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Sample records for effective attenuation lengths

  1. Electron Effective-Attenuation-Length Database

    Science.gov (United States)

    SRD 82 NIST Electron Effective-Attenuation-Length Database (PC database, no charge)   This database provides values of electron effective attenuation lengths (EALs) in solid elements and compounds at selected electron energies between 50 eV and 2,000 eV. The database was designed mainly to provide EALs (to account for effects of elastic-eletron scattering) for applications in surface analysis by Auger-electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS).

  2. Effective attenuation lengths for quantitative determination of surface composition by Auger-electron spectroscopy and X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Jablonski, A.; Powell, C.J.

    2017-01-01

    Highlights: • Effective attenuation lengths (EALs) for determination of surface composition by XPS. • Considerable difference from EALs used for overlayer thickness measurements. • New analytical algorithms for calculating the effective attenuation length. - Abstract: The effective attenuation length (EAL) is normally used in place of the inelastic mean free path (IMFP) to account for elastic-scattering effects when describing the attenuation of Auger electrons and photoelectrons from a planar substrate by an overlayer film. An EAL for quantitative determination of surface composition by Auger-electron spectroscopy (AES) or X-ray photoelectron spectroscopy (XPS) is similarly useful to account for elastic-scattering effects on the signal intensities. We calculated these EALs for four elemental solids (Si, Cu, Ag, and Au) and for energies between 160 eV and 1.4 keV. The XPS calculations were made for two instrumental configurations while the AES calculations were made from the XPS formalism after “switching off” the XPS anisotropy. The EALs for quantitative determination of surface composition by AES and XPS were weak functions of emission angle for emission angles between 0 and 50°. The ratios of the average values of these EALs to the corresponding IMFPs could be fitted to a second-order function of the single-scattering albedo, a convenient measure of the strength of elastic-scattering effects. EALs for quantitative determination of surface composition by AES and XPS for other materials can be simply found from this relationship.

  3. A theoretical analysis of ballistic electron emission microscopy: band structure effects and attenuation lengths

    International Nuclear Information System (INIS)

    Andres, P.L. de; Reuter, K.; Garcia-Vidal, F.J.; Flores, F.; Hohenester, U.; Kocevar, P.

    1998-01-01

    Using quantum mechanical approach, we compute the ballistic electron emission microscopy current distribution in reciprocal space to compare experimental and theoretical spectroscopic I(V) curves. In the elastic limit, this formalism is a 'parameter free' representation of the problem. At low voltages, low temperatures, and for thin metallic layers, the elastic approximation is enough to explain the experiments (ballistic conditions). At low temperatures, inelastic effects can be taken into account approximately by introducing an effective electron-electron lifetime as an imaginary part in the energy. Ensemble Monte Carlo calculations were also performed to obtain ballistic electron emission microscopy currents in good agreement with the previous approach. (author)

  4. Photoelectron spectroscopy of liquid water and aqueous solution: Electron effective attenuation lengths and emission-angle anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Ottosson, Niklas [Department of Physics, Uppsala University, SE-75121 Uppsala (Sweden); Faubel, Manfred [Max-Planck-Institut fuer Dynamik und Selbstorganisation, Bunsenstrasse 10, D-37073 Goettingen (Germany); Bradforth, Stephen E. [Department of Chemistry, University of Southern California, Los Angeles, CA 90089 (United States); Jungwirth, Pavel [Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, and Center for Biomolecules and Complex Molecular Systems, Flemingovo nam. 2, 16610 Prague 6 (Czech Republic); Winter, Bernd, E-mail: winter@bessy.d [Helmholtz-Zentrum Berlin fuer Materialien und Energie, and BESSY, Albert-Einstein-Strasse 15, D-12489 Berlin (Germany); Max-Born-Institut, Max-Born-Strasse 2A, D-12489 Berlin (Germany)

    2010-03-15

    Photoelectron (PE) spectroscopy measurements from liquid water and from a 4 m NaI aqueous solution are performed using a liquid microjet in combination with soft X-ray synchrotron radiation. From the oxygen 1s PE signal intensity from liquid water, measured as a function of photon energy (up to 1500 eV), we quantitatively determine relative electron inelastic effective attenuation lengths (EAL) for (photo)electron kinetic energies in the 70-900 eV range. In order to determine the absolute electron escape depths a calibration point is needed, which is not directly accessible by experiment. This information can instead be indirectly derived by comparing PE experiments and molecular dynamics (MD) simulations of an aqueous solution interface where density profiles of water, anions, and cations are distinctively different. We have chosen sodium iodide in water because iodide has a considerable propensity for the solution surface, whereas the sodium cation is repelled from the surface. By measuring the intensities of photoelectrons emitted from different orbitals of different symmetries from each aqueous ion we also evaluate whether gas-phase ionization cross sections and asymmetry parameters can describe the photoemission from ions at and near the aqueous solution/vapor interface. We show that gas-phase data reproduce surprisingly well the experimental observations for hydrated ions as long as the photon energy is sufficiently far above the ionization threshold. Electrons detected at the higher photon energies originate predominantly from deeper layers, suggesting that bulk-solution electron elastic scattering is relatively weak.

  5. Moderate and intense exercise lifestyles attenuate the effects of aging on telomere length and the survival and composition of T cell subpopulations.

    Science.gov (United States)

    Silva, Léia Cristina Rodrigues; de Araújo, Adriana Ladeira; Fernandes, Juliana Ruiz; Matias, Manuella de Sousa Toledo; Silva, Paulo Roberto; Duarte, Alberto J S; Garcez Leme, Luiz Eugênio; Benard, Gil

    2016-02-01

    Studies indicate that exercise might delay human biological aging, but the effects of long-term exercise on T cell function are not well known. We tested the hypothesis that moderate or intense exercise lifestyle may attenuate the effects of aging on the telomere length and the survival and composition of T cell subpopulations. Elderly (65-85 years) with intense training lifestyle (IT, n = 15), moderate training lifestyle (MT, n = 16), and who never trained (NT, n = 15) were studied. Although the three groups presented the age-associated contraction of the TCD4(+)/TCD8(+) naïve compartments and expansion of the memory compartments, both training modalities were associated with lower proportion of terminally differentiated (CD45RA(+)CCR7(neg)) TCD4(+) and TCD8(+) cells, although among the latter cells, the reduction reached statistical significance only with IT. MT was associated with higher proportion of central memory TCD4(+) cells, while IT was associated with higher proportion of effector memory TCD8(+) cells. However, both training lifestyles were unable to modify the proportion of senescent (CD28(neg)) TCD8(+) cells. Telomeres were longer in T cells in both training groups; with IT, telomere length increased mainly in TCD8(+) cells, whereas with MT, a modest increase in telomere length was observed in both TCD8(+) and TCD4(+) cells. Reduced commitment to apoptosis of resting T cells, as assessed by caspase-3 and Bcl-2 expression, was seen predominantly with IT. Measurement of pro-inflammatory cytokines in serum and peripheral blood mononuclear cell (PBMC)'s supernatants did not show chronic low-grade inflammation in any of the groups. In conclusion, MT and IT lifestyles attenuated some of the effects of aging on the immune system.

  6. Measuring the attenuation length of water in the CHIPS-M water Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Amat, F.; Bizouard, P. [Aix Marseille University Saint-Jerome, 13013 Marseille (France); Bryant, J. [Department of Physics and Astronomy, UCL, Gower St, London WC1E 6BT (United Kingdom); Carroll, T.J.; Rijck, S. De [Department of Physics, University of Texas at Austin, Austin, TX 78712 (United States); Germani, S. [Department of Physics and Astronomy, UCL, Gower St, London WC1E 6BT (United Kingdom); Joyce, T. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Kriesten, B. [Department of Physics, College of William & Mary, Williamsburg, VA 23187 (United States); Marshak, M.; Meier, J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Nelson, J.K. [Department of Physics, College of William & Mary, Williamsburg, VA 23187 (United States); Perch, A.J.; Pfützner, M.M. [Department of Physics and Astronomy, UCL, Gower St, London WC1E 6BT (United Kingdom); Salazar, R. [Department of Physics, University of Texas at Austin, Austin, TX 78712 (United States); Thomas, J., E-mail: jennifer.thomas@ucl.ac.uk [Department of Physics and Astronomy, UCL, Gower St, London WC1E 6BT (United Kingdom); Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Trokan-Tenorio, J. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Vahle, P. [Department of Physics, College of William & Mary, Williamsburg, VA 23187 (United States); Wade, R. [Avenir Consulting, Abingdon, Oxfordshire (United Kingdom); Wendt, C. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Whitehead, L.H. [Department of Physics and Astronomy, UCL, Gower St, London WC1E 6BT (United Kingdom); and others

    2017-02-01

    The water at the proposed site of the CHIPS water Cherenkov detector has been studied to measure its attenuation length for Cherenkov light as a function of filtering time. A scaled model of the CHIPS detector filled with water from the Wentworth 2W pit, proposed site of the CHIPS deployment, in conjunction with a 3.2 m vertical column filled with this water, was used to study the transmission of 405 nm laser light. Results consistent with attenuation lengths of up to 100 m were observed for this wavelength with filtration and UV sterilization alone.

  7. Does length or neighborhood size cause the word length effect?

    Science.gov (United States)

    Jalbert, Annie; Neath, Ian; Surprenant, Aimée M

    2011-10-01

    Jalbert, Neath, Bireta, and Surprenant (2011) suggested that past demonstrations of the word length effect, the finding that words with fewer syllables are recalled better than words with more syllables, included a confound: The short words had more orthographic neighbors than the long words. The experiments reported here test two predictions that would follow if neighborhood size is a more important factor than word length. In Experiment 1, we found that concurrent articulation removed the effect of neighborhood size, just as it removes the effect of word length. Experiment 2 demonstrated that this pattern is also found with nonwords. For Experiment 3, we factorially manipulated length and neighborhood size, and found only effects of the latter. These results are problematic for any theory of memory that includes decay offset by rehearsal, but they are consistent with accounts that include a redintegrative stage that is susceptible to disruption by noise. The results also confirm the importance of lexical and linguistic factors on memory tasks thought to tap short-term memory.

  8. An apparatus to measure water optical attenuation length for LHAASO-MD

    Science.gov (United States)

    Li, Cong; Xiao, Gang; Feng, Shaohui; Wang, Lingyu; Li, Xiurong; Zuo, Xiong; Cheng, Ning; Wang, Hui; Gao, Bo; Duan, Zhihao; Liu, Jia; He, Huihai; Saeed, Mohsin; Lhaaso Collaboration

    2018-06-01

    The large high altitude air shower observatory (LHAASO) is being constructed at 4400 m a.s.l. in Daocheng, Sichuan Province, aiming to reveal the secrets of cosmic rays origin. And it has the largest surface muon detector array in the world. Due to the needs of calibration and construction of muon detector, we developed a water optical attenuation measurement device using an 8 m long water tank. The results are presented for filtered water at wavelength of 405 nm, which proves this apparatus can reach an accuracy of about 20% at 100 m. This apparatus has not only a high precision measurement of water attenuation length up to 100 m but is also very convenient to be used, which is crucial for water optical properties study during LHAASO detector construction.

  9. Noise Attenuation Estimation for Maximum Length Sequences in Deconvolution Process of Auditory Evoked Potentials

    Directory of Open Access Journals (Sweden)

    Xian Peng

    2017-01-01

    Full Text Available The use of maximum length sequence (m-sequence has been found beneficial for recovering both linear and nonlinear components at rapid stimulation. Since m-sequence is fully characterized by a primitive polynomial of different orders, the selection of polynomial order can be problematic in practice. Usually, the m-sequence is repetitively delivered in a looped fashion. Ensemble averaging is carried out as the first step and followed by the cross-correlation analysis to deconvolve linear/nonlinear responses. According to the classical noise reduction property based on additive noise model, theoretical equations have been derived in measuring noise attenuation ratios (NARs after the averaging and correlation processes in the present study. A computer simulation experiment was conducted to test the derived equations, and a nonlinear deconvolution experiment was also conducted using order 7 and 9 m-sequences to address this issue with real data. Both theoretical and experimental results show that the NAR is essentially independent of the m-sequence order and is decided by the total length of valid data, as well as stimulation rate. The present study offers a guideline for m-sequence selections, which can be used to estimate required recording time and signal-to-noise ratio in designing m-sequence experiments.

  10. Resonance effects in neutron scattering lengths

    Energy Technology Data Exchange (ETDEWEB)

    Lynn, J.E.

    1989-06-01

    The nature of neutron scattering lengths is described and the nuclear effects giving rise to their variation is discussed. Some examples of the shortcomings of the available nuclear data base, particularly for heavy nuclei, are given. Methods are presented for improving this data base, in particular for obtaining the energy variation of the complex coherent scattering length from long to sub-/angstrom/ wave lengths from the available sources of slow neutron cross section data. Examples of this information are given for several of the rare earth nuclides. Some examples of the effect of resonances in neutron reflection and diffraction are discussed. This report documents a seminar given at Argonne National Laboratory in March 1989. 18 refs., 18 figs.

  11. Resonance effects in neutron scattering lengths

    International Nuclear Information System (INIS)

    Lynn, J.E.

    1989-01-01

    The nature of neutron scattering lengths is described and the nuclear effects giving rise to their variation is discussed. Some examples of the shortcomings of the available nuclear data base, particularly for heavy nuclei, are given. Methods are presented for improving this data base, in particular for obtaining the energy variation of the complex coherent scattering length from long to sub-angstrom wave lengths from the available sources of slow neutron cross section data. Examples of this information are given for several of the rare earth nuclides. Some examples of the effect of resonances in neutron reflection and diffraction are discussed. This report documents a seminar given at Argonne National Laboratory in March 1989. 18 refs., 18 figs

  12. Attenuation length measurements of a liquid scintillator with LabVIEW and reliability evaluation of the device

    International Nuclear Information System (INIS)

    Gao Long; Yu Boxiang; Ding Yayun

    2013-01-01

    An attenuation length measurement device was constructed using an oscilloscope and LabVIEW for signal acquisition and processing. The performance of the device has been tested in a variety of ways. The test results show that the set-up has a good stability and high precision (sigma/mean reached 0.4 percent). Besides, the accuracy of the measurement system will decrease by about 17 percent if a filter is used. The attenuation length of a gadolinium-loaded liquid scintillator (Gd-LS) was measured as 15.10±0.35 m where Gd-LS was heavily used in the Daya Bay Neutrino Experiment. In addition, one method based on the Beer-Lambert law was proposed to investigate the reliability of the measurement device, the R-square reached 0.9995. Moreover, three purification methods for Linear Alkyl Benzene (LAB) production were compared in the experiment. (authors)

  13. The Effective Coherence Length in Anisotropic Superconductors

    International Nuclear Information System (INIS)

    Polturak, E.; Koren, G.; Nesher, O

    1999-01-01

    If electrons are transmitted from a normal conductor(N) into a superconductor(S), common wisdom has it that the electrons are converted into Cooper pairs within a coherence length from the interface. This is true in conventional superconductors with an isotropic order parameter. We have established experimentally that the situation is rather different in high Tc superconductors having an anisotropic order parameter. We used epitaxial thin film S/N bilayers having different interface orientations in order to inject carriers from S into N along different directions. The distance to which these carriers penetrate were determined through their effect on the Tc of the bilayers. We found that the effective coherence length is 20A only along the a or b directions, while in other directions we find a length of 250dr20A out of plane, and an even larger value for in-plane, off high symmetry directions. These observations can be explained using the Blonder-Tinkham-Klapwijk model adapted to anisotropic superconductivity. Several implications of our results on outstanding problems with high Tc junctions will be discussed

  14. Modeling relaxation length and density of acacia mangium wood using gamma - ray attenuation technique

    International Nuclear Information System (INIS)

    Tamer A Tabet; Fauziah Abdul Aziz

    2009-01-01

    Wood density measurement is related to the several factors that influence wood quality. In this paper, density, relaxation length and half-thickness value of eight ages, 3, 5, 7, 10, 11, 13 and 15 year-old of Acacia mangium wood were determined using gamma radiation from 137 Cs source. Results show that Acacia mangium tree of age 3 year has the highest relaxation length of 83.33 cm and least density of 0.43 gcm -3 , while the tree of age 15 year has the least Relaxation length of 28.56 cm and highest density of 0.76 gcm -3 . Results also show that the 3 year-old Acacia mangium wood has the highest half thickness value of 57.75 cm and 15 year-old tree has the least half thickness value of 19.85 cm. Two mathematical models have been developed for the prediction of density, variation with relaxation length and half-thickness value of different age of tree. A good agreement (greater than 85% in most cases) was observed between the measured values and predicted ones. Very good linear correlation was found between measured density and the age of tree (R2 = 0.824), and between estimated density and Acacia mangium tree age (R2 = 0.952). (Author)

  15. Word length, set size, and lexical factors: Re-examining what causes the word length effect.

    Science.gov (United States)

    Guitard, Dominic; Gabel, Andrew J; Saint-Aubin, Jean; Surprenant, Aimée M; Neath, Ian

    2018-04-19

    The word length effect, better recall of lists of short (fewer syllables) than long (more syllables) words has been termed a benchmark effect of working memory. Despite this, experiments on the word length effect can yield quite different results depending on set size and stimulus properties. Seven experiments are reported that address these 2 issues. Experiment 1 replicated the finding of a preserved word length effect under concurrent articulation for large stimulus sets, which contrasts with the abolition of the word length effect by concurrent articulation for small stimulus sets. Experiment 2, however, demonstrated that when the short and long words are equated on more dimensions, concurrent articulation abolishes the word length effect for large stimulus sets. Experiment 3 shows a standard word length effect when output time is equated, but Experiments 4-6 show no word length effect when short and long words are equated on increasingly more dimensions that previous demonstrations have overlooked. Finally, Experiment 7 compared recall of a small and large neighborhood words that were equated on all the dimensions used in Experiment 6 (except for those directly related to neighborhood size) and a neighborhood size effect was still observed. We conclude that lexical factors, rather than word length per se, are better predictors of when the word length effect will occur. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  16. Debye screening length effects of nanostructured materials

    CERN Document Server

    Ghatak, Kamakhya Prasad

    2014-01-01

    This monograph solely investigates the Debye Screening Length (DSL) in semiconductors and their nano-structures. The materials considered are quantized structures of non-linear optical, III-V, II-VI, Ge, Te, Platinum Antimonide, stressed materials, Bismuth, GaP, Gallium Antimonide, II-V and Bismuth Telluride respectively. The DSL in opto-electronic materials and their quantum confined counterparts is studied in the presence of strong light waves and intense electric fields on the basis of newly formulated electron dispersion laws that control the studies of such quantum effect devices. The suggestions for the experimental determination of 2D and 3D DSL and the importance of measurement of band gap in optoelectronic materials under intense built-in electric field in nano devices and strong external photo excitation (for measuring photon induced physical properties) have also been discussed in this context. The influence of crossed electric and quantizing magnetic fields on the DSL and the DSL in heavily doped ...

  17. Effect of duct shape, Mach number, and lining construction on measured suppressor attenuation and comparison with theory

    Science.gov (United States)

    Olsen, W. A.; Krejsa, E. A.; Coats, J. W.

    1972-01-01

    Noise attenuation was measured for several types of cylindrical suppressors that use a duct lining composed of honeycomb cells covered with a perforated plate. The experimental technique used gave attenuation data that were repeatable and free of noise floors and other sources of error. The suppressor length, the effective acoustic diameter, suppressor shape and flow velocity were varied. The agreement among the attenuation data and two widely used analytical models was generally satisfactory. Changes were also made in the construction of the acoustic lining to measure their effect on attenuation. One of these produced a very broadband muffler.

  18. Memory for tonal pitches: a music-length effect hypothesis.

    Science.gov (United States)

    Akiva-Kabiri, Lilach; Vecchi, Tomaso; Granot, Roni; Basso, Demis; Schön, Daniele

    2009-07-01

    One of the most studied effects of verbal working memory (WM) is the influence of the length of the words that compose the list to be remembered. This work aims to investigate the nature of musical WM by replicating the word length effect in the musical domain. Length and rate of presentation were manipulated in a recognition task of tone sequences. Results showed significant effects for both factors (length and presentation rate) as well as their interaction, suggesting the existence of different strategies (e.g., chunking and rehearsal) for the immediate memory of musical information, depending upon the length of the sequences.

  19. Effective Debye length in closed nanoscopic systems: a competition between two length scales.

    Science.gov (United States)

    Tessier, Frédéric; Slater, Gary W

    2006-02-01

    The Poisson-Boltzmann equation (PBE) is widely employed in fields where the thermal motion of free ions is relevant, in particular in situations involving electrolytes in the vicinity of charged surfaces. The applications of this non-linear differential equation usually concern open systems (in osmotic equilibrium with an electrolyte reservoir, a semi-grand canonical ensemble), while solutions for closed systems (where the number of ions is fixed, a canonical ensemble) are either not appropriately distinguished from the former or are dismissed as a numerical calculation exercise. We consider herein the PBE for a confined, symmetric, univalent electrolyte and quantify how, in addition to the Debye length, its solution also depends on a second length scale, which embodies the contribution of ions by the surface (which may be significant in high surface-to-volume ratio micro- or nanofluidic capillaries). We thus establish that there are four distinct regimes for such systems, corresponding to the limits of the two parameters. We also show how the PBE in this case can be formulated in a familiar way by simply replacing the traditional Debye length by an effective Debye length, the value of which is obtained numerically from conservation conditions. But we also show that a simple expression for the value of the effective Debye length, obtained within a crude approximation, remains accurate even as the system size is reduced to nanoscopic dimensions, and well beyond the validity range typically associated with the solution of the PBE.

  20. Word Length Effects in Long-Term Memory

    Science.gov (United States)

    Tehan, Gerald; Tolan, Georgina Anne

    2007-01-01

    The word length effect has been a central feature of theorising about immediate memory. The notion that short-term memory traces rapidly decay unless refreshed by rehearsal is based primarily upon the finding that serial recall for short words is better than that for long words. The decay account of the word length effect has come under pressure…

  1. Syllabic Length Effect in Visual Word Recognition

    Directory of Open Access Journals (Sweden)

    Roya Ranjbar Mohammadi

    2014-07-01

    Full Text Available Studies on visual word recognition have resulted in different and sometimes contradictory proposals as Multi-Trace Memory Model (MTM, Dual-Route Cascaded Model (DRC, and Parallel Distribution Processing Model (PDP. The role of the number of syllables in word recognition was examined by the use of five groups of English words and non-words. The reaction time of the participants to these words was measured using reaction time measuring software. The results indicated that there was syllabic effect on recognition of both high and low frequency words. The pattern was incremental in terms of syllable number. This pattern prevailed in high and low frequency words and non-words except in one syllable words. In general, the results are in line with the PDP model which claims that a single processing mechanism is used in both words and non-words recognition. In other words, the findings suggest that lexical items are mainly processed via a lexical route.  A pedagogical implication of the findings would be that reading in English as a foreign language involves analytical processing of the syllable of the words.

  2. EFFECT OF EXERCISE ON CYCLE LENGTH IN ATRIAL-FLUTTER

    NARCIS (Netherlands)

    VANDENBERG, MP; CRIJNS, HJGM; SZABO, BM; BROUWER, J; LIE, KI

    Objective-To examine the effect of exercise on cycle length in atrial flutter. Patients-15 patients with chronic atrial flutter. Seven patients were taking digoxin and six verapamil; two were not taking medication. Methods-All patients underwent bicycle ergometry. Flutter cycle length was measured

  3. Does neighborhood size really cause the word length effect?

    Science.gov (United States)

    Guitard, Dominic; Saint-Aubin, Jean; Tehan, Gerald; Tolan, Anne

    2018-02-01

    In short-term serial recall, it is well-known that short words are remembered better than long words. This word length effect has been the cornerstone of the working memory model and a benchmark effect that all models of immediate memory should account for. Currently, there is no consensus as to what determines the word length effect. Jalbert and colleagues (Jalbert, Neath, Bireta, & Surprenant, 2011a; Jalbert, Neath, & Surprenant, 2011b) suggested that neighborhood size is one causal factor. In six experiments we systematically examined their suggestion. In Experiment 1, with an immediate serial recall task, multiple word lengths, and a large pool of words controlled for neighborhood size, the typical word length effect was present. In Experiments 2 and 3, with an order reconstruction task and words with either many or few neighbors, we observed the typical word length effect. In Experiment 4 we tested the hypothesis that the previous abolition of the word length effect when neighborhood size was controlled was due to a confounded factor: frequency of orthographic structure. As predicted, we reversed the word length effect when using short words with less frequent orthographic structures than the long words, as was done in both of Jalbert et al.'s studies. In Experiments 5 and 6, we again observed the typical word length effect, even if we controlled for neighborhood size and frequency of orthographic structure. Overall, the results were not consistent with the predictions of Jalbert et al. and clearly showed a large and reliable word length effect after controlling for neighborhood size.

  4. Effects of attenuation map accuracy on attenuation-corrected micro-SPECT images

    NARCIS (Netherlands)

    Wu, C.; Gratama van Andel, H.A.; Laverman, P.; Boerman, O.C.; Beekman, F.J.

