Babol, Northern Iran. In the first phase, the frequencies of stillbirths and live birth deliveries were collected for the period of 1999-2008. In the second phase, a case-control study of 150 stillbirths cases and 300 live births as controls was conducted. The risk factors data included maternal age, gestational age, gravity, history of stillbirth, abortion, diabetes mellitus, preeclampsia, fetal sex, residence area, birth interval and prenatal care. The odds ratio for risk factors with 95% confidence interval for stillbirths was calculated using the logistic regression model. Results: Stillbirth rate was reduced significantly from 10.51 in 1999 to 8.57 per 1000 deliveries in 2008 (p=0.001. A significant association was found between preterm delivery (p=0.001 and preeclampsia (p=0.01 with stillbirths. Although the proportion of stillbirths was higher among mothers with history of diabetes, abortion and maternal age of more than 35 years, the odds ratio was not statistically significant. Conclusion: There is a relationship between stillbirth, preterm delivery and preeclampsia. Thus, we can considerably prevent stillbirths with sanitary remedial interference on these risk factors.

  19. Prevalence Rate and Risk Factors of Depression in Outpatients with Premature Ejaculation

    Directory of Open Access Journals (Sweden)

    Xiansheng Zhang

    2013-01-01

    Full Text Available The purpose of this study is to investigate the prevalence rate and risk factors of depression in outpatients who were diagnosed with PE. Therefore, between September 2009 and September 2011, 1801 outpatients at andrology clinics were enrolled and consented to participate in our survey by completed a verbal questionnaire. It included the following: (1 demographic data (e.g., age, body mass index, (2 PE duration, medical history, and sexual history, (3 self-estimated intravaginal ejaculatory latency times, (4 the Zung Self-rating Depression Scale (SDS, and (5 the National Institute of Health Chronic Prostatitis Symptom Index (NIH-CPSI and (6 the International Index of Erectile Function (IIEF-5. The results showed that a total of 1,206 patients were diagnosed with PE. The prevalence rate of depression in these PE patients was 26.78%. Depression was associated with PE duration, NIH-CPSI score, and IIEF-5 score. Risk factors for depression specifically included PE durations for 13–24, 25–60, or ≥61 months, CPSI scores of 15–30 or ≥31, and IIEF-5 scores <22. These findings suggested that several associated factors (PE duration, CPSI scores, and IIEF-5 scores were the risk factors of depression in men with PE.

  20. Factors influencing the recession rate of Niagara Falls since the 19th century

    Science.gov (United States)

    Hayakawa, Yuichi S.; Matsukura, Yukinori

    2009-09-01

    The rate of recession of Niagara Falls (Horseshoe and American Falls) in northeastern North America has been documented since the 19th century; it shows a decreasing trend from ca. 1 m y - 1 a century ago to ca. 0.1 m y - 1 at present. Reduction of the flow volume in the Niagara River due to diversion into bypassing hydroelectric schemes has often been taken to be the factor responsible, but other factors such as changes in the waterfall shape could play a role and call for a quantitative study. Here, we examine the effect of physical factors on the historically varying recession rates of Niagara Falls, using an empirical equation which has previously been proposed based on a non-dimensional multiparametric model which incorporates flow volume, waterfall shape and bedrock strength. The changes in recession rates of Niagara Falls in the last century are successfully modeled by this empirical equation; these changes are caused by variations in flow volume and lip length. This result supports the validity of the empirical equation for waterfalls in rivers carrying little transported sediment. Our analysis also suggests that the decrease in the recession rate of Horseshoe Falls is related to both artificial reduction in river discharge and natural increase in waterfall lip length, whereas that of American Falls is solely due to the reduction in flow volume.

  1. Crystal structures of bacterial lipoprotein localization factors, LolA and LolB

    OpenAIRE

    Takeda, Kazuki; Miyatake, Hideyuki; Yokota, Naoko; Matsuyama, Shin-ichi; Tokuda, Hajime; Miki, Kunio

    2003-01-01

    Lipoproteins having a lipid-modified cysteine at the N-terminus are localized on either the inner or the outer membrane of Escherichia coli depending on the residue at position 2. Five Lol proteins involved in the sorting and membrane localization of lipoprotein are highly conserved in Gram-negative bacteria. We determined the crystal structures of a periplasmic chaperone, LolA, and an outer membrane lipoprotein receptor, LolB. Despite their dissimilar amino acid sequences, the structures of ...

  2. Relationship Between Net Photosynthetic Rate of Cassava SC205 and Its Physio-ecological Factors

    Institute of Scientific and Technical Information of China (English)

    Yong SONG; Xuan LIN; Jinhui YANG; Yuping DENG; Xingyao XIONG

    2014-01-01

    [Objective]The aim was to measure photosynthetic characters of SC 205, a cassava cultivar, and explore the relationships of the net photosynthetic rate (Pn) with physiological and ecological factors. [Method] The diurnal variations of photosyn-thesis in leaves of SC205 were studied by LICOR-6400 portable photosynthesis system, and the relationships of the net photosynthetic rate (Pn) with physiological and ecological factors were studied by simple correlation analysis and path analysis. [Result] The curve of diurnal variation of Pn showed single peak at 10:00 am at 24.07 μ mol CO2 m2/s, without showing midday depression; the diurnal changes of stomatal conductance (Gs), transpiration rate (Tr), leaf temperature (Tl), air tempera-ture (Ta) and photosynthetic active radiation (PAR) al showed single peak curves, and there were positive relationships of Pn with Gs, Tr, Tl, Ta and PAR. The diur-nal variations of intercellular CO2 concentration (Ci), atmospheric CO2 concentration (Ca), relative humidity (RH) showed in a U-shape curve. There were highly signifi-cant positive correlation of Pn with Gs and PAR; the diurnal variation of Pn had highly significant negative correlations with Ci and Ca. The direct impact of physio-logical factors on Pn was as fol ows: Ci>Gs>Tl>Tr, and the direct impact of ecologi-cal factors was RH>PAR>Ca>Ta. [Conclusion] The research showed that Ci, Gs and Tr play very important roles in the changes of Pn among the physiological fac-tors, and PAR and Ca affect the changes of Pn among the ecological factors.

  3. Risk factors and outcomes of high peritonitis rate in continuous ambulatory peritoneal dialysis patients

    Science.gov (United States)

    Tian, Yuanshi; Xie, Xishao; Xiang, Shilong; Yang, Xin; Zhang, Xiaohui; Shou, Zhangfei; Chen, Jianghua

    2016-01-01

    Abstract Peritonitis remains a major complication of peritoneal dialysis (PD). A high peritonitis rate (HPR) affects continuous ambulatory peritoneal dialysis (CAPD) patients’ technique survival and mortality. Predictors and outcomes of HPR, rather than the first peritonitis episode, were rarely studied in the Chinese population. In this study, we examined the risk factors associated with HPR and its effects on clinical outcomes in CAPD patients. This is a single center, retrospective, observational cohort study. A total of 294 patients who developing at least 1 episode of peritonitis were followed up from March 1st, 2002, to July 31, 2014, in our PD center. Multivariate logistic regression was used to determine the factors associated with HPR, and the Cox proportional hazard model was conducted to assess the effects of HPR on clinical outcomes. During the study period of 2917.5 patient-years, 489 episodes of peritonitis were recorded, and the total peritonitis rate was 0.168 episodes per patient-year. The multivariate analysis showed that factors associated with HPR include a quick occurrence of peritonitis after CAPD initiation (shorter than 12 months), and a low serum albumin level at the start of CAPD. In the Cox proportional hazard model, HPR was a significant predictor of technique failure. There were no differences between HPR and low peritonitis rate (LPR) group for all-cause mortality. However, when the peritonitis rate was considered as a continuous variable, a positive correlation was observed between the peritonitis rate and mortality. We found the quick peritonitis occurrence after CAPD and the low serum albumin level before CAPD were strongly associated with an HPR. Also, our results verified that HPR was positively correlated with technique failure. More importantly, the increase in the peritonitis rate suggested a higher risk of all-cause mortality. These results may help to identify and target patients who are at higher risk of HPR at the start

  4. How initiation factors tune the rate of initiation of protein synthesis in bacteria

    Science.gov (United States)

    Antoun, Ayman; Pavlov, Michael Y; Lovmar, Martin; Ehrenberg, Måns

    2006-01-01

    The kinetics of initiator transfer RNA (tRNA) interaction with the messenger RNA (mRNA)-programmed 30S subunit and the rate of 50S subunit docking to the 30S preinitiation complex were measured for different combinations of initiation factors in a cell-free Escherichia coli system for protein synthesis with components of high purity. The major results are summarized by a Michaelis–Menten scheme for initiation. All three initiation factors are required for maximal efficiency (kcat/KM) of initiation and for maximal in vivo rate of initiation at normal concentration of initiator tRNA. Spontaneous release of IF3 from the 30S preinitiation complex is required for subunit docking. The presence of initiator tRNA on the 30S subunit greatly increases the rate of 70S ribosome formation by increasing the rate of IF3 dissociation from the 30S subunit and the rate of 50S subunit docking to the IF3-free 30S preinitiation complex. The reasons why IF1 and IF3 are essential in E. coli are discussed in the light of the present observations. PMID:16724118

  5. Semantic Factors Predict the Rate of Lexical Replacement of Content Words.

    Directory of Open Access Journals (Sweden)

    Susanne Vejdemo

    Full Text Available The rate of lexical replacement estimates the diachronic stability of word forms on the basis of how frequently a proto-language word is replaced or retained in its daughter languages. Lexical replacement rate has been shown to be highly related to word class and word frequency. In this paper, we argue that content words and function words behave differently with respect to lexical replacement rate, and we show that semantic factors predict the lexical replacement rate of content words. For the 167 content items in the Swadesh list, data was gathered on the features of lexical replacement rate, word class, frequency, age of acquisition, synonyms, arousal, imageability and average mutual information, either from published databases or gathered from corpora and lexica. A linear regression model shows that, in addition to frequency, synonyms, senses and imageability are significantly related to the lexical replacement rate of content words-in particular the number of synonyms that a word has. The model shows no differences in lexical replacement rate between word classes, and outperforms a model with word class and word frequency predictors only.

  6. Feature analysis of the scale factor variation on a constant rate biased ring laser gyro

    Institute of Scientific and Technical Information of China (English)

    Shiqiao Qin; Zongsheng Huang; Xingshu Wang

    2007-01-01

    Scale factor of a constant rate biased ring laser gyro (RLG) is studied both theoretically and experimentally.By analyzing experimental data, we find that there are three main terms contributing to the scale factor deviation. One of them is independent of time, the second varies linearly with time and the third varies exponentially with time. Theoretical analyses show that the first term is caused by experimental setup,the second and the third are caused by un-uniform thermal expension and cavity loss variation of the RLG.

  7. Factors influencing the recession rate of Niagara Falls since the 19th century

    OpenAIRE

    Hayakawa, Yuichi S.; Matsukura, Yukinori

    2009-01-01

    The rate of recession of Niagara Falls (Horseshoe and American Falls) in northeastern North America has been documented since the 19th century; it shows a decreasing trend from ca. 1 m y− 1 a century ago to ca. 0.1 m y− 1 at present. Reduction of the flow volume in the Niagara River due to diversion into bypassing hydroelectric schemes has often been taken to be the factor responsible, but other factors such as changes in the waterfall shape could play a role and call for a quantitative study...

  8. Assessments of fluid friction factors for use in leak rate calculations

    Energy Technology Data Exchange (ETDEWEB)

    Chivers, T.C. [Berkeley Technology Centre, Glos (United Kingdom)

    1997-04-01

    Leak before Break procedures require estimates of leakage, and these in turn need fluid friction to be assessed. In this paper available data on flow rates through idealized and real crack geometries are reviewed in terms of a single friction factor k It is shown that for {lambda} < 1 flow rates can be bounded using correlations in terms of surface R{sub a} values. For {lambda} > 1 the database is less precise, but {lambda} {approx} 4 is an upper bound, hence in this region flow calculations can be assessed using 1 < {lambda} < 4.

  9. Crystal Structure of a Fibroblast Growth Factor Homologous Factor (FHF) Defines a Conserved Surface on FHFs for Binding and Modulation of Voltage-gated Sodium Channels

    Energy Technology Data Exchange (ETDEWEB)

    Goetz, R.; Dover, K; Laezza, F; Shtraizent, N; Huang, X; Tchetchik, D; Eliseenkova, A; Goldfarb, M; Mohammadi, M; et. al.

    2009-01-01

    Voltage-gated sodium channels (Nav) produce sodium currents that underlie the initiation and propagation of action potentials in nerve and muscle cells. Fibroblast growth factor homologous factors (FHFs) bind to the intracellular C-terminal region of the Nav alpha subunit to modulate fast inactivation of the channel. In this study we solved the crystal structure of a 149-residue-long fragment of human FHF2A which unveils the structural features of the homology core domain of all 10 human FHF isoforms. Through analysis of crystal packing contacts and site-directed mutagenesis experiments we identified a conserved surface on the FHF core domain that mediates channel binding in vitro and in vivo. Mutations at this channel binding surface impaired the ability of FHFs to co-localize with Navs at the axon initial segment of hippocampal neurons. The mutations also disabled FHF modulation of voltage-dependent fast inactivation of sodium channels in neuronal cells. Based on our data, we propose that FHFs constitute auxiliary subunits for Navs.

  10. Planar ring-shaped phononic crystal anchoring boundaries for enhancing the quality factor of Lamb mode resonators

    Science.gov (United States)

    Binci, L.; Tu, C.; Zhu, H.; Lee, J. E.-Y.

    2016-11-01

    We report the use of planar ring-shaped phononic crystals (PnCs) as anchor boundaries of very-high-frequency band piezoelectric-on-silicon Lamb mode resonators for the purpose of enhancing their quality factor (Q). Here, we exploit the acoustic bandgap associated with the PnC anchoring boundaries to reduce acoustic energy leakage out of the micromechanical resonator. The proposed approach provides greater mechanical robustness (by merit of interlocking the cells in a matrix) and the possibility of electrical routing through the PnC cells. We experimentally show enhancements in Q by a factor of three using the proposed approach of hybridizing planar ring-shaped PnCs with micromechanical resonators. The effect of these PnCs on resonator Q is further corroborated by their effects in suppressing transmission when incorporated into a delay line.

  11. Configuration Confirmation of Euphorbia Factor L1 by Single-crystal X-ray Diffraction

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A 6,(17)-epoxylathyrol diterpenoid ((2S*3S*4R*5R*6S*9S*11S*15R*)-5,15-diacetoxy-3- phenylacetoxy-14-oxolathyra-6(17),(12E)-diene-6(17)-epoxide) was isolated from the seeds of Euhporbia lathyris L. Its configuration was puzzled because of the incomplete X-ray results reported before. In this work, the atom connectivity and configuration were confirmed by single-crystal X-ray diffraction together with ESI-MS, 1H-, and 13C-NMR spectroscopy. The compound crystallizes in monoclinic, space group P21 with a = 11.386(1), b = 8.2839(7), c = 17.192(2)(A), β = 108.305(2)o, Z = 2, V = 1539.5(2)(A)3, C32H40O8, Mr = 552.64, Dc = 1.192 g/m3, F(000) = 592, μ(MoKα) = 0.085 mm-1, T = 293(2) K, the final R = 0.0398 and wR = 0.0950 for 2057 observed reflections with I > 2σ(I). The molecule shows a tricyclic terpenoid skeleton, consisting of fused five-, eleven- and three-membered rings. The configuration at C(5) is R* and that at C(6) S*.

  12. LD-pumped high repetition rate Q-switched Nd:YVO4 laser by using La3Ga5SiO14 single crystal electro-optic modulator

    Institute of Scientific and Technical Information of China (English)

    Chunyu Wang; Huaguo Zang; Xiaoli Li; Yutian Lu; Xiaolei Zhu

    2006-01-01

    A diode-end-pumped electro-optic (EO) Q-switched Nd:YVO4 laser operating at repetition rate of 10 kpps (pulses per second) was reported. A block of La3Ga5SiO14 (LGS) single crystal was used as a Q-switch and the driver was a metal oxide semiconductor field effect transistor (MOS-FET) pulser of high repetition rate and high voltage. At continuous wave (CW) operation, the slope efficiency of the laser was 46%, and maximum optical-to-optical efficiency was 38.5%. Using an output coupler with transmission of 70%, a 10-kpps Q-switched pulse train with 0.4-mJ monopulse energy and 8.2-ns pulse width was achieved, the optical conversion efficiency was around 15%, and the beam quality M2 factor was less than 1.2.

  13. Study on landslide hazard zonation based on factor weighting-rating theory in Slanic Prahova

    Science.gov (United States)

    Maftei, R.-M.; Vina, G.; Filipciuc, C.

    2012-04-01

    Studying the risks caused by landslides is important in the context of its forecast triggering. This study mainly integrates the background data that are related to historical and environmental factors and also current triggering factors. The theory on zoning hazard caused by landslides, Landslide Hazard Zonation, (LHZ) appeared in the 1960s. In this period the U.S. and many European countries began to use other triggers factors, besides the slope factor, in achieving hazard zoning. This theory has progressed due to the development of remote sensing and GIS technology, which were used to develop and analys methods and techniques consisting in combining data from different sources. The study of an area involves analysing the geographical position data, estimating the surface, the type of terrain, altitude, identifing the landslides in the area and some geological summary data. Data sources. The data used in this study are: · Landsat 7 satellite images; · 30 m spatial resolution, from which is derived the vegetation index; · topographic maps 1:25 000 from which we can obtain the numerical altitude model (DEM) (used to calculate the slope and relative altitude to land) · geological maps 1:50 000. Studied factors. The main factors used and studied in achieving land slides hazard zoning are: - the rate of displacement, the angle of slope, lithology - the index of vegetation or ground coverage of vegetation (NDVI) - river network, structural factor 1. The calculation of normalized vegetation index is made based on Landsat ETM satellite images. This vegetation factor can be both a principal and a secondary trigger factor in landslides. In areas devoid of vegetation, landslides are triggered more often compared with those in which coverage is greater. 2. Factors derived from the numerical model are the slope and elevation relative altitude. This operation was made using the topographic map 1:25 000 from were the level curvs contour was extracted by digitization, and

  14. LOW ENDOPHTHALMITIS RATES AFTER INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR INJECTIONS IN AN OPERATION ROOM

    DEFF Research Database (Denmark)

    Freiberg, Florentina J; Brynskov, Troels; Munk, Marion R

    2017-01-01

    PURPOSE: To evaluate the rate of presumed endophthalmitis (EO) after intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections in three European hospitals performed in an operation room (OR) under sterile conditions. METHODS: A retrospective multicenter study between 2003 and 2016...... at three European sites, City Hospital Triemli Zurich, Switzerland (CHT), Zealand University Hospital Roskilde, Denmark (ZUH) and University Clinic Bern, Switzerland (UCB). Intravitreal injection (IVI) database of each department was reviewed. All anti-vascular endothelial growth factor injections were.......0074% per injection (95% CI: 0.0070-0.0078%). Positive cultures were found in 4 out of 10 presumed endophthalmitis cases. CONCLUSION: The standardized sterile technique in an operation room with laminar airflow showed very low rates of endophthalmitis at three European sites....

  15. Factors influencing the adolescent pregnancy rate in the Greater Giyani Municipality, Limpopo Province – South Africa

    OpenAIRE

    Lenny Mushwana; Lydia Monareng; Solina Richter; Helene Muller

    2015-01-01

    A quantitative, descriptive and explorative survey was conducted to determine factors that influence adolescent pregnancy rate among teenage girls (n = 147) attending four high schools in the Greater Giyani Municipality in South Africa. Data was collected using a validated questionnaire which had a reliability of 0.65. Response frequency distributions, two-way frequency tables, Chi-square tests and Cochran–Armitage Trend Tests were used to determine the effect with the demographic characteris...

  16. Nephrostomy tube related pyelonephritis in patients with cancer: epidemiology, infection rate and risk factors.

    Science.gov (United States)

    Bahu, Ramez; Chaftari, Anne-Marie; Hachem, Ray Y; Ahrar, Kamran; Shomali, William; El Zakhem, Aline; Jiang, Ying; AlShuaibi, Munirah; Raad, Issam I

    2013-01-01

    Nephrostomy tube placement is often necessary to avert acute renal failure in patients with cancer with obstructive uropathy or in patients with ureteral leak. However, there have been limited published studies on the rate and risk of nephrostomy tube related pyelonephritis in patients with cancer. Therefore, in this study we determined rates of nephrostomy tube related pyelonephritis and predisposing risk factors in patients with cancer. We retrospectively reviewed patients who underwent nephrostomy tube placement between September 1, 2009 and September 16, 2010 at MD Anderson Cancer Center. Patients were followed for 90 days. The primary outcome assessed was the development of nephrostomy tube related pyelonephritis and the secondary outcome was the development of asymptomatic bacteriuria. We also determined risk factors associated with pyelonephritis. Of the 200 patients analyzed 38 (19%) had pyelonephritis and 15 (7.5%) had asymptomatic bacteriuria. Of the nephrostomy tube related infections 34 cases (89%) were with the primary nephrostomy tube. Subsequently 4 of the patients who underwent nephrostomy tube exchange had an episode of pyelonephritis. Pyelonephritis developed within the first month in 19 (10%) patients. Prior urinary tract infection and neutropenia were found to be significant risk factors for pyelonephritis (p = 0.047 and 0.03, respectively). The placement of nephrostomy tubes in patients with cancer is associated with a significant rate of pyelonephritis. Neutropenia and history of urinary tract infection were significant risk factors for pyelonephritis. This finding warrants further investigation into preventive strategies to reduce the infection rate. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  17. Platelets interact with tissue factor immobilized on surfaces: effects of shear rate.

    Science.gov (United States)

    Tonda, R; Lopez-Vilchez, I; Navalon, F; Pino, M; Hernandez, M R; Escolar, G; Galan, A M

    2008-01-01

    While procoagulant activities of Tissue Factor (TF) have been widely investigated, its possible pro-adhesive properties towards platelets have not been studied in detail. We explored the interaction of platelets with human Tissue Factor (hTF) firmly adsorbed on a synthetic surface of polyvinilidene difluoride (PVDF) using different shear rates. For studies at 250 and 600 s(-1), TF firmly adsorbed was exposed to flowing anticoagulated blood in flat perfusion devices. Deposition of platelets and fibrin were evaluated by morphometric, immunocytochemical and ultrastructural methods. Prothrombin fragment 1 + 2 (F1 + 2) levels were also measured. Experiments at 5000 s(-1), were performed on the Platelet Function Analyzer (PFA-100) with experimental cartridges with collagen (COL) or collagen-hTF (COL + TF). Haemostatic effect of recombinant activated FVIIa (rFVIIa) was assessed in the same experimental settings. Platelet deposition on hTF reached 19.8 +/- 1.3% and 26.1 +/- 3.4% of the total surface, at 250 and 600 s(-1), respectively. Fibrin formation was significantly higher at 250 s(-1) than at 600 s(-1) (P hTF (154.09 +/- 14.69 s vs. 191.45 +/- 16.09 s COL alone; P hTF is an adhesive substrate for platelets and suggest that the von Willebrand factor could mediate these interactions. At low and intermediate shear rates, rFVIIa enhanced the procoagulant action of hTF, but this effect was not observed at very high shear rates.

  18. Solar radiation increases suicide rate after adjusting for other climate factors in South Korea.

    Science.gov (United States)

    Jee, Hee-Jung; Cho, Chul-Hyun; Lee, Yu Jin; Choi, Nari; An, Hyonggin; Lee, Heon-Jeong

    2017-03-01

    Previous studies have indicated that suicide rates have significant seasonal variations. There is seasonal discordance between temperature and solar radiation due to the monsoon season in South Korea. We investigated the seasonality of suicide and assessed its association with climate variables in South Korea. Suicide rates were obtained from the National Statistical Office of South Korea, and climatic data were obtained from the Korea Meteorological Administration for the period of 1992-2010. We conducted analyses using a generalized additive model (GAM). First, we explored the seasonality of suicide and climate variables such as mean temperature, daily temperature range, solar radiation, and relative humidity. Next, we identified confounding climate variables associated with suicide rate. To estimate the adjusted effect of solar radiation on the suicide rate, we investigated the confounding variables using a multivariable GAM. Suicide rate showed seasonality with a pattern similar to that of solar radiation. We found that the suicide rate increased 1.008 times when solar radiation increased by 1 MJ/m(2) after adjusting for other confounding climate factors (P suicide after adjusting for region, other climate variables, and time trends. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. OSD’s Obligation & Expenditure Rate Goals: An Examination of the Factors Contributing to the Interference

    Science.gov (United States)

    2015-04-30

    Delays (F24) fell below x while four factors rose above x: Shortage of Cost Estimators (F29), Shortage of Business and Finance Management Personnel (F30...ååì~ä=^Åèìáëáíáçå= oÉëÉ~êÅÜ=póãéçëáìã= qÜìêëÇ~ó=pÉëëáçåë= sçäìãÉ=ff= = OSD’s Obligation & Expenditure Rate Goals: An Examination of the Factors ...the Factors Contributing to the Interference 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER 5e

  20. Analysis of Factors Influencing Telephone Call Response Rate in an Epidemiological Study

    Directory of Open Access Journals (Sweden)

    Jorge Matías-Guiu

    2014-01-01

    Full Text Available Descriptive epidemiology research involves collecting data from large numbers of subjects. Obtaining these data requires approaches designed to achieve maximum participation or response rates among respondents possessing the desired information. We analyze participation and response rates in a population-based epidemiological study though a telephone survey and identify factors implicated in consenting to participate. Rates found exceeded those reported in the literature and they were higher for afternoon calls than for morning calls. Women and subjects older than 40 years were the most likely to answer the telephone. The study identified geographical differences, with higher RRs in districts in southern Spain that are not considered urbanized. This information may be helpful for designing more efficient community epidemiology projects.

  1. DETERMINANTS OF SOVEREIGN RATING: FACTOR BASED ORDERED PROBIT MODELS FOR PANEL DATA ANALYSIS MODELING FRAMEWORK

    Directory of Open Access Journals (Sweden)

    Dilek Teker

    2013-01-01

    Full Text Available The aim of this research is to compose a new rating methodology and provide credit notches to 23 countries which of 13 are developed and 10 are emerging. There are various literature that explains the determinants of credit ratings. Following the literature, we select 11 variables for our model which of 5 are eliminated by the factor analysis. We use specific dummies to investigate the structural breaks in time and cross section such as pre crises, post crises, BRIC membership, EU membership, OPEC membership, shipbuilder country and platinum reserved country. Then we run an ordered probit model and give credit notches to the countries. We use FITCH ratings as benchmark. Thus, at the end we compare the notches of FITCH with the ones we derive out of our estimated model.

  2. Significance and influence of the ambient temperature as a rate factor of steel reinforcement corrosion

    Indian Academy of Sciences (India)

    V Živica

    2002-10-01

    The rate of corrosion of reinforcement being an electrochemical process, undoubtedly is dependent even on the level of the ambient temperature. Therefore, the ambient temperature seems to be an important factor of the corrosion rate and the durability of the reinforced concrete structures in aggressive environment. The present data on the influence and significance of the ambient temperature in the process of corrosion of reinforcement of the reinforced structures are surprisingly limited and poor. It seems that it is supposed to be a simple increase of corrosion rate when the ambient temperature is increased. The lack of information was a motivation for the present study. It was aimed at the experimental research of the influence of the increase of the ambient temperature on the rate of chloride induced corrosion of steel reinforcement. The results obtained show that the influence of the studied factor is more complex showing an acceleration effect till a temperature of 40°C diversified by the inhibition effects with further increase of the ambient temperature.

  3. Rates and risk factors for suicide, suicidal ideation, and suicide attempts in chronic epilepsy.

    Science.gov (United States)

    Jones, Jana E; Hermann, Bruce P; Barry, John J; Gilliam, Frank G; Kanner, Andres M; Meador, Kimford J

    2003-10-01

    Studies of causes of death among people with epilepsy suggest that the lifetime prevalence rate of suicide is elevated. Although not all of the studies have reported an increased risk for suicide, the collective data yield an average rate of approximately 12% among people with epilepsy, compared with 1.1-1.2% in the general population. The increased risk for suicide appears to affect children and adolescents as well as adults. Rates of suicide attempts have also been reported to be elevated among people with epilepsy. A suicide attempt is a significant risk factor for completed suicide. Certain psychiatric disorders, including primary mood disorders, also increase the risk for suicide. Among people with epilepsy, psychiatric comorbidity is common, and rates of mood disorders, particularly major depression, have consistently been reported to be elevated. Other potential risk factors are family issues, physical health, personality, life stress, previous suicidal behavior, and access to firearms. Assessing severity of risk helps to determine the appropriate level of intervention. The suicidality module of the Mini-International Neuropsychiatric Interview is a practical tool to help quantify current suicide risk.

  4. Sudden infant death syndrome in Canada: trends in rates and risk factors, 1985-1998.

    Science.gov (United States)

    Rusen, I D; Liu, Shiliang; Sauve, Reg; Joseph, K S; Kramer, Michael S

    2004-01-01

    In Canada, sudden infant death syndrome (SIDS) remains the leading cause of postneonatal death. However, SIDS rates have been declining in many countries, including Canada. This decline has been largely attributed to recommendations to avoid placing infants to sleep in the prone position. We examined the postneonatal rate of mortality due to SIDS and to other causes in relation to the initial risk reduction campaign. The postneonatal mortality rate due to SIDS decreased from 0.97 to 0.54 per 1,000 neonatal survivors between 1985-1989 and 1994-1998 (relative risk [RR] = 0.56, 95% confidence interval [CI] 0.51-0.62). The rate of postneonatal mortality due to other causes also decreased during the same period, though to a smaller extent, from 1.19 to 0.86 (RR = 0.72, 95% CI 0.66-0.78). With the exception of seasonality, established risk factors for SIDS remained essentially unchanged between the two time periods. The observed reduction in postneonatal SIDS is consistent with a positive impact of the initial recommendations regarding risk reduction. However, the lack of reliable risk factor data limits the extent to which the decline can be attributed directly to the campaign.

  5. Crime and violence in Brazil: Systematic review of time trends, prevalence rates and risk factors.

    Science.gov (United States)

    Murray, Joseph; Cerqueira, Daniel Ricardo de Castro; Kahn, Tulio

    2013-09-01

    Between 1980 and 2010 there were 1 million homicides in Brazil. Dramatic increases in homicide rates followed rises in inequality, more young men in the population, greater availability of firearms, and increased drug use. Nevertheless, disarmament legislation may have helped reduce homicide rates in recent years. Despite its very high rate of lethal violence, Brazil appears to have similar levels of general criminal victimization as several other Latin American and North American countries. Brazil has lower rates of drug use compared to other countries such as the United States, but the prevalence of youth drug use in Brazil has increased substantially in recent years. Since 1990, the growth of the Brazilian prison population has been enormous, resulting in the fourth largest prison population in the world. Through a systematic review of the literature, we identified 10 studies assessing the prevalence of self-reported offending in Brazil and 9 studies examining risk factors. Levels of self-reported offending seem quite high among school students in Brazil. Individual and family-level risk factors identified in Brazil are very similar to those found in high-income countries.

  6. Design and performance of SiPM-based readout of PbF2 crystals for high-rate, precision timing applications

    Science.gov (United States)

    Kaspar, J.; Fienberg, A. T.; Hertzog, D. W.; Huehn, M. A.; Kammel, P.; Khaw, K. S.; Peterson, D. A.; Smith, M. W.; Van Wechel, T. D.; Chapelain, A.; Gibbons, L. K.; Sweigart, D. A.; Ferrari, C.; Fioretti, A.; Gabbanini, C.; Venanzoni, G.; Iacovacci, M.; Mastroianni, S.; Giovanetti, K.; Gohn, W.; Gorringe, T.; Pocanic, D.

    2017-01-01

    We have developed a custom amplifier board coupled to a large-format 16-channel Hamamatsu silicon photomultiplier device for use as the light sensor for the electromagnetic calorimeters in the Muon g - 2 experiment at Fermilab. The calorimeter absorber is an array of lead-fluoride crystals, which produces short-duration Cherenkov light. The detector sits in the high magnetic field of the muon storage ring. The SiPMs selected, and their accompanying custom electronics, must preserve the short pulse shape, have high quantum efficiency, be non-magnetic, exhibit gain stability under varying rate conditions, and cover a fairly large fraction of the crystal exit surface area. We describe an optimized design that employs the new-generation of thru-silicon via devices. The performance is documented in a series of bench and beam tests.