    2013-01-01

    Background In single-photon emission computed tomography (SPECT), attenuation of photon flux in tissue affects quantitative accuracy of reconstructed images. Attenuation maps derived from X-ray computed tomography (CT) can be employed for attenuation correction. The attenuation coefficients as well

  5. Patient position alters attenuation effects in multipinhole cardiac SPECT.

    Science.gov (United States)

    Timmins, Rachel; Ruddy, Terrence D; Wells, R Glenn

    2015-03-01

    Dedicated cardiac cameras offer improved sensitivity over conventional SPECT cameras. Sensitivity gains are obtained by large numbers of detectors and novel collimator arrangements such as an array of multiple pinholes that focus on the heart. Pinholes lead to variable amounts of attenuation as a source is moved within the camera field of view. This study evaluated the effects of this variable attenuation on myocardial SPECT images. Computer simulations were performed for a set of nine point sources distributed in the left ventricular wall (LV). Sources were placed at the location of the heart in both an anthropomorphic and a water-cylinder computer phantom. Sources were translated in x, y, and z by up to 5 cm from the center. Projections were simulated with and without attenuation and the changes in attenuation were compared. A LV with an inferior wall defect was also simulated in both phantoms over the same range of positions. Real camera data were acquired on a Discovery NM530c camera (GE Healthcare, Haifa, Israel) for five min in list-mode using an anthropomorphic phantom (DataSpectrum, Durham, NC) with 100 MBq of Tc-99m in the LV. Images were taken over the same range of positions as the simulations and were compared based on the summed perfusion score (SPS), defect width, and apparent defect uptake for each position. Point sources in the water phantom showed absolute changes in attenuation of ≤8% over the range of positions and relative changes of ≤5% compared to the apex. In the anthropomorphic computer simulations, absolute change increased to 20%. The changes in relative attenuation caused a change in SPS of position-dependent changes were removed with attenuation correction. Translation of a source relative to a multipinhole camera caused only small changes in homogeneous phantoms with SPS changing position-dependent changes in attenuation.

  6. The frequency attenuation effect in identity and associative priming.

    Science.gov (United States)

    Nievas, Francisco

    2010-05-01

    Three lexical decision experiments were carried out, where the masked priming paradigm is used to study the role of the frequency attenuation effect (more priming in low-frequency target words than in high-frequency target words) in repetition and associative priming, manipulating Prime Duration (PD) and Stimulus Onset Asynchrony (SOA). A new concept was introduced, Minimum Time Threshold (MTT), this is, the minimum time interval of exposure to the masked word in order to become aware of it. Results support the notion that MTT is a key to the appearance of the frequency attenuation effect when enough word processing time is allowed. Results do not support the unified explanation of masked priming and long-term priming as proposed by Bodner and Masson (2001). Moreover, information feedback from the semantic level was not the reason for the frequency attenuation effect in repetition priming.

  7. Patient position alters attenuation effects in multipinhole cardiac SPECT

    International Nuclear Information System (INIS)

    Timmins, Rachel; Ruddy, Terrence D.; Wells, R. Glenn

    2015-01-01

    Purpose: Dedicated cardiac cameras offer improved sensitivity over conventional SPECT cameras. Sensitivity gains are obtained by large numbers of detectors and novel collimator arrangements such as an array of multiple pinholes that focus on the heart. Pinholes lead to variable amounts of attenuation as a source is moved within the camera field of view. This study evaluated the effects of this variable attenuation on myocardial SPECT images. Methods: Computer simulations were performed for a set of nine point sources distributed in the left ventricular wall (LV). Sources were placed at the location of the heart in both an anthropomorphic and a water-cylinder computer phantom. Sources were translated in x, y, and z by up to 5 cm from the center. Projections were simulated with and without attenuation and the changes in attenuation were compared. A LV with an inferior wall defect was also simulated in both phantoms over the same range of positions. Real camera data were acquired on a Discovery NM530c camera (GE Healthcare, Haifa, Israel) for five min in list-mode using an anthropomorphic phantom (DataSpectrum, Durham, NC) with 100 MBq of Tc-99m in the LV. Images were taken over the same range of positions as the simulations and were compared based on the summed perfusion score (SPS), defect width, and apparent defect uptake for each position. Results: Point sources in the water phantom showed absolute changes in attenuation of ≤8% over the range of positions and relative changes of ≤5% compared to the apex. In the anthropomorphic computer simulations, absolute change increased to 20%. The changes in relative attenuation caused a change in SPS of <1.5 for the water phantom but up to 4.2 in the anthropomorphic phantom. Changes were larger for axial than for transverse translations. These results were supported by SPS changes of up to six seen in the physical anthropomorphic phantom for axial translations. Defect width was also seen to significantly increase. The

  8. Minimal Length Effects on Tunnelling from Spherically Symmetric Black Holes

    Directory of Open Access Journals (Sweden)

    Benrong Mu

    2015-01-01

    Full Text Available We investigate effects of the minimal length on quantum tunnelling from spherically symmetric black holes using the Hamilton-Jacobi method incorporating the minimal length. We first derive the deformed Hamilton-Jacobi equations for scalars and fermions, both of which have the same expressions. The minimal length correction to the Hawking temperature is found to depend on the black hole’s mass and the mass and angular momentum of emitted particles. Finally, we calculate a Schwarzschild black hole's luminosity and find the black hole evaporates to zero mass in infinite time.

  9. Study on effective MOSFET channel length extracted from gate capacitance

    Science.gov (United States)

    Tsuji, Katsuhiro; Terada, Kazuo; Fujisaka, Hisato

    2018-01-01

    The effective channel length (L GCM) of metal-oxide-semiconductor field-effect transistors (MOSFETs) is extracted from the gate capacitances of actual-size MOSFETs, which are measured by charge-injection-induced-error-free charge-based capacitance measurement (CIEF CBCM). To accurately evaluate the capacitances between the gate and the channel of test MOSFETs, the parasitic capacitances are removed by using test MOSFETs having various channel sizes and a source/drain reference device. A strong linear relationship between the gate-channel capacitance and the design channel length is obtained, from which L GCM is extracted. It is found that L GCM is slightly less than the effective channel length (L CRM) extracted from the measured MOSFET drain current. The reason for this is discussed, and it is found that the capacitance between the gate electrode and the source and drain regions affects this extraction.

  10. Is the word-length effect linked to subvocal rehearsal?

    Science.gov (United States)

    Jacquemot, Charlotte; Dupoux, Emmanuel; Bachoud-Lévi, Anne-Catherine

    2011-04-01

    Models of phonological short-term memory (pSTM) generally distinguish between two components: a phonological buffer and a subvocal rehearsal. Evidence for these two components comes, respectively, from the phonological similarity effect and the word-length effect which disappears under articulatory suppression. But alternative theories posit that subvocal rehearsal is only an optional component of the pSTM. According to them, the depletion of the length effect under articulatory suppression results from the interference of the self-produced speech rather than the disruption of subvocal rehearsal. In order to disentangle these two theories, we tested two patients with a short-term memory deficit. FA, who presents a pseudoword repetition deficit, and FL, who does not. FA's deficit allowed for the observance of an ecological case of subvocal rehearsal disruption without any articulatory suppression task. FA's performance in pSTM tasks reveals as controls a phonological similarity effect, and contrary to controls no word-length effect. In contrast, the second patient, FL, exhibits the same effects as control subjects. This result is in accordance with models of pSTM in which the word-length effect emerges from subvocal rehearsal and disappears when this latter is disrupted. Copyright © 2010 Elsevier Srl. All rights reserved.

  11. Measurements of attenuation lengths through concrete and iron for neutrons produced by 800-MeV proton on tantalum target at ISIS

    CERN Document Server

    Nunomiya, T; Wright, P; Nakamura, T; Kim, E; Kurosawa, T; Taniguchi, S; Sasaki, M; Iwase, H; Uwamino, Y; Shibata, T; Ito, S; Perry, D R

    2002-01-01

    A deep penetration experiment through a thick bulk shield was performed at an intense spallation neutron source facility, ISIS, of the Rutherford Appleton Laboratory (RAL), United Kingdom. ISIS is a 800 MeV-200 mu A proton accelerator facility. Neutrons are produced from a tantalum target, and are shielded with approximately 3-m thick steel and 1-m thick ordinary concrete. On top of the shield, we measured the neutron flux attenuation through concrete and iron shields, which were additionally placed up to 120-cm and 60-cm thickness, respectively, using activation detectors of graphite and bismuth. The attenuation lengths of concrete and iron for high-energy neutrons above 20 MeV were obtained from the sup 1 sup 2 C(n, 2n) sup 1 sup 1 C reaction of graphite.

  12. Inertial Effects on Finite Length Pipe Seismic Response

    Directory of Open Access Journals (Sweden)

    Virginia Corrado

    2012-01-01

    Full Text Available A seismic analysis for soil-pipe interaction which accounts for length and constraining conditions at the ends of a continuous pipe is developed. The Winkler model is used to schematize the soil-structure interaction. The approach is focused on axial strains, since bending strains in a buried pipe due to the wave propagation are typically a second-order effect. Unlike many works, the inertial terms are considered in solving equations. Accurate numerical simulations are carried out to show the influence of pipe length and constraint conditions on the pipe seismic strain. The obtained results are compared with results inferred from other models present in the literature. For free-end pipelines, inertial effects have significant influence only for short length. On the contrary, their influence is always important for pinned pipes. Numerical simulations show that a simple rigid model can be used for free-end pipes, whereas pinned pipes need more accurate models.

  13. Numerical Simulations of Finite-Length Effects in Diocotron Modes

    Science.gov (United States)

    Mason, Grant W.; Spencer, Ross L.

    2000-10-01

    Over a decade ago Driscoll and Fine(C. F. Driscoll and K. S. Fine, Phys. Fluids B 2) (6), 1359, June 1990. reported experimental observations of an exponential instability in the self-shielded m=1 diocotron mode for an electron plasma confined in a Malmberg-Penning trap. More recently, Finn et al(John M. Finn, Diego del-Castillo-Negrete and Daniel C. Barnes, Phys. Plasmas 6) (10), 3744, October 1999. have given a theoretical explanation of the instability as a finite-length end effect patterned after an analogy to theory for shallow water fluid vortices. However, in a test case selected for comparison, the growth rate in the experiment exceeds the theoretical value by a factor of two. We present results from a two-dimensional, finite length drift-kinetic code and a fully three-dimensional particle-in-cell code written to explore details of finite-length effects in diocotron modes.

  14. Effects of methods of attenuation correction on source parameter determination

    Science.gov (United States)

    Sonley, Eleanor; Abercrombie, Rachel E.

    We quantify the effects of using different approaches to model individual earthquake spectra. Applying different approaches can introduce significant variability in the calculated source parameters, even when applied to the same data. To compare large and small earthquake source parameters, the results of multiple studies need to be combined to extend the magnitude range, but the variability introduced by the different approaches hampers the outcome. When studies are combined, there is large uncertainty and large scatter and some systematic differences have been neglected. We model individual earthquake spectra from repeating earthquakes (M˜2) at Parkfield, CA, recorded by a borehole network. We focus on the effects of trade-offs between attenuation (Q) and corner frequency in spectral fitting and the effect of the model shape at the corner frequency on radiated energy. The trade-off between attenuation and corner frequency can increase radiated energy by up to 400% and seismic moment by up to 100%.

  15. Infants' Memory Processing of a Serial List: List Length Effects.

    Science.gov (United States)

    Gulya, Michele; Sweeney, Becky; Rovee-Collier, Carolyn

    1999-01-01

    Three experiments demonstrated that increasing the length of a mobile serial list impaired 6-month olds' memory for serial order. Findings indicated that the primacy effect was absent on a 24-hour delayed recognition test and was exhibited on a reactivation test, adding to growing evidence that young infants possess two functionally distinct…

  16. Porosity effects in flame length of the porous burners

    Directory of Open Access Journals (Sweden)

    Fatemeh Bahadori

    2014-10-01

    Full Text Available Furnaces are the devices for providing heat to the industrial systems like boilers, gas turbines and etc. The main challenge of furnaces is emission of huge air pollutants. However, porous burners produce less contaminant compared to others. The quality of the combustion process in the porous burners depends on the length of flame in the porous medium. In this paper, the computational fluid dynamic (CFD is used to investigate the porosity effects on the flame length of the combustion process in porous burner. The simulation results demonstrate that increasing the porosity increases the flame length and the combustion zone extends forward. So, combustion quality increases and production of carbon monoxide decrease. It is possible to conclude that temperature distribution in low porosity burner is lower and more uniform than high porosity one. Therefore, by increasing the porosity of the burner, the production of nitrogen oxides increases. So, using an intermediate porosity in the burner appears to be reasonable.

  17. Viscothermal Coupling Effects on Sound Attenuation in Concentrated Colloidal Dispersions.

    Science.gov (United States)

    Han, Wei

    1995-11-01

    This thesis describes a Unified Coupled Phase Continuum (UCPC) model to analyze sound propagation through aerosols, emulsions and suspensions in terms of frequency dependent attenuation coefficient and sound speed. Expressions for the viscous and thermal coupling coefficients explicitly account for the effects of particle size, shape factor, orientation as well as concentration and the sound frequency. The UCPC model also takes into account the intrinsic acoustic absorption within the fluid medium due to its viscosity and heat conductivity. The effective complex wave number as a function of frequency is derived. A frequency- and concentration-dependent complex Nusselt number for the interfacial thermal coupling coefficient is derived using an approximate similarity between the 'viscous skin drag' and 'heat conduction flux' associated with the discontinuous suspended phase, on the basis of a cell model. The theoretical predictions of attenuation spectra provide satisfactory agreement with reported experimental data on two concentrated suspensions (polystyrene latex and kaolin pigment), two concentrated emulsions (toluene -in-water, n-hexadecane-in-water), and two aerosols (oleic acid droplets-in-nitrogen, alumina-in-air), covering a wide range of relative magnitudes (from 10^ {-3} to 10^{3}) of thermal versus viscous contributions, for dispersed phase volume fractions as high as 50%. The relative differences between the additive result of separate viscous and thermal loss estimates and combined viscothermal absorption results are also presented. Effects of particle shape on viscous attenuation of sound in concentrated suspensions of non-spherical clay particles are studied. Attenuation spectra for 18 frequencies from 3 to 100 MHz are measured and analyzed for eleven kaolin clay slurries with solid concentrations ranging from 0.6% to 35% (w/w). A modified viscous drag coefficient that considers frequency, concentration, particle size, shape and orientation of

  18. Variability in word reading performance of dyslexic readers: effects of letter length, phoneme length and digraph presence

    NARCIS (Netherlands)

    Marinus, E.; de Jong, P.F.

    2010-01-01

    The marked word-length effect in dyslexic children suggests the use of a letter-by-letter reading strategy. Such a strategy should make it more difficult to infer the sound of digraphs. Our main aim was to disentangle length and digraph-presence effects in word and pseudoword reading. In addition,

  19. Effect of Amphiphilic Alkyl Chain Length Upon Purified LATEX Stability

    International Nuclear Information System (INIS)

    Amira Amir Hassan; Amir Hashim Mohd Yatim

    2015-01-01

    Rubber particles in purified latex (PL) are stabilized by a film of protein and fatty acid soap (surfactant). Saturated straight-chain fatty acid soaps can assist an enhancement of latex stability. However, whether the alkyl chain length plays an important role in increasing the stability is still an issue. The aim of this study is to investigate the effect of alkyl chain length of anionic surfactant on the stability of purified latex. The fatty acid soap of decanoate (9), laurate (11), sodium dodecyl sulphate (SDS) (12) and palmitate (15) were used. The numbers in parentheses indicating the number of carbon present in alkyl chain of the soap. The results showed that the impact of alkyl chain length on the stability of latex is in the order of laurate > decanoate > SDS > palmitate > purified latex accordingly. The alkyl chain length does giving a significant effect on latex stability after longer stirring time. The particle size of latex with the presence of surfactant is greater compare to a single particle itself due to extension of particles diameter. Thus suitable interaction of the nonpolar tail of surfactant with the hydrophobic regions of latex surface played a major role in maintaining a stable latex system. (author)

  20. A study of the heated length to diameter effects

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Ho; Baek, Won Pil; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1997-12-31

    An analytical and experimental investigation has been performed on the heated length-to-diameter effect on critical heat flux exit conditions. A L/D correction factor is developed by applying artificial neural network and conventional regression techniques to the KAIST CHF data base. In addition, experiment is being performed to validate the developed L/D correction factor with independent data. Assessment shows that the developed correction factor is promising for practical applications. 6 refs., 8 figs. (Author)

  1. A study of the heated length to diameter effects

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yong Ho; Baek, Won Pil; Chang, Soon Heung [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

    1998-12-31

    An analytical and experimental investigation has been performed on the heated length-to-diameter effect on critical heat flux exit conditions. A L/D correction factor is developed by applying artificial neural network and conventional regression techniques to the KAIST CHF data base. In addition, experiment is being performed to validate the developed L/D correction factor with independent data. Assessment shows that the developed correction factor is promising for practical applications. 6 refs., 8 figs. (Author)

  2. Coulomb corrections to scattering length and effective radius

    International Nuclear Information System (INIS)

    Mur, V.D.; Kudryavtsev, A.E.; Popov, V.S.

    1983-01-01

    The problem considered is extraction of the ''purely nuclear'' scattering length asub(s) (corresponding to the strong potential Vsub(s) at the Coulomb interaction switched off) from the Coulomb-nuclear scattering length asub(cs), which is an object of experimental measurement. The difference between asub(s) and asub(cs) is especially large if the potential Vsub(s) has a level (real or virtual) with an energy close to zero. For this case formulae are obtained relating the scattering lengths asub(s) and asub(cs), as well as the effective radii rsub(s) and rsub(cs). The results are extended to states with arbitrary angular momenta l. It is shown that the Coulomb correction is especially large for the coefficient with ksup(2l) in the expansion of the effective radius; in this case the correction contains a large logarithm ln(asub(B)/rsub(0)). The Coulomb renormalization of other terms in the effective radius espansion is of order (rsub(0)/asub(B)), where r 0 is the nuclear force radius, asub(B) is the Bohr radius. The obtained formulae are tried on a number of model potentials Vsub(s), used in nuclear physics

  3. Ultrashort Channel Length Black Phosphorus Field-Effect Transistors.

    Science.gov (United States)

    Miao, Jinshui; Zhang, Suoming; Cai, Le; Scherr, Martin; Wang, Chuan

    2015-09-22

    This paper reports high-performance top-gated black phosphorus (BP) field-effect transistors with channel lengths down to 20 nm fabricated using a facile angle evaporation process. By controlling the evaporation angle, the channel length of the transistors can be reproducibly controlled to be anywhere between 20 and 70 nm. The as-fabricated 20 nm top-gated BP transistors exhibit respectable on-state current (174 μA/μm) and transconductance (70 μS/μm) at a VDS of 0.1 V. Due to the use of two-dimensional BP as the channel material, the transistors exhibit relatively small short channel effects, preserving a decent on-off current ratio of 10(2) even at an extremely small channel length of 20 nm. Additionally, unlike the unencapsulated BP devices, which are known to be chemically unstable in ambient conditions, the top-gated BP transistors passivated by the Al2O3 gate dielectric layer remain stable without noticeable degradation in device performance after being stored in ambient conditions for more than 1 week. This work demonstrates the great promise of atomically thin BP for applications in ultimately scaled transistors.

  4. Effect of canal length and curvature on working length alteration with WaveOne reciprocating files.

    Science.gov (United States)

    Berutti, Elio; Chiandussi, Giorgio; Paolino, Davide Salvatore; Scotti, Nicola; Cantatore, Giuseppe; Castellucci, Arnaldo; Pasqualini, Damiano

    2011-12-01

    This study evaluated the working length (WL) modification after instrumentation with WaveOne Primary (Dentsply Maillefer, Ballaigues, Switzerland) reciprocating files and the incidence of overinstrumentation in relation to the initial WL. Thirty-two root canals of permanent teeth were used. The angles of curvature of the canals were calculated on digital radiographs. The initial WL with K-files was transferred to the matched WaveOne Primary reciprocating files. After glide paths were established with PathFile (Dentsply Maillefer, Ballaigues, Switzerland), canals were shaped with WaveOne Primary referring to the initial WL. The difference between the postinstrumentation canal length and the initial canal length was analyzed by using a fiberoptic inspection microscope. Data were analyzed with a balanced 2-way factorial analysis of variance (P < .05). Referring to the initial WL, 24 of 32 WaveOne Primary files projected beyond the experimental apical foramen (minimum-maximum, 0.14-0.76 mm). A significant decrease in the canal length after instrumentation (95% confidence interval ranging from -0.34 mm to -0.26 mm) was detected. The canal curvature significantly influenced the WL variation (F(1) = 30.65, P < .001). The interaction between the initial canal length and the canal curvature was statistically significant (F(2) = 4.38, P = .014). Checking the WL before preparation of the apical third of the root canal is recommended when using the new WaveOne NiTi single-file system. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. Effect of random edge failure on the average path length

    Energy Technology Data Exchange (ETDEWEB)

    Guo Dongchao; Liang Mangui; Li Dandan; Jiang Zhongyuan, E-mail: mgliang58@gmail.com, E-mail: 08112070@bjtu.edu.cn [Institute of Information Science, Beijing Jiaotong University, 100044, Beijing (China)

    2011-10-14

    We study the effect of random removal of edges on the average path length (APL) in a large class of uncorrelated random networks in which vertices are characterized by hidden variables controlling the attachment of edges between pairs of vertices. A formula for approximating the APL of networks suffering random edge removal is derived first. Then, the formula is confirmed by simulations for classical ER (Erdoes and Renyi) random graphs, BA (Barabasi and Albert) networks, networks with exponential degree distributions as well as random networks with asymptotic power-law degree distributions with exponent {alpha} > 2. (paper)

  6. Memory effects in attenuation and amplification quantum processes

    International Nuclear Information System (INIS)

    Lupo, Cosmo; Giovannetti, Vittorio; Mancini, Stefano

    2010-01-01

    With increasing communication rates via quantum channels, memory effects become unavoidable whenever the use rate of the channel is comparable to the typical relaxation time of the channel environment. We introduce a model of a bosonic memory channel, describing correlated noise effects in quantum-optical processes via attenuating or amplifying media. To study such a channel model, we make use of a proper set of collective field variables, which allows us to unravel the memory effects, mapping the n-fold concatenation of the memory channel to a unitarily equivalent, direct product of n single-mode bosonic channels. We hence estimate the channel capacities by relying on known results for the memoryless setting. Our findings show that the model is characterized by two different regimes, in which the cross correlations induced by the noise among different channel uses are either exponentially enhanced or exponentially reduced.

  7. Effective slip lengths for flows over surfaces with nanobubbles: the effects of finite slip

    International Nuclear Information System (INIS)

    Hendy, S C; Lund, N J

    2009-01-01

    We consider effective slip lengths for flows of simple liquids over surfaces contaminated by gaseous nanobubbles. In particular, we examine whether the effects of finite slip over the liquid-bubble interface are important in limiting effective slip lengths over such surfaces. Using an expression that interpolates between the perfect slip and finite slip regimes for flow over bubbles, we conclude that for the bubble dimensions and coverages typically reported in the literature the effects of finite slip are secondary, reducing effective slip lengths by only 10%. Further, we find that nanobubbles do not significantly increase slip lengths beyond those reported for bare hydrophobic surfaces.

  8. The gravitational Schwinger effect and attenuation of gravitational waves

    Science.gov (United States)

    McDougall, Patrick Guarneri

    This paper will discuss the possible production of photons from gravitational waves. This process is shown to be possible by examining Feynman diagrams, the Schwinger Effect, and Hawking Radiation. The end goal of this project is to find the decay length of a gravitational wave and assert that this decay is due to photons being created at the expense of the gravitational wave. To do this, we first find the state function using the Klein Gordon equation, then find the current due to this state function. We then take the current to be directly proportional to the production rate per volume. This is then used to find the decay length that this kind of production would produce, gives a prediction of how this effect will change the distance an event creating a gravitational wave will be located, and shows that this effect is small but can be significant near the source of a gravitational wave.

  9. Effect of heated length on the Critical Heat Flux of subcooled flow boiling. 2. Effective heated length under axially nonuniform heating condition

    International Nuclear Information System (INIS)

    Kinoshita, Hidetaka; Yoshida, Takuya; Nariai, Hideki; Inasaka, Fujio

    1998-01-01

    Effect of heated length on the Critical Heat Flux (CHF) of subcooled flow boiling with water was experimentally investigated by using direct current heated tube made of stainless steel a part of whose wall thickness was axially cut for realizing nonuniform heat flux condition. The higher enhancement of the CHF was derived for shorter tube length. The effective heated length was determined for the tube under axially nonuniform heat flux condition. When the lower heat flux part below the Net Vapor Generation (NVG) heat flux exists at the middle of tube length, then the effective heated length becomes the tube length downstream the lower heat flux parts. However, when the lower heat flux part is above the NVG, then the effective heated length is full tube length. (author)

  10. Attenuation, dispersion and nonlinearity effects in graphene-based waveguides

    Directory of Open Access Journals (Sweden)

    Almir Wirth Lima Jr.

    2015-05-01

    Full Text Available We simulated and analyzed in detail the behavior of ultrashort optical pulses, which are typically used in telecommunications, propagating through graphene-based nanoribbon waveguides. In this work, we showed the changes that occur in the Gaussian and hyperbolic secant input pulses due to the attenuation, high-order dispersive effects and nonlinear effects. We concluded that it is possible to control the shape of the output pulses with the value of the input signal power and the chemical potential of the graphene nanoribbon. We believe that the obtained results will be highly relevant since they can be applied to other nanophotonic devices, for example, filters, modulators, antennas, switches and other devices.

  11. Sound attenuation of a finite length dissipative flow duct silencer with internal mean flow in the absorbent

    Science.gov (United States)

    Cummings, A.; Chang, I.-J.

    1988-11-01

    Internal mean flow within the pores of a bulk-reacting porous acoustic absorbent, driven by mean static pressure gradients, is shown here to be an important feature of the acoustics of dissipative silencers in flow ducts, particularly in the case of internal combustion engine exhaust silencers. Theoretical treatments are presented here, both to describe the effect of internal flow on the bulk acoustic perties of the porous medium and to find the effect of the absorbent in situ, in the form of the sound transmission loss of the silencer. The measured transmission loss of an experimental silencer is compared to predicted data and good agreement between the two is obtained. The effects of mean fluid flow in the central passage and internal flow in the absorbent are separately demonstrated.

  12. The word-length effect and disyllabic words.

    Science.gov (United States)

    Lovatt, P; Avons, S E; Masterson, J

    2000-02-01

    Three experiments compared immediate serial recall of disyllabic words that differed on spoken duration. Two sets of long- and short-duration words were selected, in each case maximizing duration differences but matching for frequency, familiarity, phonological similarity, and number of phonemes, and controlling for semantic associations. Serial recall measures were obtained using auditory and visual presentation and spoken and picture-pointing recall. In Experiments 1a and 1b, using the first set of items, long words were better recalled than short words. In Experiments 2a and 2b, using the second set of items, no difference was found between long and short disyllabic words. Experiment 3 confirmed the large advantage for short-duration words in the word set originally selected by Baddeley, Thomson, and Buchanan (1975). These findings suggest that there is no reliable advantage for short-duration disyllables in span tasks, and that previous accounts of a word-length effect in disyllables are based on accidental differences between list items. The failure to find an effect of word duration casts doubt on theories that propose that the capacity of memory span is determined by the duration of list items or the decay rate of phonological information in short-term memory.

  13. Quantitative SPECT brain imaging: Effects of attenuation and detector response

    International Nuclear Information System (INIS)

    Gilland, D.R.; Jaszczak, R.J.; Bowsher, J.E.; Turkington, T.G.; Liang, Z.; Greer, K.L.; Coleman, R.E.

    1993-01-01

    Two physical factors that substantially degrade quantitative accuracy in SPECT imaging of the brain are attenuation and detector response. In addition to the physical factors, random noise in the reconstructed image can greatly affect the quantitative measurement. The purpose of this work was to implement two reconstruction methods that compensate for attenuation and detector response, a 3D maximum likelihood-EM method (ML) and a filtered backprojection method (FB) with Metz filter and Chang attenuation compensation, and compare the methods in terms of quantitative accuracy and image noise. The methods were tested on simulated data of the 3D Hoffman brain phantom. The simulation incorporated attenuation and distance-dependent detector response. Bias and standard deviation of reconstructed voxel intensities were measured in the gray and white matter regions. The results with ML showed that in both the gray and white matter regions as the number of iterations increased, bias decreased and standard deviation increased. Similar results were observed with FB as the Metz filter power increased. In both regions, ML had smaller standard deviation than FB for a given bias. Reconstruction times for the ML method have been greatly reduced through efficient coding, limited source support, and by computing attenuation factors only along rays perpendicular to the detector

  14. Classical anomalous absorption in strongly magnetized plasmas and effective shielding length

    International Nuclear Information System (INIS)

    Matsuda, K.

    1981-01-01

    The high-frequency conductivity tensor of a plasma in a magnetic field has been evaluated. An anomalous perpendicular conductivity is obtained for a strongly magnetized plasma. Contrarily to the previous prediction, the effective shielding length is found to be the Debye length even when the Debye length is larger than the electron gyroradius. The effective shielding length is further discussed by presenting the generalized Balescu-Lenard equation

  15. The effect of gate length on SOI-MOSFETS operation | Baedi ...

    African Journals Online (AJOL)

    The effect of gate length on the operation of silicon-on-insulator (SOI) MOSFET structure with a layer of buried silicon oxide added to isolate the device body has been simulated. Three transistors with gate lengths of 100, 200 and 500 nm were simulated. Simulations showed that with a fixed channel length, when the gate ...

  16. Effects of preservation method on length and weight of pond raised ...

    African Journals Online (AJOL)

    Length and weight measurements of fish used for taxonomy and determination of length-weight relationship are taken from preserved specimen. This study sets out to investigate the effects of two preservatives, 70% alcohol and 10% formalin and freezing method on the length and weight of preserved specimens of tilapia ...

  17. Effect of interference of capillary length on evaporation at meniscus

    Science.gov (United States)

    Soma, Shu; Kunugi, Tomoaki; Yokomine, Takehiko; Kawara, Zensaku

    2017-11-01

    In this study, the experimental results on the evaporation characteristics of meniscus in various geometrical configurations which enable to vary a perimeter of liquid-vapor interface and a meniscus curvature were obtained, and the main factor in evaporation process was clarified. As the experimental conditions, the perimeter was adjusted from 1mm to 100mm order, and the curvature from the inverse of capillary length, κ( 0.4mm-1) , to about 10mm-1 . Measuring devices for evaporation rate, which consisted of a test section on an electric balance, was set to a reduced pressure environment for making the purified water in the test section evaporate. There is no heater in the test section and system was set to be isolated from outside environment. It was found that the evaporation rate and flux could be organized by the perimeter if the curvature is constant at κ. On the other hand, when the curvature is larger than κ, it was found that the curvature is the dominant factor in the evaporation process. It can be considered that an interference of capillary length is a key to understand these results.

  18. Effect of attenuation correction on surface amplitude distribution of wind waves

    Digital Repository Service at National Institute of Oceanography (India)

    Varkey, M.J.

    Some selected wave profiles recorded using a ship borne wave recorder are analysed to study the effect of attenuation correction on the distribution of the surface amplitudes. A new spectral width parameter is defined to account for wide band...

  19. Improving work zone safety for freight vehicles : effective design patterns for vehicle mounted attenuators.

    Science.gov (United States)

    2010-12-01

    This report presents a study of driver perceptions using a driving simulator carried out on the effectiveness of : four markings which vary in striping patterns and color combinations used at the rear of vehicle mounted : attenuators (VMAs) in work z...

  20. Modeling the length effect: Specifying the relation with visual and phonological correlates of reading

    NARCIS (Netherlands)

    van den Boer, M.; de Jong, P.F.; Haentjens-van Meeteren, M.M.

    2013-01-01

    Beginning readers' reading latencies increase as words become longer. This length effect is believed to be a marker of a serial reading process. We examined the effects of visual and phonological skills on the length effect. Participants were 184 second-grade children who read 3- to 5-letter words

  1. Phase Aberration and Attenuation Effects on Acoustic Radiation Force-Based Shear Wave Generation.

    Science.gov (United States)

    Carrascal, Carolina Amador; Aristizabal, Sara; Greenleaf, James F; Urban, Matthew W

    2016-02-01

    Elasticity is measured by shear wave elasticity imaging (SWEI) methods using acoustic radiation force to create the shear waves. Phase aberration and tissue attenuation can hamper the generation of shear waves for in vivo applications. In this study, the effects of phase aberration and attenuation in ultrasound focusing for creating shear waves were explored. This includes the effects of phase shifts and amplitude attenuation on shear wave characteristics such as shear wave amplitude, shear wave speed, shear wave center frequency, and bandwidth. Two samples of swine belly tissue were used to create phase aberration and attenuation experimentally. To explore the phase aberration and attenuation effects individually, tissue experiments were complemented with ultrasound beam simulations using fast object-oriented C++ ultrasound simulator (FOCUS) and shear wave simulations using finite-element-model (FEM) analysis. The ultrasound frequency used to generate shear waves was varied from 3.0 to 4.5 MHz. Results: The measured acoustic pressure and resulting shear wave amplitude decreased approximately 40%-90% with the introduction of the tissue samples. Acoustic intensity and shear wave displacement were correlated for both tissue samples, and the resulting Pearson's correlation coefficients were 0.99 and 0.97. Analysis of shear wave generation with tissue samples (phase aberration and attenuation case), measured phase screen, (only phase aberration case), and FOCUS/FEM model (only attenuation case) showed that tissue attenuation affected the shear wave generation more than tissue aberration. Decreasing the ultrasound frequency helped maintain a focused beam for creation of shear waves in the presence of both phase aberration and attenuation.

  2. Effective x-ray attenuation measurements with full field digital mammography

    International Nuclear Information System (INIS)

    Heine, John J.; Behera, Madhusmita

    2006-01-01

    This work shows that effective x-ray attenuation coefficients may be estimated by applying Beer's Law to phantom image data acquired with the General Electric Senographe 2000D full field digital mammography system. Theoretical developments are provided indicating that an approximate form of the Beer's relation holds for polychromatic x-ray beams. The theoretical values were compared with experimentally determined measured values, which were estimated at various detector locations. The measured effective attenuation coefficients are in agreement with those estimated with theoretical developments and numerical integration. The work shows that the measured quantities show little spatial variation. The main ideas are demonstrated with polymethylmethacrylate and breast tissue equivalent phantom imaging experiments. The work suggests that the effective attenuation coefficients may be used as known values for radiometric standardization applications that compensate for the image acquisition influences. The work indicates that it is possible to make quantitative attenuation coefficient measurements from a system designed for clinical purposes

  3. Effective length of short Fabry-Perot cavity formed by uniform fiber Bragg gratings.

    Science.gov (United States)

    Barmenkov, Yuri O; Zalvidea, Dobryna; Torres-Peiró, Salvador; Cruz, Jose L; Andrés, Miguel V

    2006-07-10

    In this paper, we describe the properties of Fabry-Perot fiber cavity formed by two fiber Bragg gratings in terms of the grating effective length. We show that the grating effective length is determined by the group delay of the grating, which depends on its diffraction efficiency and physical length. We present a simple analytical formula for calculation of the effective length of the uniform fiber Bragg grating and the frequency separation between consecutive resonances of a Fabry-Perot cavity. Experimental results on the cavity transmission spectra for different values of the gratings' reflectivity support the presented theory.

  4. Chemical effect on total mass attenuation coefficients of V, Cr, Mn, Co and Ni

    International Nuclear Information System (INIS)

    Soeguet, Oe.; Colak, S.; Bueyuekkasap, E.; Kuecuekoender, A.

    2002-01-01

    Detailed interpretation of data obtained from X-ray transmission measurements usually depends on the assumption that the contribution of each element is additive. This assumption yields the mixture rule for X-ray attenuation coefficients which is valid if molecular and chemical effects are negligible. Total mass attenuation coefficients of V, Cr, Mn, Co and Ni in various their compounds was measured. Absorption corrections were carried on data for ligands in the compounds. It was found that V, Cr, Mn, Co and Ni had different total mass attenuation coefficients in the different compounds. Results were compared with theoretical values of HUBBELL and SELTZER. (author)

  5. Theoretical evaluation of transcriptional pausing effect on the attenuation in trp leader sequence

    OpenAIRE

    Suzuki, H.; Kunisawa, T.; Otsuka, J.

    1986-01-01

    The effect of transcriptional pausing on attenuation is investigated theoretically on the basis of the attenuation control mechanism presented by Oxender et al. (Oxender, D. L., G. Zurawski, and C. Yanofsky, 1979, Proc. Natl. Acad. Sci. USA. 76:5524-5528). An extended stochastic model including the RNA polymerase pausing in the leader region is developed to calculate the probability of relative position between the RNA polymerase transcribing the trp leader sequence and the ribosome translati...

  6. The effect of word length and other sublexical, lexical, and semantic variables on developmental reading deficits.

    Science.gov (United States)

    De Luca, Maria; Barca, Laura; Burani, Cristina; Zoccolotti, Pierluigi

    2008-12-01

    To examine the effect of word length and several sublexical, and lexico-semantic variables on the reading of Italian children with a developmental reading deficit. Previous studies indicated the role of word length in transparent orthographies. However, several factors that may interact with word length were not controlled for. Seventeen impaired and 34 skilled sixth-grade readers were presented words of different lengths, matched for initial phoneme, bigram frequency, word frequency, age of acquisition, and imageability. Participants were asked to read aloud, as quickly and as accurately as possible. Reaction times at the onset of pronunciation and mispronunciations were recorded. Impaired readers' reaction times indicated a marked effect of word length; in skilled readers, there was no length effect for short words but, rather, a monotonic increase from 6-letter words on. Regression analyses confirmed the role of word length and indicated the influence of word frequency (similar in impaired and skilled readers). No other variables predicted reading latencies. Word length differentially influenced word recognition in impaired versus skilled readers, irrespective of the action of (potentially interfering) sublexical, lexical, and semantic variables. It is proposed that the locus of the length effect is at a perceptual level of analysis. The independent influence of word frequency on the reading performance of both groups of participants indicates the sparing of lexical activation in impaired readers.

  7. Cooperative effect of the attenuation determinants derived from poliovirus sabin 1 strain is essential for attenuation of enterovirus 71 in the NOD/SCID mouse infection model.

    Science.gov (United States)

    Arita, Minetaro; Ami, Yasushi; Wakita, Takaji; Shimizu, Hiroyuki

    2008-02-01

    Enterovirus 71 (EV71) is a causative agent of hand, foot, and mouth disease and is also associated with serious neurological disorders. An attenuated EV71 strain [EV71(S1-3')] has been established in the cynomolgus monkey infection model; this strain contains the attenuation determinants derived from the type 1 poliovirus vaccine strain, Sabin 1 [PV1(Sabin)], in the 5' nontranslated region (NTR), 3D polymerase, and 3' NTR. In this study, we analyzed the effect of the attenuation determinants of PV1(Sabin) on EV71 infection in a NOD/SCID mouse infection model. We isolated a mouse-adapted EV71 strain [EV71(NOD/SCID)] that causes paralysis of the hind limbs in 3- to 4-week-old NOD/SCID mice by adaptation of the virulent EV71(Nagoya) strain in the brains of NOD/SCID mice. A single mutation at nucleotide 2876 that caused an amino acid change in capsid protein VP1 (change of the glycine at position 145 to glutamic acid) was essential for the mouse-adapted phenotype in NOD/SCID mice. Next, we introduced attenuation determinants derived from PV1(Sabin) along with the mouse adaptation mutation into the EV71(Nagoya) genome. In 4-week-old mice, the determinants in the 3D polymerase and 3' NTR, which are the major temperature-sensitive determinants, had a strong effect on attenuation. In contrast, the effect of individual determinants was weak in 3-week-old NOD/SCID mice, and all the determinants were required for substantial attenuation. These results suggest that a cooperative effect of the attenuation determinants of PV1(Sabin) is essential for attenuated neurovirulence of EV71.

  8. Effects of Ultraviolet (UV) Radiations at Different Wave Lengths on ...

    African Journals Online (AJOL)

    Prof. Ogunji

    The effects of UV-radiation on the bacterial load and yeast viability of palm wine were ... shelf life due to the uncontrolled metabolic activities of yeast and bacteria. .... Process. Biochemistry International 8:23-220. Okafor, N. (2007). Palm Wine ...

  9. effects of hatching egg weight and length of storage period

    African Journals Online (AJOL)

    metinpetek

    There were no significant effects of egg storage period on body weight and feed ... chicks from all groups were reared under the same growing conditions in battery ... on hatching time, apparent fertility, hatchability of fertile and total eggs data ...

  10. MRI-guided attenuation correction in whole-body PET/MR. Assessment of the effect of bone attenuation

    International Nuclear Information System (INIS)

    Akbarzadeh, A.; Ay, M.R.; Ahmadian, A.; Riahi Alam, N.; Zaidi, H.

    2013-01-01

    Hybrid positron emission tomography (PET)/MRI presents many advantages in comparison with its counterpart PET/CT in terms of improved soft-tissue contrast, decrease in radiation exposure, and truly simultaneous and multi-parametric imaging capabilities. However, the lack of well-established methodology for MR-based attenuation correction is hampering further development and wider acceptance of this technology. We assess the impact of ignoring bone attenuation and using different tissue classes for generation of the attenuation map on the accuracy of attenuation correction of PET data. This work was performed using simulation studies based on the XCAT phantom and clinical input data. For the latter, PET and CT images of patients were used as input for the analytic simulation model using realistic activity distributions where CT-based attenuation correction was utilized as reference for comparison. For both phantom and clinical studies, the reference attenuation map was classified into various numbers of tissue classes to produce three (air, soft tissue and lung), four (air, lungs, soft tissue and cortical bones) and five (air, lungs, soft tissue, cortical bones and spongeous bones) class attenuation maps. The phantom studies demonstrated that ignoring bone increases the relative error by up to 6.8% in the body and up to 31.0% for bony regions. Likewise, the simulated clinical studies showed that the mean relative error reached 15% for lesions located in the body and 30.7% for lesions located in bones, when neglecting bones. These results demonstrate an underestimation of about 30% of tracer uptake when neglecting bone, which in turn imposes substantial loss of quantitative accuracy for PET images produced by hybrid PET/MRI systems. Considering bones in the attenuation map will considerably improve the accuracy of MR-guided attenuation correction in hybrid PET/MR to enable quantitative PET imaging on hybrid PET/MR technologies. (author)

  11. Measurement of the x-ray mass-attenuation coefficients of gold, derived quantities between 14 keV and 21 keV and determination of the bond lengths of gold

    International Nuclear Information System (INIS)

    Glover, J L; Chantler, C T; Barnea, Z; Rae, N A; Tran, C Q

    2010-01-01

    The x-ray mass-attenuation coefficients of gold are measured at 91 energies between 14 keV and 21 keV using synchrotron radiation. The measurements are accurate to between 0.08% and 0.1%. The photoelectric mass-absorption coefficients and the imaginary component of the form factors of gold are also determined. The results include the L I edge and are the most accurate and extensive gold dataset available in this energy range. An analysis of the L I edge XAFS showed excellent agreement between the measured and simulated XAFS and yielded highly accurate values of the bond lengths of gold. When our results are compared with earlier measurements and with predictions of major theoretical tabulations, significant discrepancies are noted. The comparison raises questions about the nature of discrepancies between experimental and theoretical values of mass-attenuation coefficients.

  12. Topological analysis of polymeric melts: chain-length effects and fast-converging estimators for entanglement length.

    Science.gov (United States)

    Hoy, Robert S; Foteinopoulou, Katerina; Kröger, Martin

    2009-09-01

    Primitive path analyses of entanglements are performed over a wide range of chain lengths for both bead spring and atomistic polyethylene polymer melts. Estimators for the entanglement length N_{e} which operate on results for a single chain length N are shown to produce systematic O(1/N) errors. The mathematical roots of these errors are identified as (a) treating chain ends as entanglements and (b) neglecting non-Gaussian corrections to chain and primitive path dimensions. The prefactors for the O(1/N) errors may be large; in general their magnitude depends both on the polymer model and the method used to obtain primitive paths. We propose, derive, and test new estimators which eliminate these systematic errors using information obtainable from the variation in entanglement characteristics with chain length. The new estimators produce accurate results for N_{e} from marginally entangled systems. Formulas based on direct enumeration of entanglements appear to converge faster and are simpler to apply.

  13. Effectiveness of computed tomography attenuation values in characterization of pericardial effusion.

    Science.gov (United States)

    Çetin, Mehmet Serkan; Özcan Çetin, Elif Hande; Özdemir, Mustafa; Topaloğlu, Serkan; Aras, Dursun; Temizhan, Ahmet; Aydoğdu, Sinan

    2017-04-01

    The aim of this study was to evaluate the effectiveness of computed tomography (CT) attenuation values in the characterization of pericardial effusion. This study consisted of 96 patients with pericardial effusion who underwent pericardiocentesis. For further diagnostic evaluation of pericardial effusion, all the patients were assessed by thorax CT. CT attenuation values were measured from at least 5 different areas of pericardial fluid by specifying the largest region of interest. The average of these measurements was computed and considered as the CT attenuation value of the patient. The patients were classified into two groups: patients with transudative pericardial effusion and those with exudative pericardial effusion. CT attenuation values were significantly higher in patients with exudative pericardial effusion than in those with transudative pericardial effusion [14.85±10.7 Hounsfield unit (HU) vs. 1.13±4.3 HU, peffusion. In addition, a cut-off value of 6.5 HU had 71.4% sensitivity and 72.3% specificity for the prediction of cardiac tamponade. In patients with pericardial effusion, CT attenuation values seem to be correlated with the characterization parameters of the fluid and may distinguish exudative pericardial effusion from transudative pericardial effusion. This parameter was also found to be a predictor of cardiac tamponade. CT attenuation values can be a useful tool in the clinical evaluation of patients with pericardial effusion.

  14. Effect of evaporation section and condensation section length on thermal performance of flat plate heat pipe

    International Nuclear Information System (INIS)

    Wang Shuangfeng; Chen Jinjian; Hu Yanxin; Zhang Wei

    2011-01-01

    Flat plate heat pipes (FPHPs) are one of the available technologies to deal with the high density electronic cooling problem due to their high thermal conductivity, reliability, and low weight penalty. A series of experiments were performed to investigate the effect of evaporation and condensation length on thermal performance of flat plate heat pipes. In the experiments, the FPHP had heat transfer length of 255 mm and width of 25 mm, and pure water was used as the working fluid. The results show that comparing to vapor chamber, the FPHP could realize long-distance heat transfer; comparing to the traditional heat pipe, the FPHP has large area contact with heat sources; the thermal resistance decreased and the heat transfer limit increased with the increase of evaporation section length; the FPHP would dry out at a lower heating power with the increase of condensation section length, which indicated that the heat transfer limit decreased, but the evaporator temperature also decreased; when the condensation section length approached to evaporation section length, the FPHP had a better thermal performance. - Highlights: → A strip sintered FPHP is proposed and tested. → The total heat transfer length reaches 255 mm → The efficiency of heat transport reaches 94.4%. → When the condensation section length approached to evaporation section length, the FPHP has better overall performance.

  15. Dynamical effects of electron-hole correlation and giant quantum attenuation of ultrasound in semimetals

    International Nuclear Information System (INIS)

    Kuramoto, Y.

    1982-01-01

    The giant quantum attenuation of ultrasound in bismuth and other semimetals is noticeably enhanced when certain pair of Landau subbands of electrons and holes participate simultaneously in an attenuation peak. A theoretical analysis is presented which emphasizes importance of dynamical effects of the electron-hole correlation. In the temperature range between 1K and 4K covered by most experiments, the correlation effect is found to be weak on the real part of the relevant response function which gives change in sound velocity. This implies that equilibrium properties of the system are not much influenced by the correlation effect. Nonetheless, the electron-hole correlation is shown to have a drastic consequence on the imaginary part of the response function probed by the ultrasonic attenuation. Proposal for experiment is advanced to discriminate relative importance of this exciton-like correlation from that of repulsive correlation between carriers with the same charge. (orig.)

  16. The effect of genotype and birth type on gestation length and linear ...

    African Journals Online (AJOL)

    The effect of genotype and birth type on gestation length and linear body ... was conducted in Enugu State University of Science and Technology, in the then ... Weekly weights and live body measurements of the kids were recorded from ...

  17. Novel odd/even effect of alkylene chain length on the photopolymerizability of organogelators.

    Science.gov (United States)

    Aoki, Ken'ichi; Kudo, Masabumi; Tamaoki, Nobuyuki

    2004-10-28

    [reaction: see text] Starting from diactylene diacarboxylic acids, we have synthesized a series of photopolymerizable organogelators that possess simple amide structures, different alkylene chain lengths, and either optically active or racemic 3,7-dimethyl-1-octylamine units. The alkylene chain length of these compounds exhibits a prominent odd/even effect with respect to the photopolymerization in the gel state and is accompanied by a stereostructural effect on the gelation ability.

  18. Effects of diffraction and target finite size on coherent transition radiation spectra in bunch length measurements

    Energy Technology Data Exchange (ETDEWEB)

    Castellano, M.; Cianchi, A.; Verzilov, V.A. [Istituto Nazionale di Fisica Nucleare, Frascati, RM (Italy). Laboratori Nazionali di Frascati; Orlandi, G. [Istituto Nazionale di Fisica Nucleare, Rome (Italy)]|[Rome Univ., Tor Vergata, Rome (Italy)

    1999-07-01

    Effects of diffraction and the size of the target on TR in the context of CTR-based bunch length measurements are studied on the basis of Kirchhoff diffraction theory. Spectra of TR from the finite-size target for several schemes of measurements are calculated in the far-infrared region showing strong distortion at low frequencies. Influence of the effect on the accuracy of bunch length measurements is estimated.

  19. Attenuation Effects of Plasma on Ka-Band Wave Propagation in Various Gas and Pressure Environments

    Directory of Open Access Journals (Sweden)

    Joo Hwan Lee

    2018-01-01

    Full Text Available This work demonstrates attenuation effects of plasma on waves propagating in the 26.5–40 GHz range. The effect is investigated via experiments measuring the transmission between two Ka-band horn antennas set 30 cm apart. A dielectric-barrier-discharge (DBD plasma generator with a size of 200 mm × 100 mm × 70 mm and consisting of 20 layers of electrodes is placed between the two antennas. The DBD generator is placed in a 400 mm × 300 mm × 400 mm acrylic chamber so that the experiments can be performed for plasma generated under various conditions of gas and pressure, for instance, in air, Ar, and He environments at 0.001, 0.05, and 1 atm of pressure. Attenuation is calculated by the difference in the transmission level, with and without plasma, which is generated with a bias voltage of 20 kV in the 0.1–1.4 kHz range. Results show that the attenuation varies from 0.05 dB/m to 9.0 dB/m depending on the environment. Noble gas environments show higher levels of attenuation than air, and He is lossier than Ar. In all gas environments, attenuation increases as pressure increases. Finally, electromagnetic models of plasmas generated in various conditions are provided.