  7. Design and performance of SiPM-based readout of PbF 2 crystals for high-rate, precision timing applications

    Energy Technology Data Exchange (ETDEWEB)

    Kaspar, J.; Fienberg, A. T.; Hertzog, D. W.; Huehn, M. A.; Kammel, P.; Khaw, K. S.; Peterson, D. A.; Smith, M. W.; Wechel, T. D. Van; Chapelain, A.; Gibbons, L. K.; Sweigart, D. A.; Ferrari, C.; Fioretti, A.; Gabbanini, C.; Venanzoni, G.; Iacovacci, M.; Mastroianni, S.; Giovanetti, K.; Gohn, W.; Gorringe, T.; Pocanic, D.

    2017-01-01

    We have developed a custom amplifier board coupled to a large-format 16-channel Hamamatsu silicon photomultiplier device for use as the light sensor for the electromagnetic calorimeters in the Muon g-2 experiment at Fermilab. The calorimeter absorber is an array of lead-fluoride crystals, which produces short-duration Cherenkov light. The detector sits in the high magnetic field of the muon storage ring. The SiPMs selected, and their accompanying custom electronics, must preserve the short pulse shape, have high quantum efficiency, be non-magnetic, exhibit gain stability under varying rate conditions, and cover a fairly large fraction of the crystal exit surface area. We describe an optimized design that employs the new-generation of thru-silicon via devices. The performance is documented in a series of bench and beam tests.

  8. Design and performance of SiPM-based readout of PbF2 crystals for high-rate, precision timing applications

    CERN Document Server

    Kaspar, J; Hertzog, D W; Huehn, M A; Kammel, P; Khaw, K S; Peterson, D A; Smith, M W; Van Wechel, T D; Chapelain, A; Gibbons, L K; Sweigart, D A; Ferrari, C; Fioretti, A; Gabbanini, C; Venanzoni, G; Giovanetti, K; Gohn, W; Gorringe, T; Pocanic, D

    2016-01-01

    We have developed a custom amplifier board coupled to a large-format 16-channel Hamamatsu silicon photomultiplier device for use as the light sensor for the electromagnetic calorimeters in the Muon g-2 experiment at Fermilab. The calorimeter absorber is an array of lead-fluoride crystals, which produces short-duration Cherenkov light. The detector sits in the high magnetic field of the muon storage ring. The SiPMs selected, and their accompanying custom electronics, must preserve the short pulse shape, have high quantum efficiency, be non-magnetic, exhibit gain stability under varying rate conditions, and cover a fairly large fraction of the crystal exit surface area. We describe an optimized design that employs the new-generation of thru-silicon via devices. The performance is documented in a series of bench and beam tests.

  9. Purification and crystallization of the yeast translation elongation factor eEF3

    DEFF Research Database (Denmark)

    Andersen, Christian Folsted; Anand, Monika; Boesen, Thomas

    2004-01-01

    A Saccharomyces cerevisiae strain expressing full-length histidine-tagged translation elongation factor 3 (eEF3) as the only form of the protein facilitated purification of the factor for both structural and functional studies. Additionally, an identical full-length form has been successfully...

  10. A laboratory investigation on the influence of adsorbed gases and particles from the exhaust of a kerosene burner on the evaporation rate of ice crystals and the ice nucleating ability of the exhaust particles

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, K.; Mitra, S.K.; Pruppacher, H.R. [Johannes Gutenberg Univ., Mainz (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    Laboratory experiments are described during which the influence of the exhausts of a kerosene burner on microphysical processes were studied. In one experimental investigation the evaporation rates of polluted ice crystals were compared with the evaporation rates of pure ice crystals. During another experimental investigation the ice nucleating ability of the exhaust particles was studied. The results show that the evaporation rate of polluted ice crystals was significantly reduced and also that ice nucleation takes place between -20 and -38 deg C. (author) 7 refs.

  11. A discrete-time two-factor model for pricing bonds and interest rate derivatives under random volatility

    OpenAIRE

    Heston, Steven L.; Nandi, Saikat

    1999-01-01

    This paper develops a discrete-time two-factor model of interest rates with analytical solutions for bonds and many interest rate derivatives when the volatility of the short rate follows a GARCH process that can be correlated with the level of the short rate itself. Besides bond and bond futures, the model yields analytical solutions for prices of European options on discount bonds (and futures) as well as other interest rate derivatives such as caps, floors, average rate options, yield curv...

  12. The Effects of Hospital-Level Factors on Patients' Ratings of Physician Communication.

    Science.gov (United States)

    Al-Amin, Mona; Makarem, Suzanne C

    2016-01-01

    The quality of physician-patient communication influences patient health outcomes and satisfaction with healthcare delivery. Yet, little is known about contextual factors that influence physicians' communication with their patients. The main purpose of this article is to examine organizational-level factors that influence patient perceptions of physician communication in inpatient settings. We used the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey and American Hospital Association data to determine patients' ratings of physician communication at the hospital level, and to collect information about hospital-level factors that can potentially influence physician communication. Our sample consisted of 2,756 hospitals. We ran a regression analysis to determine the predictors of poor physician communication, measured as the percentage of patients in a hospital who reported that physicians sometimes or never communicated well. In our sample of hospitals, this percentage ranged between 0% and 21%, with 25% of hospitals receiving poor ratings from more than 6% of patients. Three organizational factors had statistically significant negative associations with physician communication: for-profit ownership, hospital size, and hospitalists providing care in the hospital, On the other hand, the number of full-time-equivalent physicians and dentists per 10,000 inpatient days, physician ownership of the hospital, Medicare share of inpatient days, and public ownership were positively associated with patients' ratings of physician communication. Physician staffing levels are an understudied area in healthcare research. Our findings indicate that physician staffing levels affect the quality of physician communication with patients. Moreover, for-profit and larger hospitals should invest more in physician communication given the role that HCAHPS plays in value-based purchasing.

  13. Rates and risk factors of injury in CrossFitTM: a prospective cohort study.

    Science.gov (United States)

    Moran, Sebastian; Booker, Harry; Staines, Jacob; Williams, Sean

    2017-09-01

    CrossFitTM is a strength and conditioning program that has gained widespread popularity since its inception approximately 15 years ago. However, at present little is known about the level of injury risk associated with this form of training. Movement competency, assessed using the Functional Movement ScreenTM (FMS), has been identified as a risk factor for injury in numerous athletic populations, but its role in CrossFit participants is currently unclear. The aim of this study was to evaluate the level of injury risk associated with CrossFit training, and examine the influence of a number of potential risk factors (including movement competency). A cohort of 117 CrossFit participants were followed prospectively for 12 weeks. Participants' characteristics, previous injury history and training experience were recorded at baseline, and an FMS assessment was conducted. The overall injury incidence rate was 2.10 per 1000 training hours (90% confidence limits: 1.32-3.33). A multivariate Poisson regression model identified males (rate ratio [RR]: 4.44 ×/÷ 3.30, very likely harmful) and those with previous injuries (RR: 2.35 ×/÷ 2.37, likely harmful) as having a higher injury risk. Inferences relating to FMS variables were unclear in the multivariate model, although number of asymmetries was a clear risk factor in a univariate model (RR per two additional asymmetries: 2.62 ×/÷ 1.53, likely harmful). The injury incidence rate associated with CrossFit training was low, and comparable to other forms of recreational fitness activities. Previous injury and gender were identified as risk factors for injury, whilst the role of movement competency in this setting warrants further investigation.

  14. [Morbidity rate of obesity in children in ukraine. Overweight as noncontagious disease risk factor].

    Science.gov (United States)

    Заболотна, Ірина Е

    The upsurge of prevalence rate of obesity and overweight that in the majority of cases traces back to childhood is a risk factor of the most common noncontagious diseases in adults. The aim was to analyze prevalence of obesity in children in Ukraine and to conduct the pilot study of medical condition of overweight children. Official state statistics of prevalence rate of obesity in kids and screening data of anthropometric characteristics, arterial tension levels, physical performance decrement and medical condition of children (boys - 50, girls - 90, average age - 15,1±0,1 years) was used in research. Data calculation performed by Statistica v. 6.0 software. Over the past few decades, the morbidity rate of obesity in children in Ukraine has greatly increased, especially in year class 15-17. Insufficient diagnosis of obesity in children is the consequence of the inadequacy of the existing system of preventive care and monitoring survey of decease risk factors. Children with body mass index (BMI) above normal have a risk of work decrement in 5,2 times (odds ratio, OR=5,2, CI95%: 1,7-10,6). Such children have higher risk of development of the diseases of the respiratory system (OR=8,1; CI95%: 3,9-13,6) and allergic dermatitis (OR=7,7; CI95%: 3,7-12,9). The odds ratio of arterial hypertension in such children is equal to 3,46±0,3 (95%CI: 2,0-5,9). According to prediction calculations, the situation with the increase of prevalence rate of obesity in children in Ukraine is unfavorable. The introduction of measures aimed at finding children with obesity, their registration and monitoring of patients' health with due regard to decease risk factors at the primary care level would conduce to improving prevention of obesity and prevention of alimentary diseases progression.

  15. Stratification of surgical site infection by operative factors and comparison of infection rates after hernia repair.

    Science.gov (United States)

    Olsen, Margaret A; Nickel, Katelin B; Wallace, Anna E; Mines, Daniel; Fraser, Victoria J; Warren, David K

    2015-03-01

    To investigate whether operative factors are associated with risk of surgical site infection (SSI) after hernia repair. Retrospective cohort study. Patients Commercially insured enrollees aged 6 months-64 years with International Classification of Diseases, Ninth Revision, Clinical Modification procedure or Current Procedural Terminology, fourth edition, codes for inguinal/femoral, umbilical, and incisional/ventral hernia repair procedures from January 1, 2004, through December 31, 2010. SSIs within 90 days after hernia repair were identified by diagnosis codes. The χ2 and Fisher exact tests were used to compare SSI incidence by operative factors. A total of 119,973 hernia repair procedures were analyzed. The incidence of SSI differed significantly by anatomic site, with rates of 0.45% (352/77,666) for inguinal/femoral, 1.16% (288/24,917) for umbilical, and 4.11% (715/17,390) for incisional/ventral hernia repair. Within anatomic sites, the incidence of SSI was significantly higher for open versus laparoscopic inguinal/femoral (0.48% [295/61,142] vs 0.34% [57/16,524], P=.020) and incisional/ventral (4.20% [701/16,699] vs 2.03% [14/691], P=.005) hernia repairs. The rate of SSI was higher following procedures with bowel obstruction/necrosis than procedures without obstruction/necrosis for open inguinal/femoral (0.89% [48/5,422] vs 0.44% [247/55,720], P<.001) and umbilical (1.57% [131/8,355] vs 0.95% [157/16,562], P<.001), but not incisional/ventral hernia repair (4.01% [224/5,585] vs 4.16% [491/11,805], P=.645). The incidence of SSI was highest after open procedures, incisional/ventral repairs, and hernia repairs with bowel obstruction/necrosis. Stratification of hernia repair SSI rates by some operative factors may facilitate accurate comparison of SSI rates between facilities.

  16. Factor structure of Bech's version of the Brief Psychiatric Rating Scale in Brazilian patients

    Directory of Open Access Journals (Sweden)

    J.A.S. Crippa

    2002-10-01

    Full Text Available The objective of the present study was to evaluate the factor structure of Bech's version of the Brief Psychiatric Rating Scale (BPRS, translated into Portuguese. The BPRS was administered to a heterogeneous group of psychiatric inpatients (N = 98 and outpatients (N = 62 in a University Hospital. Each patient was evaluated from one to eight times. The interval between consecutive interviews was one week for the inpatients and one month for the outpatients. The results were submitted to factorial analysis. The internal consistency of the total scale and of each factor was also estimated. Factorial analysis followed by normalized orthogonal rotation (Varimax yielded four factors: Withdrawal-Retardation, Thinking Disorder, Anxious-Depression and Activation. Internal consistency measured by Cronbach's alpha coefficient ranged from 0.766 to 0.879. The data show that the factor structure of the present instrument is similar to that of the American version of the BPRS which contains 18 items, except for the absence of the fifth factor of the latter scale, Hostile-Suspiciousness.

  17. Structure factors for tunneling ionization rates of molecules: General Hartree-Fock-based integral representation

    Science.gov (United States)

    Madsen, Lars Bojer; Jensen, Frank; Dnestryan, Andrey I.; Tolstikhin, Oleg I.

    2017-07-01

    In the leading-order approximation of the weak-field asymptotic theory (WFAT), the dependence of the tunneling ionization rate of a molecule in an electric field on its orientation with respect to the field is determined by the structure factor of the ionizing molecular orbital. The WFAT yields an expression for the structure factor in terms of a local property of the orbital in the asymptotic region. However, in general quantum chemistry approaches molecular orbitals are expanded in a Gaussian basis which does not reproduce their asymptotic behavior correctly. This hinders the application of the WFAT to polyatomic molecules, which are attracting increasing interest in strong-field physics. Recently, an integral-equation approach to the WFAT for tunneling ionization of one electron from an arbitrary potential has been developed. The structure factor is expressed in an integral form as a matrix element involving the ionizing orbital. The integral is not sensitive to the asymptotic behavior of the orbital, which resolves the difficulty mentioned above. Here, we extend the integral representation for the structure factor to many-electron systems treated within the Hartree-Fock method and show how it can be implemented on the basis of standard quantum chemistry software packages. We validate the methodology by considering noble-gas atoms and the CO molecule, for which accurate structure factors exist in the literature. We also present benchmark results for CO2 and for NH3 in the pyramidal and planar geometries.

  18. Influence of Four Factors on Discharge Capacity and Self-Discharge Rate of Iron Electrode

    Institute of Scientific and Technical Information of China (English)

    Dongfeng LIN; Shihai YE; Rong CAI; Deying SONG; Panwen SHEN

    2003-01-01

    Ni-Fe rechargeable batteries possess the advantages of long cycle life, high theoretical specific energy, abundant raw material,Iow price and environmental friendship. It has a wide applied perspective. The advantages, disadvantages and preparation methods of iron electrodes were summarized. The influence of four factors on discharge capacity and self-discharge rate of iron electrode were discussed by means of orthogonal experiments, galvanostatic charges and discharges. The influences of graphite on the discharge capacity and self-discharge rate of iron electrode were the most remarkable, the most unapparent influences on the discharge capacity and self-discharge rate were HPMC (hydroxy propoxy methoxy cellulose) and sodium sulphide, respectively. The aim of the present research was to study the effects of graphite, HPMC and iron powder added in the electrodes, sodium sulphide added in the electrolytes on the discharge capacity and self-discharge rate of iron electrodes.The largest discharge capacity of the iron electrodes was 488.5 mAh/g-Fe at 66.4 mA/g-Fe in the first ten cycles, and the average self-discharge rate was 0.367% per hour.

  19. Preferred Barefoot Step Frequency is Influenced by Factors Beyond Minimizing Metabolic Rate

    Science.gov (United States)

    Yandell, Matthew B.; Zelik, Karl E.

    2016-03-01

    Humans tend to increase their step frequency in barefoot walking, as compared to shod walking at the same speed. Based on prior studies and the energy minimization hypothesis we predicted that people make this adjustment to minimize metabolic cost. We performed an experiment quantifying barefoot walking metabolic rate at different step frequencies, specifically comparing preferred barefoot to preferred shod step frequency. We found that subjects increased their preferred frequency when walking barefoot at 1.4 m/s (~123 vs. ~117 steps/min shod, P = 2e-5). However, average barefoot walking metabolic rates at the preferred barefoot and shod step frequencies were not significantly different (P = 0.40). Instead, we observed subject-specific trends: five subjects consistently reduced (‑8% average), and three subjects consistently increased (+10% average) their metabolic rate at preferred barefoot vs. preferred shod frequency. Thus, it does not appear that people ubiquitously select a barefoot step frequency that minimizes metabolic rate. We concluded that preferred barefoot step frequency is influenced by factors beyond minimizing metabolic rate, such as shoe properties and/or perceived comfort. Our results highlight the subject-specific nature of locomotor adaptations and how averaging data across subjects may obscure meaningful trends. Alternative experimental designs may be needed to better understand individual adaptations.

  20. [The effect of assertiveness training on communication related factors and personnel turnover rate among hospital nurses].

    Science.gov (United States)

    Kang, Myung Ja; Lee, Haejung

    2006-08-01

    The purpose of this study was to investigate the effects of assertiveness training on nurses' assertive behaviors, interpersonal relations, communication conflicts, conflict management style and personnel turnover rate. A non-equivalent control group pretest-posttest design was used in this study. Nurses were assigned into the experimental or control groups, each consisting of 39 nurses. Data was collected between January to March 2004. An 'Assertiveness Training Program' for Nurses developed by Park was used for the study. To emphasize assertiveness practice, 5 practice sessions utilizing ABCDE principles were added to Park's program. To examine the effects of the program, differences between the two groups in assertive behaviors, interpersonal relations, communication conflicts, conflict management style and personnel turnover rate were analyzed using ANCOVA. The assertiveness training was effective in improving the nurses' assertiveness behaviors, but was not effective in improving interpersonal relations, reducing the subjects' communication conflicts, changing the conflict management style or reducing their personnel turnover rate. There have been many studies about factors affecting nurses' personnel turnover rates, but few have been done about methods of intervention to reduce the personnel turnover rate. Thus, this study provides a significant contribution in attempting such an intervention from nursing management perspectives.

  1. VOC emission rates and emission factors for a sheetfed offset printing shop.

    Science.gov (United States)

    Wadden, R A; Scheff, P A; Franke, J E; Conroy, L M; Javor, M; Keil, C B; Milz, S A

    1995-04-01

    Emission rates were determined during production for a sheetfed offset printing shop by combining the measured concentrations and ventilation rates with mass balance models that characterized the printing space. Air samples were collected simultaneously on charcoal tubes for 12 separate 1-hour periods at 6 locations. Air samples and cleaning solvents were analyzed by gas chromatography for total volatile organic compounds (VOC) and 13 hydrocarbons. The average VOC emission rate was 470 g/hr with a range of 160-1100 g/hr. These values were in good agreement with the amounts of VOC, hexane, toluene, and aromatic C9s determined from estimated solvent usage and measured solvent compositions. Comparison of the emission rates with source activities indicated an emission factor of 30-51 g VOC/press cleaning. Based on the test observations it was estimated that this typical small printing facility was likely to release 1-2 T VOC/year. The methodology also may be useful for the surface coating industry, as emission rates in this study were determined without recourse to a temporary total enclosure and without interfering with worker activities, increasing worker exposure, or increasing safety and explosion hazards.

  2. Simultaneous field estimates of urea hydrolysis rates and ammonium retardation factors in a fractured rock aquifer

    Science.gov (United States)

    Smith, R. W.; Taylor, J. L.; Fujita, Y.

    2005-12-01

    Knowledge of the rates of in situ biogeochemical processes is critical to the design and implementation of active and passive environmental remediation strategies. However, often rate determinations require the collection of samples in the field followed by laboratory studies that may occur days or weeks later. Artificial laboratory conditions as well as sample storage effects can lead to erroneous conclusions regarding kinetic processes in nature. We have been investigating in field and laboratory studies the microbial hydrolysis of urea as a method to facilitate calcium carbonate precipitation and co-precipitation of divalent metal and radionuclide contaminants (such as 90Sr). In conjunction with a single well "push-pull" test conducted in a fractured basalt aquifer near the Idaho National Laboratory, in situ rates of urea hydrolysis were estimated by tracking the disappearance of urea and a conservative tracer and measuring the increase in ammonium concentration. The analysis of rates was complicated by cation exchange reactions of ammonium with the aquifer matrix. However, we were able to derive and parameterize a rate law that explicitly included a retardation factor. With this approach, we are able to characterize in situ ureolysis kinetics without resorting to laboratory studies.

  3. Stroke in young adults: Incidence rate, risk factors, treatment and prognosis.

    Science.gov (United States)

    González-Gómez, F J; Pérez-Torre, P; DeFelipe, A; Vera, R; Matute, C; Cruz-Culebras, A; Álvarez-Velasco, R; Masjuan, J

    2016-10-01

    To analyse the incidence, risk factors, aetiology, treatment and clinical evolution of young patients with stroke. Retrospective registry of patients aged 55 years or younger hospitalised in a stroke unit during 2014. We recorded the incidence rate for all strokes and analysed demographic data, risk factors, degree of stress, stroke type and aetiology, reperfusion treatments and clinical evolution. The study included 110 patients, the majority of whom were men (60.9%, 1.6:1 ratio). The incidence rate was 13.3% (110 of 830 strokes). Most of the patients had cardiovascular risk factors. Smoking was the most common risk factor (56.4%), followed by arterial hypertension (50%), dyslipidaemia (42.7%), obesity (33%), diabetes (18.2%) and emboligenic heart disease (12.7%). Some 64.3% of the heart disease cases and 51.1% of the dyslipidaemia cases were discovered during hospitalisation. Some 57.2% of the patients experienced psychosocial stress in the stage prior to the stroke. Some 83.6% of the stroke cases were ischaemic, 12.7% were haemorrhagic and 3.6% were venous sinus thrombosis. Of the ischaemic stroke cases, 30.4% were cryptogenic, 23.9% were lacunar, 16.3% were from uncommon causes, 15.2% were atherothrombotic and 14.1% were cardioembolic. Some 78.6% of the cerebral haemorrhage cases were hypertensive. Some 23.3% of the ischaemic stroke cases underwent reperfusion treatments in the acute phase, achieving levels of functional independence at 3 months of 62.5%. The majority of stroke events in patients 55 years of age or younger appear to be related to a high prevalence of classical cardiovascular risk factors and possibly to psychosocial stress. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

  4. Factors associated with self-rated health in older people living in institutions

    Directory of Open Access Journals (Sweden)

    Pastor-Barriuso Roberto

    2008-02-01

    Full Text Available Abstract Background Although self-rated health has been extensively studied in community older people, its determinants have seldom been investigated in institutional settings. We carried out a cross-sectional study to describe the physical, mental, and social factors associated with self-rated health in nursing homes and other geriatric facilities. Methods A representative sample of 800 subjects 65 years of age and older living in 19 public and 30 private institutions of Madrid was randomly selected through stratified cluster sampling. Residents, caregivers, physicians, and nurses were interviewed by trained geriatricians using standardized instruments to assess self-rated health, chronic illnesses, functional capacity, cognitive status, depressive symptoms, vision and hearing problems, and social support. Results Of the 669 interviewed residents (response rate 84%, 55% rated their health as good or very good. There was no association with sex or age. Residents in private facilities and those who completed primary education had significantly better health perception. The adjusted odds ratio (95% confidence interval for worse health perception was 1.18 (1.07–1.28 for each additional chronic condition, 2.37 (1.38–4.06 when comparing residents with moderate dependency to those functionally independent, and 10.45 (5.84–18.68 when comparing residents with moderate/severe depressive symptoms to those without symptoms. Visual problems were also associated with worse health perception. Similar results were obtained in subgroup analyses, except for inconsistencies in cognitively impaired individuals. Conclusion Chronic conditions, functional status, depressive symptoms and socioeconomic factors were the main determinants of perceived health among Spanish institutionalized elderly persons. Doubts remain about the proper assessment of subjective health in residents with altered cognition.

  5. Factors which influence directional coarsening of Gamma prime during creep in nickel-base superalloy single crystals

    Science.gov (United States)

    Mackay, R. A.; Ebert, L. J.

    1984-01-01

    Changes in the morphology of the gamma prime precipitate were examined as a function of time during creep at 982 C in 001 oriented single crystals of a Ni-Al-Mo-Ta superalloy. In this alloy, which has a large negative misfit of -0.80 pct., the gamma prime particles link together during creep to form platelets, or rafts, which are aligned with their broad faces perpendicular to the applied tensile axis. The effects of initial microstructure and alloy composition of raft development and creep properties were investigated. Directional coarsening of gamma prime begins during primary creep and continues well after the onset of second state creep. The thickness of the rafts remains constant up through the onset of tertiary creep a clear indication of the stability of the finely-spaced gamma/gamma prime lamellar structure. The thickness of the rafts which formed was equal to the initial gamma prime size which was present prior to testing. The single crystals with the finest gamma prime size exhibited the longest creep lives, because the resultant rafted structure had a larger number of gamma/gamma prime interfaces per unit volume of material. Reducing the Mo content by only 0.73 wt. pct. increased the creep life by a factor of three, because the precipitation of a third phase was eliminated.

  6. Factors which influence directional coarsening of gamma-prime during creep in nickel-base superalloy single crystals

    Science.gov (United States)

    Mackay, R. A.; Ebert, L. J.

    1984-01-01

    Changes in the morphology of the gamma prime precipitate were examined as a function of the time during creep at 982 C in 001 oriented single crystals of a Ni-Al-Mo-Ta superalloy. In this alloy, which has a large negative misfit of -0.80 pct., the gamma prime particles link together during creep to form platelets, or rafts, which are aligned with their broad faces perpendicular to the applied tensile axis. The effects of initial microstructure and alloy composition of raft development and creep properties were investigated. Directional coarsening of gamma prime begins during primary creep and continues well after the onset of second state creep. The thickness of the rafts remains constant up through the onset of tertiary creep, a clear indication of the stability of the finely-spaced gamma/gamma prime lamellar structure. The thickness of the rafts which formed was equal to the initial gamma prime size which was present prior to testing. The single crystals with the finest gamma prime size exhibited the longest creep lives, because the resultant rafted structure had a larger number of gamma/gamma prime interfaces per unit volume of material. Reducing the Mo content by only 0.73 wt. pct. increased the creep life by a factor of three, because the precipitation of a third phase was eliminated.

  7. Purification, crystallization and X-ray crystallographic studies of a Bacillus cereus MepR-like transcription factor, BC0657.

    Science.gov (United States)

    Cho, Min Uk; Kim, Meong Il; Hong, Minsun

    2015-06-01

    Transcription factors of the MarR family respond to internal and external changes and regulate a variety of biological functions through ligand association with microorganisms. MepR belongs to the MarR family, and its mutations are associated with the development of multidrug resistance in Staphylococcus aureus, which has caused a growing health problem. In this study, a Bacillus cereus MepR-like transcription regulator, BC0657, was crystallized. The BC0657 crystals diffracted to 2.05 Å resolution and belonged to either space group P6(2)22 or P6(4)22, with unit-cell parameters a = 110.57, b = 110.57, c = 67.29 Å. There was one molecule per asymmetric unit. Future comparative structural studies on BC0657 would extend knowledge of ligand-induced transcriptional regulatory mechanisms in the MarR family and would make a significant contribution to the design of antibiotic drugs against multidrug-resistant bacteria.

  8. High heart rate: more than a risk factor. Lessons from a clinical practice survey.

    Science.gov (United States)

    Barrios, Vivencio; Escobar, Carlos; Bertomeu, Vicente; Murga, Nekane; de Pablo, Carmen; Asín, Enrique

    2009-11-12

    Several epidemiological studies have reported that an elevated heart rate (HR) is associated with coronary atherosclerosis independently of other risk factors. Nevertheless, it is still unclear whether HR is itself the cause or there is merely an association between HR and mortality in this population. A total of 1686 patients with hypertension and chronic ischemic heart disease were included in this study. According to the resting HR, the patients were distributed in 3 groups (group 1: HR82 bpm). 580 patients (34.4%) belonged to group 1; 936 (55.5%) to group 2 and 170 (10.1%) to group 3. Patients with high HR exhibited a poorer prognosis not only due to a worse clinical profile (more concomitant cardiovascular risk factors and organ damage), but suggestively because despite the use of a similar number of drugs, patients with higher HR were associated with lesser risk control rates in daily clinical practice. Despite current guidelines that do not still recognize HR as a cardiovascular risk factor, it appears that physicians should pay more attention to it in clinical practice since high HR is warning about an increased risk.

  9. Rate of Utilization of Skilled Birth Attendant and the Influencing Factors in an Urban Myanmar Population.

    Science.gov (United States)

    Chamroonsawasdi, Kanittha; Soe, Malar; Charupoonphol, Phitaya; Srisorrachatr, Suwat

    2015-07-01

    A survey study aimed at identifying rates and predictive factors on utilization of skilled birth attendant (SBA) among pregnant women. A stratified random sampling technique was used to select 200 Myanmar women aged 18 to 49 years in Kalay Township. Data were collected by interview questionnaire from March 1 to 15, 2012, and data were analyzed by frequency, percentage, mean and standard deviation, χ(2) test, and multiple logistic regression analysis. The utilization rate of SBA was 74%. Factors significantly predicting utilization of SBA (P utilized SBA 2.7 times more than those who had a poor level of knowledge (odds ratio = 2.705, 95% confidence interval = 1.31-5.57). The women who had a positive attitude toward SBA utilized SBA 7.7 times more than those who had a negative attitude (odds ratio = 7.708, 95% confidence interval = 3.71-15.98). The women who had high accessibility to MCH services utilized SBA 1.4 times more than those who had low accessibility (odds ratio = 1.477, 95% confidence interval = 1.05-2.21). These factors were able to correctly predict utilization of SBA at 74.9%. MCH knowledge and information on utilization of SBA should be strengthened during every antenatal care visit to enhance positive attitude on utilization of SBA and to increase accessibility to MCH services by providing community antenatal care or home visits. © 2015 APJPH.

  10. Choosing Surgery: Identifying Factors Leading to Increased General Surgery Matriculation Rate.

    Science.gov (United States)

    Pointer, David T; Freeman, Matthew D; Korndorffer, James R; Meade, Peter C; Jaffe, Bernard M; Slakey, Douglas P

    2017-03-01

    Tulane graduates have, over the past six years, chosen general surgical residency at a rate above the national average (mean 9.6% vs 6.6%). With much of the recent career choice research focusing on disincentives and declining general surgery applicants, we sought to identify factors that positively influenced our students' decision to pursue general surgery. A 50-question survey was developed and distributed to graduates who matched into a general surgery between the years 2006 and 2014. The survey evaluated demographics, exposure to surgery, and factors affecting interest in a surgical career. We achieved a 54 per cent (61/112) response rate. Only 43 per cent considered a surgical career before medical school matriculation. Fifty-nine per cent had strongly considered a career other than surgery. Sixty-two per cent chose to pursue surgery during or immediately after their surgery clerkship. The most important factors cited for choosing general surgery were perceived career enjoyment of residents and faculty, resident/faculty relationship, and mentorship. Surgery residents and faculty were viewed as role models by 72 and 77 per cent of responders, respectively. This study demonstrated almost half of those choosing a surgical career did so as a direct result of the core rotation experience. We believe that structuring the medical student education experience to optimize the interaction of students, residents, and faculty produces a positive environment encouraging students to choose a general surgery career.

  11. Conflicts at work--the relationship with workplace factors, work characteristics and self-rated health.

    Science.gov (United States)

    Oxenstierna, Gabriel; Magnusson Hanson, Linda L; Widmark, Maria; Finnholm, Kristina; Stenfors, Cecilia; Elofsson, Stig; Theorell, Töres

    2011-01-01

    Few studies have considered the work environment in relation to workplace conflicts and those who have been published have included relatively few psychosocial work environment factors. Little research has been published on the consequences of workplace conflicts in terms of employee health. In this study, the statistical relationships between work and workplace characteristics on one hand and conflicts on the other hand are examined. In addition, the relationship between conflicts at work and self-rated health are described. The study population was derived from the Swedish Longitudinal Occupational Survey of Health (SLOSH) 2006; n=5,141. Among employees at workplaces with more than 20 employees (n=3,341), 1,126 (33.7%) responded that they had been involved in some type of conflict during the two years preceding the survey. Among the work and workplace characteristics studied, the following factors were independently associated with increased likelihood of ongoing conflicts: Conflicting demands, emotional demands, risk of transfer or dismissal, poor promotion prospects, high level of employee influence and good freedom of expression. Factors that decreased the likelihood of ongoing conflicts were: Good resources, good relations with management, good confidence in management, good procedural justice (fairness of decisions) and good social support. After adjustment for socioeconomic conditions the odds ratio for low self-rated health associated with ongoing conflict at work was 2.09 (1.60-2.74). The results provide a good starting point for intervention and prevention work.