  20. Agmatine attenuates the discriminative stimulus and hyperthermic effects of methamphetamine in male rats.

    Science.gov (United States)

    Thorn, David A; Li, Jiuzhou; Qiu, Yanyan; Li, Jun-Xu

    2016-09-01

    Methamphetamine abuse remains an alarming public heath challenge, with no approved pharmacotherapies available. Agmatine is a naturally occurring cationic polyamine that has previously been shown to attenuate the rewarding and psychomotor-sensitizing effects of methamphetamine. This study examined the effects of agmatine on the discriminative stimulus and hyperthermic effects of methamphetamine. Adult male rats were trained to discriminate 0.32 mg/kg methamphetamine from saline. Methamphetamine dose dependently increased drug-associated lever responding. The nonselective dopamine receptor antagonist haloperidol (0.1 mg/kg) significantly attenuated the discriminative stimulus effects of methamphetamine (5.9-fold rightward shift). Agmatine (10-100 mg/kg) did not substitute for methamphetamine, but significantly attenuated the stimulus effects of methamphetamine, leading to a maximum of a 3.5-fold rightward shift. Acute 10 mg/kg methamphetamine increased the rectal temperature by a maximum of 1.96±0.17°C. Agmatine (10-32 mg/kg) pretreatment significantly attenuated the hyperthermic effect of methamphetamine. Agmatine (10 mg/kg) also significantly reversed methamphetamine-induced temperature increase. Together, these results support further exploration of the value that agmatine may have for the treatment of methamphetamine abuse and overdose.

  1. Bending of marble with intrinsic length scales: a gradient theory with surface energy and size effects

    International Nuclear Information System (INIS)

    Vardoulakis, I.; Kourkoulis, S.K.; Exadaktylos, G.

    1998-01-01

    A gradient bending theory is developed based on a strain energy function that includes the classical Bernoulli-Euler term, the shape correction term (microstructural length scale) introduced by Timoshenko, and a term associated with surface energy (micromaterial length scale) accounting for the bending moment gradient effect. It is shown that the last term is capable to interpret the size effect in three-point bending (3PB), namely the decrease of the failure load with decreasing beam length for the same aspect ratio. This theory is used to describe the mechanical behaviour of Dionysos-Pentelikon marble in 3PB. Series of tests with prismatic marble beams of the same aperture but with different lengths were conducted and it was concluded that the present theory predicts well the size effect. (orig.)

  2. Attenuative effects of G-CSF in radiation induced intestinal injury

    International Nuclear Information System (INIS)

    Kim, Joong Sun; Gong, Eun Ji; Kim, Sung Dae; Heo, Kyu; Ryoo, Seung Bum; Yang, Kwang Mo

    2011-01-01

    Granulocyte colony stimulating factor (G-CSF) has been reported to protect from radiationinduced myelosuppression. Growing evidence suggests that G-CSF also has many important non-hematopoietic functions in other tissues, including the intestine (Kim et al., 2010; Kim et al., 2011). However, little is known about the influence of G-CSF on intestinal injury. Examination 12 hours after radiation (5 Gy) revealed that the G-CSF treated mice were significantly protected from apoptosis of jejunal crypt, compared with radiation controls. G-CSF treatment attenuated intestinal morphological changes such as decreased survival crypt, the number of villi, villous shortening, crypt depth and length of basal lamina of 10 enterocytes compared with the radiation control 3.5 days after radiation (10 Gy). G-CSF attenuated the change of peripheral blood from radiation-induced myelosuppression and displayed attenuation of mortality in lethally-irradiated (10 Gy) mice. The present results support the suggestion that G-CSF administrated prior to radiation plays an important role in the survival of irradiated mice, possibly due to the protection of hematopoietic cells and intestinal stem cells against radiation. The results indicate that G-CSF protects from radiation-mediated intestinal damage and from hematopoietic injury. G-CSF treatment may be useful clinically in the prevention of injury following radiation.

  3. Effect of extrapolation length on the phase transformation of epitaxial ferroelectric thin films

    International Nuclear Information System (INIS)

    Hu, Z.S.; Tang, M.H.; Wang, J.B.; Zheng, X.J.; Zhou, Y.C.

    2008-01-01

    Effects of extrapolation length on the phase transformation of epitaxial ferroelectric thin films on dissimilar cubic substrates have been studied on the basis of the mean-field Landau-Ginzburg-Devonshire (LGD) thermodynamic theory by taking an uneven distribution of the interior stress with thickness into account. It was found that the polarization of epitaxial ferroelectric thin films is strongly dependent on the extrapolation length of films. The physical origin of the extrapolation length during the phase transformation from paraelectric to ferroelectric was revealed in the case of ferroelectric thin films

  4. Disentangling the effects of alternation rate and maximum run length on judgments of randomness

    Directory of Open Access Journals (Sweden)

    Sabine G. Scholl

    2011-08-01

    Full Text Available Binary sequences are characterized by various features. Two of these characteristics---alternation rate and run length---have repeatedly been shown to influence judgments of randomness. The two characteristics, however, have usually been investigated separately, without controlling for the other feature. Because the two features are correlated but not identical, it seems critical to analyze their unique impact, as well as their interaction, so as to understand more clearly what influences judgments of randomness. To this end, two experiments on the perception of binary sequences orthogonally manipulated alternation rate and maximum run length (i.e., length of the longest run within the sequence. Results show that alternation rate consistently exerts a unique effect on judgments of randomness, but that the effect of alternation rate is contingent on the length of the longest run within the sequence. The effect of maximum run length was found to be small and less consistent. Together, these findings extend prior randomness research by integrating literature from the realms of perception, categorization, and prediction, as well as by showing the unique and joint effects of alternation rate and maximum run length on judgments of randomness.

  5. Calculation of radiation attenuation coefficients, effective atomic numbers and electron densities for some building materials

    International Nuclear Information System (INIS)

    Damla, N.; Baltas, H.; Celik, A.; Kiris, E.; Cevik, U.

    2008-01-01

    Some building materials, regularly used in Turkey, such as sand, cement, gas concrete (lightweight, aerated concrete), tile and brick, have been investigated in terms of mass attenuation coefficient, effective atomic, numbers (Z eff ), effective electron densities (N e ) and photon interaction cross section (σ a ) at 14 different energies from 81- to 1332-keV gamma-ray energies. The gamma rays were detected by using gamma-ray spectroscopy, a High Purity Germanium (HPGe) detector. The elemental compositions of samples were analysed using an energy dispersive X-ray fluorescence spectrometer. Mass attenuation coefficients of these samples have been compared with tabulations based upon the results of WinXcom. The theoretical mass attenuation coefficients were estimated using the mixture rule and the experimental values of investigated parameters were compared with the calculated values. The agreement of measured values of mass attenuation coefficient, effective atomic numbers, effective electron densities and photon interaction cross section with the theory has been found to be quite satisfactory. (authors)

  6. Effects of Hearing Protection Device Attenuation on Unmanned Aerial Vehicle (UAV) Audio Signatures

    Science.gov (United States)

    2016-03-01

    UAV ) Audio Signatures by Melissa Bezandry, Adrienne Raglin, and John Noble Approved for public release; distribution...Research Laboratory Effects of Hearing Protection Device Attenuation on Unmanned Aerial Vehicle ( UAV ) Audio Signatures by Melissa Bezandry...Aerial Vehicle ( UAV ) Audio Signatures 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Melissa Bezandry

  7. ANTIANDROGENIC EFFECTS OF VINCLOZOLIN ON MALE RATS ARE PARTIALLY ATTENUATED BY TESTOSTERONE PROPIONATE

    Science.gov (United States)

    ANTIANDROGENIC EFFECTS OF VINCLOZOLIN ON MALE RATS ARE PARTIALLY ATTENUATED BY TESTOSTERONE PROPIONATECynthia Wolf1,2 , Joe Ostby1, Jonathan Furr 1, Gerald A. LeBlanc2, and L. Earl Gray, Jr.11 US Environmental Protection Agency, NHEERL, RTD, RTP, NC 27711, 2 Departmen...

  8. Tripeptide tyroserleutide plus doxorubicin: therapeutic synergy and side effect attenuation

    International Nuclear Information System (INIS)

    Zhu, Zhi-feng; Yao, Zhi; Chen, Li-juan; Lu, Rong; Jia, Jing; Liang, Yu; Xu, Qiong; Zhou, Chun-lei; Wang, Li; Wang, Song

    2008-01-01

    Tripeptide tyroserleutide (YSL) is a novel small molecule anti-tumor polypeptide that has been shown to inhibit the growth of human liver cancer cells. In this study, we investigated the effects of YSL plus doxorubicin on the growth of human hepatocellular carcinoma BEL-7402 cells that had been transplanted into nude mice. Nude mice bearing human hepatocellular carcinoma BEL-7402 tumors were treated with successive intraperitoneal injections of saline; low-, mid-, or high-dose doxorubicin; or low-, mid-, or high-dose doxorubicin plus YSL. Effects on the weight and volume of the tumors were evaluated. Co-administration of YSL and high-dose doxorubicin (6 mg/kg every other day) prolonged the survival time of tumor-bearing mice as compared to high-dose doxorubicin alone. As well, the anti-tumor effects of mid- and low-dose doxorubicin (2 and 0.7 mg/kg every other day, respectively) were enhanced when supplemented with YSL; the tumor growth inhibition rates for YSL plus doxorubicin were greater than the inhibition rates for the same dosages of doxorubicin alone. The combination of YSL and doxorubicin decreased chemotherapy-associated weight loss, leukocyte depression, and heart, liver, and kidney damage as compared to doxorubicin alone. The combination of YSL plus doxorubicin enhances the anti-tumor effect and reduces the side effects associated with doxorubicin chemotherapy

  9. Effect of length scale on mechanical properties of Al-Cu eutectic alloy

    Science.gov (United States)

    Tiwary, C. S.; Roy Mahapatra, D.; Chattopadhyay, K.

    2012-10-01

    This paper attempts a quantitative understanding of the effect of length scale on two phase eutectic structure. We first develop a model that considers both the elastic and plastic properties of the interface. Using Al-Al2Cu lamellar eutectic as model system, the parameters of the model were experimentally determined using indentation technique. The model is further validated using the results of bulk compression testing of the eutectics having different length scales.

  10. No effect of embryo culture media on birthweight and length of newborns.

    Science.gov (United States)

    Lin, Shengli; Li, Ming; Lian, Ying; Chen, Lixue; Liu, Ping

    2013-07-01

    Does the type of media used to culture embryos for IVF influence the birthweight and length of neonates? No significant differences were observed in birthweight and length among the three embryo culture media used for in vitro embryo culture. Since the establishment of IVF as an assisted reproductive technology (ART), many different culture systems have been used for the development of human embryos. Some studies have shown that the types of culture media influence the newborn birthweight; however, other studies have shown no effect. To further explore this contradictory issue, we compared the birthweight and length of neonates born after the transfer of embryos cultured in one of three commercially available media. This retrospective analysis of birthweight and length of newborns included 1201 women who delivered singletons and 445 women who delivered twins. The following three commercially available culture media were used: G5™, Global and Quinn's advantage media. Women who underwent IVF-ET cycles between 2008 and 2010 were analyzed. Patients younger than 40 years of age with a body mass index (BMI) culture medium. Inter-twin mean birthweight and length disparities were analyzed, but were not shown to be significantly different. Multiple linear regression analysis showed that maternal weight, maternal height, gestational age and infant gender were significantly related to birthweight, and paternal height, gestational age and newborn complications were significantly associated with birth length. The current study showed that birthweight and length of newborns were not associated with the embryo culture medium. More research needs to be performed to analyze the effects of other culture medium formulations and to evaluate the long-term effects of embryo culture medium on the health of children conceived through ART. WIDER IMPLICATIONS OF THESE FINDINGS: Our retrospective study suggests that embryo culture medium does not influence neonatal birthweight and length

  11. The Effect of Physical Activity agains the Telomere Length in the Leukocytes Cells of KONI Athletes

    Directory of Open Access Journals (Sweden)

    Endang Purwaningsih

    2017-07-01

    Full Text Available Telomeres are strands of non coding DNA at the ends of chromosomes that have the primary function to protect DNA from damage and maintain chromosomal stability. Physical exercise will increase the antioxidant activity can increase telomere proteins, lengthen telomeres and or protein networks associated with telomere so that the telomere remains long, or stopping telomere shortening. Telomere length was also associated with age. The purpose of the research was to determine telomere length of leukocyte cells in the KONI (Indonesian National Sports Committee athletes in Jakarta. The research method is descriptive, by measuring telomere length using quantitative PCR on leukocyte cells. Samples are KONI athletes from several sports, including men and women athletes, with ages between 15-20 years. Used a control group (not athletes is students of the Faculty of Medicine, University of YARSI. The results showed that there was no significant difference (p> 0.05 between telomere length group of athletes with the control group in both sexes. Similarly, telomere length between athlete male with female athletes also showed no significant difference (p> 0.05. It was concluded that physical exercise in athletes KONI at the age of 15- 20 years had no effect on telomere length in leukocytes. The results of this study provide information about the telomere length in Indonesian athletes at an early age.

  12. Muscarinic receptor M4 positive allosteric modulators attenuate central effects of cocaine

    DEFF Research Database (Denmark)

    Dall, Camilla; Weikop, Pia; Dencker, Ditte

    2017-01-01

    BACKGROUND: Cocaine addiction is a chronic brain disease affecting neurotransmission. Muscarinic cholinergic receptors modulate dopaminergic signaling in the reward system, and muscarinic receptor stimulation can block direct reinforcing effects of cocaine. Here, we tested the hypothesis...... that specific muscarinic M4receptor stimulation can attenuate the discriminative stimulus effects and conditioned rewarding effects of cocaine, measures believed to predict the ability of cocaine and cocaine-associated cues to elicit relapse to drug taking. METHODS: We tested the M4-selective positive...

  13. Cervical Length and Androgens in Pregnant Women With Polycystic Ovary Syndrome: Has Metformin Any Effect?

    Science.gov (United States)

    Shetelig Løvvik, Tone; Stridsklev, Solhild; Carlsen, Sven M; Salvesen, Øyvind; Vanky, Eszter

    2016-06-01

    Women with polycystic ovary syndrome (PCOS) have increased risk of preterm delivery. Shortening of the cervix is a sign of preterm delivery. This study aimed to investigate potential effect of metformin on cervical length and whether androgen levels correlate with cervical length in PCOS pregnancies. This was a sub-study of a randomized, placebo-controlled, multicenter study (The PregMet study) performed at 11 secondary or tertiary centers from 2005 to 2009. Two-hundred sixty-one pregnancies of 245 women with PCOS, age 18-42 years participated. Participants were randomly assigned to metformin or placebo from first trimester to delivery. We compared cervical length and androgen levels in metformin and placebo groups at gestational weeks 19 and 32. We also explored whether cervical length correlated with androgen levels. We found no difference in cervical length between the metformin and the placebo groups at gestational week 19 and 32. Dehydroepiandrosterone (DHEAS) tended to be higher in the metformin group. There were no correlations between androgens and cervical length at week 19. At gestational week 32, androstenedione (P = .02) and DHEAS (P = .03) showed a trend toward negative correlation to cervical length. High androstenedione level correlated with shortening of cervical length from week 19 to 32 when adjusted for confounders (P = .003). T (P = .03), DHEAS (P = .02), and free testosterone index (P = .03) showed a similar trend. Metformin in pregnancy did not affect cervical length in women with PCOS. High maternal androgen levels correlated with cervical shortening from the second to the third trimester of pregnancy, as a sign of cervical ripening.

  14. The Long Term Effect on Children of Increasing the Length of Parents' Birth Related Leave

    DEFF Research Database (Denmark)

    Wurtz, Astrid

    related leave from 14 to 20 weeks. We use differences-in-differences regression discontinuity design to identify the causal effect of the leave reform and it estimated whether such a large increase in the mandated leave period has a large measurable and persistent effect on children's cognitive...... and educational outcomes. A 100% sample Danish population born in May, June, July, and August 1983, 1984, and 1985 and a dataset with Danish PISA-2000 scores are used for the estimations. Preliminary results indicate there is no positive effect on children's cognitive outcomes from increasing parents' mandated......    The length of parents' total birth related leave was increased with almost 50% in 1984 in Denmark. The previous length of the Danish maternity leave was long, especially compared to e.g. the U.S. today. This paper investigates the long term effects on children of increasing length of birth...

  15. Determination of the Pt spin diffusion length by spin-pumping and spin Hall effect

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei; Pearson, John E.; Hoffmann, Axel [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Vlaminck, Vincent [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Colegio de Ciencias e Ingenería, Universidad San Fransciso de Quito, Quito (Ecuador); Divan, Ralu [Center for Nanoscale Materials, Argonne National Laboratory, Illinois 60439 (United States); Bader, Samuel D. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Center for Nanoscale Materials, Argonne National Laboratory, Illinois 60439 (United States)

    2013-12-09

    The spin diffusion length of Pt at room temperature and at 8 K is experimentally determined via spin pumping and spin Hall effect in permalloy/Pt bilayers. Voltages generated during excitation of ferromagnetic resonance from the inverse spin Hall effect and anisotropic magnetoresistance effect were investigated with a broadband approach. Varying the Pt layer thickness gives rise to an evolution of the voltage line shape due to the superposition of the above two effects. By studying the ratio of the two voltage components with the Pt layer thickness, the spin diffusion length of Pt can be directly extracted. We obtain a spin diffusion length of ∼1.2 nm at room temperature and ∼1.6 nm at 8 K.

  16. Modeling of Air Attenuation Effects on Gamma Detection at Altitude

    International Nuclear Information System (INIS)

    Detwiler, R. S.

    2002-01-01

    This paper focuses on modeling the detection capabilities of NaI sensor systems at high altitudes for ground sources. The modeling was done with the Monte Carlo N-Transport (MCNP) code developed at Los Alamos National Laboratory. The specific systems modeled were the fixed wing and helicopter aircraft sensor systems, assets of the U. S. Department of Energy's National Nuclear Security Administration Nevada Operations Office (NNSA/NV) Aerial Measuring System (AMS). In previous (2001) modeling, Sodium Iodine (NaI) detector responses were simulated for both point and distributed surface sources as a function of gamma energy and altitude. For point sources, photo-peak efficiencies were calculated for a zero radial distance and an offset equal to the altitude. For distributed sources approximating an infinite plane, gross count efficiencies were calculated and normalized to a uniform surface deposition of 1 (micro)Ci/m 2 . To validate the calculations, benchmark measurements were made for simple source-detector configurations. The 2002 continuation of the modeling presented here includes checking models against available data, and modifications to allow more effective and accurate directional biasing of ground point and distributed sources. Fixed-wing data results will be shown for two point sources as a function of altitude

  17. Exercise attenuates the metabolic effects of dim light at night.

    Science.gov (United States)

    Fonken, Laura K; Meléndez-Fernández, O Hecmarie; Weil, Zachary M; Nelson, Randy J

    2014-01-30

    Most organisms display circadian rhythms that coordinate complex physiological and behavioral processes to optimize energy acquisition, storage, and expenditure. Disruptions to the circadian system with environmental manipulations such as nighttime light exposure alter metabolic energy homeostasis. Exercise is known to strengthen circadian rhythms and to prevent weight gain. Therefore, we hypothesized providing mice a running wheel for voluntary exercise would buffer against the effects of light at night (LAN) on weight gain. Mice were maintained in either dark (LD) or dim (dLAN) nights and provided either a running wheel or a locked wheel. Mice exposed to dim, rather than dark, nights increased weight gain. Access to a functional running wheel prevented body mass gain in mice exposed to dLAN. Voluntary exercise appeared to limit weight gain independently of rescuing changes to the circadian system caused by dLAN; increases in daytime food intake induced by dLAN were not diminished by increased voluntary exercise. Furthermore, although all of the LD mice displayed a 24h rhythm in wheel running, nearly half (4 out of 9) of the dLAN mice did not display a dominant 24h rhythm in wheel running. These results indicate that voluntary exercise can prevent weight gain induced by dLAN without rescuing circadian rhythm disruptions. © 2013.

  18. The effect of self-reported habitual sleep quality and sleep length on autobiographical memory

    NARCIS (Netherlands)

    Murre, J.M.J.; Kristo, G.; Janssen, S.M.J.

    2014-01-01

    A large number of studies have recently shown effects of sleep on memory consolidation. In this study the effects of the sleep quality and sleep length on the retention of autobiographical memories are examined, using an Internet-based diary technique (Kristo, Janssen, & Murre, 2009). Each of over

  19. Modeling the Effects of Argument Length and Validity on Inductive and Deductive Reasoning

    Science.gov (United States)

    Rotello, Caren M.; Heit, Evan

    2009-01-01

    In an effort to assess models of inductive reasoning and deductive reasoning, the authors, in 3 experiments, examined the effects of argument length and logical validity on evaluation of arguments. In Experiments 1a and 1b, participants were given either induction or deduction instructions for a common set of stimuli. Two distinct effects were…

  20. Cardiac Effects of Attenuating Gsα - Dependent Signaling.

    Directory of Open Access Journals (Sweden)

    Marcus R Streit

    Full Text Available Inhibition of β-adrenergic signalling plays a key role in treatment of heart failure. Gsα is essential for β-adrenergic signal transduction. In order to reduce side-effects of beta-adrenergic inhibition diminishing β-adrenergic signalling in the heart at the level of Gsα is a promising option.We analyzed the influence of Gsα on regulation of myocardial function and development of cardiac hypertrophy, using a transgenic mouse model (C57BL6/J mice overexpressing a dominant negative Gsα-mutant under control of the α-MHC-promotor. Cardiac phenotype was characterized in vivo and in vitro and under acute and chronic β-adrenergic stimulation. At rest, Gsα-DN-mice showed bradycardia (602 ± 13 vs. 660 ± 17 bpm, p<0.05 and decreased dp/dtmax (5037 ± 546- vs. 6835 ± 505 mmHg/s, p = 0.02. No significant differences were found regarding ejection fraction, heart weight and cardiomyocyte size. β-blockade by propranolol revealed no baseline differences of hemodynamic parameters between wildtype and Gsα-DN-mice. Acute adrenergic stimulation resulted in decreased β-adrenergic responsiveness in Gsα-DN-mice. Under chronic adrenergic stimulation, wildtype mice developed myocardial hypertrophy associated with increase of LV/BW-ratio by 23% (4.4 ± 0.2 vs. 3.5 ± 0.1 mg/g, p<0.01 and cardiac myocyte size by 24% (14927 ± 442 px vs. 12013 ± 583 px, p<0.001. In contrast, both parameters were unchanged in Gsα-DN-mice after chronic isoproterenol stimulation.Overexpression of a dominant negative mutant of Gsα leads to decreased β-adrenergic responsiveness and is protective against isoproterenol-induced hypertrophy. Thus, Gsα-DN-mice provide novel insights into β-adrenergic signal transduction and its modulation in myocardial overload and failure.

  1. Customization of biliopancreatic limb length to modulate and sustain antidiabetic effect of gastric bypass surgery.

    Science.gov (United States)

    Pal, A; Rhoads, D B; Tavakkoli, A

    2018-02-01

    Although Roux-en-Y Gastric Bypass (RYGB) remains the most effective treatment for obesity and type 2 diabetes (T2D), many patients fail to achieve remission, or relapse. Increasing intestinal limb lengths of RYGB may improve outcomes, but the mechanistic basis for this remains unclear. We hypothesize biliopancreatic (BP) limb length modulates the antidiabetic effect of RYGB. Rats underwent RYGB with a 20-cm (RYGB-20cm) or 40-cm (RYGB-40cm) BP limb and were compared with control animals. After 2 and 4 wk, portal and systemic blood was sampled during intestinal glucose infusion. Portosystemic gradient was used to calculate intestinal glucose utilization (G util ), absorption (G absorp ), and hormone secretion. Intestinal morphology and gene expression were assessed. At 2 wk, G absorp progressively decreased with increasing BP limb length; this pattern persisted at 4 wk. G util increased ≈70% in both RYGB-20cm and -40cm groups at 2 wk. At 4 wk, G util progressively increased with limb length. Furthermore, Roux limb weight, and expression of hexokinase and preproglucagon, exhibited a similar progressive increase. At 4 wk, glucagon-like peptide-1 and -2 levels were higher after RYGB-40cm, with associated increased secretion. We conclude that BP limb length modulates multiple antidiabetic mechanisms, analogous to the dose-response relationship of a drug. Early postoperatively, a longer BP limb reduces G absorp . Later, G util , Roux limb hypertrophy, hormone secretion, and hormone levels are increased with longer BP limb. Sustained high incretin levels may prevent weight regain and T2D relapse. These data provide the basis for customizing BP limb length according to patient characteristics and desired metabolic effect. NEW & NOTEWORTHY Biliopancreatic limb length in gastric bypass modulates multiple antidiabetic mechanisms, analogous to the dose-response relationship of a drug. With a longer biliopancreatic limb, Roux limb hypertrophy, increased glucose utilization

  2. Effect of altering starting length and activation timing of muscle on fiber strain and muscle damage.

    Science.gov (United States)

    Butterfield, Timothy A; Herzog, Walter

    2006-05-01

    Muscle strain injuries are some of the most frequent injuries in sports and command a great deal of attention in an effort to understand their etiology. These injuries may be the culmination of a series of subcellular events accumulated through repetitive lengthening (eccentric) contractions during exercise, and they may be influenced by a variety of variables including fiber strain magnitude, peak joint torque, and starting muscle length. To assess the influence of these variables on muscle injury magnitude in vivo, we measured fiber dynamics and joint torque production during repeated stretch-shortening cycles in the rabbit tibialis anterior muscle, at short and long muscle lengths, while varying the timing of activation before muscle stretch. We found that a muscle subjected to repeated stretch-shortening cycles of constant muscle-tendon unit excursion exhibits significantly different joint torque and fiber strains when the timing of activation or starting muscle length is changed. In particular, measures of fiber strain and muscle injury were significantly increased by altering activation timing and increasing the starting length of the muscle. However, we observed differential effects on peak joint torque during the cyclic stretch-shortening exercise, as increasing the starting length of the muscle did not increase torque production. We conclude that altering activation timing and muscle length before stretch may influence muscle injury by significantly increasing fiber strain magnitude and that fiber dynamics is a more important variable than muscle-tendon unit dynamics and torque production in influencing the magnitude of muscle injury.