  12. Oxygen Consumption by Postfermentation Wine Yeast Lees: Factors Affecting Its Rate and Extent under Oenological Conditions

    Directory of Open Access Journals (Sweden)

    Jonas Müller

    2016-01-01

    Full Text Available Postfermentation wine yeast lees show antioxidant properties based on their ability to consume dissolved oxygen. The oxygen consumption capacity of suspended yeast lees obtained after fermentations with six commercial active dry yeast strains was investigated in model, white and red wines using fluorescence-based oxygen sensors operating in a nondestructive way. In model solution, the oxygen consumption rate of yeast lees was shown to depend on their amount, yeast strain, sulfur dioxide and temperature. It is slightly lower in red than in white wines. It is strongly decreased by current levels of free sulfur dioxide, thus excluding the complementary use of both as antioxidants in wine. However, in 25 randomly sampled white wines produced under commercial conditions, the rate and extent of oxygen consumption during the first six months of postfermentation had no significant correlation with any of these interacting factors, making it difficult to predict the actual antioxidant effect of yeast lees. In these wines, yeast lees consumed 0 to 47 % of the dissolved oxygen. Although total oxygen consumption capacity of yeast lees is not a limiting factor under commercial winemaking conditions, their oxygen consumption proceeds at a limited rate that reduces but cannot totally prevent concomitant chemical oxidation of the wine.

  13. Oxygen Consumption by Postfermentation Wine Yeast Lees: Factors Affecting Its Rate and Extent under Oenological Conditions

    Science.gov (United States)

    Müller, Jonas; Schmidt, Dominik

    2016-01-01

    Summary Postfermentation wine yeast lees show antioxidant properties based on their ability to consume dissolved oxygen. The oxygen consumption capacity of suspended yeast lees obtained after fermentations with six commercial active dry yeast strains was investigated in model, white and red wines using fluorescence-based oxygen sensors operating in a nondestructive way. In model solution, the oxygen consumption rate of yeast lees was shown to depend on their amount, yeast strain, sulfur dioxide and temperature. It is slightly lower in red than in white wines. It is strongly decreased by current levels of free sulfur dioxide, thus excluding the complementary use of both as antioxidants in wine. However, in 25 randomly sampled white wines produced under commercial conditions, the rate and extent of oxygen consumption during the first six months of postfermentation had no significant correlation with any of these interacting factors, making it difficult to predict the actual antioxidant effect of yeast lees. In these wines, yeast lees consumed 0 to 47% of the dissolved oxygen. Although total oxygen consumption capacity of yeast lees is not a limiting factor under commercial winemaking conditions, their oxygen consumption proceeds at a limited rate that reduces but cannot totally prevent concomitant chemical oxidation of the wine. PMID:28115896

  14. A retrospective study on related factors affecting the survival rate of dental implants

    Science.gov (United States)

    Kang, Jeong-Kyung; Lee, Ki; Lee, Yong-Sang; Park, Pil-Kyoo

    2011-01-01

    PURPOSE The aim of this retrospective study is to analyze the relationship between local factors and survival rate of dental implant which had been installed and restored in Seoul Veterans Hospital dental center for past 10 years. And when the relationship is found out, it could be helpful to predict the prognosis of dental implants. MATERIALS AND METHODS A retrospective study of patients receiving root-shaped screw-type dental implants placed from January 2000 to December 2009 was conducted. 6385 implants were placed in 3755 patients. The following data were collected from the dental records and radiographs: patient's age, gender, implant type and surface, length, diameter, location of implant placement, bone quality, prosthesis type. The correlations between these data and survival rate were analyzed. Statistical analysis was performed with the use of Kaplan-Meier analysis, Chi-square test and odds ratio. RESULTS In all, 6385 implants were placed in 3755 patients (3120 male, 635 female; mean age 65 ± 10.58 years). 108 implants failed and the cumulative survival rate was 96.33%. There were significant differences in age, implant type and surface, length, location and prosthesis type (P.05). CONCLUSION Related factors such as age, implant type, length, location and prosthesis type had a significant effect on the implant survival. PMID:22259704

  15. Direct detection of transcription factors in cotyledons during seedling development using sensitive silicon-substrate photonic crystal protein arrays.

    Science.gov (United States)

    Jones, Sarah I; Tan, Yafang; Shamimuzzaman, Md; George, Sherine; Cunningham, Brian T; Vodkin, Lila

    2015-03-01

    Transcription factors control important gene networks, altering the expression of a wide variety of genes, including those of agronomic importance, despite often being expressed at low levels. Detecting transcription factor proteins is difficult, because current high-throughput methods may not be sensitive enough. One-dimensional, silicon-substrate photonic crystal (PC) arrays provide an alternative substrate for printing multiplexed protein microarrays that have greater sensitivity through an increased signal-to-noise ratio of the fluorescent signal compared with performing the same assay upon a traditional aminosilanized glass surface. As a model system to test proof of concept of the silicon-substrate PC arrays to directly detect rare proteins in crude plant extracts, we selected representatives of four different transcription factor families (zinc finger GATA, basic helix-loop-helix, BTF3/NAC [for basic transcription factor of the NAC family], and YABBY) that have increasing transcript levels during the stages of seedling cotyledon development. Antibodies to synthetic peptides representing the transcription factors were printed on both glass slides and silicon-substrate PC slides along with antibodies to abundant cotyledon proteins, seed lectin, and Kunitz trypsin inhibitor. The silicon-substrate PC arrays proved more sensitive than those performed on glass slides, detecting rare proteins that were below background on the glass slides. The zinc finger transcription factor was detected on the PC arrays in crude extracts of all stages of the seedling cotyledons, whereas YABBY seemed to be at the lower limit of their sensitivity. Interestingly, the basic helix-loop-helix and NAC proteins showed developmental profiles consistent with their transcript patterns, indicating proof of concept for detecting these low-abundance proteins in crude extracts.

  16. Effects of synthesis factors on the morphology, crystallinity and crystal size of hydroxyapatite precipitation

    Institute of Scientific and Technical Information of China (English)

    GUO Lian-feng; WANG Wei-hua; ZHANG Wen-guang; WANG Cheng-tao

    2005-01-01

    The growing necessity of biomaterials has increased the interest in hydroxyapatite. Small differences in particle sizes, stoichiometry, morphology, crystallinity could lead to different clinical behaviors. In the present work, stoichiometry and nanocrystal hydroxyapatite were prepared by wet chemical precipitation method.The effects of concentration of reagents, reaction temperatures and reaction time were studied. Transmission Electron Microscopy, Electron Diffraction, X - ray Diffraction, Fourier Transform Infrared Spectroscopy, and Inductively Coupled Plasma Spectroscopy were used to characterize the precipitated hydroxyapatite powders. X -ray Diffraction and TEM micrographs results showed that crystallinity, morphology and particle sizes were largely dependent on reaction temperature. Chemical analysis showed that the purity of the precipitated hydroxyapatite depends on reaction time and reaction temperature. Degree of supersaturation and stirring could affect the crystallization process. Particles showed acicular morphology, and had a size of 20 -30 nm in length at 20 ℃and 37 ℃ and 150 - 160 nm in length at 75 ℃. Particles were monocrystalline at 20 ℃ and 37 ℃, and were polycrystalline at 55 ℃ and 75 ℃. The results showed that hydroxyapatite powders with different particle size and morphology could be obtained with carefully controlled reaction conditions.

  17. Crystal Structure and Activity of the Endoribonuclease Domain of the piRNA Pathway Factor Maelstrom

    Directory of Open Access Journals (Sweden)

    Naoki Matsumoto

    2015-04-01

    Full Text Available PIWI-interacting RNAs (piRNAs protect the genome from transposons in animal gonads. Maelstrom (Mael is an evolutionarily conserved protein, composed of a high-mobility group (HMG domain and a MAEL domain, and is essential for piRNA-mediated transcriptional transposon silencing in various species, such as Drosophila and mice. However, its structure and biochemical function have remained elusive. Here, we report the crystal structure of the MAEL domain from Drosophila melanogaster Mael, at 1.6 Å resolution. The structure reveals that the MAEL domain has an RNase H-like fold but lacks canonical catalytic residues conserved among RNase H-like superfamily nucleases. Our biochemical analyses reveal that the MAEL domain exhibits single-stranded RNA (ssRNA-specific endonuclease activity. Our cell-based analyses further indicate that ssRNA cleavage activity appears dispensable for piRNA-mediated transcriptional transposon silencing in Drosophila. Our findings provide clues toward understanding the multiple roles of Mael in the piRNA pathway.

  18. Single-crystal sapphire resonator at millikelvin temperatures: Observation of thermal bistability in high- Q factor whispering gallery modes

    Science.gov (United States)

    Creedon, Daniel L.; Tobar, Michael E.; Le Floch, Jean-Michel; Reshitnyk, Yarema; Duty, Timothy

    2010-09-01

    Resonance modes in single crystal sapphire (α-Al2O3) exhibit extremely high electrical and mechanical Q factors ( ≈109 at 4 K), which are important characteristics for electromechanical experiments at the quantum limit. We report the cool down of a bulk sapphire sample below superfluid liquid-helium temperature (1.6 K) to as low as 25 mK. The electromagnetic properties were characterized at microwave frequencies, and we report the observation of electromagnetically induced thermal bistability in whispering gallery modes due to the material T3 dependence on thermal conductivity and the ultralow dielectric loss tangent. We identify “magic temperatures” between 80 and 2100 mK, the lowest ever measured, at which the onset of bistability is suppressed and the frequency-temperature dependence is annulled. These phenomena at low temperatures make sapphire suitable for quantum metrology and ultrastable clock applications, including the possible realization of the quantum-limited sapphire clock.

  19. Electrically tunable high Q-factor micro-ring resonator based on blue phase liquid crystal cladding.

    Science.gov (United States)

    Wang, Chun-Ta; Li, Yuan-Cheng; Yu, Jui-Hao; Wang, Cheng Yu; Tseng, Chih-Wei; Jau, Hung-Chang; Chen, Yung-Jui; Lin, Tsung-Hsien

    2014-07-28

    This work demonstrates an electrically tunable silicon nitride (SiN) micro-ring resonator with polymer-stabilized blue phase liquid crystals (PSBPLCs) cladding. An external vertical electric field is applied to modulate the refractive index of the PSBPLCs by exploiting its fast-response Kerr effect-induced birefringence. The consequent change in the refractive index of the cladding can vary the effective refractive index of the micro-ring resonator and shift the resonant wavelength. Crystalline structures of PSBPLCs with a scale of the order of hundreds of nanometers ensure that the resonator has a very low optical loss. The measured tuning range is 0.45 nm for TM polarized light under an applied voltage of 150V and the corresponding response time is in the sub-millisecond range with a Q-factor of greater than 20,000.

  20. High quality factor and high sensitivity chalcogenide 1D photonic crystal microbridge cavity for mid-infrared sensing

    Science.gov (United States)

    Xu, Peipeng; Yu, Zenghui; Shen, Xiang; Dai, Shixun

    2017-01-01

    We present and theoretically investigate a mid-infrared (mid-IR) optical sensor based on a Ge11.5As24Se64.5 one-dimensional photonic crystal microbridge cavity (PhC-MC). Optimizing the structure of the PhC-MC strongly confines the resonant mode field to the air region, thereby greatly enhancing the overlap and interaction of the light field and target analytes. A high calculated sensitivity (2280 nm per refractive index unit) is achieved with a resonant wavelength of 4132 nm. The figure of merit of the device for sensing is extremely high (929,750) because of the high quality factor and sensitivity of the cavity. The sensing part of the cavity is also small (50×3 μm2). The proposed PhC-MC can be an ideal platform for on-chip integrated mid-IR optical sensing.

  1. More accurate determination of the quantity of ice crystallized at low cooling rates in the glycerol and 1,2-propanediol aqueous solutions: comparison with equilibrium.

    Science.gov (United States)

    Boutron, P

    1984-04-01

    It is generally assumed that when cells are cooled at rates close to those corresponding to the maximum of survival, once supercooling has ceased, above the eutectic melting temperature the extracellular ice is in equilibrium with the residual solution. This did not seem evident to us due to the difficulty of ice crystallization in cryoprotective solutions. The maximum quantities of ice crystallized in glycerol and 1,2-propanediol solutions have been calculated from the area of the solidification and fusion peaks obtained with a Perkin-Elmer DSC-2 differential scanning calorimeter. The accuracy has been improved by several corrections: better defined baseline, thermal variation of the heat of fusion of the ice, heat of solution of the water from its melting with the residual solution. More ice crystallizes in the glycerol than in the 1,2-propanediol solutions, of which the amorphous residue contains about 40 to 55% 1,2-propanediol. The equilibrium values are unknown in the presence of 1,2-propanediol. With glycerol, in our experiments, the maximum is first lower than the equilibrium but approaches it as the concentration increases. It is not completely determined by the colligative properties of the solutes.

  2. Factors Affecting the Rate of Pediatric Pneumonia in Developing Countries: a Review and Literature Study

    Directory of Open Access Journals (Sweden)

    Monir Ramezani

    2015-12-01

    Full Text Available Introduction: Millions of children less than 5 years old die from pneumonia globally and about 75-70% of these deaths occur in infants. Persian and English articles of International and National databases such as “WHO, Scopus and the Cochrane, Pub Med, Science Direct, Wiley, Google Scholar, SID, Iran Medex, Magiran, Med Lib and Iran Doc were searched from 1970 to 2014. Result: The factors such as low birth weight, malnutrition, lack of breast feeding, micronutrient deficiencies, smoking tobacco, kindergarten and maternal education are the most important factors affecting the rate of pneumonia in developing countries. Conclusion: Actions such as nutritional interventions develop effective strategies on abstinence of smoking, promote the knowledge and practice of mothers about proper care of infants could have a significant effect on the reduction of morbidity and mortality of pneumonia in the infants.

  3. Probing the interplay between factors determining reaction rates on silica gel using termolecular systems.

    Science.gov (United States)

    Kirkpatrick, Iain; Worrall, David R; Williams, Siân L; Buck, Craig J T; Meseguer, Rafael G

    2012-10-01

    In this study we have compared energy and electron transfer reactions in termolecular systems using a nanosecond diffuse reflectance laser flash photolysis technique. We have previously investigated these processes on silica gel surfaces for bimolecular systems and electron transfer in termolecular systems. The latter systems involved electron transfer between three arene molecules with azulene acting as a molecular shuttle. In this study we present an alternative electron transfer system using trans β-carotene as an electron donor in order to effectively immobilise all species except the shuttle, providing the first unambiguous evidence for radical ion mobility. In the energy transfer system we use naphthalene, a structural isomer of azulene, as the shuttle, facilitating energy transfer from a selectively excited benzophenone sensitiser to 9-cyanoanthracene. Bimolecular rate constants for all of these processes have been measured and new insights into the factors determining the rates of these reactions on silica gel have been obtained.

  4. Factors influencing the family consent rate for organ donation in the UK.

    Science.gov (United States)

    Hulme, W; Allen, J; Manara, A R; Murphy, P G; Gardiner, D; Poppitt, E

    2016-09-01

    The refusal rate for organ donation in the UK is 42%, among the highest in Europe. We extracted data on every family approach for donation in UK ICUs or Emergency Departments between 1st April 2012 and 30th September 2013, and performed multiple logistic regression to identify modifiable factors associated with consent. Complete data were available for 4703 of 4899 approaches during the study period. Consent for donation after brain death was 68.9%, and for donation after circulatory death 56.5% (p donation in the approach were strongly associated with consent (p donation after circulatory death than for donation after brain death, even after accounting for the impact of prior knowledge of patients' wishes. Involvement of the specialist nurse in the approach, encouraging family discussions about donation wishes and promotion of the organ donor register are key strategies to increase UK consent rates, and are supported by this study.

  5. Longitudinal dating violence victimization among Latino teens: Rates, risk factors, and cultural influences.

    Science.gov (United States)

    Sabina, Chiara; Cuevas, Carlos A; Cotignola-Pickens, Heather M

    2016-02-01

    This study uses data from two waves of the Dating Violence Among Latino Adolescents (DAVILA) study and focuses on the 1) rates of dating violence victimization by gender, 2) risk of experiencing dating violence victimization over time, 3) association of dating violence victimization with other forms of victimization, and 4) association of immigrant status, acculturation, and familial support with dating violence victimization over time. A total of 547 Latino adolescents, from across the USA, aged 12-18 at Wave 1 participated in both waves of the study. Rates of dating violence were around 19% across waves. Dating violence at Wave 1 and non-dating violence victimization were associated with an elevated risk of dating violence during Wave 2. Cultural factors did not distinguish between dating violence trajectories, except for immigrant status and familial support being associated with no dating violence victimization. Overall, dating violence affects a large number of Latino teens and tends to continue over time.

  6. Recurrence rate of basal cell carcinoma with positive histopathological margins and related risk factors*

    Science.gov (United States)

    Lara, Fernanda; Santamaría, Jesus Rodriguez; Garbers, Luiz Eduardo Fabricio de Melo

    2017-01-01

    BACKGROUND The best way to approach surgically removed basal cell carcinoma with positive histopathological margins is a controversial issue. Some authors believe that the more appropriate treatment is an immediate reoperation while others prefer a periodic follow up. The rates of recurrence are variable in literature, between 10% and 67%. OBJECTIVE To define the recurrence rate of basal cell carcinoma with positive margins after surgery. Secondarily, identify morphological aspects that can suggest a more frequent tumoral recurrence. METHODS This was a retrospective and observational study made by analysis of medical records of 487 patients between January 2003 and December 2009 in Hospital de Clínicas da Universidade Federal do Paraná (HC-UFPR). From 402 basal cell carcinomas surgically treated, 41 fulfilled inclusion criteria and were evaluated for five years or more. Recurrence rate of these tumors was analyzed in all patients and clinical characteristics such as sex, age, tumor size, tumor site, ulceration, and histological type were evaluated in order to find if they were related to more common tumoral recurrence. RESULTS The rate of positive margins after surgery was 12.18%. There were five cases of tumoral recurrence in the observation group and three cases in the re-excision group. Tumor size, site, histological type, ulceration and type of positive margin did not differ statistically between groups. It was not possible to consider if these factors were important in recurrence rates. STUDY LIMITATIONS Ideally, a prospective study with a larger sample would be more accurate. CONCLUSION The treatment of choice in basal cell carcinoma with positive margins must be individualized to reduce recurrence rates. PMID:28225958

  7. Qualitatively distinct factors contribute to elevated rates of paranoia in autism and schizophrenia.

    Science.gov (United States)

    Pinkham, Amy E; Sasson, Noah J; Beaton, Derek; Abdi, Hervé; Kohler, Christian G; Penn, David L

    2012-08-01

    A converging body of clinical and empirical reports indicates that autism features elevated rates of paranoia comparable to those of individuals with paranoid schizophrenia. However, the distinct developmental courses and symptom manifestations of these two disorders suggest that the nature of paranoid ideation may differ between them in important and meaningful ways. To evaluate this hypothesis, we compared patterns of responses on the Paranoia Scale between actively paranoid individuals with schizophrenia (SCZP), individuals with schizophrenia who were not actively paranoid (SCZNP), adults with an Autism Spectrum Disorder (ASD), and healthy controls. Despite an overall similar level of heightened paranoia in the ASD and SCZP groups, discriminant correspondence analysis (DiCA) revealed that these groups were characterized by unique underlying factors. Paranoia in the SCZP group was defined by a factor based upon victimization, suspicion, and threat of harm. Whereas paranoia in the ASD group was partially characterized by this factor, it was distinguished from SCZP by an additional pattern of responses reflective of increased social cynicism. These findings indicate that paranoia in ASD is supported by qualitative factors distinct from schizophrenia and highlight mechanistic differences in the formation of paranoid ideation that may inform the development of disorder-specific treatments.

  8. Factorial invariance of the Five-Factor Model Rating Form across gender.

    Science.gov (United States)

    Samuel, Douglas B; South, Susan C; Griffin, Sarah A

    2015-02-01

    The Five-Factor Model Rating Form (FFMRF) provides a brief, one-page assessment of the Five-Factor Model. An important and unique aspect of the FFMRF is that it is the only brief measure that includes scales for the 30 facets proposed by Costa and McCrae. The current study builds on existing validity support for the FFMRF by evaluating its factorial invariance across gender within a sample of 699 undergraduate students. Consistent with other measures of the Five-Factor Model, men scored lower than women on the domains of neuroticism, extraversion, agreeableness, and conscientiousness but slightly higher on openness. The novel contribution of the current study is the use of exploratory structural equation modeling to determine that the FFMRF displayed a five-factor structure that demonstrated strong measurement invariance across gender. This factorial invariance adds important support for the validity of the FFMRF as a self-report measure as it indicates that the scores assess the same latent constructs in men and women. Although future work is needed to clarify some facet-level findings and evaluate for potential predictive biases, the present results add to the increasing body of research supporting the validity of the FFMRF as a self-report measure of personality. © The Author(s) 2014.

  9. Factors affecting recurrence rate of ingrown toenail treated with marginal toenail ablation.

    Science.gov (United States)

    Kuru, Ilhami; Sualp, Turan; Ferit, Dereboy; Gunduz, Tezeren

    2004-06-01

    This retrospective study analyzed marginal toenail ablation for ingrowing toenails and the factors affecting recurrences. Recurrence was defined as a return of the previous symptoms, regrowth of the nail edge, or patient dissatisfaction with the clinical outcome. Based on these criteria, nine patients (10.7%) were considered to have had a failed operation. There were significant differences for recurrence rate (p <.05) in the patients operated on under local anesthesia and in previously treated patients. Full exposure and excision of the germinal matrix were essential to avoid recurrence.

  10. FACTORS AFFECTING FATIGUE CRACK GROWTH RATES OF FIBER REINFORCED METAL LAMINATES

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Based upon an analytical model for predicting the crack growth in fiber reinforced metal laminates (FRMLs), some factors affecting the fatigue crack growth rates of FRMLs were analyzed, including the lay-up of FRMLs, the modulus of the fibers, the residual stresses in FRMLs, the bonding strength and the shear modulus of the adhesive, etc.It was shown from the present analysis that the interface number of the laminates, the modulus of the fibers and the residual stresses in FRMLs have very great effects on the fatigue lives of FRMLs, but the effects of the bonding strength and the shear modulus of the adhesive are relatively small.

  11. Rate limiting factors in trichloroethylene co-metabolic degradation by phenol-grown aerobic granules.

    Science.gov (United States)

    Zhang, Yi; Tay, Joo Hwa

    2014-04-01

    The potential of aerobic granular sludge in co-metabolic removal of recalcitrant substances was evaluated using trichloroethylene (TCE) as the model compound. Aerobic granules cultivated in a sequencing batch reactor with phenol as the growth substrate exhibited TCE and phenol degradation activities lower than previously reported values. Depletion of reducing energy and diffusion limitation within the granules were investigated as the possible rate limiting factors. Sodium formate and citrate were supplied to the granules in batch studies as external electron sources. No significant enhancing effect was observed on the instant TCE transformation rates, but 10 mM formate could improve the ultimate transformation capacity by 26 %. Possible diffusion barrier was studied by sieving the biomass into five size fractions, and determining their specific TCE and phenol degradation rates and capacities. Biomass in the larger size fractions generally showed lower activities. Large granules of >700 μm diameter exhibited only 22 % of the flocs' TCE transformation capacity and 35 % of its phenol dependent SOUR, indicating the possible occurrence of diffusion limitation in larger biomass. However, the highest specific TCE transformation rate was observed with the fraction that mostly consisted of small granules (150-300 μm), suggesting an optimal size range while applying aerobic granules in TCE co-metabolic removal.

  12. Factors Influencing Patients' Perspectives of Radiology Imaging Centers: Evaluation Using an Online Social Media Ratings Website.

    Science.gov (United States)

    Doshi, Ankur M; Somberg, Molly; Rosenkrantz, Andrew B

    2016-02-01

    The goal of this study was to use patient reviews posted on Yelp.com, an online ratings website, to identify factors most commonly associated with positive versus negative patient perceptions of radiology imaging centers across the United States. A total of 126 outpatient radiology centers from the 46 largest US cities were identified using Yelp.com; 1,009 patient reviews comprising 2,582 individual comments were evaluated. Comments were coded as pertaining to either the radiologist or other service items, and as expressing either a positive or negative opinion. Distribution of comments was compared with center ratings using Fisher's exact test. Overall, 14% of comments were radiologist related; 86% pertained to other aspects of service quality. Radiologist-related negative comments more frequent in low-performing centers (mean rating ≤2 on 1-5 scale) than high-performing centers (rating ≥4) pertained to imaging equipment (25% versus 7%), report content (25% versus 2%), and radiologist professionalism (25% versus 2%) (P culture throughout their practice. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  13. Factors influencing the contamination rate of human organ-cultured corneas.

    Science.gov (United States)

    Röck, Daniel; Wude, Johanna; Bartz-Schmidt, Karl U; Yoeruek, Efdal; Thaler, Sebastian; Röck, Tobias

    2017-03-21

    To assess the influence of donor, environment and storage factors on the contamination rate of organ-cultured corneas, to consider the microbiological species causing corneal contamination and to investigate the corresponding sensitivities. Data from 1340 consecutive donor corneas were analysed retrospectively. Logistic regression analysis was used to assess the influence of different factors on the contamination rate of organ-cultured corneas for transplantation. The mean annual contamination rate was 1.8 ± 0.4% (range: 1.3-2.1%); 50% contaminations were of fungal origin with exclusively Candida species, and 50% contaminations were of bacterial origin with Staphylococcus species being predominant. The cause of donor death including infection and multiple organ dysfunction syndrome increased the risk of bacterial or fungal contamination during organ culture (p = 0.007 and p = 0.014, respectively). Differentiating between septic and aseptic donors showed an increased risk of contamination for septic donors (p = 0.0020). Mean monthly temperature including warmer months increased the risk of contamination significantly (p = 0.0031). Sex, donor age, death to enucleation, death to corneoscleral disc excision and storage time did not increase the risk of contamination significantly. The genesis of microbial contamination in organ-cultured donor corneas seems to be multifactorial. The main source of fungal or bacterial contamination could be resident species from the skin flora. The rate of microbial contamination in organ-cultured donor corneas seems to be dependent on the cause of donor death and mean monthly temperature. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  14. Facet stability of crystals I. Factors determining the polyhedral (in)-stability of silver single crystals during electrocrystallization at high current densities

    Science.gov (United States)

    Nanev, Chr. N.; Rashkov, R. St.

    1992-06-01

    Loss of the polyhedral stability as a result of emerging depressions on crystal faces has been observed during both vapour and solution growth under diffusion control, as well as by electrocrystallization at high current densities. A difference was found only when a quantitative comparison of the stability of the crystal shapes with the existing theoretical predictions was attempted. With the growth of zinc and cadmium single crystals from the vapour phase this phenomenon appears earlier, i.e. at smaller sizes than the expected figures, while the silver single crystals are more steady — they withstand one order of magnitude higher of current densities than the calculated values before the appearance of the depressions, in spite of the fact that the presence of an (inhomogeneous) electrical field in the second case has to decrease the polyhedral stability. One possible explanation of this fact is that the electrocrystallization of silver proceeds in highly concentrated solutions, for which Seeger's equation, laying in the base of the quantitative elucidations in this case, does not hold true. Correspondingly, here (part I of the paper) we are trying a more general approach, while part II represents a new, alternative way for explaining the higher stability of the faceted forms of the silver single crystals.

  15. Numerical investigation of factors affecting the shape of the crystal-melt interface in edge-defined film-fed growth of sapphire crystals

    Science.gov (United States)

    Stelian, C.; Barthalay, N.; Duffar, T.

    2017-07-01

    Numerical modeling is used to investigate the shape of the crystal-melt interface in edge-defined film-fed growth (EFG) of large size sapphire rods and sheets. The present analysis shows that the temperature distribution in the meniscus is significantly affected by the internal radiative exchanges in the sapphire crystal. 2D axisymmetric computations performed in the case of sapphire rods, show a concave shape of the interface for opaque crystals, and a convex shaped interface for semi-transparent crystals. The temperature gradient across the meniscus increases significantly in the case which accounts for the internal radiative effect in the crystal. Large temperature differences along the free surface of the meniscus generate intense Marangoni flow, which can influence the shape of the growth interface. In this case, the meniscus height increases, producing instabilities in the growth process. The effect of die geometry on the interface shape is analyzed by increasing the angle between the working edges of the die. Computations shows that the interface curvature decreases as this angle increases, but the solidification isotherm moves up, leading to an increased meniscus height. 3D modeling is applied to investigate the EFG growth of large size sapphire sheets. Numerical results show a non-uniform temperature distribution in the meniscus, and a complex 3D flow pattern. However, the intensity of the flow is low in this case, having no influence on the temperature field and interface shape.

  16. High sensitivity and high Q-factor nanoslotted parallel quadrabeam photonic crystal cavity for real-time and label-free sensing

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Daquan [Rowland Institute at Harvard University, Cambridge, Massachusetts 02142 (United States); State Key Laboratory of Information Photonics and Optical Communications, School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876 (China); School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Kita, Shota; Wang, Cheng; Lončar, Marko [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Liang, Feng; Quan, Qimin [Rowland Institute at Harvard University, Cambridge, Massachusetts 02142 (United States); Tian, Huiping; Ji, Yuefeng [State Key Laboratory of Information Photonics and Optical Communications, School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876 (China)

    2014-08-11

    We experimentally demonstrate a label-free sensor based on nanoslotted parallel quadrabeam photonic crystal cavity (NPQC). The NPQC possesses both high sensitivity and high Q-factor. We achieved sensitivity (S) of 451 nm/refractive index unit and Q-factor >7000 in water at telecom wavelength range, featuring a sensor figure of merit >2000, an order of magnitude improvement over the previous photonic crystal sensors. In addition, we measured the streptavidin-biotin binding affinity and detected 10 ag/mL concentrated streptavidin in the phosphate buffered saline solution.

  17. Crystal Structure of the HEAT Domain from the Pre-mRNA Processing Factor Symplekin

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, Sarah A.; Frazier, Monica L.; Steiniger, Mindy; Mast, Ann M.; Marzluff, William F.; Redinbo, Matthew R.; (UNC)

    2010-09-30

    The majority of eukaryotic pre-mRNAs are processed by 3'-end cleavage and polyadenylation, although in metazoa the replication-dependent histone mRNAs are processed by 3'-end cleavage but not polyadenylation. The macromolecular complex responsible for processing both canonical and histone pre-mRNAs contains the {approx} 1160-residue protein Symplekin. Secondary-structural prediction algorithms identified putative HEAT domains in the 300 N-terminal residues of all Symplekins of known sequence. The structure and dynamics of this domain were investigated to begin elucidating the role Symplekin plays in mRNA maturation. The crystal structure of the Drosophila melanogaster Symplekin HEAT domain was determined to 2.4 {angstrom} resolution with single-wavelength anomalous dispersion phasing methods. The structure exhibits five canonical HEAT repeats along with an extended 31-amino-acid loop (loop 8) between the fourth and fifth repeat that is conserved within closely related Symplekin sequences. Molecular dynamics simulations of this domain show that the presence of loop 8 dampens correlated and anticorrelated motion in the HEAT domain, therefore providing a neutral surface for potential protein-protein interactions. HEAT domains are often employed for such macromolecular contacts. The Symplekin HEAT region not only structurally aligns with several established scaffolding proteins, but also has been reported to contact proteins essential for regulating 3'-end processing. Together, these data support the conclusion that the Symplekin HEAT domain serves as a scaffold for protein-protein interactions essential to the mRNA maturation process.

  18. Factors influencing the crystallization and the densification of ultrafine Si/N/C powders

    Energy Technology Data Exchange (ETDEWEB)

    Lences, Z. [Slovenska Akademia Vied, Bratislava (Slovakia). Inst. of Inorganic Chemistry; Bellosi, A. [CNR IRTEC, Research Institute for Ceramics Technology, Via Granarolo 64, 48018 Faenza (Italy); Monteverde, F. [CNR IRTEC, Research Institute for Ceramics Technology, Via Granarolo 64, 48018 Faenza (Italy)

    1995-06-01

    The employment of nanocomposite Si/N/C laser-formed powders to produce high performance ceramics results in several technological problems related to their nanometer particle size and to their high affinity for oxygen, which influence phase composition and densification. This study has focused on several aspects: the improvement of experimental methodologies for processing of ultrafine powders in a compact green body and for the addition of sintering aids; the evaluation of the starting composition of the Si/N/C ultrafine amorphous powders and of the thermal treatment conditions (temperature, time, atmosphere) on phase composition, thermal stability, grain size, specific surface area and crystallite size; and the production and characterization of dense Si{sub 3}N{sub 4}/SiC composites. Above 1400 C the amorphous Si/N/C powders crystallize in {alpha}- and {beta}-Si{sub 3}N{sub 4}, SiC and Si{sub 2}N{sub 2}O, their relative amounts and grain sizes depending on processing conditions. The phenomena are discussed on the basis of a series of reactions involving the formation of intermediates in the system Si-C-N-O. After densification by hot pressing, a very fine microstructure ({approx}100 nm) was observed in the dense Si{sub 3}N{sub 4}/SiC composites. High values of hardness (H{sub V}{>=}21 GPa) and good values of fracture toughness (K{sub IC}{approx}4.8 MPa m{sup 1/2}) were measured. ((orig.))

  19. Influence of crystals fields on the magnetic form factor of samarium

    NARCIS (Netherlands)

    Wijn, H.W. de; Diepen, A.M. van; Buschow, K.H.J.

    1974-01-01

    It is calculated that crstal fields, with inclusion of mixing of higher multiplets into the ground J = 5/2 state, have a substantial effect on the magnetic form factor of Sm3+. From the neutron diffraction data obtained by Koehler and Moon for the cubic site in Sm metal it follows that the quartet Γ

  20. DNA binding by the plant-specific NAC transcription factors in crystal and solution

    DEFF Research Database (Denmark)

    Welner, Ditte Hededam; Lindemose, Søren; Grossmann, J. Günter;

    2012-01-01

    NAC (NAM/ATAF/CUC) plant transcription factors regulate essential processes in development, stress responses and nutrient distribution in important crop and model plants (rice, Populus, Arabidopsis), which makes them highly relevant in the context of crop optimization and bioenergy production. Th...

  1. Effect of growth rate on crystallization of HfO2 thin films deposited by RF magnetron sputtering

    Science.gov (United States)

    Dhanunjaya, M.; Manikanthababu, N.; Pathak, A. P.; Rao, S. V. S. Nageswara

    2016-05-01

    Hafnium oxide (HfO2) is the potentially useful dielectric material in both; electronics to replace the conventional SiO2 as gate dielectric and in Optics as anti-reflection coating material. In this present work we have synthesized polycrystalline HfO2 thin films by RF magnetron sputtering deposition technique with varying target to substrate distance. The deposited films were characterized by X-ray Diffraction, Rutherford Backscattering Spectrometry (RBS) and transmission and Reflection (T&R) measurements to study the growth behavior, microstructure and optical properties. XRD measurement shows that the samples having mixed phase of monoclinic, cubic and tetragonal crystal structure. RBS measurements suggest the formation of Inter Layer (IL) in between Substrate and film

  2. Exclusive breastfeeding rate and factors associated with infant feeding practices in Indonesia

    Directory of Open Access Journals (Sweden)

    Yovita Ananta

    2016-05-01

    Full Text Available Background Breast milk is the ideal food for infants. According to the 2007 Indonesian National Household Health Survey, only 23% of mothers exclusively breastfeed for six months.Objectives To determine the rate of exclusive breastfeeding in Indonesia, to evaluate factors associated with infant feeding practices, and to compare the nutritional and developmental status between exclusively-breastfed and formula-fed infants.Methods A survey was conducted in hospitals located in 17 provinces in Indonesia. The rate of exclusive breastfeeding was calculated. Many variables were investigated as potential predictors for exclusive breastfeeding using a multivariable logistic regression analysis. Further analysis was performed to compare the nutritional and developmental status between exclusively breastfed and formula-fed infants at the time of survey.Results From 1,804 infant subjects, the overall rate of exclusive breastfeeding was 46.3%, ranging from 10.5% in East Java to 66.9% in Jambi. Predominant breastfeeding, complementary feeding, and formula feeding rates were 14.3%, 8.6%, and 30.7%, respectively. Maternal unemployment was associated with a longer duration of breastfeeding (P=0.000. There were significantly more formula-fed infants who were undernourished compared to exclusively-breastfed infants (14% vs. 8%, P=0.001. There were also significantly more infants in the formula-fed group who had abnormal head circumference compared to those in the exclusively-breastfed group (9% vs. 6%, P=0.031. Child development, as assessed by the Pre-screening Developmental Questionnaire, was similar between the two groups (P=0.996.Conclusion The overall rate of exclusive breastfeeding in Indonesia is 46.3%. Maternal unemployment is associated with longer duration of breastfeeding. Exclusive breastfed infants have significant better growth and head circumference compared to formula fed infants, while the development is similar between the two groups.

  3. Exclusive breastfeeding rate and factors associated with infant feeding practices in Indonesia

    Directory of Open Access Journals (Sweden)

    Yovita Ananta

    2016-05-01

    Full Text Available Background Breast milk is the ideal food for infants. According to the 2007 Indonesian National Household Health Survey, only 23% of mothers exclusively breastfeed for six months. Objectives To determine the rate of exclusive breastfeeding in Indonesia, to evaluate factors associated with infant feeding practices, and to compare the nutritional and developmental status between exclusively-breastfed and formula-fed infants. Methods A survey was conducted in hospitals located in 17 provinces in Indonesia. The rate of exclusive breastfeeding was calculated. Many variables were investigated as potential predictors for exclusive breastfeeding using a multivariable logistic regression analysis. Further analysis was performed to compare the nutritional and developmental status between exclusively breastfed and formula-fed infants at the time of survey. Results From 1,804 infant subjects, the overall rate of exclusive breastfeeding was 46.3%, ranging from 10.5% in East Java to 66.9% in Jambi. Predominant breastfeeding, complementary feeding, and formula feeding rates were 14.3%, 8.6%, and 30.7%, respectively. Maternal unemployment was associated with a longer duration of breastfeeding (P=0.000. There were significantly more formula-fed infants who were undernourished compared to exclusively-breastfed infants (14% vs. 8%, P=0.001. There were also significantly more infants in the formula-fed group who had abnormal head circumference compared to those in the exclusively-breastfed group (9% vs. 6%, P=0.031. Child development, as assessed by the Pre-screening Developmental Questionnaire, was similar between the two groups (P=0.996. Conclusion The overall rate of exclusive breastfeeding in Indonesia is 46.3%. Maternal unemployment is associated with longer duration of breastfeeding. Exclusive breastfed infants have significant better growth and head circumference compared to formula fed infants, while the development is similar between the two groups.

  4. Preparation, crystallization and preliminary X-ray diffraction analysis of the DNA-binding domain of the Ets transcription factor in complex with target DNA

    Energy Technology Data Exchange (ETDEWEB)

    Suwa, Yoshiaki; Nakamura, Teruya; Toma, Sachiko; Ikemizu, Shinji; Kai, Hirofumi; Yamagata, Yuriko, E-mail: yamagata@gpo.kumamoto-u.ac.jp [Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973 (Japan)

    2008-03-01

    The complex between the Ets domain of Ets2 and its target DNA has been crystallized. The crystals diffracted to 3.0 Å resolution. The Ets2 transcription factor is a member of the Ets transcription-factor family. Ets2 plays a role in the malignancy of cancer and in Down’s syndrome by regulating the transcription of various genes. The DNA-binding domain of Ets2 (Ets domain; ETSD), which contains residues that are highly conserved among Ets transcription-factor family members, was expressed as a GST-fusion protein. The aggregation of ETSD produced after thrombin cleavage could be prevented by treatment with NDSB-195 (nondetergent sulfobetaine 195). ETSD was crystallized in complex with DNA containing the Ets2 target sequence (GGAA) by the hanging-drop vapour-diffusion method. The best crystals were grown using 25% PEG 3350, 80 mM magnesium acetate, 50 mM sodium cacodylate pH 5.0/5.5 as the reservoir at 293 K. The crystals belonged to space group C2, with unit-cell parameters a = 85.89, b = 95.52, c = 71.89 Å, β = 101.7° and a V{sub M} value of 3.56 Å{sup 3} Da{sup −1}. Diffraction data were collected to a resolution of 3.0 Å.

  5. The rates and patterns of deletions in the human factor IX gene

    Energy Technology Data Exchange (ETDEWEB)

    Ketterling, R.P.; Vielhaber, E.L.; Lind, T.J.; Thorland, E.C.; Sommer S.S. (Mayo Clinic/Foundation, Rochester, MN (United States))

    1994-02-01

    Deletions are commonly observed in genes with either segments of highly homologous sequences or excessive gene length. However, in the factor IX gene and in most genes, deletions (of [ge]21 bp) are uncommon. The authors have analyzed DNA from 290 families with hemophilia B (203 independent mutations) and have found 12 deletions >20 bp. Eleven of these are >2 kb (range >3-163 kb), and one is 1.1 kb. The junctions of the four deletions that are completely contained within the factor IX gene have been determined. A novel mutation occurred in patient HB128: the data suggest that a 26.8-kb deletion occurred between two segments of alternating purines and pyrimidines and that a 2.3-kb sense strand segment derived from the deleted region was inserted. For a sample of 203 independent mutations, the authors estimate the [open quotes]baseline[close quotes] rates of deletional mutation per base pair per generation as a function of size. The rate for large (>2 kb)I deletions is exceedingly low. For every mutational event in which a given base is at the junction of a large deletion, there are an estimated 58 microdeletions (<20 bp) and 985 single-base substitutions at that base. Analysis of the nine reported deletion junctions in the factor IX gene literature reveals that (i) five are associated with inversion, orphan sequences, or sense strand insertions; (ii) four are simple deletions that display an excess of short direct repeats at their junctions; (iii) there is no dramatic clustering of junctions within the gene; and (iv) with the exception of alternating purines and pyrimidines, deletion junctions are not preferentially associated with repetitive DNA. 58 refs., 5 figs., 5 tabs.

  6. Injury rates and injury risk factors among federal bureau of investigation new agent trainees

    Directory of Open Access Journals (Sweden)

    Knapik Joseph J

    2011-12-01

    Full Text Available Abstract Background A one-year prospective examination of injury rates and injury risk factors was conducted in Federal Bureau of Investigation (FBI new agent training. Methods Injury incidents were obtained from medical records and injury compensation forms. Potential injury risk factors were acquired from a lifestyle questionnaire and existing data at the FBI Academy. Results A total of 426 men and 105 women participated in the project. Thirty-five percent of men and 42% of women experienced one or more injuries during training. The injury incidence rate was 2.5 and 3.2 injuries/1,000 person-days for men and women, respectively (risk ratio (women/men = 1.3, 95% confidence interval = 0.9-1.7. The activities most commonly associated with injuries (% of total were defensive tactics training (58%, physical fitness training (20%, physical fitness testing (5%, and firearms training (3%. Among the men, higher injury risk was associated with older age, slower 300-meter sprint time, slower 1.5-mile run time, lower total points on the physical fitness test (PFT, lower self-rated physical activity, lower frequency of aerobic exercise, a prior upper or lower limb injury, and prior foot or knee pain that limited activity. Among the women higher injury risk was associated with slower 300-meter sprint time, slower 1.5-mile run time, lower total points on the PFT, and prior back pain that limited activity. Conclusion The results of this investigation supported those of a previous retrospective investigation emphasizing that lower fitness and self-reported pain limiting activity were associated with higher injury risk among FBI new agents.

  7. Development of Tissue to Total Mass Correction Factor for Porites divaricata in Calcification Rate Studies

    Science.gov (United States)

    Cannone, T. C.; Kelly, S. K.; Foster, K.

    2013-05-01

    One anticipated result of ocean acidification is lower calcification rates of corals. Many studies currently use the buoyant weights of coral nubbins as a means of estimating skeletal weight during non-destructive experiments. The objectives of this study, conducted at the Little Cayman Research Centre, were twofold: (1) to determine whether the purple and yellow color variations of Porites divaricata had similar tissue mass to total mass ratios; and (2) to determine a correction factor for tissue mass based on the total coral mass. T-test comparisons indicated that the tissue to total mass ratios were statistically similar for purple and yellow cohorts, thus allowing them to be grouped together within a given sample population. Linear regression analysis provided a correction factor (r2 = 0.69) to estimate the tissue mass from the total mass, which may eliminate the need to remove tissue during studies and allow subsequent testing on the same nubbins or their return to the natural environment. Additional work is needed in the development of a correction factor for P. divaricata with a higher prediction accuracy.

  8. Is Cholesteatoma a Risk Factor for Graft Success Rate in Chronic Otitis Media Surgery?

    Directory of Open Access Journals (Sweden)

    Mohammad Faramarzi

    2015-11-01

    Materials and Methods: The present retrospective, study-controlled study investigated 422 ears undergoing COM surgery. The minimum and maximum postoperative follow-up periods were 6 and 48 months, respectively. The study group consisted of patients with cholesteatomatous COM, while the control group included patients with non-cholesteatomatous COM, who had undergone ear surgery.  Postoperative graft success rate and audiological test results were recorded and the effect of cholesteatoma on graft success rate was investigated.  Results: The overall GSR was 92.4%. In the study group (COM with cholesteatoma,the postoperative GSR, mean speech reception threshold improvement, and mean air-bone gap gain were 95.3%, 2.1 dB, and 3.2 dB, respectively. In the control group (COM without cholesteatoma, however, these measurements were 90.9%, 9.4 dB, and 9.1 dB, respectively. The difference between the two groups was not statistically significant.  Conclusion:  The study results suggest that cholesteatoma is not a significant prognostic factor in graft success rate.

  9. Rates and risk factors of unplanned 30-day readmission following general and thoracic pediatric surgical procedures.

    Science.gov (United States)

    Polites, Stephanie F; Potter, Donald D; Glasgow, Amy E; Klinkner, Denise B; Moir, Christopher R; Ishitani, Michael B; Habermann, Elizabeth B

    2017-08-01

    Postoperative unplanned readmissions are costly and decrease patient satisfaction; however, little is known about this complication in pediatric surgery. The purpose of this study was to determine rates and predictors of unplanned readmission in a multi-institutional cohort of pediatric surgical patients. Unplanned 30-day readmissions following general and thoracic surgical procedures in children Pediatric. Time-dependent rates of readmission per 30 person-days were determined to account for varied postoperative length of stay (pLOS). Patients were randomly divided into 70% derivation and 30% validation cohorts which were used for creation and validation of a risk model for readmission. Readmission occurred in 1948 (3.6%) of 54,870 children for a rate of 4.3% per 30 person-days. Adjusted predictors of readmission included hepatobiliary procedures, increased wound class, operative duration, complications, and pLOS. The predictive model discriminated well in the derivation and validation cohorts (AUROC 0.710 and 0.701) with good calibration between observed and expected readmission events in both cohorts (p>.05). Unplanned readmission occurs less frequently in pediatric surgery than what is described in adults, calling into question its use as a quality indicator in this population. Factors that predict readmission including type of procedure, complications, and pLOS can be used to identify at-risk children and develop prevention strategies. III. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Numerical Studies on Heat Release Rate in Room Fire on Liquid Fuel under Different Ventilation Factors

    Directory of Open Access Journals (Sweden)

    N. Cai

    2012-01-01

    Full Text Available Heat release rate (HRR of the design fire is the most important parameter in assessing building fire hazards. However, HRR in room fire was only studied by computational fluid dynamics (CFD in most of the projects determining fire safety provisions by performance-based design. In contrast to ten years ago, officers in the Far East are now having better knowledge of CFD. Two common questions are raised on CFD-predicted results on describing free boundaries; and on computing grid size. In this work, predicting HRR by the CFD model was justified with experimental room pool fire data reported earlier. The software fire dynamics simulator (FDS version 5 was selected as the CFD simulation tool. Prescribed input heating rate based on the experimental results was used with the liquid fuel model in FDS. Five different free boundary conditions were investigated to predict HRR. Grid sensitivity study was carried out using one stretched mesh and multiple uniform meshes with different grid sizes. As it is difficult to have the entire set of CFD predicted results agreed with experiments, macroscopic flow parameters on the mass flow rate through door opening predicted by CFD were also justified by another four conditions with different ventilation factors.

  11. Monte Carlo calculation of dose rate conversion factors for external exposure to photon emitters in soil

    CERN Document Server

    Clouvas, A; Antonopoulos-Domis, M; Silva, J

    2000-01-01

    The dose rate conversion factors D/sub CF/ (absorbed dose rate in air per unit activity per unit of soil mass, nGy h/sup -1/ per Bq kg/sup -1/) are calculated 1 m above ground for photon emitters of natural radionuclides uniformly distributed in the soil. Three Monte Carlo codes are used: 1) The MCNP code of Los Alamos; 2) The GEANT code of CERN; and 3) a Monte Carlo code developed in the Nuclear Technology Laboratory of the Aristotle University of Thessaloniki. The accuracy of the Monte Carlo results is tested by the comparison of the unscattered flux obtained by the three Monte Carlo codes with an independent straightforward calculation. All codes and particularly the MCNP calculate accurately the absorbed dose rate in air due to the unscattered radiation. For the total radiation (unscattered plus scattered) the D/sub CF/ values calculated from the three codes are in very good agreement between them. The comparison between these results and the results deduced previously by other authors indicates a good ag...

  12. Effect of chemical and physical factors to improve the germination rate of Echinacea angustifolia seeds.

    Science.gov (United States)

    Chuanren, Duan; Bochu, Wang; Wanqian, Liu; Jing, Chen; Jie, Lian; Huan, Zhao

    2004-09-01

    Seeds of Echinacea angustifolia are known for their deep dormancy. In this paper, we studied the responses of E. angustifolia seeds to some chemical and physical factors, such as scarification, chilling (5 degrees C) period, light and applied BA (6-benzylaminopurine), GA3 (gibberellic acid) and sound stimulation. When the seed coat layers were removed, the germination rate grew up from 6 to 20% (incubated in light) and the mean time germination (MTG) was reduced from 18 to 6.6 days. On the basis of layers-removed, chilling and continuous light gave significantly higher germination rate (up to 70%). Compare the data of seeds chilled by 0, 6, 12, 18 and 24 days, the maximum germination rate (up to 70%) achieved at 18-days chilling treatment. Further increases in the chilling period could slightly improve germination. Exogenous application of 0.1, 0.2, 0.3 mg/L GA3 or BA in the previous pretreatment increased germination to 78, 90 and 84% or 76, 86 and 84%, respectively. Obviously, the best concentration of GA or BA is 0.3 mg/L. And the GA3 or BA treatment shortened the MTG to about 4 days. The influence of sound stimulation was also tested in the experiment. The result showed that one 100 dB and 1000 Hz sound wave (sine-wave) was beneficial to the germination of E. angustifolia seeds.

  13. Factor Analysis and Norms for Parent Ratings on the Aberrant Behavior Checklist-Community for Young People in Special Education.

    Science.gov (United States)

    Brown, Elaine C.; Aman, Michael G.; Havercamp, Susan M.

    2002-01-01

    Parents of 601 children and adolescents with mental retardation rated their children on the Aberrant Behavior Checklist-Community (ABC). Factor analysis revealed a factor structure similar to the original ABC but without the inappropriate speech factor. Analysis of subject variables revealed main effects for gender, age, and classroom assignment…

  14. Cloning, expression, purification and crystallization of a pair of novel virulence factors, SghA and SghR, from Agrobacterium tumefaciens

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Fuzhou [Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Wang, Chao [Institute of Molecular and Cell Biology, 61 Biopolis Drive, Singapore 138673 (Singapore); National Cancer Centre Singapore, 11 Hospital Drive, Singapore 169610 (Singapore); Fu, Qinqin [Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Zhang, Lian-hui [Institute of Molecular and Cell Biology, 61 Biopolis Drive, Singapore 138673 (Singapore); Gao, Yong-gui, E-mail: ygao@ntu.edu.sg [Nanyang Technological University, 60 Nanyang Drive, Singapore 637551 (Singapore); Institute of Molecular and Cell Biology, 61 Biopolis Drive, Singapore 138673 (Singapore)

    2015-08-25

    The crystallization of the novel virulence factors SghA and SghR is reported. Two proteins, SghA and SghR, which were recently identified and characterized as novel bacterial virulence factors regulating the infection of plant hosts by Agrobacterium, were cloned, overexpressed and purified with high yield. Both SghA and SghR form dimers in solution. The purified SghA and SghR were crystallized and the crystals diffracted to 1.9 and 2.1 Å resolution, respectively. Data were collected and processed, and the crystallographic parameters were within acceptable ranges. These results will help in the determination of their structures in order to uncover the molecular mechanism of how these two proteins together control the release of plant defence signals against agrobacteria during pathogen–host interaction.

  15. The Crystal Structure of Cdc42 in Complex with Collybisin II, a Gephyrin-Interacting Guanine Nucleotide Exchange Factor

    Energy Technology Data Exchange (ETDEWEB)

    Xiang,S.; Kim, E.; Connelly, J.; Nassar, N.; Kirsch, J.; WinkingSchwartz, G.; Schindelin, H.

    2006-01-01

    The synaptic localization of ion channel receptors is essential for efficient synaptic transmission and the precise regulation of diverse neuronal functions. In the central nervous system, ion channel receptors reside in the postsynaptic membrane where they are juxtaposed to presynaptic terminals. For proper function, these ion channels have to be anchored to the cytoskeleton, and in the case of the inhibitory glycine and {gamma}-amino-butyric acid type A (GABA{sub A}) receptors this interaction is mediated by a gephyrin centered scaffold. Highlighting its central role in this receptor anchoring scaffold, gephyrin interacts with a number of proteins, including the neurospecific guanine nucleotide exchange factor collybistin. Collybistin belongs to the Dbl family of guanine nucleotide exchange factors, occurs in multiple splice variants, and is specific for Cdc42, a small GTPase belonging to the Rho family. The 2.3 Angstroms resolution crystal structure of the Cdc42--collybistin II complex reveals a novel conformation of the switch I region of Cdc42. It also provides the first direct observation of structural changes in the relative orientation of the Dbl-homology domain and the pleckstrin-homology domain in the same Dbl family protein. Biochemical data indicate that gephyrin negatively regulates collybistin activity.

  16. Initiation factor 2 crystal structure reveals a different domain organization from eukaryotic initiation factor 5B and mechanism among translational GTPases.

    Science.gov (United States)

    Eiler, Daniel; Lin, Jinzhong; Simonetti, Angelita; Klaholz, Bruno P; Steitz, Thomas A

    2013-09-24

    The initiation of protein synthesis uses initiation factor 2 (IF2) in prokaryotes and a related protein named eukaryotic initiation factor 5B (eIF5B) in eukaryotes. IF2 is a GTPase that positions the initiator tRNA on the 30S ribosomal initiation complex and stimulates its assembly to the 50S ribosomal subunit to make the 70S ribosome. The 3.1-Å resolution X-ray crystal structures of the full-length Thermus thermophilus apo IF2 and its complex with GDP presented here exhibit two different conformations (all of its domains except C2 domain are visible). Unlike all other translational GTPases, IF2 does not have an effecter domain that stably contacts the switch II region of the GTPase domain. The domain organization of IF2 is inconsistent with the "articulated lever" mechanism of communication between the GTPase and initiator tRNA binding domains that has been proposed for eIF5B. Previous cryo-electron microscopy reconstructions, NMR experiments, and this structure show that IF2 transitions from being flexible in solution to an extended conformation when interacting with ribosomal complexes.

  17. An Investigation of the Mortality Rate and Risk Factors in Newborn Infants With Meconium Aspiration Syndrome

    Directory of Open Access Journals (Sweden)

    Sabzehei

    2016-08-01

    Full Text Available Background One of the serious challenges facing neonatal medicine is meconium aspiration syndrome, delays in the treatment of which can lead to high mortality. Objectives This study was designed and conducted with the aim of determining the mortality rate and risk factors affecting this rate in newborn infants with meconium aspiration syndrome. Methods This study was conducted as a retrospective descriptive research on newborn infants with meconium aspiration syndrome hospitalized at the neonatal intensive care unit (NICU of Fatemieh and Be’sat hospitals in Hamadan city during a 10-year period from 2004 to 2014. Demographic information of the mother and the newborn, hospitalization course, the need for mechanical ventilation, and complications and outcomes of disease were extracted and were analyzed using the SPSS software version 22. Results Sixty-three newborn infants, diagnosed with meconium aspiration syndrome, were entered in this study, 40% of them were male, 85.7% wighed more than 2500 g, and 17.5% were post term, 25.3% had a five-minute Apgar Score (AS5min of less than seven, 39.6% were nonvigorous at birth, 31.8% needed to be placed on mechanical ventilation, and 14.3% died during the hospitalization course. There was a significant relationship between the need for mechanical ventilation, nonvigorous state at the birth, complications of disease and mortality rate. Conclusions Despite the progress made in medicine, meconium aspiration syndrome is still one of the causes of newborn infants’ mortality. The mortality and morbidity rates can be reduced by improvement in perinatal care, prevention of post term delivery, timely caesarean and effective neonatal resuscitation at birth.

  18. Recurrent rates and risk factors associated with recurrent painful bullous keratopathy after primary phototherapeutic keratectomy

    Directory of Open Access Journals (Sweden)

    Kasetsuwan N

    2015-09-01

    Full Text Available Ngamjit Kasetsuwan, Kanokorn Sakpisuttivanit, Usanee Reinprayoon, Vilavun Puangsricharern Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, Bangkok, Thailand Objective: To assess the recurrent rate, mean survival time, and risk factors associated with recurrent painful bullous keratopathy (BK after primary treatment with phototherapeutic keratectomy.Methods: Medical records from 72 patients (72 eyes who had phototherapeutic keratectomy for painful BK were evaluated. Data for sex, age, duration of BK, associated ocular and systemic diseases (hypertension, diabetes mellitus, ischemic heart disease, asthma, dyslipidemia, and rheumatoid arthritis, frequency and degree of pain (grade 1–3, visual acuity, corneal thickness, intraocular pressure, and laser setting were extracted and analyzed.Results: The mean age of the patients was 64.2±11.4 years. The mean preoperative duration of BK was 15.0±11.0 months. Most patients had pseudophakic BK (69.40%. Majority of the cases had grade 3 degree of pain (48.60%. Glaucoma and hypertension were markedly found among these patients (51.40% and 19.40%, respectively. Preoperative mean intraocular pressure and corneal thickness were 13.70±4.95 mmHg and 734.1±83.80 µm, respectively. The mean laser diameter and depth were 8.36±1.22 mm and 38.89±8.81 µm, respectively. Systemic disease was significantly associated with the risk for developing recurrent painful BK (P=0.022, hazard ratio [HR] 1.673, 95% confidence interval [CI] 1.08–2.58. The overall recurrent rate was 51%. The average duration time of recurrent painful BK was 17.3±12.9 months (range 1–50 months. The median survival time before recurrence was 29.0±6.6 months.Conclusion: Systemic disease was found to be the only risk factor significantly associated with the development of recurrent painful BK. Low recurrent rate and long mean survival time showed that phototherapeutic

  19. Prognostic factors affecting disease-free survival rate following surgical resection of primary breast cancer

    Directory of Open Access Journals (Sweden)

    K Horita

    2009-12-01

    Full Text Available In order to identify the prognostic factors that significantly influence the disease-free survival rate after surgical resection of primary breast cancers, we determined tumour and lymph node grades, and immunohistochemical staining for estrogen and progesterone receptors (ER and PR, c-erbB-2, p53, bcl-2, bax and PCNA in 76 patients. Univariate analysis showed that increased grade of tumour and lymph nodes, negative immunostaining for ER, positive immunostaining for c-erbB-2, and a high PCNA index (³30% negatively influenced the disease- free survival rate, but PR, p53, bcl-2 and bax had no predictive value. Although p53 was not an independent prognostic factor by itself, the combination of p53, bcl-2, and bax proved to correlate with the disease-free survival, with the best prognosis noted in tumours negative for p53 and positive for both bcl-2 and bax, intermediate prognosis in tumours negative for p53 and positive for either bcl- 2 or bax and worst prognosis in tumors negative for p53 as well as bcl-2 and bax. Tumour grade correlated positively with PCNA index, while positive staining for ER correlated negatively with tumour grade as well as with PCNA index, although this was statistically insignificant. Immunostaining of breast cancers for Bcl-2 correlated negatively with tumour grade and PCNA index. Immunostaining for c-erbB-2 correlated positively with PCNA but not with tumour grade. Immunostaining for p53 tended to correlate positively with PCNA, but not with tumour grade. Immunostaining for PR and bax did not correlate with tumour grade and PCNA index. These results suggest that in addition to tumour size and lymph node involvement, immunostaining for ER, c-erbB-2, and a high PCNA index are important prognostic factors in human breast cancer. Wild-type p53 with preserved bcl-2 and bax gene products is also a favorable prognostic factor indicating breast cancer at an early stage of cancer progression.

  20. The surface orientation dependence of the pre-exponential factors extracted from the segregation profiles of a Cu(111/110) bi-crystal

    CSIR Research Space (South Africa)

    Jafta, CJ

    2011-07-01

    Full Text Available Previous experimental investigations have only shown, without explanation, that the pre-exponential factor (D0), in the diffusion coefficient of Sb segregating in Cu, is dependent on the surface orientation of a crystal. In this study, the surface...

  1. Investigations of defect structures and g factors for octahedral (CrO6)7- and (VO6)8- clusters in rutile-type crystals

    Science.gov (United States)

    Zhu, Lianxuan; Wang, Minjie

    2016-05-01

    The electron paramagnetic resonance (EPR) g factor formulas for Cr5+ and V4+ ions in Al2O3, TiO2 and VO2 crystals are deduced from Jahn-Teller effect and contributions of the charge transfer (CT) levels. The tetragonal distortions. ΔR(R∥- R⊥) = -0.0184,-0.0045 and -0.0124 nm, and Δ𝜃 = 0∘, - 0.001∘ and 0∘, for Al2O3:Cr5+, TiO2:V4+ and VO2, respectively. The calculations of the g factors agree well with the experimental values. The contributions of the CT levels to g factors increase with the increasing valence state. It must be taken into account in the precise calculations of g factors for the high valence state d1 ions in crystals.

  2. Factors affecting ozone removal rates in a simulated aircraft cabin environment

    DEFF Research Database (Denmark)

    Tamas, Gyöngyi; Weschler, Charles J.; Bako-Biro, Zsolt

    2006-01-01

    Ozone concentrations were measured concurrently inside a simulated aircraft cabin and in the airstream providing ventilation air to the cabin. Ozone decay rates were also measured after cessation of ozone injection into the supply airstream. By systematically varying the presence or absence...... of people, soiled T-shirts, aircraft seats and a used HEPA filter, we have been able in the course of 24 experiments to isolate the contributions of these and other factors to the removal of ozone from the cabin air. In the case of this simulated aircraft, people were responsible for almost 60% of the ozone...... removal occurring within the cabin and recirculation system; respiration can only have been responsible for about 4% of this removal. The aircraft seats removed about 25% of the ozone; the loaded HEPA filter, 7%; and the other surfaces, 10%. A T-shirt that had been slept in overnight removed roughly 70...

  3. Validation of cosmogenic nuclide production rate scaling factors through direct measurement

    CERN Document Server

    Graham, I J; Ditchburn, R G; Whitehead, N E

    2000-01-01

    sup 7 Be produced in water targets by nuclear interactions of cosmic rays has been measured to determine cosmogenic nuclide production rates as a function of altitude (sea level to 2 km) and geomagnetic latitude (20-79 deg. S). Relative intensities of low energy cosmic ray neutrons have at the same time been measured using neutron monitors based on IGY/NM-64 designed to efficiently thermalise ca. 2-30 MeV neutrons. The research is on-going and we present here preliminary data from the past two years. Water target and neutron flux results are in general agreement, and are consistent with the altitude-dependent scaling factors of Lal [Earth Planet. Sci. Lett. 104 (1991) 4241]. Significant differences between the sea level, latitude-dependent neutron flux data and Lal's predictions are possibly related to the response function of the detector.