  3. Independent effects of step length and foot strike pattern on tibiofemoral joint forces during running.

    Science.gov (United States)

    Bowersock, Collin D; Willy, Richard W; DeVita, Paul; Willson, John D

    2017-10-01

    The purpose of this study was to examine the effects of step length and foot strike pattern along with their interaction on tibiofemoral joint (TFJ) and medial compartment TFJ kinetics during running. Nineteen participants ran with a rear foot strike pattern at their preferred speed using a short (-10%), preferred, and long (+10%) step length. These step length conditions were then repeated using a forefoot strike pattern. Regardless of foot strike pattern, a 10% shorter step length resulted in decreased peak contact force, force impulse per step, force impulse per kilometre, and average loading rate at the TFJ and medial compartment, while a 10% increased step length had the opposite effects (all P forefoot strike pattern significantly lowered TFJ and medial compartment TFJ average loading rates compared with a rear foot strike pattern (both forefoot strike pattern produced the greatest reduction in peak medial compartment contact force (P < 0.05). Knowledge of these running modification effects may be relevant to the management or prevention of TFJ injury or pathology among runners.

  4. Effect of grass silage chop length on chewing activity and digestibility

    DEFF Research Database (Denmark)

    Garmo, T.H.; Randby, Å.T.; Eknæs, M.

    2008-01-01

    Round bale grass silage harvested early (D-value 757 g kg-1 DM) or at a normal (D-value 696 g kg-1 DM) time was used to study the effect of harvesting time, chop length and their interaction on chewing activity and digestibility by dairy cows. Six early lactating Norwegian Red cows were used in a 6...... due to reduced ET, CT = 45, 41 and 39 min kg-1 DM for rations with long, coarsely and finely chopped silage, respectively. Grass silage chop length did not influence diet digestibility, but there was a significant effect of harvesting time on digestibility. No interaction between harvesting time...

  5. The Effect of Height, Wing Length, and Wing Symmetry on Tabebuia rosea Seed Dispersal

    Directory of Open Access Journals (Sweden)

    Yasmeen Moussa

    2014-12-01

    Full Text Available The relationship between the vertical drop height and the horizontal distance traveled (dispersal ratio was investigated for a sample of fifty Tabebuia rosea seeds by dropping the seeds from five heights ranging from 1.00 to 2.00 meters. The dispersal ratio was found to be a constant 0.16 m/m for these heights. The effects of total seed length and asymmetry of seed wings on dispersal ratio were also measured using separate samples of fifty Tabebuia rosea seeds. It was found that neither seed length nor asymmetry had a significant effect on the dispersal ratio.

  6. Effective preexposure and postexposure prophylaxis of rabies with a highly attenuated recombinant rabies virus.

    Science.gov (United States)

    Faber, Milosz; Li, Jianwei; Kean, Rhonda B; Hooper, D Craig; Alugupalli, Kishore R; Dietzschold, Bernhard

    2009-07-07

    Rabies remains an important public health problem with more than 95% of all human rabies cases caused by exposure to rabid dogs in areas where effective, inexpensive vaccines are unavailable. Because of their ability to induce strong innate and adaptive immune responses capable of clearing the infection from the CNS after a single immunization, live-attenuated rabies virus (RV) vaccines could be particularly useful not only for the global eradication of canine rabies but also for late-stage rabies postexposure prophylaxis of humans. To overcome concerns regarding the safety of live-attenuated RV vaccines, we developed the highly attenuated triple RV G variant, SPBAANGAS-GAS-GAS. In contrast to most attenuated recombinant RVs generated thus far, SPBAANGAS-GAS-GAS is completely nonpathogenic after intracranial infection of mice that are either developmentally immunocompromised (e.g., 5-day-old mice) or have inherited deficits in immune function (e.g., antibody production or type I IFN signaling), as well as normal adult animals. In addition, SPBAANGAS-GAS-GAS induces immune mechanisms capable of containing a CNS infection with pathogenic RV, thereby preventing lethal rabies encephalopathy. The lack of pathogenicity together with excellent immunogenicity and the capacity to deliver immune effectors to CNS tissues makes SPBAANGAS-GAS-GAS a promising vaccine candidate for both the preexposure and postexposure prophylaxis of rabies.

  7. Dose attenuation effect of hip prostheses in a 9-MV photon beam. Commercial treatment planning system versus Monte Carlo calculations

    International Nuclear Information System (INIS)

    Mesbahi, A.; Nejad, F.S.

    2007-01-01

    The purpose of this study was to investigate the dosimetric effect of various hip prostheses on pelvis lateral fields treated by a 9-MV photon beam using Monte Carlo (MC) and effective path-length (EPL) methods. The head of the Neptun 10 pc linac was simulated using the MCNP4C MC code. The accuracy of the MC model was evaluated using measured dosimetric features including depth dose values and dose profiles in a water phantom. The Alfard treatment planning system (TPS) was used for EPL calculations. A virtual water phantom with dimensions of 30 x 30 x 30 cm 3 and a cube with dimensions of 4 x 4 x 4 cm 3 made of various metals centered in 12 cm depth was used for MC and EPL calculations. Various materials including titanium, Co-Cr-Mo, and steel alloys were used as hip prostheses. Our results showed significant attenuation in absorbed dose for points after and inside the prostheses. Attenuations of 32%, 54% and 55% were seen for titanium, Co-Cr-Mo, and steel alloys, respectively, at a distance of 5 cm from the prosthesis. Considerable dose increase (up to 18%) was found at the water-prosthesis interface due to back-scattered electrons using the MC method. The results of EPL calculations for the titanium implant were comparable to the MC calculations. This method, however, was not able to predict the interface effect or calculate accurately the absorbed dose in the presence of the Co-Cr-Mo and steel prostheses. The dose perturbation effect of hip prostheses is significant and cannot be predicted accurately by the EPL method for Co-Cr-Mo or steel prostheses. The use of MC-based TPS is recommended for treatments requiring fields passing through hip prostheses. (author)

  8. Effects of Surface Dipole Lengths on Evaporation of Tiny Water Aggregation

    International Nuclear Information System (INIS)

    Wang Shen; Wan Rongzheng; Fang Haiping; Tu Yusong

    2013-01-01

    Using molecular dynamics simulation, we compared evaporation behavior of a tiny amount of water molecules adsorbed on solid surfaces with different dipole lengths, including surface dipole lengths of 1 fold, 2 folds, 4 folds, 6 folds and 8 folds of 0.14 nm and different charges from 0.1e to 0.9e. Surfaces with short dipole lengths (1-fold system) can always maintain hydrophobic character and the evaporation speeds are not influenced, whether the surface charges are enhanced or weakened; but when surface dipole lengths get to 8 folds, surfaces become more hydrophilic as the surface charge increases, and the evaporation speeds increase gradually and monotonically. By tuning dipole lengths from 1-fold to 8-fold systems, we confirmed non-monotonic variation of the evaporation flux (first increases, then decreases) in 4 fold system with charges (0.1e–0.7e), reported in our previous paper [S. Wang, et al., J. Phys. Chem. B 116 (2012) 13863], and also show the process from the enhancement of this unexpected non-monotonic variation to its vanishment with surface dipole lengths increasing. Herein, we demonstrated two key factors to influence the evaporation flux of a tiny amount of water molecules adsorbed on solid surfaces: the exposed surficial area of water aggregation from where the water molecules can evaporate directly and the attraction potential from the substrate hindering the evaporation. In addition, more interestingly, we showed extra steric effect of surface dipoles on further increase of evaporation flux for 2-folds, 4-folds, 6-folds and 8-folds systems with charges around larger than 0.7e. (The steric effect is first reported by parts of our authors [C. Wang, et al., Sci. Rep. 2 (2012) 358]). This study presents a complete physical picture of the influence of surface dipole lengths on the evaporation behavior of the adsorbed tiny amount of water. (condensed matter: structural, mechanical, and thermal properties)

  9. Length-scale effect due to periodic variation of geometrically necessary dislocation densities

    DEFF Research Database (Denmark)

    Oztop, M. S.; Niordson, Christian Frithiof; Kysar, J. W.

    2013-01-01

    Strain gradient plasticity theories have been successful in predicting qualitative aspects of the length scale effect, most notably the increase in yield strength and hardness as the size of the deforming volume decreases. However new experimental methodologies enabled by recent developments...... of high spatial resolution diffraction methods in a scanning electron microscope give a much more quantitative understanding of plastic deformation at small length scales. Specifically, geometrically necessary dislocation densities (GND) can now be measured and provide detailed information about...... the microstructure of deformed metals in addition to the size effect. Recent GND measurements have revealed a distribution of length scales that evolves within a metal undergoing plastic deformation. Furthermore, these experiments have shown an accumulation of GND densities in cell walls as well as a variation...

  10. The effect of self-reported habitual sleep quality and sleep length on autobiographical memory.

    Science.gov (United States)

    Murre, Jaap M J; Kristo, Gert; Janssen, Steve M J

    2014-01-01

    A large number of studies have recently shown effects of sleep on memory consolidation. In this study the effects of the sleep quality and sleep length on the retention of autobiographical memories are examined, using an Internet-based diary technique (Kristo, Janssen, & Murre, 2009). Each of over 600 participants recorded one recent personal event and was contacted after a retention interval that ranged from 2 to 46 days. Recall of the content, time, and details of the event were scored and related to sleep quality and sleep length as measured with the Pittsburgh Sleep Quality Index. Hierarchical regression analyses indicated that poor sleep quality, but not short sleep length, was associated with significantly lower recall at the longer retention periods (30-46 days), but not at the shorter ones (2-15 days), although the difference in recall between good and poor sleepers was small.

  11. Effects of setting angle and chord length on performance of four blades bionic wind turbine

    Science.gov (United States)

    Yang, Z. X.; Li, G. S.; Song, L.; Bai, Y. F.

    2017-11-01

    With the energy crisis and the increasing environmental pollution, more and more efforts have been made about wind power development. In this paper, a four blades bionic wind turbine was proposed, and the outline of wind turbine was constructed by the fitted curve. This paper attempted to research the effects of setting angle and chord length on performance of four blades bionic wind turbine by computational fluid dynamics (CFD) simulation. The results showed that the setting angle and chord length of the bionic wind turbine has some significant effects on the efficiency of the wind turbine, and within the range of wind speed from 7 m/s to 15 m/s, the wind turbine achieved maximum efficiency when the setting angle is 31 degree and the chord length is 125 mm. The conclusion will work as a guideline for the improvement of wind turbine design

  12. Whole-body PET/MRI: The effect of bone attenuation during MR-based attenuation correction in oncology imaging

    Energy Technology Data Exchange (ETDEWEB)

    Aznar, M.C., E-mail: marianne.aznar@regionh.dk [Department of Oncology, Section of Radiotherapy 3994, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen (Denmark); Sersar, R., E-mail: rachidadk@hotmail.com [DTU Informatics, Technical University of Denmark, Kongens Lyngby (Denmark); Saabye, J., E-mail: julie_saa@hotmail.com [DTU Informatics, Technical University of Denmark, Kongens Lyngby (Denmark); Ladefoged, C.N., E-mail: claesnl@gmail.com [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark); Andersen, F.L., E-mail: Flemming.Andersen@regionh.dk [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark); Rasmussen, J.H., E-mail: jacobrasmu@gmail.com [Department of Oncology, Section of Radiotherapy 3994, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen (Denmark); Löfgren, J., E-mail: Johan.Loefgren@regionh.dk [Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet, Copenhagen (Denmark); Beyer, T., E-mail: thomas.beyer@meduniwien.ac.at [Centre for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna (Austria)

    2014-07-15

    Purpose: In combined PET/MRI standard PET attenuation correction (AC) is based on tissue segmentation following dedicated MR sequencing and, typically, bone tissue is not represented. We evaluate PET quantification in whole-body (WB)-PET/MRI following MR-AC without considering bone attenuation and then investigate different strategies to account for bone tissue in clinical PET/MR imaging. To this purpose, bone tissue representation was extracted from separate CT images, and different bone representations were simulated from hypothetically derived MR-based bone classifications. Methods: Twenty oncology patients referred for a PET/CT were injected with either [18F]-FDG or [18F]-NaF and imaged on PET/CT (Biograph TruePoint/mCT, Siemens) and PET/MRI (mMR, Siemens) following a standard single-injection, dual-imaging clinical WB-protocol. Routine MR-AC was based on in-/opposed-phase MR imaging (orgMR-AC). PET(/MRI) images were reconstructed (AW-OSEM, 3 iterations, 21 subsets, 4 mm Gaussian) following routine MR-AC and MR-AC based on four modified attenuation maps. These modified attenuation maps were created for each patient by non-linear co-registration of the CT images to the orgMR-AC images, and adding CT bone mask values representing cortical bone: 1200 HU (cortCT), spongiosa bone: 350 HU (spongCT), average CT value (meanCT) and original CT values (orgCT). Relative difference images of the PET following AC using the modified attenuation maps were compared. SUVmean was calculated in anatomical reference regions and for PET-positive lesions. Results: The relative differences in SUVmean across patients following orgMR-AC and orgCT in soft tissue lesions and in bone lesions were similar (range: 0.0% to −22.5%), with an average underestimation of SUVmean of 7.2% and 10.0%, respectively when using orgMR-AC. In bone lesions, spongCT values were closest to orgCT (median bias of 1.3%, range: –9.0% to 13.5%) while the overestimation of SUVmean with respect to orgCT was

  13. Photoconductivity, pH Sensitivity, Noise, and Channel Length Effects in Si Nanowire FET Sensors

    Science.gov (United States)

    Gasparyan, Ferdinand; Zadorozhnyi, Ihor; Khondkaryan, Hrant; Arakelyan, Armen; Vitusevich, Svetlana

    2018-03-01

    Silicon nanowire (NW) field-effect transistor (FET) sensors of various lengths were fabricated. Transport properties of Si NW FET sensors were investigated involving noise spectroscopy and current-voltage (I-V) characterization. The static I-V dependencies demonstrate the high quality of fabricated silicon FETs without leakage current. Transport and noise properties of NW FET structures were investigated under different light illumination conditions, as well as in sensor configuration in an aqueous solution with different pH values. Furthermore, we studied channel length effects on the photoconductivity, noise, and pH sensitivity. The magnitude of the channel current is approximately inversely proportional to the length of the current channel, and the pH sensitivity increases with the increase of channel length approaching the Nernst limit value of 59.5 mV/pH. We demonstrate that dominant 1/f-noise can be screened by the generation-recombination plateau at certain pH of the solution or external optical excitation. The characteristic frequency of the generation-recombination noise component decreases with increasing of illumination power. Moreover, it is shown that the measured value of the slope of 1/f-noise spectral density dependence on the current channel length is 2.7 which is close to the theoretically predicted value of 3.

  14. Effects of wall roughness and entry length on void profile in vertical bubbly flow

    International Nuclear Information System (INIS)

    Takamasa, Tomoji

    1988-01-01

    An experimental study of upward air-water bubbly two-phase flow in an entry region was performed with various rough wall test tubes. The objective of the work is to clarify the effects of wall roughness and entry length on void profile. The fluid flows in the vertical circular test tube of 25 mm I.D. under nearly atmospheric pressure, at room temperature. The void profile changes from a pattern similar in appearance to the saddle shape which has local void peaks near the wall, into the power law shape whose curve is approximated by a power law formula, with increasing wall roughness and/or entry length. That is, wall roughness and entry length have a similar effect upon void profile. There are two patterns in the power law shape, a pattern with sharp center peak and a pattern with obtuse center peak. As wall roughness and/or entry length increase, the void profile changes from the former pattern to the latter pattern. At enough long entry length (L/D ≅ 150), every void profile has almost the same power law shape independent of wall roughness. Some void profiles are asymmetric to the axis. (author)

  15. Category-length and category-strength effects using images of scenes.

    Science.gov (United States)

    Baumann, Oliver; Vromen, Joyce M G; Boddy, Adam C; Crawshaw, Eloise; Humphreys, Michael S

    2018-06-21

    Global matching models have provided an important theoretical framework for recognition memory. Key predictions of this class of models are that (1) increasing the number of occurrences in a study list of some items affects the performance on other items (list-strength effect) and that (2) adding new items results in a deterioration of performance on the other items (list-length effect). Experimental confirmation of these predictions has been difficult, and the results have been inconsistent. A review of the existing literature, however, suggests that robust length and strength effects do occur when sufficiently similar hard-to-label items are used. In an effort to investigate this further, we had participants study lists containing one or more members of visual scene categories (bathrooms, beaches, etc.). Experiments 1 and 2 replicated and extended previous findings showing that the study of additional category members decreased accuracy, providing confirmation of the category-length effect. Experiment 3 showed that repeating some category members decreased the accuracy of nonrepeated members, providing evidence for a category-strength effect. Experiment 4 eliminated a potential challenge to these results. Taken together, these findings provide robust support for global matching models of recognition memory. The overall list lengths, the category sizes, and the number of repetitions used demonstrated that scene categories are well-suited to testing the fundamental assumptions of global matching models. These include (A) interference from memories for similar items and contexts, (B) nondestructive interference, and (C) that conjunctive information is made available through a matching operation.

  16. The effects of annealing temperature on the permittivity and electromagnetic attenuation performance of reduced graphene oxide

    Science.gov (United States)

    Wu, Fan; Zeng, Qiao; Xia, Yilu; Sun, Mengxiao; Xie, Aming

    2018-05-01

    Reduced graphene oxide (RGO) has been prepared through the thermal reduction method with different annealing temperatures to explore the effects of temperature on the permittivity and electromagnetic attenuation performance. The real and imaginary parts of permittivity increase along with the decrease in the oxygen functional group and the increase in the filler loading ratio. A composite only loaded with 1 wt. % of RGO can possess an effective electromagnetic absorption bandwidth of 7.60 GHz, when graphene oxide was reduced under 300 °C for 2 h. With the annealing temperature increased to 700 °C and the well reduced RGO loaded 7 wt. % in the composite, the electromagnetic interference shielding efficiency can get higher than 35 dB from 2 to 18 GHz. This study shows that controlling the oxygen functional groups on the RGO surface can also obtain an ideal electromagnetic attenuation performance without any other decorated nanomaterials.

  17. The Effect of CFRP Length on the Failure Mode of Strengthened Concrete Beams

    Directory of Open Access Journals (Sweden)

    Jun Ding

    2014-06-01

    Full Text Available This paper reports the effects of carbon fiber-reinforced polymer (CFRP length on the failure process, pattern and crack propagation for a strengthened concrete beam with an initial notch. The experiments measuring load-bearing capacity for concrete beams with various CFRP lengths have been performed, wherein the crack opening displacements (COD at the initial notch are also measured. The application of CFRP can significantly improve the load-bearing capacity, and the failure modes seem different with various CFRP lengths. The stress profiles in the concrete material around the crack tip, at the end of CFRP and at the interface between the concrete and CFRP are then calculated using the finite element method. The experiment measurements are validated by theoretical derivation and also support the finite element analysis. The results show that CFRP can significantly increase the ultimate load of the beam, while such an increase stops as the length reaches 0.15 m. It is also concluded that the CFRP length can influence the stress distribution at three critical stress regions for strengthened concrete beams. However, the optimum CFRP lengths vary with different critical stress regions. For the region around the crack tip, it is 0.15 m; for the region at the interface it is 0.25 m, and for the region at the end of CFRP, it is 0.30 m. In conclusion, the optimum CFRP length in this work is 0.30 m, at which CFRP strengthening is fully functioning, which thus provides a good reference for the retrofitting of buildings.

  18. Effects of Presentation Format and List Length on Children's False Memories

    Science.gov (United States)

    Swannell, Ellen R.; Dewhurst, Stephen A.

    2013-01-01

    The effect of list length on children's false memories was investigated using list and story versions of the Deese/Roediger-McDermott procedure. Short (7 items) and long (14 items) sequences of semantic associates were presented to children aged 6, 8, and 10 years old either in lists or embedded within a story that emphasized the list theme.…

  19. Effects of Length, Complexity, and Grammatical Correctness on Stuttering in Spanish-Speaking Preschool Children

    Science.gov (United States)

    Watson, Jennifer B.; Byrd, Courtney T.; Carlo, Edna J.

    2011-01-01

    Purpose: To explore the effects of utterance length, syntactic complexity, and grammatical correctness on stuttering in the spontaneous speech of young, monolingual Spanish-speaking children. Method: Spontaneous speech samples of 11 monolingual Spanish-speaking children who stuttered, ages 35 to 70 months, were examined. Mean number of syllables,…

  20. Effect of different vine lengths on the growth and yield of orange ...

    African Journals Online (AJOL)

    Field experiment was conducted in 2014 cropping season at the Teaching and Research Farm of the Agricultural Education Department, Nwafor Orizu College of Education, Nsugbe to investigate the effect of different vine lengths on the growth and yield of orange-fleshed sweet potato (Ipomea batatas(L) Lam) in ultisols of ...

  1. Effect of TiO2 nanotube length and lateral tubular spacing on ...

    Indian Academy of Sciences (India)

    Abstract. The main objective of this study is to show the effect of TiO2 nanotube length, diameter and intertubular ... formation of nanotube arrays spread uniformly over a large area. ... 36, 48 and 72 h at an applied voltage of 40 V. The anodized ... and phase analysis for the obtained nanotubes were done .... Using an extra-.

  2. Strong and long: effects of word length on phonological binding in verbal short-term memory.

    Science.gov (United States)

    Jefferies, Elizabeth; Frankish, Clive; Noble, Katie

    2011-02-01

    This study examined the effects of item length on the contribution of linguistic knowledge to immediate serial recall (ISR). Long words are typically recalled more poorly than short words, reflecting the greater demands that they place on phonological encoding, rehearsal, and production. However, reverse word length effects--that is, better recall of long than short words--can also occur in situations in which phonological maintenance is difficult, suggesting that long words derive greater support from long-term lexical knowledge. In this study, long and short words and nonwords (containing one vs. three syllables) were presented for immediate serial recall in (a) pure lists and (b) unpredictable mixed lists of words and nonwords. The mixed-list paradigm is known to disrupt the phonological stability of words, encouraging their phonemes to recombine with the elements of other list items. In this situation, standard length effects were seen for nonwords, while length effects for words were absent or reversed. A detailed error analysis revealed that long words were more robust to the mixed-list manipulation than short words: Their phonemes were less likely to be omitted and to recombine with phonemes from other list items. These findings support an interactive view of short-term memory, in which long words derive greater benefits from lexical knowledge than short words-especially when their phonological integrity is challenged by the inclusion of nonwords in mixed lists.

  3. effect of side chain length on the stability and structural properties of 3

    African Journals Online (AJOL)

    Preferred Customer

    We report on the effect of the alkoxy chain length on the thermodynamic ... studied by Hartree-Fock (HF) and Density Functional Theory (DFT) methods. ..... with longer alkoxy substituents on the phenyl ring have lesser value of change in Gibbs ...

  4. Effect of length of lay of Nigeria indigenous chickens on their egg ...

    African Journals Online (AJOL)

    Three hundred and thirty eggs collected from the second to the seventh month of production, from a flock of the Nigeria indigenous (NI) chickens, were analysed to determine the effect of the length of lay on egg composition and shell quality. The weights of the whole egg and its components as well as shell thickness were ...

  5. The Effects of Test Length and Sample Size on Item Parameters in Item Response Theory

    Science.gov (United States)

    Sahin, Alper; Anil, Duygu

    2017-01-01

    This study investigates the effects of sample size and test length on item-parameter estimation in test development utilizing three unidimensional dichotomous models of item response theory (IRT). For this purpose, a real language test comprised of 50 items was administered to 6,288 students. Data from this test was used to obtain data sets of…

  6. Criteria for accurate determination of the magnon relaxation length from the nonlocal spin Seebeck effect

    NARCIS (Netherlands)

    Shan, Juan; Cornelissen, Ludo Johannes; Liu, Jing; Ben Youssef, J.; Liang, Lei; van Wees, Bart

    2017-01-01

    The nonlocal transport of thermally generated magnons not only unveils the underlying mechanism of the spin Seebeck effect, but also allows for the extraction of the magnon relaxation length (λm) in a magnetic material, the average distance over which thermal magnons can propagate. In this study, we

  7. CAG repeat length variation in the polymerase gamma (POLG) gene: effect on semen quality

    NARCIS (Netherlands)

    Westerveld, G. H.; Kaaij-Visser, L.; Tanck, M.; van der Veen, F.; Repping, S.

    2008-01-01

    Several case-control studies have investigated the effect of CAG repeat length variation in the POLG gene on male fertility and semen quality. Some described an association between the homozygous not10 CAG-repeat genotype and male subfertility and/or reduced semen quality, whereas others did not.

  8. Effect of Different Bar Embedment Length on Bond-Slip in Plain and Fiber Reinforced Concrete

    NARCIS (Netherlands)

    Jankovic, D.; Chopra, M.B.; Kunnath, S.K.