  4. SLUDGE MASS REDUCTION: PRIMARY COMPOSITIONAL FACTORS THAT INFLUENCE MELT RATE FOR FUTURE SLUDGE BATCH PROJECTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Newell, J; Miller, D; Stone, M; Pickenheim, B

    2008-08-28

    of the Frit 510 based system without Al-dissolution relative to the Frit 418 based system with Al-dissolution. Though the without aluminum dissolution scenario suggests a slightly higher melt rate with frit 510, several points must be taken into consideration: (1) The MRF does not have the ability to assess liquid feeds and, thus, rheology impacts. Instead, the MRF is a 'static' test bed in which a mass of dried melter feed (SRAT product plus frit) is placed in an 'isothermal' furnace for a period of time to assess melt rate. These conditions, although historically effective in terms of identifying candidate frits for specific sludge batches and mapping out melt rate versus waste loading trends, do not allow for assessments of the potential impact of feed rheology on melt rate. That is, if the rheological properties of the slurried melter feed resulted in the mounding of the feed in the melter (i.e., the melter feed was thick and did not flow across the cold cap), melt rate and/or melter operations (i.e., surges) could be negatively impacted. This could affect one or both flowsheets. (2) Waste throughput factors were not determined for Frit 510 and Frit 418 over multiple waste loadings. In order to provide insight into the mission life versus canister count question, one needs to define the maximum waste throughput for both flowsheets. Due to funding limitations, the melt rate testing only evaluated melt rate at a fixed waste loading. (3) DWPF will be processing SB5 through their facility in mid-November 2008. Insight into the over arching questions of melt rate, waste throughput, and mission life can be obtained directly from the facility. It is recommended that processing of SB5 through the facility be monitored closely and that data be used as input into the decision making process on whether to implement Al-dissolution for future sludge batches.

  5. Miss rate of colorectal neoplastic polyps and risk factors for missed polyps in consecutive colonoscopies.

    Science.gov (United States)

    Kim, Nam Hee; Jung, Yoon Suk; Jeong, Woo Shin; Yang, Hyo-Joon; Park, Soo-Kyung; Choi, Kyuyong; Park, Dong Il

    2017-07-01

    Colonoscopic polypectomy is the best diagnostic and therapeutic tool to detect and prevent colorectal neoplasms. However, previous studies have reported that 17% to 28% of colorectal polyps are missed during colonoscopy. We investigated the miss rate of neoplastic polyps and the factors associated with missed polyps from quality-adjusted consecutive colonoscopies. We reviewed the medical records of patients who were found to have colorectal polyps at a medical examination center of the Kangbuk Samsung Hospital between March 2012 and February 2013. Patients who were referred to a single tertiary academic medical center and underwent colonoscopic polypectomy on the same day were enrolled in our study. The odds ratios (ORs) associated with polyp-related and patient-related factors were evaluated using logistic regression analyses. A total of 463 patients and 1,294 neoplastic polyps were analyzed. The miss rates for adenomas, advanced adenomas, and carcinomas were 24.1% (312/1,294), 1.2% (15/1,294), and 0% (0/1,294), respectively. Flat/sessile-shaped adenomas (adjusted OR, 3.62; 95% confidence interval [CI], 2.40-5.46) and smaller adenomas (adjusted OR, 5.63; 95% CI, 2.84- 11.15 for ≤5 mm; adjusted OR, 3.18; 95% CI, 1.60-6.30 for 6-9 mm, respectively) were more frequently missed than pedunculated/sub-pedunculated adenomas and larger adenomas. In patients with 2 or more polyps compared with only one detected (adjusted OR, 2.37; 95% CI, 1.55-3.61 for 2-4 polyps; adjusted OR, 11.52; 95% CI, 4.61-28.79 for ≥5 polyps, respectively) during the first endoscopy, the risk of missing an additional polyp was significantly higher. One-quarter of neoplastic polyps was missed during colonoscopy. We encourage endoscopists to detect smaller and flat or sessile polyps by using the optimal withdrawal technique.

  6. [Perforated peptic ulcer: is the form of methamphetamine known as "crystal meth" a new risk factor?].

    Science.gov (United States)

    Martínez-Aguirre, A E; Romero-Mejía, C; Chacón-Cruz, E

    2012-01-01

    The emergence of new synthetic drugs related to peptic ulcer perforation has been reported. Recently an increase in the use of inhaled methamphetamine has been observed and we have described an association of frequent use with peptic disease symptomatology and perforation. To determine whether methamphetamine use is a factor related to peptic acid disease and perforation and to establish its demographic variables. A retrospective, comparative, descriptive, and observational study was carried out through the evaluation of medical records of patients admitted to the Surgery Service with perforated ulcer, within the time frame of January 2002 to March 2005. A descriptive analysis was carried out, along with the Z test, odds ratio, confidence interval, p value and the Student's t test. Forty-two patients were divided into 2 groups: methamphetamine users (n=25) and nonusers (n=17). There was a statistically significant difference in relation to age, which was lower in the methamphetamine user group (38,7 years vs 58,88 years, p=0.0001). In addition, there was a trend in the user group to develop peptic ulcer perforation at earlier ages compared with the nonuser group (p=0.0001). There were no statistically significant differences between the two groups in regard to clinical presentation. Methamphetamine use is related to ulcer perforation in age groups of younger patients when compared with nonuser patients. Copyright © 2011. Published by Masson Doyma México S.A.

  7. Determining the Independent Risk Factors and Mortality Rate of Nosocomial Infections in Pediatric Patients.

    Science.gov (United States)

    Aktar, Fesih; Tekin, Recep; Güneş, Ali; Ülgen, Cevat; Tan, İlhan; Ertuğrul, Sabahattin; Köşker, Muhammet; Balık, Hasan; Karabel, Duran; Yolbaş, Ilyas

    2016-01-01

    The objective of this study was to determine the rate, independent risk factors, and outcomes of healthcare-associated infections in pediatric patients. This study was performed between 2011 and 2014 in pediatric clinic and intensive care unit. 86 patients and 86 control subjects were included in the study. Of 86 patients with nosocomial infections (NIs), there were 100 NIs episodes and 90 culture growths. The median age was 32.0 months. The median duration of hospital stay of the patients was 30.0 days. The most frequent pathogens were Coagulase-negative Staphylococcus, Acinetobacter spp., Klebsiella spp., and Candida spp. Unconsciousness, prolonged hospitalization, transfusion, mechanical ventilation, use of central venous catheter, enteral feeding via a nasogastric tube, urinary catheter, and receiving carbapenems and glycopeptides were found to be significantly higher in NIs patients. Multivariate logistic regression analysis showed prolonged hospitalization, neutropenia, and use of central venous catheter and carbapenems as the independent risk factors for NIs. In the univariate analysis, unconsciousness, mechanical ventilation, enteral feeding, use of enteral feeding via a nasogastric tube, H2 receptor blockers, and port and urinary catheter were significantly associated with mortality. In the multiple logistic regression analysis, only mechanical ventilation was found as an independent predictor of mortality in patients with NIs.

  8. Determining the Independent Risk Factors and Mortality Rate of Nosocomial Infections in Pediatric Patients

    Directory of Open Access Journals (Sweden)

    Fesih Aktar

    2016-01-01

    Full Text Available The objective of this study was to determine the rate, independent risk factors, and outcomes of healthcare-associated infections in pediatric patients. This study was performed between 2011 and 2014 in pediatric clinic and intensive care unit. 86 patients and 86 control subjects were included in the study. Of 86 patients with nosocomial infections (NIs, there were 100 NIs episodes and 90 culture growths. The median age was 32.0 months. The median duration of hospital stay of the patients was 30.0 days. The most frequent pathogens were Coagulase-negative Staphylococcus, Acinetobacter spp., Klebsiella spp., and Candida spp. Unconsciousness, prolonged hospitalization, transfusion, mechanical ventilation, use of central venous catheter, enteral feeding via a nasogastric tube, urinary catheter, and receiving carbapenems and glycopeptides were found to be significantly higher in NIs patients. Multivariate logistic regression analysis showed prolonged hospitalization, neutropenia, and use of central venous catheter and carbapenems as the independent risk factors for NIs. In the univariate analysis, unconsciousness, mechanical ventilation, enteral feeding, use of enteral feeding via a nasogastric tube, H2 receptor blockers, and port and urinary catheter were significantly associated with mortality. In the multiple logistic regression analysis, only mechanical ventilation was found as an independent predictor of mortality in patients with NIs.

  9. Reading dream literature: frequency, influencing factors, and self-rated benefit.

    Science.gov (United States)

    Schredl, Michael

    2011-01-01

    Dream books have a very long history, but systematic research on how many people have read magazine articles or books on dreams and whether reading such literature is beneficial to the dreamer is scarce. In the present sample of 444 people (mostly psychology students), about 75% of the participants stated that they had read at least one magazine article on dreams, and more than 40% had read at least one book about dreams. The main factor associated with the frequency of reading dream literature was a positive attitude toward dreaming, whereas personality factors play a minor role in explaining interindividual differences in this variable. The self-rated benefit of reading dream literature varied greatly, from not helpful at all to very helpful, and was associated with dream recall frequency and positive attitude toward dreaming. Using this approach in a more sophisticated way, eliciting details about the kinds of information participants have read would help researchers learn more about what techniques of dream work are effective and thus complement the research carried out in therapist-guided sessions.

  10. Addictive Behaviors Amongst University Students: Contributing Factors, Student's Perception and Addiction Rates

    Directory of Open Access Journals (Sweden)

    Ahmad Houri

    2005-01-01

    Full Text Available Factors contributing to addictive behaviors affecting student health are analyzed in this study. Smoking, alcohol consumption, and the use of illegal drugs are assessed in a sample of 290 university students. General averages indicate that 37.2% of students smoke cigarettes, 49.8% drink alcohol regularly, and 17.9% have tried illegal drugs while 4.8% of them use it regularly. Age, academic achievement, gender, religion, family status and financial status were correlated to these addictive behaviors. Major findings show a clear relationship between smoking and most variables. The main factor involved in drinking was found to be religion, while illegal drug consumption was most clearly correlated to parents’ education and monthly income. Students’ self perception regarding smoking and tendency to use illegal drug was assessed showing that 11.7% of smokers consider themselves non-smokers while 11.8% considered trying illegal drugs acceptable. Addiction rates after initial consumption are analyzed showing 74.7% for alcohol, 51.7% for smoking cigarettes and 26.9% for drugs. A risk profile for each addiction type is presented.

  11. Factors influencing the adolescent pregnancy rate in the Greater Giyani Municipality, Limpopo Province – South Africa

    Directory of Open Access Journals (Sweden)

    Lenny Mushwana

    2015-01-01

    Full Text Available A quantitative, descriptive and explorative survey was conducted to determine factors that influence adolescent pregnancy rate among teenage girls (n = 147 attending four high schools in the Greater Giyani Municipality in South Africa. Data was collected using a validated questionnaire which had a reliability of 0.65. Response frequency distributions, two-way frequency tables, Chi-square tests and Cochran–Armitage Trend Tests were used to determine the effect with the demographic characteristics of participants. Participants reported that health services were not conveniently available for them. Their relationship with nurses was poor (p < 0.05 as reported by 73% of participants with regard to maintenance of confidentiality. Participants reported key psychosocial variables such as inadequate sexual knowledge (61%, changing attitudes towards sex (58.9% and peer pressure (56.3% as contributory to high pregnancy rate. Recommendations were made to improve school health services, reproductive education in school curricula focussing on reproductive health, sexuality and guidance for future research.

  12. [Correlative factors on prevalence rate of dislipidemia among 1 337 coal miners in Shanxi province].

    Science.gov (United States)

    Fu, Z D; Wen, D D; Wang, B; Xue, S L; Liu, G S; Li, X H; Zhao, Z H; Wang, J; Wei, B G; Wang, S P

    2017-02-10

    Objective: To understand the prevalence rate and correlative factors of dislipidemia among Shanxi coal miners and to provide evidence for the development of programs on dislipidemia prevention. Methods: We investigated 1 337 mine workers from a Coal Group in April 2016 and collected data related to their blood biochemistry. We then classified the types in accordance with the diagnostic criteria of " Guidelines for prevention and treatment of dyslipidemia in Chinese adults (2007)" , using χ(2) test and unconditional logistic regression model for analysis. Results: The overall prevalence rate of Dislipidemia was 59.1% (790/1 337), with males as 60.4% (708/1 173) and females as 50.0%(82/164) while males appeared higher (χ(2)=6.386, Pdislipidemia (χ(2)=7.117, Pdislipidemia (Pdislipidemia. Conclusion: Among the coal mine workers, those who were males, aged from 20 to 34, having high blood pressure (systolic blood pressure abnormalities) or with high BMI (≥24.0 kg/m(2)) need to be taken special attention on care and prevention of dislipidemia.

  13. A transcription factor links growth rate and metabolism in the hypersaline adapted archaeon Halobacterium salinarum.

    Science.gov (United States)

    Todor, Horia; Dulmage, Keely; Gillum, Nicholas; Bain, James R; Muehlbauer, Michael J; Schmid, Amy K

    2014-09-01

    Co-ordinating metabolism and growth is a key challenge for all organisms. Despite fluctuating environments, cells must produce the same metabolic outputs to thrive. The mechanisms underlying this 'growth homeostasis' are known in bacteria and eukaryotes, but remain unexplored in archaea. In the model archaeon Halobacterium salinarum, the transcription factor TrmB regulates enzyme-coding genes in diverse metabolic pathways in response to glucose. However, H. salinarum is thought not to catabolize glucose. To resolve this discrepancy, we demonstrate that TrmB regulates the gluconeogenic production of sugars incorporated into the cell surface S-layer glycoprotein. Additionally, we show that TrmB-DNA binding correlates with instantaneous growth rate, likely because S-layer glycosylation is proportional to growth. This suggests that TrmB transduces a growth rate signal to co-regulated metabolic pathways including amino acid, purine, and cobalamin biosynthesis. Remarkably, the topology and function of this growth homeostatic network appear conserved across domains despite extensive alterations in protein components.

  14. Factors affecting the first service conception rate of cows in smallholder dairy farms in Bangladesh.

    Science.gov (United States)

    Siddiqui, M A R; Das, Z C; Bhattacharjee, J; Rahman, M M; Islam, M M; Haque, M A; Parrish, J J; Shamsuddin, M

    2013-06-01

    The successful outcome of an insemination is a combination of both male and female fertility-linked factors. We investigated the first service conception rate of cows at artificial insemination (AI) in the smallholder dairy farms in Bangladesh. Frozen straws were prepared from ejaculates of Bos indicus (n = 7) and Bos indicus × Bos taurus (n = 7) AI bulls. Fertility was determined from 6101 first services in cows that were performed by 18 technicians in four regions between April 2004 and March 2005. Pregnancy was diagnosed by rectal palpation between 60 and 90 days post-insemination. The Asian version of Artificial Insemination Database Application (AIDA ASIA) was used for bulls-, cows- and AI-related data recording, and later retrieved for analysis. The mean ± SD number of inseminations performed from individual bulls and their conception rates were 436.0 ± 21.6 and 50.7 ± 1.9%, respectively. Logistic regression demonstrated body condition scores (BCS), heat detection signs, months of AI and their interactions had greatest effects (odds ratios: 1.24-16.65, p cows. Fertility differed (p heat detection signs of cows. Inseminations based on mounting activity (n = 2352), genital discharge (n = 3263) and restlessness and/or other signs (n = 486) yielded a conception rate of 53.6%, 48.8% and 50.1%, respectively (p cows. Fertility at AI in smallholder farms can be improved by training farmers on nutrition and reproductive management of the cows.

  15. Rates of credit obligations compliance on IFRS financial statement as a factor of financial stability

    Directory of Open Access Journals (Sweden)

    O. V. Uvarova

    2016-01-01

    Full Text Available For the purposes of effective management of economic activity of the entities of insufficiently own accounting information. For objective assessment of a financial and economic provision of the entity it is necessary to pass from separate accounting data to certain valuable ratios of major factors – to financial performance or financial ratios. Calculation and interpretation of their values the integral and essentially necessary part of a financial analysis, especially it is important if the company has credit liabilities. Conditions of credit agreements often include accomplishment of credit covenants which represent restrictions for activities and a financial position of the company in addition to timely settlement of percent and a body of the credit and provide to lessors a certain level of safety from bankruptcy of the debtor. The article considers the covenants and financial covenants definitions; the main financial covenants containing in credit agreements between large banks and borrowers; data on structure of a credit portfolio and financial debt of NLMK as at June 30, 2016; the main financial covenants containing in credit agreements of the companies of NLMK Group; definitions and formulas of calculation of financial rates based on the IFRS financial statement; calculation of covenants on the example of IFRS consolidated financial statements of NLMK; subtleties of calculation of financial rates; the main differences of financial rates calculation based on the financial statements prepared on the different principles; conclusion about stability and a financial condition of NLMK by the results received during calculation financial covenants as at end of the first half of the year 2016.

  16. Study on Purifying Technology of Andrographolide by Supercritical CO2 Secondary Gradient Crystallization

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen-cheng; PAN Jian

    2004-01-01

    The effects of the secondary gradient crystallizing pressure, temperature and time on the purity and crystallization ratio of andrographolide were investigated via single factor experiments. The shape of crystal was observed with scanning electron microscopy (SEM). The purity of andrographolide was determined by high pressure liquid chromatography (HPLC). It was found that the optimized parameters were pressure 14 MPa, temperature 55℃,time 60 min, and CO2 flow rate 15 L min-1, under these conditions the particle of andrographolide was much smaller, the crystal of andrographolide was distributed in floccule on crystal board, with the purity of andrographolide 92.5%, the crystallization ratio 48.9%.

  17. Artistic Crystal Creations

    Science.gov (United States)

    Lange, Catherine

    2008-01-01

    In this inquiry-based, integrative art and science activity, Grade 5-8 students use multicolored Epsom salt (magnesium sulfate) crystallizing solutions to reveal beautiful, cylindrical, 3-dimensional, needle-shaped structures. Through observations of the crystal art, students analyze factors that contribute to crystal size and formation, compare…

  18. Crystal Structure of the C-terminal Domain of Splicing Factor Prp8 Carrying Retinitis Pigmentosa Mutants

    Energy Technology Data Exchange (ETDEWEB)

    Zhang,L.; Shen, J.; Guarnieri, M.; Heroux, A.; Yang, K.; Zhao, R.

    2007-01-01

    Prp8 is a critical pre-mRNA splicing factor. Prp8 is proposed to help form and stabilize the spliceosome catalytic core and to be an important regulator of spliceosome activation. Mutations in human Prp8 (hPrp8) cause a severe form of the genetic disorder retinitis pigmentosa, RP13. Understanding the molecular mechanism of Prp8's function in pre-mRNA splicing and RP13 has been hindered by its large size (over 2000 amino acids) and remarkably low-sequence similarity with other proteins. Here we present the crystal structure of the C-terminal domain (the last 273 residues) of Caenorhabditis elegans Prp8 (cPrp8). The core of the C-terminal domain is an / structure that forms the MPN (Mpr1, Pad1 N-terminal) fold but without Zn{sup 2+} coordination. We propose that the C-terminal domain is a protein interaction domain instead of a Zn{sup 2+}-dependent metalloenzyme as proposed for some MPN proteins. Mapping of RP13 mutants on the Prp8 structure suggests that these residues constitute a binding surface between Prp8 and other partner(s), and the disruption of this interaction provides a plausible molecular mechanism for RP13.

  19. Phase selection during the crystallization of metal-organic frameworks; thermodynamic and kinetic factors in the lithium tartrate system.

    Science.gov (United States)

    Yeung, Hamish Hei-Man; Cheetham, Anthony Kevin

    2014-01-01

    We report the phase behaviour of chiral, racemic and meso-lithium tartrate frameworks, which was examined as a function of solvent system, temperature and ligand isomer. Through our comprehensive investigation of this system of 14 diverse phases, we have gained detailed insight into the effect of synthesis conditions on product structure, and elucidated the thermodynamic and kinetic factors involved in phase selection. Reactions in ethanol between lithium acetate and chiral, racemic and meso-tartaric acids give rise to anhydrous kinetic products; polymorphs with higher entropy tend to appear at high temperatures. Reactions at room temperature in water-ethanol mixtures give rise to hydrated kinetic products, including two new crystal structures, [Li2(D,L-tartrate)(H2O)2]n in P1 and [Li2(meso-tartrate)(H2O)(0.5)]n in C222(1), whose structures are contrasted with known anhydrous products. Reactions at elevated temperatures in water-ethanol mixtures result in the formation of low enthalpy, anhydrous products and, furthermore, the global minimum energy structure appears at high temperatures in all cases owing to in situ ligand isomerization.

  20. Manual rotation in occiput posterior or transverse positions: risk factors and consequences on the cesarean delivery rate

    National Research Council Canada - National Science Library

    Le Ray, Camille; Serres, Pauline; Schmitz, Thomas; Cabrol, Dominique; Goffinet, François

    2007-01-01

    To identify the risk factors for failure of manual rotation in patients with occiput posterior or transverse positions during labor and to study the cesarean rate according to the success of the rotation...

  1. Percutaneous transluminal angioplasty for Brescia-Cimino hemodialysis fistula dysfunction: technical success rate, patency rate and factors that influence the results

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Kiyosumi [Department of Radiology, Shiga University of Medical Science, Seta-Tsukinowa-cho, Otsu-city, Shiga 520-2192 (Japan)]. E-mail: kiyosumi@belle.shiga-med.ac.jp; Furukawa, Akira [Department of Radiology, Shiga University of Medical Science, Seta-Tsukinowa-cho, Otsu-city, Shiga 520-2192 (Japan); Yamasaki, Michio [Department of Radiology, Shiga University of Medical Science, Seta-Tsukinowa-cho, Otsu-city, Shiga 520-2192 (Japan); Murata, Kiyoshi [Department of Radiology, Shiga University of Medical Science, Seta-Tsukinowa-cho, Otsu-city, Shiga 520-2192 (Japan)

    2005-06-01

    Objective: To evaluate the initial clinical success and long-term patency rates of percutaneous transluminal angioplasty (PTA) using a venous approach for dysfunctional Brescia-Cimino fistula and to identify factors that may affect initial success and long-term patency. Materials and methods: A total of 99 PTA procedures were performed in retrograde fassion for 60 mature Brescia-Cimino shunts with dysfunction caused by anastomotic or peripheral outflow vein stenosis or occlusion. The initial clinical success rates were compared between stenosis and occlusion using Fisher's exact test. The Kaplan-Meier method was used to calculate the primary and secondary cumulative patency rates, and the log-rank test was used for comparison. Relative risks of patency loss according to clinical characteristics were determined with multivariate Cox models. Results: The initial clinical success rate of all interventions was 92%, and the rates for stenosis and occlusion were 99 and 65%, respectively (P < 0.0001). The primary and secondary cumulative patency rates for fistulas (excluding initial failure) at 12 months were 53 and 84%, respectively. The relative risks were 5.2 (P 0.004) for longer lesions and 4.5 (P = 0.007) for younger fistulas. The primary cumulative patency rate of four patients with a younger fistula and a longer stenosis at 4 months was 0%. Conclusion: Favorable primary and secondary cumulative patency rates are obtained in most patients. Long lesion length and younger age of fistulas were the two factors that reduced the patency rate after PTA.

  2. [Social class, psychosocial occupational risk factors, and the association with self-rated health and mental health in Chile].

    Science.gov (United States)

    Rocha, Kátia Bones; Muntaner, Carles; Solar, Orielle; Borrell, Carme; Bernales, Pamela; González, María José; Ibañez, Ciro; Benach, Joan; Vallebuona, Clélia

    2014-10-01

    The objective of this study was to analyze the association between social class and psychosocial occupational risk factors and self-rated health and mental health in a Chilean population. A cross-sectional study analyzed data from the First National Survey on Employment, Work, Quality of Life, and Male and Female Workers in Chile (N = 9,503). The dependent variables were self-rated health status and mental health. The independent variables were social class (neo-Marxist), psychosocial occupational risk factors, and material deprivation. Descriptive and logistic regression analyses were performed. There were inequalities in the distribution of psychosocial occupational risk factors by social class and sex. Furthermore, social class and psychosocial occupational risk factors were associated with unequal distribution of self-rated health and mental health among the working population in Chile. Occupational health interventions should consider workers' exposure to socioeconomic and psychosocial risk factors.

  3. Effects of formulation and process factors on the crystal structure of freeze-dried Myo-inositol.

    Science.gov (United States)

    Izutsu, Ken-Ichi; Yomota, Chikako; Okuda, Haruhiro; Kawanishi, Toru; Yamaki, Takuya; Ohdate, Ryohei; Yu, Zhaokun; Yonemochi, Etsuo; Terada, Katsuhide

    2014-08-01

    The objective of this study was to elucidate effects of formulation and process variables on the physical forms of freeze-dried myo-inositol. Physical properties of myo-inositol in frozen solutions, freeze-dried solids, and cooled heat-melt solids were characterized by powder X-ray diffraction (PXRD), thermal analysis (differential scanning calorimetry [DSC] and thermogravimetric), and simultaneous PXRD-DSC analysis. Cooling of heat-melt myo-inositol produced two forms of metastable anhydrate crystals that change to stable form (melting point 225 °C-228 °C) with transition exotherms at around 123 °C and 181 °C, respectively. Freeze-drying of single-solute aqueous myo-inositol solutions after rapid cooling induced crystallization of myo-inositol as metastable anhydrate (transition at 80 °C-125 °C) during secondary drying segment. Contrarily, postfreeze heat treatment (i.e., annealing) induced crystallization of myo-inositol dihydrate. Removal of the crystallization water during the secondary drying produced the stable-form myo-inositol anhydrate crystal. Shelf-ramp slow cooling of myo-inositol solutions resulted in the stable and metastable anhydrous crystal solids depending on the solute concentrations and the solution volumes. Colyophilization with phosphate buffer retained myo-inositol in the amorphous state. Crystallization in different process segments varies crystal form of freeze-dried myo-inositol solids.

  4. Generation of microwave radiation by nonlinear interaction of a high-power, high-repetition rate, 1064-nm laser in KTP crystals

    CERN Document Server

    Borghesani, A F; Carugno, G

    2013-01-01

    We report measurements of microwave (RF) generation in the centimeter band accomplished by irradiating a nonlinear KTiOPO$_4$ (KTP) crystal with a home-made, infrared laser at $1064\\,$nm as a result of optical rectification (OR). The laser delivers pulse trains of duration up to $1\\,\\mu$s. Each train consists of several high-intensity pulses at an adjustable repetition rate of approximately $ 4.6\\,$GHz. The duration of the generated RF pulses is determined by that of the pulse trains. We have investigated both microwave- and second harmonic (SHG) generation as a function of the laser intensity and of the orientation of the laser polarization with respect to the crystallographic axes of KTP.

  5. Self-Rated Health among Urban Adolescents: The Roles of Age, Gender, and Their Associated Factors.

    Directory of Open Access Journals (Sweden)

    Adriana Lúcia Meireles

    Full Text Available Health status is often analyzed in population surveys. Self-rated health (SRH is a single-item summary measure of the perception of one's health. In Brazil, studies on the SRH of adolescents remain scarce, especially those aiming to understand the domains that compose this construct. Therefore, the aim of this study is to determine the prevalence of poor SRH and its associated factors among 11- to 13-year-olds and 14- to 17-year-olds living in a large urban center in Brazil. This cross-sectional study was conducted using a household survey across Belo Horizonte that included 1,042 adolescents. Stratified logistic regression models were used for each age group to assess the associations between worse SRH and the following variables: socio-demographic, social and family support, lifestyles, psychological health, and anthropometry. Approximately 11% (95% CIs = 8.7-13.6 of the studied adolescents rated their health as poor, and SHR decreased with age among males and females. This trend was more pronounced among girls (from 6.9% among 11- to 13-year-old girls to 16.9% among 14- to 17-year-old girls than boys (from 8.3% among 11- to 13-year-old boys to 11% among 14- to 17-year-old boys. Worse SRH was associated with family support (as assessed by the absence of parent-adolescent conversations; odds ratio [OR] = 3.5 among 11- to 13-year-olds, family structure (OR = 2.8 among 14- to 17-year-olds, and argument reporting (OR = 8.2 among 14- to 17-year-olds. Among older adolescents, the consumption of fruit fewer than five times per week (OR = 2.4, life dissatisfaction (OR = 2.8, underweight status (OR = 6.7, and overweight status (OR = 2.7 were associated with poor SRH. As adolescents age, their universe expands from their relationship with their parents to include more complex issues, such as their lifestyles and life satisfaction. Therefore, these results suggest the importance of evaluating SRH across adolescent age groups and demonstrate the influence

  6. Factors Affecting College-Going Rates in California: A Study Prospectus. Working Paper WP/06-09

    Science.gov (United States)

    California Postsecondary Education Commission, 2006

    2006-01-01

    This working paper announces a report proposed by the California Postsecondary Education Commission to conduct a further statistical study on the factors affecting college-going rates in California. These factors would include school demographics, neighborhood characteristics, and regional labor market forces. Such a study could reveal insights…

  7. Relationship Between Diurnal Changes of Net Photosynthetic Rate and Influencing Factors in Rice under Saline Sodic Stress

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The net photosynthetic rate of flag leaves and influencing factors under saline sodic soil conditions were investigated at the full heading stage of rice.The net photosynthetic rate of rice leaves showed a double-peak curve in a day in both non-saline sodic and saline sodic soil treatments.The first peak of the net photosynthetic rate appeared at 9:00-10:00 and 9:00 in the saline sodic and non-saline sodic soil treatments,respectively,whereas the second peak both at 14:00.The midday depression of the net photosynthetic rate always appeared regardless of non-saline sodic or saline sodic soil conditions.In addition,the net photosynthetic rate significantly decreased in all day under saline sodic conditions compared with that under non-saline sodic conditions.Some differences were observed in correlation characters between the net photosynthetic rate and all influencing factors during 9:00-13:00.Under non-saline sodic conditions,the diurnal changes of the net photosynthetic rate in a day were mainly caused by stomatal conductance,and the limitation value and the stomatal factors served as determinants;whereas under saline soclic stress,the diurnal changes of the net photosynthetic rate in a day were mainly caused by non stomatal factors including light intensity and air temperature.

  8. Are age-related trends in suicide rates associated with life expectancy and socio-economic factors?

    Science.gov (United States)

    Shah, Ajit

    2009-01-01

    Background. A recent cross-national study reported that suicide rates increased, decreased or remained unchanged with increasing age in individual countries. The relationship between age-related trends in suicide rates and child mortality rates, life expectancy and socio-economic factors was examined. Methods. Countries with an increase, decrease and no change in suicide rates with increasing age were ascertained from an earlier study (Shah, 2007a, International Psychogeriatrics, 19, 1141), which analysed data from the World Health Organisation (WHO). The relationship between age-related trends in suicide rates and (i) child mortality rates, (ii) life expectancy and (iii) markers of socio-economic status (per capita gross national domestic product (GDP) and the Gini coeffcient) was examined using data from the WHO and the United Nations. Results. The main findings were: (i) child mortality rates were significantly lower in countries with an increase in suicide rates with increasing age when compared to countries without a change in suicide rates with increasing age in males; (ii) life expectancy was significantly higher in countries with an increase in suicide rates with increasing age when compared to countries without a change in suicide rates with increasing age in males; and (iii) the Gini coefficient was significantly lower in countries with an increase in suicide rates with increasing age when compared to countries without a change or a decline in suicide rates with increasing age in females. Conclusions. Potential explanations for these findings and the interaction of life expectancy and socio-economic factors with other factors that differentially influence suicide rates in different age and sex groups requires further examination.

  9. Mortality, Rehospitalisation and Violent Crime in Forensic Psychiatric Patients Discharged from Hospital: Rates and Risk Factors.

    Directory of Open Access Journals (Sweden)

    Seena Fazel

    Full Text Available To determine rates and risk factors for adverse outcomes in patients discharged from forensic psychiatric services.We conducted a historical cohort study of all 6,520 psychiatric patients discharged from forensic psychiatric hospitals between 1973 and 2009 in Sweden. We calculated hazard ratios for mortality, rehospitalisation, and violent crime using Cox regression to investigate the effect of different psychiatric diagnoses and two comorbidities (personality or substance use disorder on outcomes.Over mean follow-up of 15.6 years, 30% of patients died (n = 1,949 after discharge with an average age at death of 52 years. Over two-thirds were rehospitalised (n = 4,472, 69%, and 40% violently offended after discharge (n = 2,613 with a mean time to violent crime of 4.2 years. The association between psychiatric diagnosis and outcome varied-substance use disorder as a primary diagnosis was associated with highest risk of mortality and rehospitalisation, and personality disorder was linked with the highest risk of violent offending. Furthermore comorbid substance use disorder typically increased risk of adverse outcomes.Violent offending, premature mortality and rehospitalisation are prevalent in patients discharged from forensic psychiatric hospitals. Individualised treatment plans for such patients should take into account primary and comorbid psychiatric diagnoses.