    2001-01-01

    This research aims to study the behaviour of the concrete-steel bond using numerical models, taking into account the effect of the different bar embedment length. Both plain and fiber reinforced concrete (FRC) are modeled. The interface bond stress as well as load-displacement response of the

  9. A study of charged hadron yields and the multidimensional nuclear attenuation effect at the HERMES experiment

    International Nuclear Information System (INIS)

    Ararat, Karyan Gevorg

    2013-06-01

    In this thesis the determination of the multiplicities of π ± , K ± , p, and anti p in semi-inclusive deep inelastic e ± scattering on D, Ne, Kr, and Xe targets at an energy of 27.6 GeV is described. By determination of the ratios of the multiplicities on Ne, Kr, and Xe targets to those on the D target the effect of nuclear attenuation is studied. (HSI)

  10. A study of charged hadron yields and the multidimensional nuclear attenuation effect at the HERMES experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ararat, Karyan Gevorg

    2013-06-15

    In this thesis the determination of the multiplicities of {pi}{sup {+-}}, K{sup {+-}}, p, and anti p in semi-inclusive deep inelastic e{sup {+-}} scattering on D, Ne, Kr, and Xe targets at an energy of 27.6 GeV is described. By determination of the ratios of the multiplicities on Ne, Kr, and Xe targets to those on the D target the effect of nuclear attenuation is studied. (HSI)

  11. Effective preexposure and postexposure prophylaxis of rabies with a highly attenuated recombinant rabies virus

    OpenAIRE

    Faber, Milosz; Li, Jianwei; Kean, Rhonda B.; Hooper, D. Craig; Alugupalli, Kishore R.; Dietzschold, Bernhard

    2009-01-01

    Rabies remains an important public health problem with more than 95% of all human rabies cases caused by exposure to rabid dogs in areas where effective, inexpensive vaccines are unavailable. Because of their ability to induce strong innate and adaptive immune responses capable of clearing the infection from the CNS after a single immunization, live-attenuated rabies virus (RV) vaccines could be particularly useful not only for the global eradication of canine rabies but also for late-stage r...

  12. The effect of regular strength training on telomere length in human skeletal muscle

    DEFF Research Database (Denmark)

    Kadi, F.; Ponsot, Elodie; Piehl-Aulin, Karin

    2008-01-01

    PURPOSE: The length of DNA telomeres is an important parameter of the proliferative potential of tissues. A recent study has reported abnormally short telomeres in skeletal muscle of athletes with exercise-associated fatigue. This important report raises the question of whether long-term practice...... of sports might have deleterious effects on muscle telomeres. Therefore, we aimed to compare telomere length of a group of power lifters (PL; N = 7) who trained for 8 +/- 3 yr against that of a group of healthy, active subjects (C; N = 7) with no history of strength training. METHODS: Muscle biopsies were...

  13. Effects of fine root length density and root biomass on soil preferential flow in forest ecosystems

    Directory of Open Access Journals (Sweden)

    Yinghu Zhang

    2015-04-01

    Full Text Available Aim of study: The study was conducted to characterize the impacts of plant roots systems (e.g., root length density and root biomass on soil preferential flow in forest ecosystems. Area of study: The study was carried out in Jiufeng National Forest Park, Beijing, China. Material and methods: The flow patterns were measured by field dye tracing experiments. Different species (Sophora japonica Linn,Platycladus orientalis Franco, Quercus dentata Thunbwere quantified in two replicates, and 12 soil depth were applied. Plant roots were sampled in the sieving methods. Root length density and root biomass were measured by WinRHIZO. Dye coverage was implied in the image analysis, and maximum depth of dye infiltration by direct measurement. Main results: Root length density and root biomass decreased with the increasing distance from soil surface, and root length density was 81.6% higher in preferential pathways than in soil matrix, and 66.7% for root biomass with respect to all experimental plots. Plant roots were densely distributed in the upper soil layers. Dye coverage was almost 100% in the upper 5-10 cm, but then decreased rapidly with soil depth. Root length density and root biomass were different from species: Platycladus orientalis Franco > Quercus dentata Thunb > Sophora japonica Linn. Research highlights: The results indicated that fine roots systems had strong effects on soil preferential flow, particularly root channels enhancing nutrition transport across soil profiles in forest dynamics.

  14. Effect Evaluation of Utterance Length on Speech Dysfluency in Stuttering and Nonstuttering Persian-Speaker Children

    Directory of Open Access Journals (Sweden)

    Fateme Haresabadi

    2011-06-01

    Full Text Available Background and Aim: The correlation of stuttering and different linguistic factors is assessed in many studies. The obtained results can pave the way to reach a better understanding of stuttering, as well as finding more appropriate treatments. This study investigates the effect of utterance length on speech dysfluency comparing stuttering Persian(Farsi -speaking children and nonstuttering ones.Methods: Ten stuttering and ten nonstuttering Persian-speaking children between 4 and 6 years of age, matched by age and gender where included in this cross-sectional study. All individuals were investigated by ten sets of simple and complex sentences. Morphemes were added one by one to sentences in each set in order to assess the impact of utterance length on dysfluency. Data analysis was performed using SPSS software. Results: In practicing ten sets of sentences, the speech dysfluency shows significant enhance with increase of utterance length in both stuttering and nonstuttering children (p=0.001. Furthermore, while comparing two groups of simple and complex sentences, significant increase of speech dysfluency was observed by length enhance of utterance, in both stuttering and nonstuttering children (p<0.05. The comparison of stuttering and nonstuttering children showed significant difference between the two groups as well (p=0.001. Conclusions: The results of this study show that increase in utterance length in both simple and complex sentences lead to increase in dysfluency in stuttering and nonstuttering children. Stuttering children indicated more dysfluency than nonstuttering ones.

  15. Effect of axial length on laser spot size during photodynamic therapy: an experimental study in monkeys.

    Science.gov (United States)

    Kondo, Mineo; Ito, Yasuki; Miyata, Kentaro; Kondo, Nagako; Ishikawa, Kohei; Terasaki, Hiroko

    2006-01-01

    To investigate the effect of shorter axial length on the laser spot size and laser energy during photodynamic therapy (PDT) in monkeys. Experimental study with four rhesus monkeys. PDT was performed on the normal retina of monkeys whose ocular axial lengths are shorter (19.55 to 20.25 mm) than that of humans. After the PDT, the eyes were enucleated, and the diameter of the irradiated laser spot was measured with a microcaliper. The area of actual laser spot was only 0.56 to 0.61 times of the planned area, which indicated that the laser energy/area was 1.64 to 1.78 times more intense than planned initially. These results are the in vivo demonstration that the diameter of PDT laser spot is smaller for eyes with shorter axial lengths.

  16. Effect of defect length on rolling contact fatigue crack propagation in high strength steel

    Directory of Open Access Journals (Sweden)

    T. Makino

    2015-10-01

    Full Text Available The objective of the present paper is to clarify the effect of defect length in depth direction on rolling contact fatigue (RCF crack propagation in high strength steel. RCF test and synchrotron radiation micro computed tomography (SR micro CT imaging were conducted. In the case of the defect with the 15 m diameter, flaking life decreased with increasing defect length. In a comparison of the CT image and the SEM view, the shapes of defects and the locations of the horizontal cracks were almost the same respectively. The mechanism of RCF crack propagation was discussed by finite element (FE analysis. Defects led to higher tensile residual stress than that without defects in the region where the defect exists. The shear stress range at 0.1 mm in depth on the middle line of the defect and the range of mode II stress intensity factor at the bottom of a vertical crack increased with increasing defect length.

  17. Eye movements and word skipping during reading: Effects of word length and predictability

    Science.gov (United States)

    Rayner, Keith; Slattery, Timothy J.; Drieghe, Denis; Liversedge, Simon P.

    2012-01-01

    The extent to which target words were predictable from prior context was varied: half of the target words were predictable and the other half were unpredictable. In addition, the length of the target word varied: the target words were short (4–6 letters), medium (7–9 letters), or long (10–12 letters). Length and predictability both yielded strong effects on the probability of skipping the target words and on the amount of time readers fixated the target words (when they were not skipped). However, there was no interaction in any of the measures examined for either skipping or fixation time. The results demonstrate that word predictability (due to contextual constraint) and word length have strong and independent influences on word skipping and fixation durations. Furthermore, since the long words extended beyond the word identification span, the data indicate that skipping can occur on the basis of partial information in relation to word identity. PMID:21463086

  18. Experimental investigation of tube length effect on nucleate pool boiling heat transfer

    International Nuclear Information System (INIS)

    Kang, Myeong-Gie

    1998-01-01

    The effect of a vertically installed tube length on the nucleate pool boiling heat transfer coefficient under atmospheric pressure has been empirically obtained using various combination of major parameters for application to advanced light water reactor design. The experimental data for q'' versus ΔT test are counted as 1,063 points and can cover the extent of D = 9.7 ∼ 25.4 mm, ε = 15.1 ∼ 60.9 nm, H = 5.25 ∼ 30.93, and q'' ≤ 160 kW/m 2 . The experimental results show that a shorter tube is more efficient to increase heat transfer rate due to smaller bubble slug formation on the tube surface. The effect of tube length is greatly observed before H(= L/D) gets 50. After that, the heat flux decreases linearly with H increase. To quantify tube length effect, a new empirical correlation has been developed based on the experimental data bank for pool boiling heat transfer and some parametric studies have been done using the newly developed empirical correlation to broaden its applicability. The newly developed empirical correlation has the form of q'' 0.019ε 0.570 ΔT 4.676 /(D 1.238 H 0.072 ) and can predict the experimental data within ± 20% bound. Heat transfer characteristics can be changed with tube length variation and the transition point is H ∼ 50. Before the transition point, bubble coalescence is active and heat transfer rate gets rapidly decreased with increasing tube length. After that, heat transfer gets somewhat slowly decreased since bubble coalescence effect gets nearly equilibrium with liquid agitation effect

  19. The influence of finite-length flaw effects on PTS analyses

    International Nuclear Information System (INIS)

    Keeney-Walker, J.; Dickson, T.L.

    1993-01-01

    Current licensing issues within the nuclear industry dictate a need to investigate the effects of cladding on the extension of small finite-length cracks near the inside surface of a vessel. Because flaws having depths of the order of the combined clad and heat affected zone thickness dominate the frequency distribution of flaws, their initiation probabilities can govern calculated vessel failure probabilities. Current pressurized-thermal-shock (PTS) analysis computer programs recognize the influence of the inner-surface cladding layer in the heat transfer and stress analysis models, but assume the cladding fracture toughness is the same as that for the base material. The programs do not recognize the influence cladding may have in inhibiting crack initiation and propagation of shallow finite-length surface flaws. Limited experimental data and analyses indicate the cladding can inhibit the propagation of certain shallow flaws. This paper describes an analytical study which was carried out to determine (1) the minimum flaw depth for crack initiation under PTS loading for semicircular surface flaws in a clad reactor pressure vessel and (2) the impact, in terms of the conditional probability of vessel failure, of using a semicircular surface flaw as the initial flaw and assuming that the flaw cannot propagate in the cladding. The analytical results indicate that for initiation a much deeper critical crack depth is required for the finite-length flaw than for the infinite-length flaw, except for the least severe transient. The minimum flaw depths required for crack initiation from the finite-length flaw analyses were incorporated into a modified version of the OCA-P code. The modified code was applied to the analysis of selected PTS transients, and the results produced a substantial decrease in the conditional probability of failure. This initial study indicates a significant effect on probabilistic fracture analyses by incorporating finite-length flaw results

  20. Effects of Pedal Speed and Crank Length on Pedaling Mechanics during Submaximal Cycling

    Science.gov (United States)

    BARRATT, PAUL RICHARD; MARTIN, JAMES C.; ELMER, STEVE J.; KORFF, THOMAS

    2016-01-01

    ABSTRACT During submaximal cycling, the neuromuscular system has the freedom to select different intermuscular coordination strategies. From both a basic science and an applied perspective, it is important to understand how the central nervous system adjusts pedaling mechanics in response to changes in pedaling conditions. Purpose To determine the effect of changes in pedal speed (a marker of muscle shortening velocity) and crank length (a marker of muscle length) on pedaling mechanics during submaximal cycling. Methods Fifteen trained cyclists performed submaximal isokinetic cycling trials (90 rpm, 240 W) using pedal speeds of 1.41 to 1.61 m·s−1 and crank lengths of 150 to 190 mm. Joint powers were calculated using inverse dynamics. Results Increases in pedal speed and crank length caused large increases knee and hip angular excursions and velocities (P 0.05). Joint moments and joint powers were less affected by changes in the independent variables, but some interesting effects and trends were observed. Most noteworthy, knee extension moments and powers tended to decrease, whereas hip extension power tended to increase with an increase in crank length. Conclusions The distribution of joint moments and powers is largely maintained across a range of pedaling conditions. The crank length induced differences in knee extension moments, and powers may represent a trade-off between the central nervous system’s attempts to simultaneously minimize muscle metabolic and mechanical stresses. These results increase our understanding of the neural and mechanical mechanisms underlying multi-joint task performance, and they have practical relevance to coaches, athletes, and clinicians. PMID:26559455

  1. Effect of marital distance on birth weight and length of offspring

    Directory of Open Access Journals (Sweden)

    Kozieł Sławomir

    2017-09-01

    Full Text Available Marital distance (MD, the geographical distance between birthplaces of spouses, is considered an agent favouring occurrence of heterosis and can be used as a measure of its level. Heterosis itself is a phenomenon of hybrid vigour and seems to be an important factor regulating human growth and development. The main aim of the study is to examine potential effects of MD on birth weight and length of offspring, controlling for socioeconomic status (SES, mother’s age and birth order. Birth weight (2562 boys and 2572 girls and length (2526 boys, 2542 girls of children born in Ostrowiec Swietokrzyski (Poland in 1980, 1983, 1985 and 1988 were recorded during cross-sectional surveys carried out between 1994-1999. Data regarding the socio-demographic variables of families were provided by the parents. Analysis of covariance showed that MD significantly affected both birth weight and length, allowing for sex, birth order, mother’s age and SES of family. For both sexes, a greater marital distance was associated with a higher birth weight and a longer birth length. Our results support the hypothesis that a greater geographical distance between the birth places of parents may contribute to the heterosis effects in offspring. Better birth outcomes may be one of the manifestations of these effects.

  2. The effect of epoch length on estimated EEG functional connectivity and brain network organisation

    Science.gov (United States)

    Fraschini, Matteo; Demuru, Matteo; Crobe, Alessandra; Marrosu, Francesco; Stam, Cornelis J.; Hillebrand, Arjan

    2016-06-01

    Objective. Graph theory and network science tools have revealed fundamental mechanisms of functional brain organization in resting-state M/EEG analysis. Nevertheless, it is still not clearly understood how several methodological aspects may bias the topology of the reconstructed functional networks. In this context, the literature shows inconsistency in the chosen length of the selected epochs, impeding a meaningful comparison between results from different studies. Approach. The aim of this study was to provide a network approach insensitive to the effects that epoch length has on functional connectivity and network reconstruction. Two different measures, the phase lag index (PLI) and the amplitude envelope correlation (AEC) were applied to EEG resting-state recordings for a group of 18 healthy volunteers using non-overlapping epochs with variable length (1, 2, 4, 6, 8, 10, 12, 14 and 16 s). Weighted clustering coefficient (CCw), weighted characteristic path length (L w) and minimum spanning tree (MST) parameters were computed to evaluate the network topology. The analysis was performed on both scalp and source-space data. Main results. Results from scalp analysis show a decrease in both mean PLI and AEC values with an increase in epoch length, with a tendency to stabilize at a length of 12 s for PLI and 6 s for AEC. Moreover, CCw and L w show very similar behaviour, with metrics based on AEC more reliable in terms of stability. In general, MST parameters stabilize at short epoch lengths, particularly for MSTs based on PLI (1-6 s versus 4-8 s for AEC). At the source-level the results were even more reliable, with stability already at 1 s duration for PLI-based MSTs. Significance. The present work suggests that both PLI and AEC depend on epoch length and that this has an impact on the reconstructed network topology, particularly at the scalp-level. Source-level MST topology is less sensitive to differences in epoch length, therefore enabling the comparison of brain

  3. Effect of deep stripping massage alone or with eccentric resistance on hamstring length and strength.

    Science.gov (United States)

    Forman, Jeffrey; Geertsen, Lisbeth; Rogers, Michael E

    2014-01-01

    Many studies have evaluated the effects of different interventions on hamstring length. However, little research has been conducted on the effects of deep stripping massage strokes (DSMS) alone, or combined with eccentric resistance, on hamstring length and strength. To determine: 1) if DSMS have an effect on hamstring length and strength and 2) if the effects on hamstring length and strength are any different when DSMS are combined with eccentric exercise. 89 Community College students and community members between the ages of 18 and 62 volunteered for the study. Of these, 64 demonstrated tight hamstrings on either one or both sides as defined by supine, passive terminal knee extension of ≤75° and participated in the study. Strength was assessed by pressing the posterior calcaneus into a strain gauge for approximately 5 s while seated with the knee flexed to 90°. On their tighter side, participants were administered longitudinal DSMS during 15, 10-s bouts of eccentric resistance with an elastic resistance band. On their other hamstring, participants were administered 15, 10-s longitudinal DSMS while lying passive. All massage strokes were performed at a depth of 7 out of 10 on a verbal pressure scale index. Afterwards, the hamstring flexibility and strength tests were repeated. Both DSMS with eccentric resistance (10.7%) and DSMS alone (6.3%) resulted in improved (p alone. Strength was not significantly affected by either treatment. These results suggest that DSMS increases hamstring length in less than 3 min but has no affect on strength. Furthermore, combining DSMS with eccentric resistance produces more hamstring flexibility gains than DSMS alone and does not affect strength. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Cost-effective management of hydrocarbon plumes using monitored natural attenuation: case studies

    International Nuclear Information System (INIS)

    Borg, G.A.

    2000-01-01

    Engineered remediation of hydrocarbon plumes in groundwater at operating service station sites is expensive, disruptive, does not improve the management of risks to receptors, and does not provide certainty of outcome. When plumes are delineated, potential receptors identified and primary sources removed, monitored natural attenuation (MINA) is a cost-effective remediation option. If available, hydrocarbon concentration data from successive groundwater monitoring events showing that a plume is stable or reducing will provide enough primary evidence that natural attenuation is occurring. Where potential receptors will not be impacted in the short to medium term, MNA provides the same level of risk management as engineered remediation with much less cost, no disruption to the service station business, and with a certainty of meeting the objectives of the remediation

  5. An effective approach to attenuate random noise based on compressive sensing and curvelet transform

    International Nuclear Information System (INIS)

    Liu, Wei; Cao, Siyuan; Zu, Shaohuan; Chen, Yangkang

    2016-01-01

    Random noise attenuation is an important step in seismic data processing. In this paper, we propose a novel denoising approach based on compressive sensing and the curvelet transform. We formulate the random noise attenuation problem as an L _1 norm regularized optimization problem. We propose to use the curvelet transform as the sparse transform in the optimization problem to regularize the sparse coefficients in order to separate signal and noise and to use the gradient projection for sparse reconstruction (GPSR) algorithm to solve the formulated optimization problem with an easy implementation and a fast convergence. We tested the performance of our proposed approach on both synthetic and field seismic data. Numerical results show that the proposed approach can effectively suppress the distortion near the edge of seismic events during the noise attenuation process and has high computational efficiency compared with the traditional curvelet thresholding and iterative soft thresholding based denoising methods. Besides, compared with f-x deconvolution, the proposed denoising method is capable of eliminating the random noise more effectively while preserving more useful signals. (paper)

  6. The effect of lactation length on greenhouse gas emissions from the national dairy herd.

    Science.gov (United States)

    Wall, E; Coffey, M P; Pollott, G E

    2012-11-01

    Many governments have signed up to greenhouse gas emission (GHGE) reduction programmes under their national climate change obligations. Recently, it has been suggested that the use of extended lactations in dairy herds could result in reduced GHGE. Dairy GHGE were modelled on a national basis and the model was used to compare emissions from lactations of three different lengths (305, 370 and 440 days), and a current 'base' scenario on the basis of maintaining current milk production levels. In addition to comparing GHGE from the average 'National Herd' under these scenarios, results were used to investigate how accounting for lactations of different lengths might alter the estimation of emissions calculated from the National Inventory methodology currently recommended by Intergovernmental Panel on Climate Change. Data for the three lactation length scenarios were derived from nationally recorded dairy performance information and used in the GHGE model. Long lactations required fewer milking cows and replacements to maintain current milk yield levels than short ones, but GHGEs were found to rise from 1214 t of CO2 equivalent (CE)/farm per year for lactations of 305 days to 1371 t CE/farm per year for 440-day lactations. This apparent anomaly can be explained by the less efficient milk production (kg milk produced per kg cow weight) found in later lactation, a more pronounced effect in longer lactations. The sensitivity of the model to changes in replacement rate, persistency and level of milk yield was investigated. Changes in the replacement rate from 25% to 20% and in persistency by −10% to +20% resulted in very small changes in GHGE. Differences in GHGE due to the level of milk yield were much more dramatic with animals in the top 10% for yield, producing about 25% less GHGE/year than the average animal. National Inventory results were investigated using a more realistic spread of lactation lengths than recommended for such calculations using emissions

  7. [Effect of flooding time length on mycorrhizal colonization of three AM fungi in two wetland plants].

    Science.gov (United States)

    Ma, Lei-Meng; Wang, Peng-Teng; Wang, Shu-Guang

    2014-01-01

    In order to provide information for elucidating effect of flooding on the formation and function of AM in wetland plants, three AM fungi (Glomus intraradices, Glomus versiforme, Glomus etunicatum) were used to investigate the effects of flooding time length on their colonization in cattail (Typha orientalis) and rice (Oryza sativa L. ). The results showed that the mycorrhizal colonization rate (MCR) presented downtrend with increasing flooding time length. In cattail, MCR of the fungus F3 was higher than those of fungi F1 and F2, but no significant difference in MCR was found between fungi F1 and F2. In rice, the MCRs of fungi F2 and F3 were higher than that of E1. In both plants, the proportional frequency of hyphae was the highest while the proportional frequency of arbuscules and vesicles was very low in all treatments, indicating that hyphal colonization was the main route for AM formation. The proportional frequency of hyphae in cattail increased with the flooding time length, but no significant trend was observed in rice plant. The proportional frequency of arhuscules decreased with the increase of flooding time, and was the highest in the treatment without flooding (treatment IV). The number of spores produced by AM fungi increased with increasing flooding time, and reached the highest in the treatment of long time flooding (treatment I). In the same treatment, the fungus F3 produced more spores than fungi F1 and F2. Changes in wet weight of the two plants showed that AM could increase cattail growth under flooding, hut little effect on rice growth was found. It is concluded that flooding time length significantly affected the mycorrhizal colonization rate and the proportional frequency of colonization. AM could enhance the growth of wetland plant, but this depends on the mycorrhizal dependence of host plant on AM fungi. Therefore, flooding time length should be considered in the inoculation of wetland plants with AM fungi.

  8. The effect of word length in short-term memory: Is rehearsal necessary?

    Science.gov (United States)

    Campoy, Guillermo

    2008-05-01

    Three experiments investigated the effect of word length on a serial recognition task when rehearsal was prevented by a high presentation rate with no delay between study and test lists. Results showed that lists of short four-phoneme words were better recognized than lists of long six-phoneme words. Moreover, this effect was equivalent to that observed in conditions in which there was a delay between lists, thereby making rehearsal possible in the interval. These findings imply that rehearsal does not play a central role in the origin of the word length effect. An alternative explanation based on differences in the degree of retroactive interference generated by long and short words is proposed.

  9. Simulation of photon attenuation coefficients for high effective shielding material Lead-Boron Polyethyene

    Science.gov (United States)

    Zhang, L.; Jia, M. C.; Gong, J. J.; Xia, W. M.

    2017-12-01

    The mass attenuation coefficient of various Lead-Boron Polyethylene samples which can be used as the photon shielding materials in marine reactor, have been simulated using the MCNP-5 code, and compared with the theoretical values at the photon energy range 0.001MeV—20MeV. A good agreement has been observed. The variations of mass attenuation coefficient, linear attenuation coefficient and mean free path with photon energy between 0.001MeV to 100MeV have been plotted. The result shows that all the coefficients strongly depends on the photon energy, material atomic composition and density. The dose transmission factors for source Cesium-137 and Cobalt-60 have been worked out and their variations with the thickness of various sample materials have also been plotted. The variations show that with the increase of materials thickness the dose transmission factors decrease continuously. The results of this paper can provide some reference for the use of the high effective shielding material Lead-Boron Polyethyene.

  10. Coconut oil attenuates the effects of amyloid-β on cortical neurons in vitro.

    Science.gov (United States)

    Nafar, Firoozeh; Mearow, Karen M

    2014-01-01

    Dietary supplementation has been studied as an approach to ameliorating deficits associated with aging and neurodegeneration. We undertook this pilot study to investigate the effects of coconut oil supplementation directly on cortical neurons treated with amyloid-β (Aβ) peptide in vitro. Our results indicate that neuron survival in cultures co-treated with coconut oil and Aβ is rescued compared to cultures exposed only to Aβ. Coconut oil co-treatment also attenuates Aβ-induced mitochondrial alterations. The results of this pilot study provide a basis for further investigation of the effects of coconut oil, or its constituents, on neuronal survival focusing on mechanisms that may be involved.

  11. Effectiveness of Group-Delivered Cognitive Therapy and Treatment Length in Women Veterans with PTSD

    Directory of Open Access Journals (Sweden)

    Diane T. Castillo

    2014-01-01

    Full Text Available The effectiveness and length of group-delivered cognitive treatment for Posttraumatic Stress Disorder (PTSD was examined in a sample of women veterans. The sample included 271 primarily non-Hispanic white (61% and Hispanic (25% women veterans treated in 8-, 10-, or 12-group length sessions with manualized cognitive therapy for PTSD. Outcome was measured with the PTSD Symptom Checklist (PCL in an intention-to-treat analysis (N = 271, in completer subjects (n = 172, and with group as the unit of analysis (n = 47 groups. Significant decreases in PTSD were found in the full sample (effect size [ES] range = 0.27 to 0.38, completers (ES range = 0.37 to 0.54, and group as the unit of analysis (ES range = 0.71 to 0.92, suggesting effectiveness of cognitive group treatment for PTSD. PCL scores significantly improved in the 8, 10, and 12 group lengths, with no differences between each. Clinical improvement showed a third decreasing 10 or more PCL points and 22% no longer meeting PTSD diagnostic criteria, with the best results in the 10-session group. The results suggest group-delivered cognitive therapy is an effective, efficient, time-limited treatment for PTSD.

  12. Mechanical properties of rubberwood oriented strand lumber (OSL: The effect of strand length

    Directory of Open Access Journals (Sweden)

    Buhnnum Kyokong

    2005-09-01

    Full Text Available Effect of strand length on mechanical properties (tension, compression and bending of oriented strand lumber (OSL made of rubberwood (Hevea brasiliensis Muell. Arg. was reported. Three strand lengths of 50 mm, 100 mm, and 150 mm with 1 mm thickness and 15 mm width were used. The strands were mixed with 5% pMDI glue (weight basis in a tumble mixer. The OSL specimens were formed by hot pressing process of unidirectionally aligned strands. Average specific gravity and moisture content were 0.76 and 8.34%, respectively. Tension and compression tests were carried out for directions both parallel and perpendicular to grain while bending test was performed only in parallel direction. Ultimate stresses and moduli of elasticity were examined from the stress-strain curves. It was found that for the parallel-to-grain direction, the longer strand OSL gave higher strength. The role of the strand length did not appear for the direction normal to the grain. The relationship between the mechanical properties of OSL and strand length was well described by the modified Hankinson formula.

  13. Effects of Circular DNA Length on Transfection Efficiency by Electroporation into HeLa Cells.

    Science.gov (United States)

    Hornstein, Benjamin D; Roman, Dany; Arévalo-Soliz, Lirio M; Engevik, Melinda A; Zechiedrich, Lynn

    2016-01-01

    The ability to produce extremely small and circular supercoiled vectors has opened new territory for improving non-viral gene therapy vectors. In this work, we compared transfection of supercoiled DNA vectors ranging from 383 to 4,548 bp, each encoding shRNA against GFP under control of the H1 promoter. We assessed knockdown of GFP by electroporation into HeLa cells. All of our vectors entered cells in comparable numbers when electroporated with equal moles of DNA. Despite similar cell entry, we found length-dependent differences in how efficiently the vectors knocked down GFP. As vector length increased up to 1,869 bp, GFP knockdown efficiency per mole of transfected DNA increased. From 1,869 to 4,257 bp, GFP knockdown efficiency per mole was steady, then decreased with increasing vector length. In comparing GFP knockdown with equal masses of vectors, we found that the shorter vectors transfect more efficiently per nanogram of DNA transfected. Our results rule out cell entry and DNA mass as determining factors for gene knockdown efficiency via electroporation. The length-dependent effects we have uncovered are likely explained by differences in nuclear translocation or transcription. These data add an important step towards clinical applications of non-viral vector delivery.

  14. Investigating the effects of exam length on performance and cognitive fatigue.

    Directory of Open Access Journals (Sweden)

    Jamie L Jensen

    Full Text Available This study examined the effects of exam length on student performance and cognitive fatigue in an undergraduate biology classroom. Exams tested higher order thinking skills. To test our hypothesis, we administered standard- and extended-length high-level exams to two populations of non-majors biology students. We gathered exam performance data between conditions as well as performance on the first and second half of exams within conditions. We showed that lengthier exams led to better performance on assessment items shared between conditions, possibly lending support to the spreading activation theory. It also led to greater performance on the final exam, lending support to the testing effect in creative problem solving. Lengthier exams did not result in lower performance due to fatiguing conditions, although students perceived subjective fatigue. Implications of these findings are discussed with respect to assessment practices.

  15. The Effects of Two Different Deficit Irrigation Managements on the Root Length of Maize

    Directory of Open Access Journals (Sweden)

    M. Gheysari

    2015-06-01

    Full Text Available The response of root to water stress is one of the most important parameters for researchers. Study of growth and distribution of root under different irrigation managements helpsresearchersto a better understanding of soil water content, and the availability of water and nutrition in water stress condition. To investigate the effects of four levels of irrigation under two different deficit irrigation managements on the root length of maize, a study was conducted in 2009. Irrigation managements included fixed irrigation interval-variable irrigation depth (M1 and variable irrigation interval-fixed irrigation depth (M2. Maize plants were planted in 120 large 110-liter containers in a strip-plot design in a randomized complete block with three replications. Root data sampling was done after root washing in five growth stages. The results showed that the effect of irrigation levels on root length was significant (P

  16. Effects of gamma irradiation on the shoot length of Cicer seeds

    International Nuclear Information System (INIS)

    Toker, Cengiz; Uzun, Bulent; Canci, Huseyin; Oncu Ceylan, F.

    2005-01-01

    The effects of radiation on the shoot and root lengths of germinated seedling of irradiated seeds of Cicer species, i.e. three kabuli types and four desi types of cultivated chickpea (Cicer arietinum Ladiz.) and 2 annual wild types (C. reticulatum Ladiz. and C. bijugum K.H. Rech.) were investigated. The seeds were irradiated with a 60 Co gamma source using 0, 200, 300 and 400 Gy doses at 1.66 kGy h -1 . At 200 Gy minor effects could be observed, but at 400 Gy an obvious depression of shoot length was observed. The kabuli types were more affected than the desi ones. The critical dose that prevented the shoot and root elongation varied among species and also ranged from genotypes to genotype within species

  17. Hormetic Effect of Berberine Attenuates the Anticancer Activity of Chemotherapeutic Agents.

    Directory of Open Access Journals (Sweden)

    Jiaolin Bao

    Full Text Available Hormesis is a phenomenon of biphasic dose response characterized by exhibiting stimulatory or beneficial effects at low doses and inhibitory or toxic effects at high doses. Increasing numbers of chemicals of various types have been shown to induce apparent hormetic effect on cancer cells. However, the underlying significance and mechanisms remain to be elucidated. Berberine, one of the major active components of Rhizoma coptidis, has been manifested with notable anticancer activities. This study aims to investigate the hormetic effect of berberine and its influence on the anticancer activities of chemotherapeutic agents. Our results demonstrated that berberine at low dose range (1.25 ~ 5 μM promoted cell proliferation to 112% ~170% of the untreated control in various cancer cells, while berberine at high dose rage (10 ~ 80 μM inhibited cell proliferation. Further, we observed that co-treatment with low dose berberine could significantly attenuate the anticancer activity of chemotherapeutic agents, including fluorouracil (5-FU, camptothecin (CPT, and paclitaxel (TAX. The hormetic effect and thereby the attenuated anticancer activity of chemotherapeutic drugs by berberine may attributable to the activated protective stress response in cancer cells triggered by berberine, as evidenced by up-regulated MAPK/ERK1/2 and PI3K/AKT signaling pathways. These results provided important information to understand the potential side effects of hormesis, and suggested cautious application of natural compounds and relevant herbs in adjuvant treatment of cancer.

  18. COMPARATIVE ANALYSIS OF THE METHODS FOR EVALUATING THE EFFECTIVE LENGTH OF COLUMNS

    OpenAIRE

    Paschal Chimeremeze Chiadighikaobi

    2017-01-01

    This article looks into the effective length of columns using different methods. The codes in use in this article are those from the AISC (American Institute of Steel Construction). And that of AS 4100 (Australian Steel code). A conclusion was drawn after investigating a frame using three different methods. Solved Exercise 6 (LeMessurier Method) was investigated using same frame but different dimension. Further analysis and investigation will be done using Java codes to analyze the frames.

  19. COMPARATIVE ANALYSIS OF THE METHODS FOR EVALUATING THE EFFECTIVE LENGTH OF COLUMNS

    Directory of Open Access Journals (Sweden)

    Paschal Chimeremeze Chiadighikaobi

    2017-08-01

    Full Text Available This article looks into the effective length of columns using different methods. The codes in use in this article are those from the AISC (American Institute of Steel Construction. And that of AS 4100 (Australian Steel code. A conclusion was drawn after investigating a frame using three different methods. Solved Exercise 6 (LeMessurier Method was investigated using same frame but different dimension. Further analysis and investigation will be done using Java codes to analyze the frames.

  20. Importance of the Debye screening length on nanowire field effect transistor sensors.

    Science.gov (United States)

    Stern, Eric; Wagner, Robin; Sigworth, Fred J; Breaker, Ronald; Fahmy, Tarek M; Reed, Mark A

    2007-11-01

    Nanowire field effect transistors (NW-FETs) can serve as ultrasensitive detectors for label-free reagents. The NW-FET sensing mechanism assumes a controlled modification in the local channel electric field created by the binding of charged molecules to the nanowire surface. Careful control of the solution Debye length is critical for unambiguous selective detection of macromolecules. Here we show the appropriate conditions under which the selective binding of macromolecules is accurately sensed with NW-FET sensors.

  1. Detection beyond Debye's length with an electrolyte-gated organic field-effect transistor.

    Science.gov (United States)

    Palazzo, Gerardo; De Tullio, Donato; Magliulo, Maria; Mallardi, Antonia; Intranuovo, Francesca; Mulla, Mohammad Yusuf; Favia, Pietro; Vikholm-Lundin, Inger; Torsi, Luisa

    2015-02-04

    Electrolyte-gated organic field-effect transistors are successfully used as biosensors to detect binding events occurring at distances from the transistor electronic channel that are much larger than the Debye length in highly concentrated solutions. The sensing mechanism is mainly capacitive and is due to the formation of Donnan's equilibria within the protein layer, leading to an extra capacitance (CDON) in series to the gating system. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Payment for multiple forest benefits alters the effect of tree disease on optimal forest rotation length.

    Science.gov (United States)

    Macpherson, Morag F; Kleczkowski, Adam; Healey, John R; Hanley, Nick

    2017-04-01

    Forests deliver multiple benefits both to their owners and to wider society. However, a wave of forest pests and pathogens is threatening this worldwide. In this paper we examine the effect of disease on the optimal rotation length of a single-aged, single rotation forest when a payment for non-timber benefits, which is offered to private forest owners to partly internalise the social values of forest management, is included. Using a generalisable bioeconomic framework we show how this payment counteracts the negative economic effect of disease by increasing the optimal rotation length, and under some restrictive conditions, even makes it optimal to never harvest the forest. The analysis shows a range of complex interactions between factors including the rate of spread of infection and the impact of disease on the value of harvested timber and non-timber benefits. A key result is that the effect of disease on the optimal rotation length is dependent on whether the disease affects the timber benefit only compared to when it affects both timber and non-timber benefits. Our framework can be extended to incorporate multiple ecosystem services delivered by forests and details of how disease can affect their production, thus facilitating a wide range of applications.

  3. The effect of distal ulnar implant stem material and length on bone strains.

    Science.gov (United States)

    Austman, Rebecca L; Beaton, Brendon J B; Quenneville, Cheryl E; King, Graham J W; Gordon, Karen D; Dunning, Cynthia E

    2007-01-01

    Implant design parameters can greatly affect load transfer from the implant stem to the bone. We have investigated the effect of length or material of distal ulnar implant stems on the surrounding bone strains. Eight cadaveric ulnas were instrumented with 12 strain gauges and secured in a customized jig. Strain data were collected while loads (5-30 N) were applied to the medial surface of the native ulnar head. The native ulnar head was removed, and a stainless steel implant with an 8-cm-long finely threaded stem was cemented into the canal. After the cement had cured, the 8-cm stem was removed, leaving a threaded cement mantle in the canal that could accept shorter threaded stems of interest. The loading protocol was then repeated for stainless steel stems that were 7, 5, and 3 cm in length, as well as for a 5-cm-long titanium alloy (TiAl(6)V(4)) stem. Other stainless steel stem lengths between 3 and 7 cm were tested at intervals of 0.5 cm, with only a 20 N load applied. No stem length tested matched the native strains at all gauge locations. No significant differences were found between any stem length and the native bone at the 5th and 6th strain gauge positions. Strains were consistently closer to the native bone strains with the titanium stem than the stainless steel stem for each gauge pair that was positioned on the bone overlying the stem. The 3-cm stem results were closer to the native strains than the 7-cm stem for all loads at gauges locations that were on top of the stem. The results from this study suggest that the optimal stem characteristics for distal ulnar implants from a load transfer point of view are possessed by shorter (approximately 3 to 4 cm) titanium stems.

  4. Effect of Ceramide Tail Length on the Structure of Model Stratum Corneum Lipid Bilayers.

    Science.gov (United States)

    Moore, Timothy C; Hartkamp, Remco; Iacovella, Christopher R; Bunge, Annette L; McCabe, Clare

    2018-01-09

    Lipid bilayers composed of non-hydroxy sphingosine ceramide (CER NS), cholesterol (CHOL), and free fatty acids (FFAs), which are components of the human skin barrier, are studied via molecular dynamics simulations. Since mixtures of these lipids exist in dense gel phases with little molecular mobility at physiological conditions, care must be taken to ensure that the simulations become decorrelated from the initial conditions. Thus, we propose and validate an equilibration protocol based on simulated tempering, in which the simulation takes a random walk through temperature space, allowing the system to break out of metastable configurations and hence become decorrelated from its initial configuration. After validating the equilibration protocol, which we refer to as random-walk molecular dynamics, the effects of the lipid composition and ceramide tail length on bilayer properties are studied. Systems containing pure CER NS, CER NS + CHOL, and CER NS + CHOL + FFA, with the CER NS fatty acid tail length varied within each CER NS-CHOL-FFA composition, are simulated. The bilayer thickness is found to depend on the structure of the center of the bilayer, which arises as a result of the tail-length asymmetry between the lipids studied. The hydrogen bonding between the lipid headgroups and with water is found to change with the overall lipid composition, but is mostly independent of the CER fatty acid tail length. Subtle differences in the lateral packing of the lipid tails are also found as a function of CER tail length. Overall, these results provide insight into the experimentally observed trend of altered barrier properties in skin systems where there are more CERs with shorter tails present. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  5. Pertussis toxin treatment attenuates some effects of insulin in BC3H-1 murine myocytes

    International Nuclear Information System (INIS)

    Luttrell, L.M.; Hewlett, E.L.; Romero, G.; Rogol, A.D.

    1988-01-01

    The effects of pertussis toxin (PT) treatment on insulin-stimulated myristoyl-diacylglycerol (DAG) generation, hexose transport, and thymidine incorporation were studied in differentiated BC3H-1 mycocytes. Insulin treatment caused a biphasic increase in myristoyl-DAG production which was abolished in myocytes treated with PT. There was no effect of PT treatment on basal (nonstimulated) myristoyl-DAG production. Insulin-stimulated hydrolysis of a membrane phosphatidylinositol glycan was blocked by PT treatment. ADP-ribosylation of BC3H-1 plasma membranes with [ 32 P]NAD revealed a 40-kDa protein as the major PT substrate in vivo and in vitro. The time course and dose dependence of the effects of PT on diacylglycerol generation correlated with the in vivo ADP-ribosylation of the 40-kDa substrate. Pertussis toxin treatment resulted in a 71% attenuation of insulin-stimulated hexose uptake without effect on either basal or phorbol ester-stimulated uptake. The stimulatory effects of insulin and fetal calf serum on [ 3 H]thymidine incorporation into quiescent myocytes were attenuated by 61 and 59%, respectively, when PT was added coincidently with the growth factors. Nonstimulated and EGF-stimulated [ 3 H]thymidine incorporation was unaffected by PT treatment. These data suggest that a PT-sensitive G protein is involved in the cellular signaling mechanisms of insulin

  6. Inhibitory effect of live-attenuated Listeria monocytogenes-based vaccines expressing MIA gene on malignant melanoma.

    Science.gov (United States)

    Qian, Yue; Zhang, Na; Jiang, Ping; Chen, Siyuan; Chu, Shujuan; Hamze, Firas; Wu, Yan; Luo, Qin; Feng, Aiping

    2012-08-01

    Listeria monocytogenes (LM), a Gram-positive facultative intracellular bacterium, can be used as an effective exogenous antigen expression vector in tumor-target therapy. But for successful clinical application, it is necessary to construct attenuated LM stain that is safe yet retains the potency of LM based on the full virulent pathogen. In this study, attenuated LM and recombinants of LM expressing melanoma inhibitory activity (MIA) were constructed successfully. The median lethal dose (LD(50)) and invasion efficiency of attenuated LM strains were detected. The recombinants were utilized for immunotherapy of animal model of B16F10 melanoma. The level of MIA mRNA expression in tumor tissue was detected by using real-time polymerase chain reaction (PCR) with specific sequence, meanwhile the anti-tumor immune response was assayed by flow cytometric analysis and enzyme-linked immunosorbent spot (ELISPOT) assay. The results showed the toxicity and invasiveness of attenuated LM were decreased as compared with LM, and attenuated LM expressing MIA, especially the double-genes attenuated LM recombinant, could significantly induce anti-tumor immune response and inhibit tumor growth. This study implicates attenuated LM may be a safer and more effective vector for immunotherapy of melanoma.

  7. Fundamental length

    International Nuclear Information System (INIS)

    Pradhan, T.

    1975-01-01

    The concept of fundamental length was first put forward by Heisenberg from purely dimensional reasons. From a study of the observed masses of the elementary particles known at that time, it is sumrised that this length should be of the order of magnitude 1 approximately 10 -13 cm. It was Heisenberg's belief that introduction of such a fundamental length would eliminate the divergence difficulties from relativistic quantum field theory by cutting off the high energy regions of the 'proper fields'. Since the divergence difficulties arise primarily due to infinite number of degrees of freedom, one simple remedy would be the introduction of a principle that limits these degrees of freedom by removing the effectiveness of the waves with a frequency exceeding a certain limit without destroying the relativistic invariance of the theory. The principle can be stated as follows: It is in principle impossible to invent an experiment of any kind that will permit a distintion between the positions of two particles at rest, the distance between which is below a certain limit. A more elegant way of introducing fundamental length into quantum theory is through commutation relations between two position operators. In quantum field theory such as quantum electrodynamics, it can be introduced through the commutation relation between two interpolating photon fields (vector potentials). (K.B.)

  8. Anxiolytic effects of environmental enrichment attenuate sex-related anxiogenic effects of scopolamine in rats.

    Science.gov (United States)

    Hughes, Robert N; Otto, Maria T

    2013-01-10

    In groups of four same-sexed animals, PVG/c hooded rats were housed for 4.5 months in standard or enriched cages containing several objects that could be explored and manipulated. On separate occasions, each rat then experienced two consecutive daily trials in an open field, a light-dark box or a Y maze with arm inserts that enabled an acquisition trial comprising one black and one white arm to be changed for a retention trial consisting of two black arms. Before their trials in the open field and light-dark box, and following each acquisition trial in the Y maze, the rats received an intraperitoneal injection of 2 mg/kg scopolamine or isotonic saline. In the open field, enrichment led to higher levels of ambulation, walking, rearing and occupancy of the center of the apparatus and shorter emergence latencies from the dark into the light compartment of the light-dark box accompanied by more entries of this compartment. Enrichment also increased entries of and time spent in the changed (or novel) Y-maze arm only for male rats treated with scopolamine. The drug decreased rearing and increased grooming in the open field as well as increasing emergence latencies and decreasing entries of and the time spent on the light compartment of the light-dark box. The main results were interpreted as enrichment having attenuated anxiogenic effects of the behavioral testing and the action of scopolamine for male (but not female) rats in their choices of the novel arm in the Y maze. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Acoustic Velocity and Attenuation in Magnetorhelogical fluids based on an effective density fluid model

    Directory of Open Access Journals (Sweden)

    Shen Min

    2016-01-01

    Full Text Available Magnetrohelogical fluids (MRFs represent a class of smart materials whose rheological properties change in response to the magnetic field, which resulting in the drastic change of the acoustic impedance. This paper presents an acoustic propagation model that approximates a fluid-saturated porous medium as a fluid with a bulk modulus and effective density (EDFM to study the acoustic propagation in the MRF materials under magnetic field. The effective density fluid model derived from the Biot’s theory. Some minor changes to the theory had to be applied, modeling both fluid-like and solid-like state of the MRF material. The attenuation and velocity variation of the MRF are numerical calculated. The calculated results show that for the MRF material the attenuation and velocity predicted with this effective density fluid model are close agreement with the previous predictions by Biot’s theory. We demonstrate that for the MRF material acoustic prediction the effective density fluid model is an accurate alternative to full Biot’s theory and is much simpler to implement.

  10. The prediction of stellar effective temperatures from the mixing-length theory of convection

    International Nuclear Information System (INIS)

    Pedersen, B.B.; Vandenberg, D.A.; Irwin, A.W.

    1990-01-01

    A generalized version of the mixing-length theory (MLT) of convection, along with simplifications in the limits of high and low convective efficiency, is described. This forms the basis for a study of the effects of proposed modifications to the original (Boehm-Vitense, 1958) form of the MLT on the predicted effective temperatures of cool stars. These modifications include the parameters y and m. It is found that none of the suggested refinements to the MLT affect the location and shape of an evolutionary track on the H-R diagram in ways that cannot be mimicked to high accuracy by a suitable choice of mixing length parameters alone. Thus, if mixing length parameters is calibrated by comparing stellar models with observed main-sequence stars with well-determined properties, then the subsequent evolutionary tracks and isochrones are uniquely defined, regardless of what version of the MLT is used in the calculations. A careful examination of the Revised Yale Isochrones suggests that the Teff scale of these isochrones is inconsistent with the assumed MLT, thereby resolving much of the known discrepancies between these calculations and those of VandenBerg and Bell (1958). 44 refs

  11. Effect of Submergence and Apron Length on Spillway Scour: Case Study

    Directory of Open Access Journals (Sweden)

    Seungho Hong

    2015-10-01

    Full Text Available Large-scale water resources systems are often managed by an integrated set of hydraulic structures that are vulnerable to wider ranges of discharge and tailwater elevation than envisioned in their original design due to climate change and additional project objectives such as fostering healthy ecosystems. The present physical model study explored the performance of a spillway structure on the Kissimmee River, operated by the South Florida Water Management District, under extreme conditions of drought and flooding with accompanying low and high tailwater levels for both gate-controlled and uncontrolled spillway flow conditions. Maximum scour depths and their locations for two different riprap apron lengths downstream of the spillway stilling basin were measured along with the complex flow fields prior to scour. Effects of tailwater submergence, type of spillway flow and riprap apron length on scour results are interpreted in terms of the measured turbulent kinetic energy and velocity distributions near the bed.

  12. The Effects of Cannabis on Inpatient Agitation, Aggression, and Length of Stay.

    Science.gov (United States)

    Johnson, Joseph M; Wu, Chris Y; Winder, Gerald Scott; Casher, Michael I; Marshall, Vincent D; Bostwick, Jolene R

    2016-01-01

    This study examines the association between cannabis use and the hospital course of patients admitted to the psychiatric inpatient unit with a diagnosis of schizophrenia, schizoaffective disorder, or bipolar disorder. Many confounding variables potentially contribute to the clinical presentation of hospitalized patients in the psychiatric unit. Illicit drug use, in particular, has been associated with acute agitation, and questions can be raised as to what lasting effects drug use prior to admission may have throughout a patient's hospital stay. Subjects with a discharge diagnosis of bipolar disorder, schizophrenia, schizoaffective disorder, or psychosis not otherwise specified (N = 201) were retrospectively identified, and those with positive results of urine drug screen for cannabis on admission were compared to negative counterparts. Agitation and aggression were measured using an adaptation of the Excited Component of the Positive and Negative Syndrome Scale (PANSS-EC). These markers were also quantified by comparing charted episodes of restraint and seclusion and administration of as needed medications, such as benzodiazepines and antipsychotics. Positive urine drug screen results for cannabis was correlated with young (p = .001) males (p = .003) with bipolar disorder (p = .009) exhibiting active manic symptoms (p = .003) at the time of admission. Cannabis use was further associated with a shorter length of stay (p = .008), agitation triggering adapted PANSS-EC nursing assessments (p = .029), and oral medications as needed (p = .002) for agitation. Cannabis use, as defined by positive urine drug screen results, was more common in patients with bipolar disorder and was accompanied by a higher incidence of inpatient agitation. Although these patients also had short hospital lengths of stay, there was no clear relationship between level of agitation and length of stay across all patient groups. One possible explanation for patients with bipolar disorder

  13. Electromagnetic effects and scattering lengths extraction from experimental data on K → 3π decays

    International Nuclear Information System (INIS)

    Gevorkyan, S.R.; Madigozhin, D.T.; Tarasov, A.V.; Voskresenskaya, O.O.

    2008-01-01

    The final state interactions in K ± → π ± π 0 π 0 decays are considered using the methods of non-relativistic quantum mechanics. We show how to take into account the largest electromagnetic effect in the analysis of experimental data using the amplitudes calculated earlier. We propose the relevant expressions for amplitude corrections valid both above and below the two charged pion production threshold M π 0 π 0 2m π ± , including the average effect for the threshold bin. These formulae can be used in the procedure of pion scattering lengths measurement from M π 0 π 0 spectrum

  14. Potential increase in coastal wetland vulnerability to sea-level rise suggested by considering hydrodynamic attenuation effects

    Science.gov (United States)

    Rodríguez, José F.; Saco, Patricia M.; Sandi, Steven; Saintilan, Neil; Riccardi, Gerardo

    2017-07-01

    The future of coastal wetlands and their ecological value depend on their capacity to adapt to the interacting effects of human impacts and sea-level rise. Even though extensive wetland loss due to submergence is a possible scenario, its magnitude is highly uncertain due to limited understanding of hydrodynamic and bio-geomorphic interactions over time. In particular, the effect of man-made drainage modifications on hydrodynamic attenuation and consequent wetland evolution is poorly understood. Predictions are further complicated by the presence of a number of vegetation types that change over time and also contribute to flow attenuation. Here, we show that flow attenuation affects wetland vegetation by modifying its wetting-drying regime and inundation depth, increasing its vulnerability to sea-level rise. Our simulations for an Australian subtropical wetland predict much faster wetland loss than commonly used models that do not consider flow attenuation.