  10. Rate of Corneal Collagen Crosslinking Redo in Private Practice: Risk Factors and Safety

    Directory of Open Access Journals (Sweden)

    Joelle Antoun

    2015-01-01

    Full Text Available Objective. To report the rate of progression of keratectasia after primary crosslinking (CXL and evaluate the safety and efficiency of CXL redo. Materials and Methods. We conducted a retrospective analysis of the patients who underwent CXL between 2010 and 2013 at the Beirut Eye Specialist Hospital, Lebanon. Progression of keratectasia was based on the presence of an increase in maximum keratometry of 1.00 D, a change in the map difference between two consecutive topographies of 1.00 D, a deterioration of visual acuity, or any change in the refraction. Primary and redo CXL were done using the same protocol. Results. Among the 221 eyes of 130 patients who underwent CXL, 7 eyes (3.17% of five patients met the criteria of progression. All patients reported a history of allergic conjunctivitis and eye rubbing and progressed within 9 to 48 months. No complications were noted and all patients were stable 1 year after CXL redo. Conclusion. Allergic conjunctivitis and eye rubbing were the only risk factors associated with keratoconus progression after CXL. A close followup is thus mandatory, even years after the procedure. CXL redo seems to be a safe and efficient technique to halt the progression after a primary CXL.

  11. Age-related decline in the rate of force development scaling factor.

    Science.gov (United States)

    Bellumori, Maria; Jaric, Slobodan; Knight, Christopher A

    2013-10-01

    Physical quickness is less in older adults with implications for fall prevention, movement initiation, and activities of daily living. The purpose was to compare control of rapid contractions in young and older adults within two diverse muscle groups: powerful elbow extensors (EE) and dexterous index finger abductors (IFA). Most-rapid force pulses to a variety of levels were recorded and peak force and rate of force development (RFD) were analyzed with linear regression. The resulting slope represents the dependent variable of interest, the RFD-scaling factor (RFD-SF). RFD-SF of EE and IFA strongly correlated both overall (r = .87, p < .01) and separately in young (r = .60, p < .05) and older (r = .77, p < .01) adults. RFD-SF values were different between muscle groups (F1,28 = 19.1, p < .001) and also less in elderly (F1,28 = 32.6, p < .001). We conclude that RFD-SF provides a sensitive assessment of muscle quickness that can be used to evaluate neuromuscular function in aging humans.

  12. Expression, purification, crystallization and structure determination of the N terminal domain of Fhb, a factor H binding protein from Streptococcus suis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Chunmao [State Key Laboratory of Pathogen and Biosecurity, Beijng Institute of Microbiology and Infectious Disease, No. 20 Dongda Street, Fengtai District, Beijing 100071 (China); Yu, You [Key Laboratory for Protein Sciences of Ministry of Education, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084, Beijing (China); Yang, Maojun, E-mail: maojunyang@tsinghua.edu.cn [Key Laboratory for Protein Sciences of Ministry of Education, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, 100084, Beijing (China); Jiang, Yongqiang, E-mail: jiangyq@bmi.ac.cn [State Key Laboratory of Pathogen and Biosecurity, Beijng Institute of Microbiology and Infectious Disease, No. 20 Dongda Street, Fengtai District, Beijing 100071 (China)

    2015-10-23

    Fhb is a surface virulence protein from Streptococcus suis, which could aid bacterial evasion of host innate immune defense by recruiting complement regulator factor H to inactivate C3b deposited on bacterial surface in blood. Here we successfully expressed and purified the N terminal domain of Fhb (N-Fhb) and obtained crystals of the N-Fhb by sitting-drop vapor diffusion method with a resolution of 1.50 Å. The crystals belong to space group C2 with unit cell parameters a = 127.1 Å, b = 77.3 Å, c = 131.6 Å, α = 90°, β = 115.9°, γ = 90°. The structure of N-Fhb was determined by SAD method and the core structure of N-Fhb is a β sandwich. We speculated that binding of Fhb to human factor H may be mainly mediated by surface amino acids with negative charges. - Highlights: • We expressed N-Fhb as the soluble protein in Escherichia coli. • Crystals of N-Fhb were grown by sitting drop vapor diffusion method. • Crystals of N-Fhb could diffracted to 1.5 Å. • The core structure of N-Fhb was a β sandwich. • A part of the surface of N-Fhb was rich with negative charges.

  13. Factors affecting conception rates following artificial insemination or embryo transfer in lactating Holstein cows.

    Science.gov (United States)

    Demetrio, D G B; Santos, R M; Demetrio, C G B; Vasconcelos, J L M

    2007-11-01

    The objective of this study was to evaluate the factors that may affect conception rates (CR) following artificial insemination (AI) or embryo transfer (ET) in lactating Holstein cows. Estrous cycling cows producing 33.1 +/- 7.2 kg of milk/d received PGF2alpha injections and were assigned randomly to 1 of 2 groups (AI or ET). Cows detected in estrus (n = 387) between 48 and 96 h after the PGF2alpha injection received AI (n = 227) 12 h after detection of estrus or ET (n = 160) 6 to 8 d later (1 fresh embryo, grade 1 or 2, produced from nonlactating cows). Pregnancy was diagnosed at 28 and 42 d after estrus, and embryonic loss occurred when a cow was pregnant on d 28 but not pregnant on d 42. Ovulation, conception, and embryonic loss were analyzed by a logistic model to evaluate the effects of covariates [days in milk (DIM), milk yield, body temperature (BT) at d 7 and 14 post-AI, and serum concentration of progesterone (P4) at d 7 and 14 post-AI] on the probability of success. The first analysis included all cows that were detected in estrus. The CR of AI and ET were different on d 28 (AI, 32.6% vs. ET, 49.4%) and 42 (AI, 29.1% vs. ET, 38.8%) and were negatively influenced by high BT (d 7) and DIM. The second analysis included only cows with a corpus luteum on d 7. Ovulation rate was 84.8% and was only negatively affected by DIM. Conception rates of AI and ET were different on d 28 (AI, 37.9% vs. ET, 59.4%) and 42 (AI, 33.8% vs. ET, 46.6%) and were negatively influenced by high BT (d 7). The third analysis included only ovulating cows that were 7 d postestrus. Conception rates of AI and ET were different on d 28 (AI, 37.5% vs. ET, 63.2%) and 42 (AI, 31.7% vs. ET, 51.7%) and were negatively influenced by high BT (d 7). There was a positive effect of serum concentration of P4 and a negative effect of milk production on the probability of conception for the AI group but not for the ET group. The fourth analysis was embryonic loss (AI, 10.8% vs. ET, 21.5%). The transfer

  14. Radioablation of liver malignancies with interstitial high-dose-rate brachytherapy. Complications and risk factors

    Energy Technology Data Exchange (ETDEWEB)

    Mohnike, Konrad; Wolf, Steffen; Damm, Robert; Seidensticker, Max; Seidensticker, Ricarda; Fischbach, Frank; Pech, Maciej; Ricke, Jens [Otto-von-Guericke-Universitaet, Klinik fuer Radiologie und Nuklearmedizin, Universitaetsklinikum Magdeburg A.oe.R., Magdeburg (Germany); Peters, Nils; Hass, Peter; Gademann, Guenther [Otto-von-Guericke-Universitaet, Klinik fuer Strahlentherapie, Universitaetsklinikum Magdeburg A.oe.R., Magdeburg (Germany)

    2016-05-15

    To evaluate complications and identify risk factors for adverse events in patients undergoing high-dose-rate interstitial brachytherapy (iBT). Data from 192 patients treated in 343 CT- or MRI-guided interventions from 2006-2009 at our institution were analyzed. In 41 %, the largest tumor treated was ≥ 5 cm, 6 % of the patients had tumors ≥ 10 cm. Prior to iBT, 60 % of the patients had chemotherapy, 22 % liver resection, 19 % thermoablation or transarterial chemoembolization (TACE). Safety was the primary endpoint; survival data were obtained as the secondary endpoints. During follow-up, MRI or CT imaging was performed and clinical and laboratory parameters were obtained. The rate of major complications was below 5 %. Five major bleedings (1.5 %) occurred. The frequency of severe bleeding was significantly higher in patients with advanced liver cirrhosis. One patient developed signs of a nonclassic radiation-induced liver disease. In 3 patients, symptomatic gastrointestinal (GI) ulcers were detected. A dose exposure to the GI wall above 14 Gy/ml was a reliable threshold to predict ulcer formation. A combination of C-reactive protein ≥ 165 mg/l and/or leukocyte count ≥ 12.7 Gpt/l on the second day after the intervention predicted infection (sensitivity 90.0 %; specificity 92.8 %.) Two patients (0.6 %) died within 30 days. Median overall survival after the first liver treatment was 20.1 months for all patients and the local recurrence-free surviving proportion was 89 % after 12 months. Image-guided iBT yields a low rate of major complications and is effective. (orig.) [German] Evaluierung der Komplikationsrate und Identifizierung von Risikofaktoren fuer Komplikationen und Nebenwirkungen bei Patienten mit Lebermalignomen, die mit der hochdosierten interstitiellen Brachytherapie (iBT) behandelt wurden. Von 2006 bis 2009 wurden 192 Patienten in 343 CT- oder MRT-gefuehrten Interventionen behandelt und deren Daten ausgewertet. Der groesste behandelte Tumor war in

  15. Crystal Structure of the LasA Virulence Factor from Pseudomonas aeruginosa: Substrate Specificity and Mechanism of M23 Metallopeptidases

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, James; Murphy, Loretta M.; Conners, Rebecca; Sessions, Richard B.; Gamblin, Steven J. (Wales); (Bristol Med Sci); (NIMR)

    2010-09-21

    Pseudomonas aeruginosa is an opportunist Gram-negative bacterial pathogen responsible for a wide range of infections in immunocompromized individuals and is a leading cause of mortality in cystic fibrosis patients. A number of secreted virulence factors, including various proteolytic enzymes, contribute to the establishment and maintenance of Pseudomonas infection. One such is LasA, an M23 metallopeptidase related to autolytic glycylglycine endopeptidases such as Staphylococcus aureus lysostaphin and LytM, and to DD-endopeptidases involved in entry of bacteriophage to host bacteria. LasA is implicated in a range of processes related to Pseudomonas virulence, including stimulating ectodomain shedding of the cell surface heparan sulphate proteoglycan syndecan-1 and elastin degradation in connective tissue. Here we present crystal structures of active LasA as a complex with tartrate and in the uncomplexed form. While the overall fold resembles that of the other M23 family members, the LasA active site is less constricted and utilizes a different set of metal ligands. The active site of uncomplexed LasA contains a five-coordinate zinc ion with trigonal bipyramidal geometry and two metal-bound water molecules. Using these structures as a starting point, we propose a model for substrate binding by LasA that explains its activity against a wider range of substrates than those used by related lytic enzymes, and offer a catalytic mechanism for M23 metallopeptidases consistent with available structural and mutagenesis data. Our results highlight how LasA is a structurally distinct member of this endopeptidase family, consistent with its activity against a wider range of substrates and with its multiple roles in Pseudomonas virulence.

  16. Evidence for Lipid Packaging in the Crystal Structure of the GM2-Activator Complex with Platelet Activating Factor

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Christine S.; Mi, Li-Zhi; Rastinejad, Fraydoon (Virginia)

    2010-11-16

    GM2-activator protein (GM2-AP) is a lipid transfer protein that has the ability to stimulate the enzymatic processing of gangliosides as well as T-cell activation through lipid presentation. Our previous X-ray crystallographic studies of GM2-AP have revealed a large lipid binding pocket as the central overall feature of the structure with non-protein electron density within this pocket suggesting bound lipid. To extend these studies, we present here the 2 {angstrom} crystal structure of GM2-AP complexed with platelet activating factor (PAF). PAF is a potent phosphoacylglycerol whose toxic patho-physiological effects can be inhibited by GM2-AP. The structure shows an ordered arrangement of two bound lipids and a fatty acid molecule. One PAF molecule binds in an extended conformation within the hydrophobic channel that has an open and closed conformation, and was seen to contain bound phospholipid in the low pH apo structure. The second molecule is submerged inside the pocket in a U-shaped conformation with its head group near the single polar residue S141. It was refined as lyso-PAF as it lacks electron density for the sn-2 acetate group. The alkyl chains of PAF interact through van der Waals contacts, while the head groups bind in different environments with their phosphocholine moieties in contact with aromatic rings (Y137, F80). The structure has revealed further insights into the lipid binding properties of GM2-AP, suggesting an unexpected unique mode of lipid packaging that may explain the efficiency of GM2-AP in inhibiting the detrimental biological effects of PAF.

  17. Factors controlling cloud microphysics, precipitation rate, and brightness temperature of tropical convective and stratiform clouds

    Science.gov (United States)

    Hashino, T.; Casella, D.; Mugnai, A.; Sano, P.; Smith, E. A.; Tripoli, G.

    2008-12-01

    This paper discusses factors controlling cloud microphysics, precipitation rate and brightness temperature of tropical convective and stratiform clouds. Tropical convective and stratiform clouds are important in radiative forcing of climates and distribution of precipitation over the ocean. The possible effects of climate change on these clouds are still not well understood. Recent studies show that the higher CCN concentration in a convective cloud can lead to more vigorous updrafts and a higher evaporation/precipitation ratio. The stronger updraft often means stronger downdraft and gust fronts, which can trigger convection nearby. This implies that increases in CCN concentration can result in an increase in area coverage and persistence of tropical cirrus and stratiform clouds. The increased cloudiness would then be expected to lower sensible and latent heat flux from the ocean by lowering sea surface temperature, affecting the future development of convective clouds. The sea surface temperature may also change in a local area due to change of ocean circulation in climate change scenarios. Satellite remote sensing is a powerful tool to study tropical and global precipitation distribution. Many physically-based passive-microwave (MW) satellite precipitation algorithms make use of cloud radiation databases (CRDs), which typically consist of microphysical profiles from cloud resolving model (CRMs) and simulated MW brightness temperature (Tb). Thus, it is important to validate Tb simulated by a CRM against the observed Tb. Also, it is important to study how any changes in the tropical clouds due to aerosols and sea surface temperature translate into the precipitation and brightness temperature. The case study chosen is KWAJEX campaign that took place from 23 July to 14 September 1999. Authors have developed microphysical physical framework (Advanced Microphysics Prediction System) to predict ice particle properties explicitly in a CRM (University of Wisconsin

  18. Observer-Rated Alexithymia and its Relationship with the Five-Factor-Model of Personality

    Directory of Open Access Journals (Sweden)

    Nicole Rosenberg

    2016-06-01

    Full Text Available Studies examining the relationship between alexithymia and personality exclusively employed self-report measures of alexithymia. In the present study, we examined the relationship of both observer-rated and self-reported alexithymia with the Big Five personality dimensions. We administered the Toronto Structured Interview for Alexithymia (TSIA as an interview-based measure of alexithymia and, in addition, two self-report questionnaires, the 20-item Toronto Alexithymia Scale (TAS-20 and the Bermond-Vorst Alexithymia Questionnaire (BVAQ. Fifty-one university students were interviewed and completed the alexithymia scales and the NEO Five-Factor Inventory. In contrast to TAS-20 and BVAQ, the Difficulty identifying feelings (DIF scale of the TSIA was found to be unrelated to neuroticism, suggesting that the frequently reported association between DIF and neuroticism could be due to the use of self-report scales. In contrast, the affective dimension of alexithymia, measured by the BVAQ, was even negatively related with neuroticism. Thus, a paucity of fantasy and little emotional arousal goes together with increased emotional stability. Furthermore, we revealed negative correlations between interview-based alexithymia scores and openness to experience and agreeableness, which cross-validated the self-report findings. Finally, extraversion and conscientiousness each showed only one negative correlation, namely with subscales of the BVAQ. Taken together, our findings show that on the basis of interviews there is no evidence for a relation of DIF with neuroticism, while associations of alexithymia with low openness to experience and low agreeableness emerged irrespective of assessment approach. The relations of alexithymia with personality are discussed in the light of different measurement approaches.

  19. Factors affecting conception rate after artificial insemination and pregnancy loss in lactating dairy cows.

    Science.gov (United States)

    Chebel, Ricardo C; Santos, José E P; Reynolds, James P; Cerri, Ronaldo L A; Juchem, Sérgio O; Overton, Michael

    2004-09-01

    Objectives were to determine factors associated with conception rate (CR) and pregnancy loss (PL) in high producing lactating Holstein cows. In Study 1, CR was evaluated in 7633 artificial inseminations (AI) of 3161 dairy cows in two dairy farms. Pregnancy diagnosis was performed by palpation per rectum 39+/-3 days after AI. Environmental temperature was recorded at different intervals prior to and after AI. In Study 2, 1465 pregnancies from 1393 cows diagnosed at 31+/-3 days after AI by ultrasonography on three dairy farms were re-examined 14 days later to determine PL. Temperature > or =29 degrees C was considered to be heat stress (HS). Exposure to HS was defined as following: NH, no heat stress; HS1, exposure to at least 1 day of maximum temperature > or =29 degrees C and average daily maximum temperature (ADMT) or =29 degrees C. In Study 1, exposure of cows to HS1 and HS2 from 50 to 20 prior to AI was associated with reduced CR compared to cows not exposed to HS (28.8, 23.0, and 31.3%, respectively). Post-AI HS was not associated with CR. Cows inseminated following estrus detection or timed AI had similar CR. As the number of AI increased, CR decreased. Multiparous cows had lower CR than primiparous cows, and occurrence of milk fever and retained placenta was associated with decreased CR. In Study 2, PL was not associated with exposure to HS either prior to or after AI. Cows diagnosed with clinical mastitis experienced increased PL, but parity, number of AI, AI protocol, milk production, and days postpartum at AI were not associated with PL. In conclusion, CR was affected by HS prior to AI, parity, number of AI, and postparturient diseases, whereas PL was affected by clinical mastitis.

  20. The rate of force development scaling factor (RFD-SF): protocol, reliability, and muscle comparisons.

    Science.gov (United States)

    Bellumori, Maria; Jaric, Slobodan; Knight, Christopher A

    2011-07-01

    Performing a set of isometric muscular contractions to varied amplitudes with instructions to generate force most rapidly reveals a strong linear relationship between peak forces (PF) achieved and corresponding peak rates of force development (RFD). The slope of this relationship, termed the RFD scaling factor (RFD-SF), quantifies the extent to which RFD scales with contraction amplitude. Such scaling allows relative invariance in the time required to reach PF regardless of contraction size. Considering the increasing use of this relationship to study quickness and consequences of slowness in older adults and movement disorders, our purpose was to further develop the protocol to measure RFD-SF. Fifteen adults (19-28 years) performed 125 rapid isometric contractions to a variety of force levels in elbow extensors, index finger abductors, and knee extensors, on 2 days. Data were used to determine (1) how the number of pulses affects computation of the RFD-SF, (2) day-to-day reliability of the RFD-SF, and (3) the nature of RFD-SF differences between diverse muscle groups. While sensitive to the number of pulses used in its computation (P50 pulses (ICC>.7) and more so with 100-125 pulses (ICC=.8-.92). Despite differences in size and function across muscles, RFD-SF was generally similar (i.e., only 8.5% greater in elbow extensors than in index finger abductors and knee extensors; P=.049). Results support this protocol as a reliable means to assess how RFD scales with PF in rapid isometric contractions as well as a simple, non-invasive probe into neuromuscular health.

  1. A generalized one-factor term structure model and pricing of interest rate derivative securities

    NARCIS (Netherlands)

    Jiang, George J.

    1997-01-01

    The purpose of this paper is to propose a nonparametric interest rate term structure model and investigate its implications on term structure dynamics and prices of interest rate derivative securities. The nonparametric spot interest rate process is estimated from the observed short-term interest

  2. Possible Factors Associated with High Rates of Out-of-Marriage Births Among Adolescents.

    Science.gov (United States)

    Chilman, Catherine S.

    An exhaustive analytic review of large bodies of research indicates that rates of premarital intercourse among teenagers have risen sharply since 1966. This is particularly true for white females, for whom the rate is probably about three times that of the 1920's thru the mid-1960's; for white males the rate seems to have risen about 50%. By age…

  3. Mechanical interaction between gas bubbles and micro-crystals in magma

    Science.gov (United States)

    Dinger, Florian; Bobrowski, Nicole; Bredemeyer, Stefan; Arellano, Santiago; Platt, Ulrich; Wagner, Thomas

    2017-04-01

    The magnitude of volcanic gas emissions from low viscosity magmas is controlled by many factors. The buoyancy driven ascent of gas bubbles in the volcanic conduit is one of them. During the ascent the bubbles may collide with micro-crystals, slide along the crystal faces, and finally leave the crystal at the crystal tip. We investigate the mechanical consequences of this interaction in a static volume of magma assuming constant pressure, temperature and chemical composition and neglecting thermodynamic processes between bubbles and crystals. Explicitly, we focus on tabular crystals whose extensions are about one order of magnitude larger than the bubbles. The mechanical interaction changes the motion of both the bubbles and the crystals. The buoyancy force of the bubbles results in a torque on the crystal which ultimately orients the long axis of the crystal to the vertical direction. On the other hand, bubbles change their ascent path and velocity if they slide along a crystal face. This change in the bubble motion may have two opposing impacts on the magnitude of volcanic emissions: First, the reduced ascent velocity results in a bubble accumulation and thus enhanced bubble coalescence rate in the proximity of crystals. Second, the crystals align the bubbles in rise channels starting at the crystal tips while no bubbles access the magma volume immediately located above the crystal cross section, which we call "crystal shadow". Now, volatile degassing from supersaturated magma is a diffusive short-distance process which accelerate in the proximity of pre-existing gas bubbles. We thus infer that the orientation of the crystals influences the bulk volatile degassing rate and thus the volcanic gas emission rate due to the crystal shadow. The mechanical model suggests that all crystals get erected by the bubble-induced torque within time periods in the order of weeks to months. This has to be compared to the crystal nucleation rate in order to obtain a steady state

  4. TEM study of the cooling rate dependent crystallization behavior of (Zr{sub 65}Al{sub 10}Ni{sub 10}Cu{sub 15}){sub 98}Nb{sub 2} metallic glass

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yingmin, E-mail: apwangym@dlut.edu.c [School of Materials Science and Engineering, Dalian University of Technology, No. 2 Lingggong Road, Ganjingzi District, Dalian, Liaoning 116024 (China); Shek, Chan Hung [Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR (China); Wang, Qing; Qiang, Jianbing; Dong, Chuang [School of Materials Science and Engineering, Dalian University of Technology, No. 2 Lingggong Road, Ganjingzi District, Dalian, Liaoning 116024 (China)

    2010-08-15

    The crystallization of (Zr{sub 65}Al{sub 10}Ni{sub 10}Cu{sub 15}){sub 98}Nb{sub 2} metallic glasses has been studied using transmission electron microscopy (TEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The ribbon glass and bulk metallic glass (BMG) of this alloy exhibit different crystallization behaviors. For ribbon glass in the first stage crystallization, icosahedral quasicrystal (I-phase) precipitated together with the {eta}-Zr{sub 2}Ni (a = 1.226 nm) phase. The BMG alloy transforms into the I-phase and two coherently coexisted phases, namely, the Al{sub 2}Zr{sub 3} phase and an unknown primitive cubic phase (a = 0.76 nm) in this stage. The experimental evidence indicates that the liquid cooling rate for sample preparation has a significant effect on its crystallization behavior of this alloy glass.

  5. Effect of cooling and rewarming rate on crystallization of cryoprotectant solution for oocytes%升降温速率对低温保护剂溶液结晶性质的影响

    Institute of Scientific and Technical Information of China (English)

    李维杰; 周新丽; 刘宝林; 吕福扣

    2013-01-01

    When cells are cryopreserved,the morphology of cryoprotectant at crystallization and recrystallization would influence the survival rate of cells.The cryo-microscope system was used to observe the morphology of crystal and sizes of two cryoprotectants during cooling and rewarming at different speeds.It is found that crystals during cooling are smaller and less at higher speed than at lower speed,and the former is favorable for preservation of cells.When the vitrified cryoprotetant is rewarmed,crystals during recrystallization are smaller and less at higher speed than at lower speed,and the former with narrow danger zone is favorable for the survival of oocytes.Besides,high concentration of cryoprotectant is more favorable for the survivalrate of oocytes than lower concentration.

  6. Exploratory and confirmatory factor analyses of the pervasive developmental disorders rating scale for young children with autistic disorder.

    Science.gov (United States)

    Eaves, Ronald C; Williams, Thomas O

    2006-03-01

    In this study, the authors examined the construct validity of the Pervasive Developmental Disorder Rating Scale (PDDRS; R. C. Eaves, 1993), which is a screening instrument used to identify individuals with autistic disorder and other pervasive developmental disorders. The PDDRS is purported to measure 3 factors--arousal, affect, and cognition-that collectively make up the construct of autism. Using scores from 199 children (aged 1-6 years) diagnosed with autistic disorder, the authors submitted data to exploratory and confirmatory factor analyses. In the 1st series of analyses, the authors analyzed a user-specified 3-factor solution using principal axis factor analysis with a promax rotation to evaluate the assertion of a correlated 3-factor structure. Next, the authors analyzed 1-factor and 2-factor solutions to determine if they provided a better factor structure for the data. In the 2nd series, the authors conducted confirmatory factor analyses, which compared the theorized hierarchical 2nd-order factor model with 5 plausible competing models. The results of the exploratory analyses supported the 3-factor solution. With the confirmatory analyses, the 2nd-order factor model provided the best fit for the data. The exploratory and confirmatory analyses supported the theoretical assumptions undergirding the development of the PDDRS. The authors discuss theoretical implications, practical implications, and areas for further research.

  7. Investigation of lactose crystallization process during condensed milk cooling using native vacuum-crystallizer

    Directory of Open Access Journals (Sweden)

    E. I. Dobriyan

    2016-01-01

    Full Text Available One of the most general defects of condensed milk with sugar is its consistency heterogeneity – “candying”. The mentioned defect is conditioned by the presence of lactose big crystals in the product. Lactose crystals size up to 10 µm is not organoleptically felt. The bigger crystals impart heterogeneity to the consistency which can be evaluated as “floury”, “sandy”, “crunch on tooth”. Big crystals form crystalline deposit on the can or industrial package bottom in the form of thick layer. Industrial processing of the product with the defective process of crystallization results in the expensive equipment damage of the equipment at the confectionary plant accompanied with heavy losses. One of the factors influencing significantly lactose crystallization is the product cooling rate. Vacuum cooling is the necessary condition for provision of the product consistency homogeneity. For this purpose the vacuum crystallizers of “Vigand” company, Germany, are used. But their production in the last years has been stopped. All-Russian dairy research institute has developed “The references for development of the native vacuum crystallizer” according to which the industrial model has been manufactured. The produced vacuum – crystallizer test on the line for condensed milk with sugar production showed that the product cooling on the native vacuum-crystallizer guarantees production of the finished product with microstructure meeting the requirements of State standard 53436–2009 “Canned Milk. Milk and condensed cream with sugar”. The carried out investigations evidences that the average lactose crystals size in the condensed milk with sugar cooled at the native crystallizer makes up 6,78 µm. The granulometric composition of the product crystalline phase cooled at the newly developed vacuum-crystallizer is completely identical to granulometric composition of the product cooled at “Vigand” vacuum-crystallizer.

  8. Effects of growth temperature modulated by HCl flow rate on the surface and crystal qualities of thick GaN by HVPE

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Lubing [Research Center for Wide-gap Semiconductors, State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Wu Jiejun, E-mail: wujiejun@opt.elec.mie-u.ac.jp [Research Center for Wide-gap Semiconductors, State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Xu Ke; Yang Zhijian; Zhang Guoyi [Research Center for Wide-gap Semiconductors, State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China)

    2009-06-30

    We studied the influence of the growth temperature and HCl flow rate on the morphological evolution of crack-free thick GaN films by using a home-made horizontal hydride vapor phase epitaxy on sapphire substrates. Optical difference microscopy, scanning electron microscopy (SEM), atomic force microscopy (AFM), and cathodoluminescence (CL) were carried out to reveal the surface property of the GaN epilayer. It was found that the higher growth temperature is a key factor to obtain mirror, colorless and flat GaN surface. However, this key effect of temperature was modulated by HCl flow rate (HCl > 15 sccm). The surface RMS roughness was reduced from 206 to 2.51 nm for 10 {mu}m x 10 {mu}m scan area when GaN was grown at 1070 deg. C with HCl flow rate up to 30 sccm. These samples also reduced their (0 0 0 2) FWHM result from 1000 to 300 arcsec and showed a strong near-band-edge peak in CL spectra. Results indicated that growth temperature influence growth velocities on different crystalline planes, which will lead to the different morphologies obtained. High growth temperature can improve the lateral growth rate of vertical {l_brace}1 1 - 2 0{r_brace} facets and reduce the vertical growth rate of top {l_brace}0 0 0 1{r_brace} facet combined with higher HCl flow rate, which leads to completely coalescence of surface.

  9. Simultaneous Synchrotron WAXD and Fast Scanning (Chip) Calorimetry: On the (Isothermal) Crystallization of HDPE and PA11 at High Supercoolings and Cooling Rates up to 200 °C s(-1).

    Science.gov (United States)

    Baeten, Dorien; Mathot, Vincent B F; Pijpers, Thijs F J; Verkinderen, Olivier; Portale, Giuseppe; Van Puyvelde, Peter; Goderis, Bart

    2015-06-01

    An experimental setup, making use of a Flash DSC 1 prototype, is presented in which materials can be studied simultaneously by fast scanning calorimetry (FSC) and synchrotron wide angle X-ray diffraction (WAXD). Accumulation of multiple, identical measurements results in high quality, millisecond WAXD patterns. Patterns at every degree during the crystallization and melting of high density polyethylene at FSC typical scanning rates from 20 up to 200 °C s(-1) are discussed in terms of the temperature and scanning rate dependent material crystallinities and crystal densities. Interestingly, the combined approach reveals FSC thermal lag issues, for which can be corrected. For polyamide 11, isothermal solidification at high supercooling yields a mesomorphic phase in less than a second, whereas at very low supercooling crystals are obtained. At intermediate supercooling, mixtures of mesomorphic and crystalline material are generated at a ratio proportional to the supercooling. This ratio is constant over the isothermal solidification time.

  10. Brain-derived neurotrophic factor enhances the basal rate of protein synthesis by increasing active eukaryotic elongation factor 2 levels and promoting translation elongation in cortical neurons.

    Science.gov (United States)

    Takei, Nobuyuki; Kawamura, Mihoko; Ishizuka, Yuta; Kakiya, Naomasa; Inamura, Naoko; Namba, Hisaaki; Nawa, Hiroyuki

    2009-09-25

    The constitutive and activity-dependent components of protein synthesis are both critical for neural function. Although the mechanisms controlling extracellularly induced protein synthesis are becoming clear, less is understood about the molecular networks that regulate the basal translation rate. Here we describe the effects of chronic treatment with various neurotrophic factors and cytokines on the basal rate of protein synthesis in primary cortical neurons. Among the examined factors, brain-derived neurotrophic factor (BDNF) showed the strongest effect. The rate of protein synthesis increased in the cortical tissues of BDNF transgenic mice, whereas it decreased in BDNF knock-out mice. BDNF specifically increased the level of the active, unphosphorylated form of eukaryotic elongation factor 2 (eEF2). The levels of active eEF2 increased and decreased in BDNF transgenic and BDNF knock-out mice, respectively. BDNF decreased kinase activity and increased phosphatase activity against eEF2 in vitro. Additionally, BDNF shortened the ribosomal transit time, an index of translation elongation. In agreement with these results, overexpression of eEF2 enhanced protein synthesis. Taken together, our results demonstrate that the increased level of active eEF2 induced by chronic BDNF stimulation enhances translational elongation processes and increases the total rate of protein synthesis in neurons.

  11. Self-rated Health and Internet Addiction in Iranian Medical Sciences Students; Prevalence, Risk Factors and Complications

    OpenAIRE

    Mohammadbeigi, Abolfazl; Valizadeh, Farzaneh; Mirshojaee, Seyede Roqaie; Ahmadli, Robabeh; Mokhtari, Mohsen; GHADERI, Ebrahim; Ahmadi, Ali; Rezaei, Heshmatollah; Ansari, Hossein

    2016-01-01

    Introduction: Self-rated health is a brief measure for general health. It is a comprehensive and sensitive index for prediction of health in future. Due to the high internet usage in medical students, the current study designed to evaluate the self-rated health (SRH) in relationship with internet addiction risk factors in medical students. Methods: This cross sectional study conducted on 254 students of Qom University of Medical Sciences 2014. Participants selected by two stage sampling metho...

  12. Factors Influencing Iranian Untrained EFL Raters' Rating Group Oral Discussion Tasks: A Mixed Methods Design

    Directory of Open Access Journals (Sweden)

    Nasimeh Nouhi Jadesi

    2016-07-01

    Full Text Available Using a mixed methods design, the present study attempted to identify the factors influencing Iranian untrained EFL raters in rating group oral discussion tasks. To fulfil this aim, 16 language learners of varying proficiency levels were selected and randomly assigned to groups of four and performed a group discussion task. Thirty two untrained raters were also selected based on their volunteer participations. They listened to the audio files of the group discussions and assigned a score of one to six to each language learners based on their own judgments. They also provided comments on each language learners’ performance pointing to why they assigned such scores. The researchers had an interview with the raters after the rating session as well. The quantitative phase investigated whether linguistic features of accuracy, fluency, complexity and amount of talk were attended to by the raters in terms of having any relationship to the scores the raters assigned. Speech rate as an index of fluency and amount of talk turned out to be significantly correlated with the scores. Of more importance was the qualitative phase with the aim of identifying other factors that may account for the scores. The comments provided by the raters on each score and the interviews were codified based on Content Analysis (CA approach. It was found that the raters attend not only to the linguistic features in rating oral group discussions, but they are also sensitive to the interactional features like the roles the participants take in groups tasks and the overall interaction patterns of the groups. The findings of this study may shed light on group oral assessment in terms of training the raters rating group oral tests and developing rating scales specific for group oral assessment. Persian Abstract:پژوهش حاضر، با بهره گیری از روش تحقیق ترکیبی به بررسی عوامل مؤثر بر ارزیابان آموزش ندیده

  13. Intrauterine insemination with husband's sperm: comparison of pregnancy rates in couples with cervical factor, male factor, immunological factor and idiopathic infertility.

    Science.gov (United States)

    Kossakowski, J; Stephenson, M; Smith, H

    1993-05-01

    Intrauterine insemination with husband's sperm (IUI) is offered to couples with infertility due to various causes although there is no general agreement on which of these causes should be so treated. In this report 77 couples were diagnosed as having either cervical factor, male factor, immunological factor or unexplained infertility. Insemination was performed 24-32 hours after a rapid rise in the serum LH level. Two of 16 pregnancies which resulted miscarried, 1 was ectopic and the remainder were full term. Eleven occurred in the cervical factor group, 3 in the immunological factor and only 1 in each of the male factor and unexplained infertility groups. The differences in the number of pregnancies between the cervical factor and male and unexplained infertility groups are significant but not between the groups with cervical and immunological factors. The majority of pregnancies (81%) were achieved in the first 4 cycles. Patients with the cervical factor as the cause of their subfertility are likely to benefit from the IUI with their husband's sperm. The small number of patients with the immunological factor in this study does not allow for a conclusion. In our experience the male factor and unexplained infertility patients are unlikely to benefit from intrauterine insemination with husband's sperm.

  14. The Effect of Selected Nonmusical Factors on Adjudicators' Ratings of High School Solo Vocal Performances

    Science.gov (United States)

    Howard, Sandra A.

    2012-01-01

    The purpose of this study was to examine the effect of differentiated performance attire and stage deportment on adjudicators' ratings of high school solo vocal performances. High school choral students (n = 153) and undergraduate (n = 97) and graduate music majors (n = 32) served as adjudicators (N = 282). Adjudicators rated recorded solo vocal…

  15. Happy to Help? Exploring the Factors Associated with Variations in Rates of Volunteering across Europe

    Science.gov (United States)

    Plagnol, Anke C.; Huppert, Felicia A.

    2010-01-01

    The frequency of formal volunteering varies widely across European countries, and rates of formal volunteering are especially low among Eastern European countries. Why are there such large differences in volunteering rates when it is known that volunteering is beneficial for well-being? Using data from the latest round of the European Social…

  16. State disparities in colorectal cancer rates: Contributions of risk factors, screening, and survival differences

    NARCIS (Netherlands)

    I. Lansdorp-Vogelaar (Iris); S.L. Goede (S. Lucas); J. Ma (Jiemin); W. Xiau-Cheng (Wu); K. Pawlish (Karen); M. van Ballegooijen (Marjolein); A. Jemal (Ahmedin)

    2015-01-01

    textabstractBACKGROUND Northeastern states of the United States have shown more progress in reducing colorectal cancer (CRC) incidence and mortality rates than Southern states, and this has resulted in considerable disparities. This study quantified how the disparities in CRC rates between Louisiana

  17. Grade Inflation Rates among Different Ability Students, Controlling for Other Factors.

    Science.gov (United States)

    Mc Spirit, Stephanie; Jones, Kirk E.

    1999-01-01

    Compared grade inflation rates among students of different abilities at an open-admissions public university by examining trends in graduating grade point average from 1983 to 1996. The higher grade inflation rates among low aptitude students suggest that faculty might be using grades to encourage learning among marginal students. (SLD)

  18. Factors Differentiating Hospital Transfers from Long-term Care Facilities with High and Low Transfer Rates.

    Science.gov (United States)

    Teresi, Jeanne A.; And Others

    1991-01-01

    Examined differences among nursing homes in rates at which they transfer patients to hospitals. Data from nursing staff and charts on 286 most recent transfers from 10 nursing homes revealed that, from relatively equivalent patient populations, high-rate facilities transferred more chronically ill, physically frail patients and patients with…

  19. Understanding the factors associated with differences in caesarean section rates at hospital level: the case of Latin America.

    Science.gov (United States)

    Taljaard, Monica; Donner, Allan; Villar, José; Wojdyla, Daniel; Faundes, Anibal; Zavaleta, Nelly; Acosta, Arnaldo

    2009-11-01

    As in many other regions of the world, caesarean section (CS) rates in Latin America are increasing. Studies elsewhere have shown that providing feedback to caregivers regarding their own performance relative to their peers can significantly reduce the rates. Our objectives are to calculate risk-adjusted CS rates for hospitals in Latin America and to identify factors associated with differences among risk-adjusted rates. We included 120 randomly selected institutions in eight countries of Latin America, representing 97 095 pregnancies. We used random-effects models to calculate a risk-adjusted rate for each hospital and to identify hospitals significantly higher or lower than a benchmark rate. We conducted a regression analysis to identify characteristics of hospitals associated with differences among risk-adjusted rates. The overall CS rate was 35%, ranging from 0% to 85%. Risk-adjusted CS rates ranged from 11% to 78%. Three-quarters of hospitals had risk-adjusted rates significantly above the previously identified benchmark of 20%. Characteristics of institutions explained 48% of the variability among risk-adjusted rates, including being a private as opposed to a public institution, having some economic incentive for CS as opposed to no incentive, and having > or = 50 maternity beds. Strategies to halt further increases in CS rates and reduce rates to levels that reflect the best quality of care, are urgently needed worldwide. The involvement of local quality control departments is an essential component in achieving success. Our results can be used to identify institutions that can be targets for further interventions to reduce CS rates.

  20. Factor structure of the Behavior Rating Inventory of Executive Functions (BRIEF-P) at age three years.

    Science.gov (United States)

    Skogan, Annette Holth; Egeland, Jens; Zeiner, Pål; Øvergaard, Kristin Romvig; Oerbeck, Beate; Reichborn-Kjennerud, Ted; Aase, Heidi

    2016-01-01

    The preschool period is an important developmental period for the emergence of cognitive self-regulatory skills or executive functions (EF). To date, evidence regarding the structure of EF in preschool children has supported both unitary and multicomponent models. The aim of the present study was to test the factor structure of early EF as measured by the Behavior Rating Inventory of Executive Function-Preschool version (BRIEF-P). BRIEF-P consists of five subscales and three broader indexes, hypothesized to tap into different subcomponents of EF. Parent ratings of EF from a nonreferred sample of children recruited from the Norwegian Mother and Child Cohort Study (N = 1134; age range 37-47 months) were subjected to confirmatory factor analyses (CFA). Three theoretically derived models were assessed; the second-order three-factor model originally proposed by the BRIEF-P authors, a "true" first-order one-factor model and a second-order one-factor model. CFA fit statistics supported the original three-factor solution. However, the difference in fit was marginal between this model and the second-order one-factor model. A follow-up exploratory factor analysis (EFA) supported the existence of several factors underlying EF in early preschool years, with a considerable overlap with the five BRIEF-P subscales. Our results suggest that some differentiation in EF has taken place at age 3 years, which is reflected in behavior ratings. The internal consistency of the BRIEF-P five clinical subscales is supported. Subscale interrelations may, however, differ at this age from those observed in the preschool group as a whole.

  1. Optimization of photonic crystal cavities

    DEFF Research Database (Denmark)

    Wang, Fengwen; Sigmund, Ole

    2017-01-01

    We present optimization of photonic crystal cavities. The optimization problem is formulated to maximize the Purcell factor of a photonic crystal cavity. Both topology optimization and air-hole-based shape optimization are utilized for the design process. Numerical results demonstrate...... that the Purcell factor of the photonic crystal cavity can be significantly improved through optimization....

  2. Mobility improvement by detached solidification of CZT crystals

    Energy Technology Data Exchange (ETDEWEB)

    Gamal, G.A. [Physics Department, Faculty of Science, South Valley University, Qena 83523 (Egypt); Abou Zied, M. [Physics Department, Faculty of Science, South Valley University, Qena 83523 (Egypt); Ebnalwaled, A.A. [Physics Department, Faculty of Science, South Valley University, Qena 83523 (Egypt)]. E-mail: Kh_ebnalwaled@yahoo.com

    2007-06-15

    The mobility of undoped CdZnTe (CZT) crystals grown by vertical Bridgman method is improved by growing crystals without wall contact. Among the different factors playing an important role for appearance of detached growth, we have chosen the freezing rate as an effective factor for investigation with other factors were held constant. After growing a set of samples we have measured the dislocation densities for the grown samples by Warren-Averbach method. Unique results were obtained when we compared the dislocation densities and mobility, together with the freezing rate. This work and the included relations are published for the first time.

  3. Oral health: locus of control, health behavior, self-rated oral health and socio-demographic factors in Istanbul adults.

    Science.gov (United States)

    Peker, Kadriye; Bermek, Gulcin

    2011-01-01

    To determine oral health control beliefs of Istanbul adults using the Multidimensional Oral Health Locus of Control Scale (MOHLCS) after confirming its factorial validity and to examine the relationships between these beliefs, self-rated oral health, oral health behaviors and socio-demographic factors. The MOHLCS was administered to a sample of 1200 subjects aged ≥18 years in Istanbul chosen using a quota-sampling method (response 88%). The relationship between the MOHLCS and oral health behaviors, self-rated oral health and socio-demographic factors was assessed after confirming the factorial validity of the MOHLCS. The MOHLCS demonstrated satisfactory internal reliability. Factor analysis results showed a new four-factor solution, namely Internal, Dentist, Chance, and Socialization agents. Multivariate analysis showed that female gender, younger age, higher socioeconomic status, more frequent daily toothbrushing, and regular dental check-ups were associated with higher Internal beliefs, while older age, lower educational level, lower socioeconomic status, low toothbrushing frequency, and symptom-orientated dental attendance were associated with higher Chance beliefs. Being unmarried and low toothbrushing frequency were associated with lower Dentist beliefs. Males and older subjects had lower Socialization agents beliefs. Internal, Dentist and Chance beliefs were significantly associated with self-rated oral health. Compared with the original factor structure, the new factor structure had better goodness of fit for this sample. Self-rated oral health, socio-demographic factors, and oral health behaviors were significantly associated with oral health control beliefs. These beliefs may be useful for planning oral health promotion programs and for formulating advice given by oral health professionals about their patients' oral health behaviors.

  4. The impact of lifestyle risk factors on the rate of infection after surgery for a fracture of the ankle

    DEFF Research Database (Denmark)

    Olsen, L L; Møller, A M; Brorson, S

    2017-01-01

    risk factors for the development of infection following surgery for a fracture of the ankle. This large study brings new evidence concerning these common risk factors; although prospective studies are needed to confirm causality. Cite this article: Bone Joint J 2017;99-B:225-30.......AIMS: Lifestyle risk factors are thought to increase the risk of infection after acute orthopaedic surgery but the evidence is scarce. We aimed to investigate whether smoking, obesity and alcohol overuse are risk factors for the development of infections after surgery for a fracture of the ankle....... PATIENTS AND METHODS: We retrospectively reviewed all patients who underwent internal fixation of a fracture of the ankle between 2008 and 2013. The primary outcome was the rate of deep infection and the secondary outcome was any surgical site infection (SSI). Associations with the risk factors...

  5. Theoretical studies of the crystal-field energy levels and EPR g factors for CeFeAsO1-xFx

    Science.gov (United States)

    Dong, Hui-Ning; Zhou, Hong-Fei; Yang, Guo-Ren

    2015-08-01

    The ion-based superconductor CeFeAsO1-xFx has received much attention because this rare earth oxypnictide belongs to a new class RFeAsO1-xFx of high-Tc superconductors with critical temperatures surpassed by high-Tc copper oxides. Since the Ce3+ is situated near the superconducting FeAs plane, it can be used as a probe to study the influence of superconductivity on spin dynamic properties of the FeAs layer. It is important to determine the optical and magnetic properties of rare earth ion in oxypnictides. Here, based on the crystal-field theory, the crystal-field (CF) energy levels and electron paramagnetic resonance parameters g factors of Ce3+ in CeFeAsO1-xFx are studied by diagonalizing the full energy matrix. In the calculations, the contributions of various admixtures and interactions are all considered. The results are discussed.

  6. Long-Term Data Reveal Rate and Risk Factors for Subsequent Surgeries Following Initial ACL Reconstruction

    Science.gov (United States)

    ... and Risk Factors for Subsequent Surgeries Following Initial ACL Reconstruction Nearly one-fifth of patients who undergo ... surgery to reconstruct a torn anterior cruciate ligament (ACL) eventually need to have additional surgery on the ...

  7. Factors Influencing University Nursing Students' Measles Vaccination Rate During a Community Measles Outbreak

    Directory of Open Access Journals (Sweden)

    Ji Soo Kim, RN, PhD

    2016-03-01

    Conclusions: A systematic measles vaccination program targeting nursing students upon their entry to university is needed. In order to increase the measles vaccination rate, application of effective promotion campaigns and education programs is necessary.

  8. Happy to help? Exploring the factors associated with variations in rates of volunteering across Europe

    OpenAIRE

    2010-01-01

    The frequency of formal volunteering varies widely across European countries, and rates of formal volunteering are especially low among Eastern European countries. Why are there such large differences in volunteering rates when it is known that volunteering is beneficial for well-being? Using data from the latest round of the European Social Survey, we test three hypotheses to explain these cross-national differences in volunteering. We ask whether people in countries with low frequencies of ...

  9. International factor mobility, informal interest rate and capital market imperfection: a general equilibrium analysis

    OpenAIRE

    Chaudhuri, Sarbajit; GUPTA, Manash Ranjan

    2011-01-01

    This paper makes a pioneering attempt to provide a theory of determination of interest rate in the informal credit market in a small open economy in terms of a three-sector general equilibrium model. There are two informal sectors which obtain production loans from a monopolistic moneylender and employ labour from the informal labour market. On the other hand, the formal sector employs labour at an institutionally fixed wage rate and takes loans from the competitive formal credit market. We s...

  10. Factors that affect the variability in heart rate during endoscopic retrograde cholangiopancreatography

    DEFF Research Database (Denmark)

    Christensen, Merete; Reinert, Rebekka; Rasmussen, Verner

    2002-01-01

    OBJECTIVE: To find out if drugs, position, and endoscopic manipulation during endoscopic retrograde cholangiopancreatography (ERCP) influence the changes in the variability of heart rate. DESIGN: Single-blind randomised trial. SUBJECTS: 10 volunteers given butyscopolamine, glucagon, or saline...... intravenously on three different study days, and 10 patients who had ERCP without butylscopolamine or glucagon. MAIN OUTCOME MEASURES: Holter tape analysis for ischaemia and changes in the variability of heart rate. RESULTS: 5 volunteers developed tachycardia after butylscopolamine, while 2 developed...

  11. Dynamic tafel factor adaption for the evaluation of instantaneous corrosion rates on zinc by using gel-type electrolytes

    Science.gov (United States)

    Babutzka, M.; Heyn, A.

    2017-03-01

    Electrochemical corrosion measurements allow calculation of the instantaneous zinc corrosion rate via polarization resistances by using tafel factors. However, the determination of the actual tafel factor is problematic since it depends on the state of the formed zinc layers and the corrosion reactions taking place. Therefore, valid tafel factors are either determined in additional experiments via dynamic polarization or estimated by calculation. In most cases a constant value for tafel factors is assumed for simplification, without regard to the real conditions of the corroding system. Since naturally formed zinc layers are unstable using conventional test electrolyte solutions determination of tafel factors is hindered additionally and inaccurate interpretations can result. For some time now, the use of gel-type electrolytes in corrosion research has enabled minimally invasive investigation of zinc surface layers and thus offers new approaches to a scientifically proven determination of tafel factors. The paper presents a new method for the determination and evaluation of tafel factors using gel-type electrolytes and electrochemical frequency modulation technique (EFM). This relatively new electrochemical method offers the possibility to determine both polarization resistances and tafel factors within one measurement and in short measuring intervals. Starting from a comprehensive parameter study it is shown that a direct relationship between the two values exists that can be described mathematically. This contribution presents the determined tafel factors for the system gel-type electrolyte/zinc and discusses their applicability and their limits.

  12. Some Interactions of Speech Rate, Signal Distortion, and Certain Linguistic Factors in Listening Comprehension. Professional Paper No. 39-68.

    Science.gov (United States)

    Sticht, Thomas G.

    This experiment was designed to determine the relative effects of speech rate and signal distortion due to the time-compression process on listening comprehension. In addition, linguistic factors--including sequencing of random words into story form, and inflection and phraseology--were qualitatively considered for their effects on listening…

  13. The Relationship among Principals' Emotional Intelligence Skills with Respect to School Accountability Ratings and Selected Demographic Factors

    Science.gov (United States)

    Labby, Sandra A.

    2010-01-01

    Purpose: The purpose of this study was to determine the relationship among principals' emotional intelligence skills, school accountability ratings, and selected demographic factors. Method: The sample was comprised of Texas public school principals from elementary, middle school/junior high, and high schools and their school accountability…

  14. Inclusion of the Förster-rate orientation factor into the theory of concentration self-quenching by statistical traps

    NARCIS (Netherlands)

    Knoester, J.; Himbergen, J.E. Van

    1987-01-01

    The incorporation is studied of the orientation factor occurring in the complete Förster rate of incoherent energy transfer, into the theory of concentration self-quenching by statistical pairs of luminescent molecules. Within Burshtein’s theory of hopping transport, exact results for the steady

  15. Confirmatory Factor Analysis of the "Preschool Behavioral and Emotional Rating Scale" (PreBERS) with Preschool Children with Disabilities

    Science.gov (United States)

    Cress, Cynthia J.; Synhorst, Lori; Epstein, Michael H.; Allen, Elizabeth

    2012-01-01

    The "Preschool Behavioral and Emotional Rating Scale" (PreBERS) is a standardized, norm-referenced instrument that assesses emotional and behavioral strengths of preschool children. This study investigated whether the PreBERS four-factor structure (i.e., emotional regulation, school readiness, social confidence, and family involvement)…

  16. Crystallization of Biological Macromolecules in Microgravity

    Science.gov (United States)

    Snell, Edward H.; Chayen, N. E.; Helliwell, J. R.

    2000-01-01

    An overview of microgravity crystallization explaining why microgravity is used, factors which affect crystallization, the method of crystallization and the environment itself. Also covered is how best to make use of microgravity and what the future might hold.

  17. Crystallization of Biological Macromolecules in Microgravity

    Science.gov (United States)

    Snell, Edward H.; Chayen, N. E.; Helliwell, J. R.

    2000-01-01

    An overview of microgravity crystallization explaining why microgravity is used, factors which affect crystallization, the method of crystallization and the environment itself. Also covered is how best to make use of microgravity and what the future might hold.

  18. Lie-Algebraic Approach for Pricing Zero-Coupon Bonds in Single-Factor Interest Rate Models

    Directory of Open Access Journals (Sweden)

    C. F. Lo

    2013-01-01

    Full Text Available The Lie-algebraic approach has been applied to solve the bond pricing problem in single-factor interest rate models. Four of the popular single-factor models, namely, the Vasicek model, Cox-Ingersoll-Ross model, double square-root model, and Ahn-Gao model, are investigated. By exploiting the dynamical symmetry of their bond pricing equations, analytical closed-form pricing formulae can be derived in a straightfoward manner. Time-varying model parameters could also be incorporated into the derivation of the bond price formulae, and this has the added advantage of allowing yield curves to be fitted. Furthermore, the Lie-algebraic approach can be easily extended to formulate new analytically tractable single-factor interest rate models.

  19. Term structure of interest rate, relative factors and exchange rate prediction%利率期限结构、相对因子与汇率预测

    Institute of Scientific and Technical Information of China (English)

    李艳; 吴亮

    2016-01-01

    由于利率期限结构中包含未来经济运行的信息,利用2006年4月到2014年12月中美两国利率期限结构的月度数据,通过动态Nelson-Siegel模型抽取两国利率期限结构的相对水平,斜率和凸度三因子,基于三个相对因子检验其对人民币/美元汇率的预测能力。实证研究表明:(1)相对因子模型对汇率在1到12月期具有可预测性,相对水平因子或相对斜率因子增加1%分别导致人民币升值1%和2%而相对凸度因子增加1%会导致人民币贬值1%;(2)基于CW检验统计量的滚动窗预测表明:在所考虑的各个滚动窗下,相对因子模型预测能力优于随机游走和非抛补利率平价模型。%Since the term structure of interest rates embodies information about future economic activity, this paper uses dy-namic Nelson-Siegel model to extract relative level, slope and curvature based on monthly data of interest rate of term structure of China and United States from April in 2006 to December in 2014 and analyses forecasting ability of relative factors on Ren-minbi/Dollar exchange rate. The empirical study shows that (1) Relative factors model can predict exchange rate changes 1 to 12 months ahead, and 1 percentage point increase in relative level or slope predicts 1%and 2%annualized appreciation of the Ren-minbi respectively, 1 percentage point increase in relative curvature predicts 1% annualized depreciation of the Renminbi; (2) Rolling window forecasting based on Clark-West statistics shows that relative factors model outperforms random walk and un-covered interest parity model.

  20. Factors affecting the corrosion rates of ceramics in coal combustion systems

    Energy Technology Data Exchange (ETDEWEB)

    Hurley, J.P. [Univ. of North Dakota, Grand Forks, ND (United States)

    1995-08-01

    The concentrations of approximately a dozen elements in the products of coal combustion affect the corrosion rates of ceramics used to construct the combustion system. The elements, including H, O, Na, Mg, Al, Si, P, S, Cl, K, Ca, and Fe, affect corrosion rates in three ways: as primary corrodants of the materials, as secondary corrodants that affect the activities of the primary corrodants, and by affecting the mass transport rate of the primary corrodants. A full factorial study of corrosion rates performed by varying the concentrations of these elements would involve X{sup n} tests, where X is the number of variations of each element and n is the number of different elements. For three variations (low, medium, and high concentrations) of each of 12 elements, the number of tests is 531,441 for a single temperature and pressure condition. The numbers can be reduced with the use of a fractional factorial test matrix, but the most effective way to perform corrosion tests is to base them on realistic system conditions. In this paper, the effects of the composition and physical state of the products of coal combustion on ceramic corrosion rates are given along with suggestions of appropriate test conditions for specific system components.

  1. Factors influencing the predation rates of Anisops breddini (Hemiptera: Notonectidae feeding on mosquito larvae

    Directory of Open Access Journals (Sweden)

    R. Weterings

    2014-12-01

    Full Text Available Notonectidae are a family of water bugs that are known to be important predators of mosquito larvae and have great potential in the biological control of vector mosquitoes. An experiment was conducted to assess mosquito larvae predation by Anisops breddini, a species common to Southeast Asia. The predation rates were recorded in context of prey density, predator density, predator size and prey type. Predation rates were strongly affected by prey type and less by prey density and predator density. They ranged between 1.2 prey items per day for pupae of Aedes aegeypti and Armigeres moultoni to 5.9 for Ae. aegypti larvae. Compared with studies on other Notonectidae species, the predation rates appear low, which is probably caused by the relative small size of the specimens used in this study. An. breddini is very common in the region and often found in urban areas; therefore, the species has potential as a biological control agent.

  2. Computing arbitrage-free yields in multi-factor Gaussian shadow-rate term structure models

    OpenAIRE

    Marcel A. Priebsch

    2013-01-01

    This paper develops a method to approximate arbitrage-free bond yields within a term structure model in which the short rate follows a Gaussian process censored at zero (a "shadow-rate model" as proposed by Black, 1995). The censoring ensures that model-implied yields are constrained to be positive, but it also introduces non-linearity that renders standard bond pricing formulas inapplicable. In particular, yields are not linear functions of the underlying state vector as they are in affine t...

  3. Deposition rates of fungal spores in indoor environments, factors effecting them and comparison with non-biological aerosols

    Science.gov (United States)

    Kanaani, Hussein; Hargreaves, Megan; Ristovski, Zoran; Morawska, Lidia

    Particle deposition indoors is one of the most important factors that determine the effect of particle exposure on human health. While many studies have investigated the particle deposition of non-biological aerosols, few have investigated biological aerosols and even fewer have studied fungal spore deposition indoors. The purpose of this study was, for the first time, to investigate the deposition rates of fungal particles in a chamber of 20.4 m 3 simulating indoor environments by: (1) releasing fungal particles into the chamber, in sufficient concentrations so the particle deposition rates can be statistically analysed; (2) comparing the obtained deposition rates with non-bioaerosol particles of similar sizes, investigated under the same conditions; and (3) investigating the effects of ventilation on the particle deposition rates. The study was conducted for a wide size range of particle sizes (0.54-6.24 μm), at three different air exchange rates (0.009, 1.75 and 2.5 h -1). An Ultraviolet Aerodynamic Particle Sizer Spectrometer (UVAPS) was used to monitor the particle concentration decay rate. The study showed that the deposition rates of fungal spores ( Aspergillus niger and Penicillium species) and the other aerosols (canola oil and talcum powder) were similar, especially at very low air exchange rates (in the order of 0.009). Both the aerosol and the bioaerosol deposition rates were found to be a function of particle size. The results also showed increasing deposition rates with increasing ventilation rates, for all particles under investigation. These conclusions are important in understanding the dynamics of fungal spores in the air.

  4. The Path to Graduation: Factors Predicting On-Time Graduation Rates

    Science.gov (United States)

    Letkiewicz, Jodi; Lim, Hanna; Heckman, Stuart; Bartholomae, Suzanne; Fox, Jonathan J.; Montalto, Catherine P.

    2014-01-01

    This study uses an integrative persistence model to examine college students' expected time-to-degree as a function of sociological and economic factors. The data used in this study are from the 2010 Ohio Student Financial Wellness Survey (SFWS), a web-based survey of undergraduate college students. Of the students surveyed, 25% indicated that…

  5. RAPID COMMUNICATION: Nerve growth factor influences cleavage rate and embryo development in sheep.

    Science.gov (United States)

    Crispo, M; Dos Santos-Neto, P C; Vilariño, M; Mulet, A P; de León, A; Barbeito, L; Menchaca, A

    2016-10-01

    Recent information about Nerve growth factor (NGF), a protein traditionally associated to the nervous system that regulates survival and maturation of developing neurons, suggests that it may exert action also on different levels in the reproductive system. The aim of this study was to evaluate the effect of NGF added during in vitro oocyte maturation, fertilization or in vitro embryo development in sheep. Nerve growth factor was supplemented to the culture medium at 0, 100, or 1,000 ng/mL, during either in vitro maturation (Exp. 1), in vitro fertilization (Exp. 2), or in vitro culture (Exp. 3). In addition, NGF mRNA expression was determined in cumulus cells and oocytes. Nerve growth factor induced early cleavage when added during oocyte maturation or fertilization, improved embryo development when added during fertilization, and had no significant effect when added during embryo culture. In general, the effect was more evident with 100 rather than 1,000 ng/mL (P development in sheep. We suggest a possible effect of this growth factor on oocyte maturation and mainly on the fertilization process.

  6. Physical activity as a health factor modifying heart rate variability (HRV

    Directory of Open Access Journals (Sweden)

    Nowosielska-Swadzba Danuta

    2015-03-01

    Full Text Available Purpose: The aim of the research was the evaluation of the selected HRV factors of the training volleyball players in two training periods and non-training people. Materials and methods : The study involved 8 leading volleyball players aged 20-23 and 13 non-training persons aged 19-26. The study of the training players was conducted twice: in the pre-competition and in the competition period. The study for the non-training persons was conducted once. The selected factors of the spectral analysis have been evaluated: TP [ms 2], share of LF and HF power [n.u], LF/HF indicator and time analysis factors: RR [ms], HR [1/min], RMSSD [ms]. Results : Statistically significant differences appeared only in the selected time analysis factors (RR, HR, between the group of the training and non-training persons. Other differences in the evaluated parameters were not statistically significant. Conclusions : Physical activity influences on the HRV growth. HRV measurement may serve for the control of the changes taking place in the AUN under the influence of the physical activity.

  7. Absorption and desorption mass transfer rates in chemically enhanced reactive systems. Part I : Chemical enhancement factors

    NARCIS (Netherlands)

    Hamborg, Espen S.; Versteeg, Geert F.

    2012-01-01

    The chemical enhancement factors have been measured in a controlled environment for absorption and desorption mass transfer processes in aqueous 2.0 M MDEA solutions at temperatures of 298.15, 313.15, and 333.15 K and the loading of CO2 ranging from 0 to 0.8 in a batch-operated stirred tank reactor.

  8. Patient-perceived factors contributing to low tuberculosis cure rate at ...

    African Journals Online (AJOL)

    2014-04-03

    Apr 3, 2014 ... Objectives: The purpose of the study was to explore and describe the factors contributing to low TB ..... treatment on an empty stomach I experience abdominal pains. I ..... org.za/wp-content/uploads/2010/04/Chapter12.pdf ... in Pakistan', The Lancet 357(9257), 664–669. http://dx.doi.org/10.1016/S0140-.

  9. Child maltreatment in numbers : a multimethod study of year prevalence rates and risk factors

    NARCIS (Netherlands)

    Euser, Saskia

    2013-01-01

    How often does child maltreatment occur in the Netherlands and which factors increase the risk of child maltreatment? In this thesis we describe the findings of two epidemiological studies aimed at answering these questions. First, in the Netherlands’ Prevalence study on Maltreatment of children and

  10. The rate of handedness conversion and related factors in left-handed children.

    Science.gov (United States)

    Meng, Ling-fu

    2007-03-01

    The rate of handedness conversion was 2.7% to 11.8% in prior studies based on the total population including innately right-handed people. However, the conversion rate of innately left-handed people has not been reported. The purpose of this study was to investigate the percentage of handedness conversion in children who are innately left-handed. The data in the present study showed that 59.3% (121/211) of left-handed children had been forced to convert to right-handedness. Current handedness was also reported by 114 of the 121 informants, and the rates of right-, left-, and mixed-handedness were 56.1% (64/114), 26.3% (30/114), and 17.5% (20/114) respectively. More than half had successfully changed from left to right. Some variables, especially the educational level of the parents and the child's grade level, were related to this conversion intention. The children whose parents had less education were more likely to be forced to change handedness. Additionally, the rate of handedness conversion in younger children was lower than in older children. However, even for the children whose parents had higher education, or for the children who were younger, there was a high percentage (45.7% and 41.8% respectively) who had changed their handedness. Therefore, preventing the possible side effects for children who have undergone hand conversion should be emphasised in the future.

  11. Metabolic Rate: A Factor in Developing Obesity in Children with Down Syndrome?

    Science.gov (United States)

    Chad, Karen; And Others

    1990-01-01

    Resting metabolic rate and its relation to selected anthropomorphic measures were determined in 11 male and 7 female noninstitutionalized children with Down Syndrome. Dietary analysis was performed to determine the children's nutritional status. Results have implications for the prevention and treatment of obesity in children with Down Syndrome.…

  12. Metabolic Rate: A Factor in Developing Obesity in Children with Down Syndrome?

    Science.gov (United States)

    Chad, Karen; And Others

    1990-01-01

    Resting metabolic rate and its relation to selected anthropomorphic measures were determined in 11 male and 7 female noninstitutionalized children with Down Syndrome. Dietary analysis was performed to determine the children's nutritional status. Results have implications for the prevention and treatment of obesity in children with Down Syndrome.…

  13. Perspective of Teachers about the Role of Family, Personal, School and Environmental Factors in the Academic Survival Rate of Students in Rural Areas of Southeast of Iran

    Directory of Open Access Journals (Sweden)

    Davoud Toughi

    2016-06-01

    Full Text Available This is a descriptivestudyhas carried out to investigate some related factors on the academic survival rate of students in rural areas of Southeast of Iran. Using stratified random sampling method, 224 teachers were chosen as sample. The results showed that teachers believed that family, personal, school and environmental factors affect the academic survival rate of students in rural areas; thus, the identification of these factors increase the survival rate and decrease the dropout rate of students in rural areas.

  14. Analysis of infestation rate of Helicobacter pylori and factors affecting the infestation in Inner Mongolia border recruits

    Directory of Open Access Journals (Sweden)

    Jian-wei YU

    2014-10-01

    Full Text Available Objective To investigate the prevalence of Helicobacter pylori (H. pylori infestation and its related risk factors in the recruits at Hulunbuir pastureland and Ala Shan Desert. Methods Nine hundred male recruits (16-24 years old were enrolled in this cross-sectional study. H. pylori infection was detected by 13C-urea breath test, and the related risk factors were surveyed by using questionnaires. The data of risk factors for H.pylori infection were analyzed by using chi-square test and logistic regression. Results The H. pylori infection rate was 47.5% in recruits located in Hulunbuir pastureland, while it was 44.8% in recruits located in Ala Shan Desert. The H. pylori infection rate was higher in recruits from the West China and Central China, and higher in the recruits from the rural area than those from city (P<0.05. The level of serum pepsinogen (PG I and PGⅡ was elevated, but PGR (PGⅠ/PGⅡ lowered in the recruits with H. pylori infection (P<0.05. Logistic regression analysis revealed that the factors as hand-washing with soap, smoking, halitosis, and halitosis with acne were positively correlated with H. pylori infection. Conclusions H. pylori infection rate of new recruits is lower in Inner Mongolia compared to the finding of previous studies. Residential environment is the fact DOI: 10.11855/j.issn.0577-7402.2014.09.17

  15. [Factor structure and psychometric properties of the ICD-10-Symptom-Rating (ISR) in samples of psychosomatic patients].

    Science.gov (United States)

    Fischer, Herbert Felix; Tritt, Karin; Klapp, Burghard F; Fliege, Herbert

    2010-08-01

    The ICD-10-Symptom-Rating (ISR) is a self-rating questionnaire for patients. According to its conceptualization, the instrument was developed to closely represent the syndrome structure of the ICD-10 while assessing the extent of psychological distress an individual suffers from. The results of different factor analyses testing the postulated syndrome structure as well as item and scale characteristics are reported here. Data was collected from a consecutive sample of 1 057 psychosomatic patients of the University Hospital Charité Berlin. Evaluation of the dimensional structure of the questionnaire included exploratory and confirmatory factor analyses each computed with a randomized half of the sample. Multi-Sample-Analyses with different subgroups of the sample were performed to test the stability of the factor structure. The individual factors were constituted by the postulated syndrome units of the ICD-10 involving a high and uniform distribution of accounted variance. They also proved themselves satisfactorily stable over the different subsamples. The scales showed a high degree of internal consistency with relatively small gender and age effects, while psychological disorders had a large effect on the means of the scales. Taking a perspective of test theory, the ICD-10-Symptom-Rating is in accordance with the syndrome structure of the ICD-10 and suitable for the assessment of psychological symptoms. Other aspects pertaining to the reliability and validity of the ISR remain to be proven in future research.

  16. Effect of personal risk factors on the prevalence rate of musculoskeletal disorders among workers of an Iranian rubber factory.

    Science.gov (United States)

    Samaei, S E; Tirgar, A; Khanjani, N; Mostafaee, M; Bagheri Hosseinabadi, M

    2017-01-01

    Musculoskeletal Disorders (MSDs) are among the most common occupational disorders in many countries and have an increasing trend. The present study was conducted in order to determine the prevalence rate of MSDs in different body regions and the effect of personal factors on the prevalence rate of MSDs among rubber industry workers. This analytical and cross-sectional study was performed on 206 workers of an Iranian rubber factory in 2014. The samples were randomly selected. Data were gathered by means of personal information form, the Nordic Musculoskeletal Questionnaire (NMQ) and the Rapid Entire Body Assessment (REBA). The results were analyzed using SPSS16; by descriptive and analytical statistics. The mean age and work history of subjects were 34.54±6.36 and 12.34±6.28 years, respectively. The highest prevalence rate of MSDs in the last twelve-months was related to the lower back region with a prevalence rate of 62.1%. Based on logistic regression, a significant correlation was found between MSDs and the final REBA score so that for a one-unit increase in score, the risk or complaint of neck and low back pain increased by 48.5% and 37.1%, respectively. Many rubber factory workers experience MSDs especially in the lower back region as a consequence of occupational risk factors. Therefore, detecting the occupational risk factors, work position standards and following ergonomic interventions are highly recommended.

  17. Study of internal consistency and factor structure of three versions of the Zung’s rating instrument for anxiety disorders

    Directory of Open Access Journals (Sweden)

    Susana De La Ossa

    2009-03-01

    Full Text Available Background: The Zung’s rating instrument for anxiety disorders has been used in several Colombian researches. Its internal consistency and factor structure have not been reported among university students.Objective: To calculate the internal consistency and explore the factor structure of three versions of the Zung’s rating instrument for anxiety disorders among university students.Method: Two-hundred and twenty-one medicine and psychology students of a private university in Cartagena, Colombia, completed the 20-item version of the Zung’s rating instrument for anxiety disorders. The mean of age of students was 20.5 years (SD=2.6, 64.4% were women, and 54.3% studied medicine. Cronbach alpha was computed and exploratory factor analysis was done for the three versions.Results: The 20-item version of the Zung’s rating instrument for anxiety disorders presents Cronbach alpha coefficient of 0.77 and three principal factors accounted for 40.1% of the total variance. The 10-item version showed Cronbach alpha of 0.83 and two-dimensional structure responsible of 54.0% of the total variance. The 5-item version showed Cronbach alpha of 0.74 and one-dimensional structure accounted for 49.5% of the total variance.Conclusions: The 10- and 5-item version of the Zung’s rating instrument for anxiety disorders present better psychometric properties than the original 20-item version. It is necessary to estimate the properties of these versions compared with a gold standard.

  18. Study of internal consistency and factor structure of three versions of the Zung’s rating instrument for anxiety disorders

    Directory of Open Access Journals (Sweden)

    Susana De La Ossa

    2009-12-01

    Full Text Available Background: The Zung’s rating instrument for anxiety disorders has been used in several Colombian researches. Its internal consistency and factor structure have not been reported among university students. Objective: To calculate the internal consistency and explore the factor structure of three versions of the Zung’s rating instrument for anxiety disorders among university students. Method: Two-hundred and twenty-one medicine and psychology students of a private university in Cartagena, Colombia, completed the 20-item version of the Zung’s rating instrument for anxiety disorders. The mean of age of students was 20.5 years (SD=2.6, 64.4% were women, and 54.3% studied medicine. Cronbach alpha was computed and exploratory factor analysis was done for the three versions. Results: The 20-item version of the Zung’s rating instrument for anxiety disorders presents Cronbach alpha coefficient of 0.77 and three principal factors accounted for 40.1% of the total variance. The 10-item version showed Cronbach alpha of 0.83 and two-dimensional structure responsible of 54.0% of the total variance. The 5-item version showed Cronbach alpha of 0.74 and one-dimensional structure accounted for 49.5% of the total variance. Conclusions: The 10- and 5-item version of the Zung’s rating instrument for anxiety disorders present better psychometric properties than the original 20-item version. It is necessary to estimate the properties of these versions compared with a gold standard.

  19. Global environmental ratings as an instrument of environmental policies: what factors determine the rank of Russia?

    Science.gov (United States)

    Alekseeva, Nina; Arshinova, Marina; Milanova, Elena

    2017-04-01

    Systems of global environmental rankings have emerged as a result of the escalating need for revealing the trends of ecological development for the world and for certain countries and regions. Both the environmental indicators and indexes and the ratings made on their basis are important for the assessment and forecast of the ecological situation in order to tackle the global and regional problems of sustainable development and help to translate the research findings into policy developments. Data sources for the global environmental ratings are most often the statistical information accumulated in databases of the international organizations (World Bank, World Resources Institute, FAO, WHO, etc.) These data are highly reliable and well-comparable that makes the ratings very objective. There are also good examples of using data of sociological polls, information from social networks, etc. The global environmental ratings are produced by the international organizations (World Bank, World Resources Institute, the UN Environment Program), non-governmental associations (WWF, Climate Action Network Europe (CAN-E), Germanwatch Nord-Süd-Initiative, Friends of the Earth, World Development Movement), research structures (scientific centers of the Yale and Colombian universities, the Oak-Ridge National Laboratory, the New Economic Foundation), and also individual experts, news agencies, etc. Thematic (sectoral) ratings cover various spheres from availability of resources and anthropogenic impact on environment components to nature protection policies and perception of environmental problems. The environmental indicators cover all parameters important for understanding the current ecological situation and the trajectories of its development (the DPSIR model, i.e. drivers, pressures, state, impact and response). Complex (integral) ratings are based on environmental indexes which are combined measurement tools using a complex of aggregated indicators based on a wide range of

  20. Determination of the Astrophysical S(E) Factors or Rates for Radiative Capture Reaction with One Nucleon Transfer Reaction%Determination of the Astrophysical S(E) Factors or Rates for Radiative Capture Reaction with One Nucleon Transfer Reaction

    Institute of Scientific and Technical Information of China (English)

    李志宏; 郭冰; 李云居; 苏俊; 李二涛; 白希祥; 王友宝; 曾晟; 王宝祥; 颜胜权; 李志常; 刘建成; 连钢; 金孙均; 刘鑫; 柳卫平

    2012-01-01

    The radiative capture reaction plays an important role in nuclear astrophysics. We have indirectly measured the astrophysical S(E) factors for some proton capture reactions and reaction rates for several neutron capture reactions with one nucleon transfer reactions at HI-13 tandem accelerator in recent years. Some of them are compiled into IAEA EXFOR database and JINA REACLIB project, and used in the network calculations of Big Bang nucleosynthesis and type-I X-ray bursts.

  1. An Analysis Credit Rating Factors of Steel Distributors from Customer Perspective in Iran\\\\\\'s Market

    Directory of Open Access Journals (Sweden)

    Asghar Moshabbaki

    2016-03-01

    Full Text Available This study with aim of investigation and identification of most important determinant criteria in significant distributors selecting by retailer customers did in Iran steel market and Arvin steel distributor selected as case of study. This research is of survey type and for data collect, a questionnaire was developed from various sources in the literature, used. Sample of 107 customers of Arvin steel distributor in Tehran city was selected. Also, Structure Equation Modeling (SEM and Confirmatory Factor Analysis (CFA and two software package "SPSS and LISREL" are used for analyzing the data. in total, nine variable "managerial capability", "marketing capability", "relationship intensity", "logistics capability", "financial capability", "physical facilities", "market cover", "product line" and "reputation" of distributor identified as main determinant factors in distributor selecting. Study findings show that the effect of "managerial capability", "marketing capability", "Relationship intensity", "Logistics capability", "financial capability", "Physical facilities", "Market cover" and "reputation" on distributor choice were statistically significant.

  2. Factors affecting quality for beta dose rate measurements using ISO 6980 series I reference sources

    Energy Technology Data Exchange (ETDEWEB)

    Burns, R.E. Jr.; O`Brien, J.M. Jr. [Atlan-Tech, Rosewll, GA (United States)

    1993-12-31

    Atlan-Tech, Inc. has performed several calibrations of ISO 6980 Series 1 reference beta sources over the past two to three years. There were many problems encountered in attempting to compare the results of these calibrations with those from other laboratories, indicating the need for more standardization in the methodology employed for the measurement of the absorbed dose rate from ISO 6980 Series 1 reference beta sources. This document describes some of the problems encountered in attempting to intercompare results of beta dose-rate measurements. It proposes some solutions in an attempt to open a dialogue among facilities using reference beta standards for the purpose of promoting better measurement quality assurance through data intercomparison.

  3. Which Factors Influence the Type of Delivery and Cesarean Section Rate in Women with Gestational Diabetes?

    Science.gov (United States)

    Inocêncio, Gonçalo; Braga, António; Lima, Tânia; Vieira, Bruna; Zulmira, Rosa; Carinhas, Maria; Gonçalves, Joaquim; Silva, Clara

    2015-01-01

    To discover the differences between women with gestational diabetes mellitus (GDM) who delivered vaginally and those who delivered by cesarean section, and to assess the cesarean rate in this group of women. We divided all pregnant women with GDM into 2 groups: those who had vaginal delivery and those who gave birth by cesarean section (retrospective study of 6 years). We evaluated 460 births at term (≥ 37 weeks' gestation), for a total of 240 vaginal births and 220 cesarean births. All occurred in our institution. Of all the variables that were compared between the 2 groups, we found statistically significant differences (p cesarean section. Also, the initiation of insulin treatment at an early gestational age is associated with a higher chance of a woman delivering by cesarean section. The cesarean section rate in women with GDM was 47.8%.

  4. Socio-Environmental Factors Associated with Self-Rated Oral Health in South Africa: A Multilevel Effects Model

    Directory of Open Access Journals (Sweden)

    Bukola G. Olutola

    2012-10-01

    Full Text Available Aim: This study examined the influence of the social context in which people live on self-ratings of their oral health. Method: This study involved a representative sample of 2,907 South African adults (≥16 years who participated in the 2007 South African Social Attitude Survey (SASAS. We used the 2005 General Household Survey (n = 107,987 persons from 28,129 households to obtain living environment characteristics of SASAS participants, including sources of water and energy, and household cell-phone ownership (a proxy measure for the social network available to them. Information obtained from SASAS included socio-demographic data, respondents’ level of trust in people, oral health behaviors and self-rated oral health. Results: Of the respondents, 76.3% self-rated their oral health as good. Social context influenced women’s self-rated oral health differently from that of men. Good self-rated oral health was significantly higher among non-smokers, employed respondents and women living in areas with higher household cell-phone ownership. Furthermore, trust and higher social position were associated with good self-rated oral health among men and women respectively. Overall, 55.1% and 18.3% of the variance in self-rated oral health were explained by factors operating at the individual and community levels respectively. Conclusion: The findings highlight the potential role of social capital in improving the population’s oral health.

  5. Neural Tube Defect in Alive Neonates: Incidence Rate and Predisposing Factors

    Directory of Open Access Journals (Sweden)

    F Haghollahi

    2008-06-01

    Full Text Available Background: Neural Tube Defect (NTD characterized by failure of neural tube to close properly be the second most common born defect after congenital heart disease. The most prevalent forms of NTD are Anencephaly and Spinal-bifida. Many factors are involved in this anomaly. New researches suggest environmental factors like radiation, hyperthermia, Vitamin A and acid folic deficiency, anti epileptic drug like Carbamazepine, Phenobarbital, phenytoin, Folic acid antagonist like Sulfasalazine, Triametherine and systemic disease like diabet mellitus, obesity, genetic factors, the most schance 40 to 70 percentages.Methods: In this survey cross sectional study was conducted in five hospitals depend to Tehran university during three years. Study subject identified through review of admission and discharge at major hospital through regular contact with newborn nurseries and birth hospital.Results: In 38473 reported cases, 143 cases have neural tube defect. Among NTD cases, 11.9% of mothers had medical diseases in their previous history such as diabetes mellitus, epilepsy-psychiatric, and disorder-heart diseases. In this study group, 5.6% have preclampsia during pregnancy period. The most common NTD anomaly in this study was anencephaly and meningomyelocele that was different from studies in literature.Conclusion: NTD result from failure of neural tube close threats fetus health up to 28 days after conception. When is often prior to the recognition of pregnancy since many pregnancy are unplanned NTD prevention is best achieve by adequate daily folic acid intake thought of reproductive ages .educational effort to promote daily intake of folic acid supplemental by women of reproductive age and NTD risk factor should be done. Early diagnostic procedure for high risk pregnancy advised.

  6. The role of socio-demographic factors on self-rated happiness: The case of Malaysia

    OpenAIRE

    Cheah, Yong Kang; Tang, Chor Foon

    2011-01-01

    This study examines the role of socio-demographic determinants on individual’s level of happiness. Primary survey data on Penang, Malaysia is used for analysis. Based on the findings, being married and Malay are associated with higher probability of feeling very happy or happy. Nevertheless, individuals who suffer from chronic diseases are more likely to have unhappy or very unhappy feelings. The rest of the factors such as income, education, age, gender, and employment status are found to ha...

  7. MORTALITY RATE AND OUTCOME FACTORS IN MIXED CRYOGLOBULINAEMIA: THE IMPACT OF HEPATITIS C VIRUS

    OpenAIRE

    Salvadori, Stefano; Della Rossa, Alessandra; et, al.

    2010-01-01

    Objectives: Mixed cryoglobulinaemia (MC) is a chronic small-vessel vasculitis. Shortly after the discovery of hepatitis C virus (HCV) in 1989, an association between HCV infection and MC was being increasingly reported, suggesting the potential pathogenetic implication of HCV in most of the cases that had been previously diagnosed as essential MC. A number of studies have pointed out prognostic factors linked to mortality in this disorder. None of them, however, have clarified the impact of H...

  8. The adaptation rate of terrestrial ecosystems as a critical factor in global climate dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Fuessler, J.S.; Gassmann, F. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    A conceptual climate model describing regional two-way atmosphere-vegetation interaction has been extended by a simple qualitative scheme of ecosystem adaptation to drought stress. The results of this explorative study indicate that the role of terrestrial vegetation under different forcing scenarios depends crucially on the rate of the ecosystems adaptation to drought stress. The faster the adaptation of important ecosystems such as forests the better global climate is protected from abrupt climate changes. (author) 1 fig., 3 refs.

  9. Oxygen Consumption by Postfermentation Wine Yeast Lees: Factors Affecting Its Rate and Extent under Oenological Conditions

    OpenAIRE

    Schneider, Volker; Müller, Jonas; Schmidt, Dominik

    2016-01-01

    Postfermentation wine yeast lees show antioxidant properties based on their ability to consume dissolved oxygen. The oxygen consumption capacity of suspended yeast lees obtained after fermentations with six commercial active dry yeast strains was investigated in model, white and red wines using fluorescence-based oxygen sensors operating in a nondestructive way. In model solution, the oxygen consumption rate of yeast lees was shown to depend on their amount, yeast strain, sulfur dioxide and t...

  10. Rates, variability, and associated factors of polypharmacy in nursing home patients

    Science.gov (United States)

    Beloosesky, Yichayaou; Nenaydenko, Olga; Gross Nevo, Revital Feige; Adunsky, Abraham; Weiss, Avraham

    2013-01-01

    Objectives To determine the rate and variability of polypharmacy in nursing home (NH) residents and investigate its relationship to age, sex, functional status, length of stay, and comorbidities. Methods We conducted a cross sectional, multicenter study that included six nursing homes. Demographic, clinical characteristics, Charlson comorbidity index (CCI), the number and classes of chronic medications, rate of polypharmacy >5 drugs (per day) and polypharmacy >7 drugs (per day) were recorded. Results Nine hundred and ninety-three residents were included; 750 (75.5%) fully dependent residents and 243 (24.5%) mobile demented residents requiring institutional care. The mean age was 85.04±7.55 (65–108) years. The mean rates of polypharmacy >5 drugs and polypharmacy >7 drugs were 42.6% and 18.6%, respectively. Differences in polypharmacy >5 drugs and polypharmacy >7 drugs were observed in NHs 24.7%–56% and 4.9%–30.4%, respectively (Ppolypharmacy were found between sex and fully dependent versus mobile demented residents. The most common medications taken were for gastrointestinal, neurological, and cardiovascular disorders. Regression analysis revealed four independent variables for polypharmacy >5 drugs: groups aged 75–84 and >85 relative to 65–74, odds ratio (OR) 0.46 (95% confidence interval [CI] 0.27–0.78) P=0.004, OR 0.35 (95% confidence interval 0.19–0.53), respectively, P2 years, OR 0.51 (95% CI 0.36–0.73) Ppolypharmacy in NHs are high with significant variability. Variability rates of polypharmacy, distinct residents’ characteristics, and excessive use of certain drug groups may indicate that a decrease in medication is potentially feasible. PMID:24348028

  11. Low heart rate as a risk factor for child and adolescent proactive aggressive and impulsive psychopathic behavior.

    Science.gov (United States)

    Raine, Adrian; Fung, Annis Lai Chu; Portnoy, Jill; Choy, Olivia; Spring, Victoria L

    2014-01-01

    Although low resting heart rate has been viewed as a well-replicated biological correlate of child and adolescent antisocial behavior, little is known about how it interacts with psychosocial adversity in predisposing to both reactive-proactive aggression and psychopathy, and whether this relationship generalizes to an East Asian population. This study tests the hypothesis that low resting heart rate will be associated with aggression and psychopathic traits, and that heart rate will interact with adversity in predisposing to these antisocial traits. Resting heart rate was assessed in 334 Hong Kong male and female schoolchildren aged 11-17 years. A social adversity index was calculated from a psychosocial interview of the parent, while parents assessed their children on the Reactive-Proactive Aggression Questionnaire and the Antisocial Personality Screening Device. Low resting heart rate was significantly associated with higher proactive aggression, impulsive features of psychopathy, and total child psychopathy. Low resting heart rate interacted with high psychosocial adversity in explaining higher reactive (but not proactive) aggression, as well as impulsive psychopathy. These findings provide support for a biosocial perspective of reactive aggression and impulsive psychopathy, and document low resting heart rate as a robust correlate of both childhood impulsive psychopathic behavior and proactive aggression. To our knowledge, this study is the first to document low resting heart rate as a correlate of child psychopathy and the second to establish low heart rate as a risk factor of antisocial behavior in an East Asian population. The findings provide further evidence for both low resting heart rate as a potential biomarker for childhood psychopathic and aggressive behavior, and also a biosocial perspective on childhood antisocial behavior.

  12. Normalized impact factor (NIF): an adjusted method for calculating the citation rate of biomedical journals.

    Science.gov (United States)

    Owlia, P; Vasei, M; Goliaei, B; Nassiri, I

    2011-04-01

    The interests in journal impact factor (JIF) in scientific communities have grown over the last decades. The JIFs are used to evaluate journals quality and the papers published therein. JIF is a discipline specific measure and the comparison between the JIF dedicated to different disciplines is inadequate, unless a normalization process is performed. In this study, normalized impact factor (NIF) was introduced as a relatively simple method enabling the JIFs to be used when evaluating the quality of journals and research works in different disciplines. The NIF index was established based on the multiplication of JIF by a constant factor. The constants were calculated for all 54 disciplines of biomedical field during 2005, 2006, 2007, 2008 and 2009 years. Also, ranking of 393 journals in different biomedical disciplines according to the NIF and JIF were compared to illustrate how the NIF index can be used for the evaluation of publications in different disciplines. The findings prove that the use of the NIF enhances the equality in assessing the quality of research works produced by researchers who work in different disciplines.

  13. Software metrics: The quantitative impact of four factors on work rates experienced during software development. [reliability engineering

    Science.gov (United States)

    Gaffney, J. E., Jr.; Judge, R. W.

    1981-01-01

    A model of a software development process is described. The software development process is seen to consist of a sequence of activities, such as 'program design' and 'module development' (or coding). A manpower estimate is made by multiplying code size by the rates (man months per thousand lines of code) for each of the activities relevant to the particular case of interest and summing up the results. The effect of four objectively determinable factors (organization, software product type, computer type, and code type) on productivity values for each of nine principal software development activities was assessed. Four factors were identified which account for 39% of the observed productivity variation.

  14. Demonstration of Crystal Structure.

    Science.gov (United States)

    Neville, Joseph P.

    1985-01-01

    Describes an experiment where equal parts of copper and aluminum are heated then cooled to show extremely large crystals. Suggestions are given for changing the orientation of crystals by varying cooling rates. Students are more receptive to concepts of microstructure after seeing this experiment. (DH)

  15. Crystal science fundamentals

    OpenAIRE

    Ramachandran, V.; Halfpenny, PJ; Roberts, KJ

    2017-01-01

    The fundamentals of crystal science notably crystallography, crystal chemistry, crystal defects, crystal morphology and the surface chemistry of crystals are introduced with particular emphasis on organic crystals.

  16. Relativistic configuration interaction plus linearized-coupled-cluster calculations of U2 + energies, g factors, transition rates, and lifetimes

    Science.gov (United States)

    Savukov, I.; Safronova, U. I.; Safronova, M. S.

    2015-11-01

    Excitation energies, term designations, g factors, transition rates, and lifetimes of U2 + are determined using a relativistic configuration interaction (CI) + linearized-coupled-cluster (LCC) approach. The CI-LCC energies are compared with CI + many-body-perturbation-theory (MBPT) and available experimental energies. Close agreement has been found with experiment, within hundreds of cm-1. In addition, lifetimes of higher levels have been calculated for comparison with three experimentally measured lifetimes, and close agreement has been found within the experimental error. CI-LCC calculations constitute a benchmark test of the CI + all-order method in complex relativistic systems such as actinides and their ions with many valence electrons. The theory yields many energy levels, g factors, transition rates, and lifetimes of U2 + that are not available from experiment. The theory can be applied to other multivalence atoms and ions, which would be of interest to many applications.

  17. Survival Rate and its Related Factors in Patients with Acute Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    H Ghaffarian Shirazi

    2006-04-01

    Full Text Available ABSTRACT: Introduction & Objective: It has been noted that the myocardial infarction is an increasing episode in Islamic Republic of Iran and there are many procedures and methods which can help to reduce the number of death from this ongoing event. The aim of this study was to determine the survival rate in those patients who have had acute myocardial infarction and its association with different variables. Materials & Methods: This descriptive analytic study evaluates 111 cases of acute myocardial infarction admitted in Yasuj Imam Sajjad hospital during the year 2004 and 2005. Data were collected using a questionnaire which was completed through direct interviewing by trained personnel. The data were analyzed by standard statistical tests using SPSS software. Results: The mean age of patients was 57± 12 years. The mean time of having access to physician after MI was 4 ± 2.2 hours. The mean time of reaching hospital after physician order was 5 ± 4.9 hours. The mean time of hospitalization was 4 ± 1.67 days. Considering the past history of these patients revealed that 31 percent were smokers, 16 percent had the history of previous ischemic heart disease, 63 percent had hypertension, 8 percent had diabetes mellitus, 95 percent had clip I, 95 percent had no previous block, 82 percent had MI with Q wave. The survival rate in our study was found to be 0.91 in the first 10 hours, 0.847 in the first day, 0.829 in the first 28 days, 0.820 in the first third months, 0.792 in the first six months and 0.771 in the first 10 months of disease. Conclusion: The mortality rate during the first month among the patients with heart failure turned out to be higher than that of the other similar studies performed in other parts of the country however, the annual survival rate proved to be less. The most important causes of survival after the stroke are being single, smoking, fatness and angina pain

  18. Factors Affecting the Rate of Penetration of Large-Scale Electricity Technologies: The Case of Carbon Sequestration

    Energy Technology Data Exchange (ETDEWEB)

    James R. McFarland; Howard J. Herzog

    2007-05-14

    This project falls under the Technology Innovation and Diffusion topic of the Integrated Assessment of Climate Change Research Program. The objective was to better understand the critical variables that affect the rate of penetration of large-scale electricity technologies in order to improve their representation in integrated assessment models. We conducted this research in six integrated tasks. In our first two tasks, we identified potential factors that affect penetration rates through discussions with modeling groups and through case studies of historical precedent. In the next three tasks, we investigated in detail three potential sets of critical factors: industrial conditions, resource conditions, and regulatory/environmental considerations. Research to assess the significance and relative importance of these factors involved the development of a microeconomic, system dynamics model of the US electric power sector. Finally, we implemented the penetration rate models in an integrated assessment model. While the focus of this effort is on carbon capture and sequestration technologies, much of the work will be applicable to other large-scale energy conversion technologies.

  19. Prevalence Rate and Risk Factors of Pediculus capitis Among Primary School Children in Iran

    Directory of Open Access Journals (Sweden)

    Kassiri

    2015-12-01

    Full Text Available Background Human head lice infestations caused by Pediculus capitis are a common health problem in school aged children in many parts of the globe. Its transmission occurs directly, mostly by head to head contact, and causes scalp itching. This insect is not known to be the vector of any human disease. Objectives This descriptive-analytical study was conducted in order to determine the prevalence of pediculosis, as well as some effective treatments, among pupils in the primary schools of Glogah county in the Mazandaran province of Iran, during the 2009-2010 school year. Materials and Methods A total of three-hundred students in the first through fifth grades in boys’ and girls’ primary schools were selected via multistage, systematic, cluster, random sampling in the urban and rural areas of Glogah county. They were examined for live lice or nits by experienced educators, while a questionnaire was used to record data on the demographic features and other related information of each student. These data were compared using a chi square analysis (SPSS software, and a P value of less than 0.05 was considered to be significant. Results Based on a total of 300 pupils, 17 of them (5.7% were infested with Pediculus capitis. The prevalence rate was 6.8% in the boys and 4.8% in the girls, while the rate of infestation was 7.7% in the urban areas and 3.4% in the villages. Those children between 9 and 10 years old showed the highest prevalence rate (7.4%. There was a significant association between pediculosis and a prior infestation, number of comb uses per day, frequency of hair washing (per week, having a hygiene teacher, sharing common instruments, health care of the children, children living with parents, knowledge of pediculosis, and the spacing of the children in each class. Conclusions The results showed that the prevalence of pediculosis among the Glogah county primary school students was less than the average percentages observed in other

  20. Optical factors determined by the T-matrix method in turbidity measurement of absolute coagulation rate constants.

    Science.gov (United States)

    Xu, Shenghua; Liu, Jie; Sun, Zhiwei

    2006-12-01

    Turbidity measurement for the absolute coagulation rate constants of suspensions has been extensively adopted because of its simplicity and easy implementation. A key factor in deriving the rate constant from experimental data is how to theoretically evaluate the so-called optical factor involved in calculating the extinction cross section of doublets formed during aggregation. In a previous paper, we have shown that compared with other theoretical approaches, the T-matrix method provides a robust solution to this problem and is effective in extending the applicability range of the turbidity methodology, as well as increasing measurement accuracy. This paper will provide a more comprehensive discussion of the physical insight for using the T-matrix method in turbidity measurement and associated technical details. In particular, the importance of ensuring the correct value for the refractive indices for colloidal particles and the surrounding medium used in the calculation is addressed, because the indices generally vary with the wavelength of the incident light. The comparison of calculated results with experiments shows that the T-matrix method can correctly calculate optical factors even for large particles, whereas other existing theories cannot. In addition, the data of the optical factor calculated by the T-matrix method for a range of particle radii and incident light wavelengths are listed.