  15. Effects of optical attenuation, heat diffusion, and acoustic coherence in photoacoustic signals produced by nanoparticles

    Science.gov (United States)

    Alba-Rosales, J. E.; Ramos-Ortiz, G.; Escamilla-Herrera, L. F.; Reyes-Ramírez, B.; Polo-Parada, L.; Gutiérrez-Juárez, G.

    2018-04-01

    The behavior of the photoacoustic signal produced by nanoparticles as a function of their concentration was studied in detail. As the concentration of nanoparticles is increased in a sample, the peak-to-peak photoacoustic amplitude increases linearly up to a certain value, after which an asymptotic saturated behavior is observed. To elucidate the mechanisms responsible for these observations, we evaluate the effects of nanoparticles concentration, the optical attenuation, and the effects of heat propagation from nano-sources to their surroundings. We found that the saturation effect of the photoacoustic signal as a function of the concentration of nanoparticles is explained by a combination of two different mechanisms. As has been suggested previously, but not modeled correctly, the most important mechanism is attributed to optical attenuation. The second mechanism is due to an interference destructive process attributed to the superimposition of the photoacoustic amplitudes generated for each nanoparticle, and this explanation is reinforced through our experimental and simulations results; based on this, it is found that the linear behavior of the photoacoustic amplitude could be restricted to optical densities ≤0.5.

  16. Natural attenuation of petroleum hydrocarbons-a study of biodegradation effects in groundwater (Vitanovac, Serbia).

    Science.gov (United States)

    Marić, Nenad; Matić, Ivan; Papić, Petar; Beškoski, Vladimir P; Ilić, Mila; Gojgić-Cvijović, Gordana; Miletić, Srđan; Nikić, Zoran; Vrvić, Miroslav M

    2018-01-20

    The role of natural attenuation processes in groundwater contamination by petroleum hydrocarbons is of intense scientific and practical interest. This study provides insight into the biodegradation effects in groundwater at a site contaminated by kerosene (jet fuel) in 1993 (Vitanovac, Serbia). Total petroleum hydrocarbons (TPH), hydrochemical indicators (O 2 , NO 3 - , Mn, Fe, SO 4 2- , HCO 3 - ), δ 13 C of dissolved inorganic carbon (DIC), and other parameters were measured to demonstrate biodegradation effects in groundwater at the contaminated site. Due to different biodegradation mechanisms, the zone of the lowest concentrations of electron acceptors and the zone of the highest concentrations of metabolic products of biodegradation overlap. Based on the analysis of redox-sensitive compounds in groundwater samples, redox processes ranged from strictly anoxic (methanogenesis) to oxic (oxygen reduction) within a short distance. The dependence of groundwater redox conditions on the distance from the source of contamination was observed. δ 13 C values of DIC ranged from - 15.83 to - 2.75‰, and the most positive values correspond to the zone under anaerobic and methanogenic conditions. Overall, results obtained provide clear evidence on the effects of natural attenuation processes-the activity of biodegradation mechanisms in field conditions.

  17. PEGylation on mixed monolayer gold nanoparticles: Effect of grafting density, chain length, and surface curvature.

    Science.gov (United States)

    Lin, Jiaqi; Zhang, Heng; Morovati, Vahid; Dargazany, Roozbeh

    2017-10-15

    PEGylation on nanoparticles (NPs) is widely used to prevent aggregation and to mask NPs from the fast clearance system in the body. Understanding the molecular details of the PEG layer could facilitate rational design of PEGylated NPs that maximize their solubility and stealth ability without significantly compromising the targeting efficiency and cellular uptake. Here, we use molecular dynamics (MD) simulation to understand the structural and dynamic the PEG coating of mixed monolayer gold NPs. Specifically, we modeled gold NPs with PEG grafting densities ranging from 0-2.76chain/nm 2 , chain length with 0-10 PEG monomers, NP core diameter from 5nm to 500nm. It is found that the area accessed by individual PEG chains gradually transits from a "mushroom" to a "brush" conformation as NP surface curvature become flatter, whereas such a transition is not evident on small NPs when grafting density increases. It is shown that moderate grafting density (∼1.0chain/nm 2 ) and short chain length are sufficient enough to prevent NPs from aggregating in an aqueous medium. The effect of grafting density on solubility is also validated by dynamic light scattering measurements of PEGylated 5nm gold NPs. With respect to the shielding ability, simulations predict that increase either grafting density, chain length, or NP diameter will reduce the accessibility of the protected content to a certain size molecule. Interestingly, reducing NP surface curvature is estimated to be most effective in promoting shielding ability. For shielding against small molecules, increasing PEG grafting density is more effective than increasing chain length. A simple model that includes these three investigated parameters is developed based on the simulations to roughly estimate the shielding ability of the PEG layer with respect to molecules of different sizes. The findings can help expand our current understanding of the PEG layer and guide rational design of PEGylated gold NPs for a particular

  18. Effective screening length and quasiuniversality for the restricted primitive model of an electrolyte solution.

    Science.gov (United States)

    Janecek, Jirí; Netz, Roland R

    2009-02-21

    Monte Carlo simulations for the restricted primitive model of an electrolyte solution above the critical temperature are performed at a wide range of concentrations and temperatures. Thermodynamic properties such as internal energy, osmotic coefficient, activity coefficient, as well as spatial correlation functions are determined. These observables are used to investigate whether quasiuniversality in terms of an effective screening length exists, similar to the role played by the effective electron mass in solid-state physics. To that end, an effective screening length is extracted from the asymptotic behavior of the Fourier-transformed charge-correlation function and plugged into the Debye-Huckel limiting expressions for various thermodynamic properties. Comparison with numerical results is favorable, suggesting that correlation and other effects not captured on the Debye-Huckel limiting level can be successfully incorporated by a single effective parameter while keeping the functional form of Debye-Huckel expressions. We also compare different methods to determine mean ionic activity coefficient in molecular simulations and check the internal consistency of the numerical data.

  19. The effect of path length and display size on memory for spatial information.

    Science.gov (United States)

    Guérard, Katherine; Tremblay, Sébastien

    2012-01-01

    In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

  20. Effects of Attenuation of Gas Hydrate-bearing Sediments on Seismic Data: Example from Mallik, Northwest Territories, Canada

    Science.gov (United States)

    Bellefleur, G.; Riedel, M.; Brent, T.

    2007-05-01

    Wave attenuation is an important physical property of hydrate-bearing sediments that is rarely taken into account in site characterization with seismic data. We present a field example showing improved images of hydrate- bearing sediments on seismic data after compensation of attenuation effects. Compressional quality factors (Q) are estimated from zero-offset Vertical Seismic Profiling data acquired at Mallik, Northwest Territories, Canada. During the last 10 years, two internationally-partnered research drilling programs have intersected three major intervals of sub-permafrost gas hydrates at Mallik, and have successfully extracted core samples containing significant amount of gas hydrates. Individual gas hydrate intervals are up to 40m in thickness and are characterized by high in situ gas hydrate saturation, sometimes exceeding 80% of pore volume of unconsolidated clastic sediments having average porosities ranging from 25% to 40%. The Q-factors obtained from the VSP data demonstrate significant wave attenuation for permafrost and hydrate- bearing sediments. These results are in agreement with previous attenuation estimates from sonic logs and crosshole data at different frequency intervals. The Q-factors obtained from VSP data were used to compensate attenuation effects on surface 3D seismic data acquired over the Mallik gas hydrate research wells. Intervals of gas hydrate on surface seismic data are characterized by strong reflectivity and effects from attenuation are not perceptible from a simple visual inspection of the data. However, the application of an inverse Q-filter increases the resolution of the data and improves correlation with log data, particularly for the shallowest gas hydrate interval. Compensation of the attenuation effects of the permafrost likely explains most of the improvements for the shallow gas hydrate zone. Our results show that characterization of the Mallik gas hydrates with seismic data not corrected for attenuation would tend to

  1. Effect of reciprocating systems and working lengths on apical microcrack development: a micro-CT Study

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Bruna Paloma de; Câmara, Andréa Cruz; Duarte, Daniel Amancio; Antonino, Antonio Celso Dantas; Aguiar, Carlos Menezes, E-mail: bruna_paloma@msn.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil); Heck, Richard John [Department of Land Resource Science, University of Guelph (Canada)

    2017-11-15

    The objective of this study was to evaluate the effect of root canal preparation with single-file reciprocating systems at different working lengths on the development of apical microcracks using micro-computed tomographic (micro-CT) imaging. Forty extracted human mandibular incisors were randomly assigned to 4 groups (n=10) according to the systems and working length used to prepare the root canals: Group A - WaveOne Gold at apical foramen (AF), Group B - WaveOne Gold 1 mm short of the AF (AF-1 mm), Group C - Unicone (AF) and Group D - Unicone (AF-1 mm). Micro-CT scanning was performed before and after root canal preparation at an isotropic resolution of 14 μm. Then, three examiners assessed the cross-sectional images generated to detect microcracks in the apical portion of the roots. Apical microcracks were visualized in 3, 1, 1, and 3 specimens in groups A, B, C, and D, respectively. All these microcracks observed after root canal preparation already existed prior to instrumentation, and no new apical microcrack was detected. For all groups, the number of slices presenting microcracks after root canal preparation was the same as before canal preparation. Root canal preparation with WaveOne Gold and Unicone, regardless of the working length, was not associated with apical microcrack formation. (author)

  2. Effect of reciprocating systems and working lengths on apical microcrack development: a micro-CT Study

    International Nuclear Information System (INIS)

    Oliveira, Bruna Paloma de; Câmara, Andréa Cruz; Duarte, Daniel Amancio; Antonino, Antonio Celso Dantas; Aguiar, Carlos Menezes; Heck, Richard John

    2017-01-01

    The objective of this study was to evaluate the effect of root canal preparation with single-file reciprocating systems at different working lengths on the development of apical microcracks using micro-computed tomographic (micro-CT) imaging. Forty extracted human mandibular incisors were randomly assigned to 4 groups (n=10) according to the systems and working length used to prepare the root canals: Group A - WaveOne Gold at apical foramen (AF), Group B - WaveOne Gold 1 mm short of the AF (AF-1 mm), Group C - Unicone (AF) and Group D - Unicone (AF-1 mm). Micro-CT scanning was performed before and after root canal preparation at an isotropic resolution of 14 μm. Then, three examiners assessed the cross-sectional images generated to detect microcracks in the apical portion of the roots. Apical microcracks were visualized in 3, 1, 1, and 3 specimens in groups A, B, C, and D, respectively. All these microcracks observed after root canal preparation already existed prior to instrumentation, and no new apical microcrack was detected. For all groups, the number of slices presenting microcracks after root canal preparation was the same as before canal preparation. Root canal preparation with WaveOne Gold and Unicone, regardless of the working length, was not associated with apical microcrack formation. (author)

  3. Effect of calibration data series length on performance and optimal parameters of hydrological model

    Directory of Open Access Journals (Sweden)

    Chuan-zhe Li

    2010-12-01

    Full Text Available In order to assess the effects of calibration data series length on the performance and optimal parameter values of a hydrological model in ungauged or data-limited catchments (data are non-continuous and fragmental in some catchments, we used non-continuous calibration periods for more independent streamflow data for SIMHYD (simple hydrology model calibration. Nash-Sutcliffe efficiency and percentage water balance error were used as performance measures. The particle swarm optimization (PSO method was used to calibrate the rainfall-runoff models. Different lengths of data series ranging from one year to ten years, randomly sampled, were used to study the impact of calibration data series length. Fifty-five relatively unimpaired catchments located all over Australia with daily precipitation, potential evapotranspiration, and streamflow data were tested to obtain more general conclusions. The results show that longer calibration data series do not necessarily result in better model performance. In general, eight years of data are sufficient to obtain steady estimates of model performance and parameters for the SIMHYD model. It is also shown that most humid catchments require fewer calibration data to obtain a good performance and stable parameter values. The model performs better in humid and semi-humid catchments than in arid catchments. Our results may have useful and interesting implications for the efficiency of using limited observation data for hydrological model calibration in different climates.

  4. Conditions for similitude and the effect of finite Debye length in electroosmotic flows.

    Science.gov (United States)

    Oh, Jung Min; Kang, Kwan Hyoung

    2007-06-15

    Under certain conditions, the velocity field is similar to the electric field for electroosmotic flow (EOF) inside a channel. There was a disagreement between investigators on the necessity of the infinitesimal-Reynolds-number condition for the similarity when the Helmholtz-Smoluchowski relation is applied throughout the boundaries. What is puzzling is a recent numerical result that showed, contrary to the conventional belief, an evident Reynolds number dependence of the EOF. We show here that the notion that the infinitesimal-Reynolds-number condition is required originates from the misunderstanding that the EOF is the Stokes flow. We point out that the EOF becomes the potential flow when the Helmholtz-Smoluchowski relation is applied at the boundaries. We carry out a numerical simulation to investigate the effect of finiteness of the Debye length and the vorticity layer inherently existing at the channel wall. We show that the Reynolds number dependence of the previous numerical simulation resulted from the finiteness of the Debye length and subsequent convective transport of vorticity toward the bulk flow. We discuss in detail how the convection of vorticity occurs and what factors are involved in the transport process, after carrying out the simulation for different Reynolds numbers, Debye lengths, corner radii, and geometries.

  5. Effect of the alkyl chain length of the ionic liquid anion on polymer electrolytes properties

    International Nuclear Information System (INIS)

    Leones, Rita; Sentanin, Franciani; Nunes, Sílvia Cristina; Esperança, José M.S.S.; Gonçalves, Maria Cristina

    2015-01-01

    New polymer electrolytes (PEs) based on chitosan and three ionic liquid (IL) families ([C 2 mim][C n SO 3 ], [C 2 mim][C n SO 4 ] and [C 2 mim][diC n PO 4 ]) were synthesized by the solvent casting method. The effect of the length of the alkyl chain of the IL anion on the thermal, morphological and electrochemical properties of the PEs was studied. The solid polymer electrolytes SPE membranes were analyzed by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), polarized optical microscopy (POM), atomic force microscopy (AFM), complex impedance spectroscopy (ionic conductivity) and cyclic voltammetry (CV). The obtained results evidenced an influence of the alkyl chain length of the IL anion on the temperature of degradation, birefringence, surface roughness and ionic conductivity of the membranes. The DSC, XRD and CV results showed independency from the length of the IL-anion-alkyl chain. The PEs displayed an predominantly amorphous morphology, a minimum temperature of degradation of 135 °C, a room temperature (T = 25 °C) ionic conductivity of 7.78 × 10 −4 S cm −1 and a wide electrochemical window of ∼ 4.0 V.

  6. The effect of maternity leave length and time of return to work on breastfeeding.

    Science.gov (United States)

    Ogbuanu, Chinelo; Glover, Saundra; Probst, Janice; Liu, Jihong; Hussey, James

    2011-06-01

    We investigated the effect of maternity leave length and time of first return to work on breastfeeding. Data were from the Early Childhood Longitudinal Study-Birth Cohort. Restricting our sample to singletons whose biological mothers were the respondents at the 9-month interview and worked in the 12 months before delivery (N = 6150), we classified the length of total maternity leave (weeks) as 1 to 6, 7 to 12, ≥ 13, and did not take; paid maternity leave (weeks) as 0, 1 to 6, ≥ 7, and did not take; and time of return to work postpartum (weeks) as 1 to 6, 7 to 12, ≥ 13, and not yet returned. Analyses included χ(2) tests and multiple logistic regressions. In our study population, 69.4% initiated breastfeeding with positive variation by both total and paid maternity leave length, and time of return to work. In adjusted analyses, neither total nor paid maternity leave length had any impact on breastfeeding initiation or duration. Compared with those returning to work within 1 to 6 weeks, women who had not yet returned to work had a greater odds of initiating breastfeeding (odds ratio [OR]: 1.46 [1.08-1.97]; risk ratios [RR]: 1.13 [1.03-1.22]), continuing any breastfeeding beyond 6 months (OR: 1.41 [0.87-2.27]; RR: 1.25 [0.91-1.61]), and predominant breastfeeding beyond 3 months (OR: 2.01 [1.06-3.80]; RR: 1.70 [1.05-2.53]). Women who returned to work at or after 13 weeks postpartum had higher odds of predominantly breastfeeding beyond 3 months (OR: 2.54 [1.51-4.27]; RR: 1.99 [1.38-2.69]). If new mothers delay their time of return to work, then duration of breastfeeding among US mothers may lengthen.

  7. Effects of contract-relax vs static stretching on stretch-induced strength loss and length-tension relationship

    DEFF Research Database (Denmark)

    Balle, S S; Magnusson, S P; McHugh, M P

    2015-01-01

    The purpose of this study was to determine the acute effects of contract-relax stretching (CRS) vs static stretching (SS) on strength loss and the length-tension relationship. We hypothesized that there would be a greater muscle length-specific effect of CRS vs SS. Isometric hamstring strength wa...

  8. Effective radiation attenuation calibration for breast density: compression thickness influences and correction

    Directory of Open Access Journals (Sweden)

    Thomas Jerry A

    2010-11-01

    Full Text Available Abstract Background Calibrating mammograms to produce a standardized breast density measurement for breast cancer risk analysis requires an accurate spatial measure of the compressed breast thickness. Thickness inaccuracies due to the nominal system readout value and compression paddle orientation induce unacceptable errors in the calibration. Method A thickness correction was developed and evaluated using a fully specified two-component surrogate breast model. A previously developed calibration approach based on effective radiation attenuation coefficient measurements was used in the analysis. Water and oil were used to construct phantoms to replicate the deformable properties of the breast. Phantoms consisting of measured proportions of water and oil were used to estimate calibration errors without correction, evaluate the thickness correction, and investigate the reproducibility of the various calibration representations under compression thickness variations. Results The average thickness uncertainty due to compression paddle warp was characterized to within 0.5 mm. The relative calibration error was reduced to 7% from 48-68% with the correction. The normalized effective radiation attenuation coefficient (planar representation was reproducible under intra-sample compression thickness variations compared with calibrated volume measures. Conclusion Incorporating this thickness correction into the rigid breast tissue equivalent calibration method should improve the calibration accuracy of mammograms for risk assessments using the reproducible planar calibration measure.

  9. Partial Sleep Deprivation Attenuates the Positive Affective System: Effects Across Multiple Measurement Modalities.

    Science.gov (United States)

    Finan, Patrick H; Quartana, Phillip J; Remeniuk, Bethany; Garland, Eric L; Rhudy, Jamie L; Hand, Matthew; Irwin, Michael R; Smith, Michael T

    2017-01-01

    Ample behavioral and neurobiological evidence links sleep and affective functioning. Recent self-report evidence suggests that the affective problems associated with sleep loss may be stronger for positive versus negative affective state and that those effects may be mediated by changes in electroencepholographically measured slow wave sleep (SWS). In the present study, we extend those preliminary findings using multiple measures of affective functioning. In a within-subject randomized crossover experiment, we tested the effects of one night of sleep continuity disruption via forced awakenings (FA) compared to one night of uninterrupted sleep (US) on three measures of positive and negative affective functioning: self-reported affective state, affective pain modulation, and affect-biased attention. The study was set in an inpatient clinical research suite. Healthy, good sleeping adults (N = 45) were included. Results indicated that a single night of sleep continuity disruption attenuated positive affective state via FA-induced reductions in SWS. Additionally, sleep continuity disruption attenuated the inhibition of pain by positive affect as well as attention bias to positive affective stimuli. Negative affective state, negative affective pain facilitation, nor negative attention bias were altered by sleep continuity disruption. The present findings, observed across multiple measures of affective function, suggest that sleep continuity disruption has a stronger influence on the positive affective system relative to the negative affective affective system. © Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

  10. Effectiveness of Gamma Rays in Attenuating Rodent Malaria Parasites of Plasmodium berghei in Blood of Mice

    International Nuclear Information System (INIS)

    Syaifudin, M.; Darlina; Rahardjo, T.; Tetriana, D.; Nurhayati, S.; Surniyantoro, H.N.E.; Kisnanto, T.

    2013-01-01

    Malaria is a major public health problem in Indonesia. Therefore, an effective vaccine against this disease is actively being sought by using gamma rays to attenuate the parasites. However, the safety and efficacy of the resulting vaccine are dependent on the precise irradiation dose. The aim of this research was to determine the exact time when the parasites are attenuated by gamma ray exposure. Mice blood containing Plasmodium berghei of 5,0 X 10 7 parasites/ml was irradiated with gamma rays at doses of 0, 150, 175 and 200 Gy (doses rate of 380 Gy/h) and then was injected intraperitoneally to mice at 0, 1, 2, 3, and 4 h post irradiation. The parasitemia (parasite density) in mouse blood was observed starting with day 2 and repeated every 2-4 days up to 28 days. The survival of the mice was also observed during the experiment. The results showed that the pre-patent period advanced with exposing infected blood to 150 and 175 Gy irradiations, suggesting some degree of attenuation. The amount of radiation required to render the parasites non-viable is about 175 Gy for an inoculum of a number of parasites, but a delay of 4 h resulted in the death of parasites. There was no difference in the infectivity of irradiated parasite injected 1 h and 2 h post irradiation in terms of parasitemia and the survival of mouse. For a dose of 200 Gy which was injected 2 h post irradiation, no parasitemia was found in the blood and animals which died after times varying from 1 to 4 weeks. We concluded that irradiated parasites should be injected into the host within 1 h after irradiation. (author)

  11. Ionic Size Effects: Generalized Boltzmann Distributions, Counterion Stratification, and Modified Debye Length.

    Science.gov (United States)

    Liu, Bo; Liu, Pei; Xu, Zhenli; Zhou, Shenggao

    2013-10-01

    Near a charged surface, counterions of different valences and sizes cluster; and their concentration profiles stratify. At a distance from such a surface larger than the Debye length, the electric field is screened by counterions. Recent studies by a variational mean-field approach that includes ionic size effects and by Monte Carlo simulations both suggest that the counterion stratification is determined by the ionic valence-to-volume ratios. Central in the mean-field approach is a free-energy functional of ionic concentrations in which the ionic size effects are included through the entropic effect of solvent molecules. The corresponding equilibrium conditions define the generalized Boltzmann distributions relating the ionic concentrations to the electrostatic potential. This paper presents a detailed analysis and numerical calculations of such a free-energy functional to understand the dependence of the ionic charge density on the electrostatic potential through the generalized Boltzmann distributions, the role of ionic valence-to-volume ratios in the counterion stratification, and the modification of Debye length due to the effect of ionic sizes.

  12. Retrieval of Effective Correlation Length and Snow Water Equivalent from Radar and Passive Microwave Measurements

    Directory of Open Access Journals (Sweden)

    Juha Lemmetyinen

    2018-01-01

    Full Text Available Current methods for retrieving SWE (snow water equivalent from space rely on passive microwave sensors. Observations are limited by poor spatial resolution, ambiguities related to separation of snow microstructural properties from the total snow mass, and signal saturation when snow is deep (~>80 cm. The use of SAR (Synthetic Aperture Radar at suitable frequencies has been suggested as a potential observation method to overcome the coarse resolution of passive microwave sensors. Nevertheless, suitable sensors operating from space are, up to now, unavailable. Active microwave retrievals suffer, however, from the same difficulties as the passive case in separating impacts of scattering efficiency from those of snow mass. In this study, we explore the potential of applying active (radar and passive (radiometer microwave observations in tandem, by using a dataset of co-incident tower-based active and passive microwave observations and detailed in situ data from a test site in Northern Finland. The dataset spans four winter seasons with daily coverage. In order to quantify the temporal variability of snow microstructure, we derive an effective correlation length for the snowpack (treated as a single layer, which matches the simulated microwave response of a semi-empirical radiative transfer model to observations. This effective parameter is derived from radiometer and radar observations at different frequencies and frequency combinations (10.2, 13.3 and 16.7 GHz for radar; 10.65, 18.7 and 37 GHz for radiometer. Under dry snow conditions, correlations are found between the effective correlation length retrieved from active and passive measurements. Consequently, the derived effective correlation length from passive microwave observations is applied to parameterize the retrieval of SWE using radar, improving retrieval skill compared to a case with no prior knowledge of snow-scattering efficiency. The same concept can be applied to future radar

  13. Repeated Excessive Exercise Attenuates the Anti-Inflammatory Effects of Exercise in Older Men

    DEFF Research Database (Denmark)

    Sahl, Ronni E.; Andersen, Peter R.; Gronbaek, Katja

    2017-01-01

    Introduction/Purpose: A number of studies have investigated the effect of training with a moderate exercise dose (3–6 h/weekly) on the inflammatory profile in blood, and the data are inconsistent. Cross-sectional studies indicate a positive effect of physical activity level on inflammation levels...... inflammation, but the higher plasma IL-6 concentration concurrent with a trend toward higher insulin resistance and decreased VO2peak implies that the excessive amount of exercise probably attenuated the possible potential anti-inflammatory effects of exercise....... and risk of metabolic disease. However, it is not clear whether this may be dose dependent and if very prolonged repeated exercise therefore may be beneficial for low-grade inflammation. Based on this we studied how excessive repeated prolonged exercise influenced low-grade inflammation and adipose tissue...

  14. Effect of beam-attenuation modulation on fluctuation measurements by heavy-ion beam probe

    International Nuclear Information System (INIS)

    Ross, D.W.; Sloan, M.L.; Wootton, A.J.

    1991-03-01

    Beam-attenuation modulation arising from density fluctuations along the orbit of the heavy-ion beam probe can distort the local amplitude, coherence, and phase derived from one- and two-point correlation measurements. Path-integral expressions for these effects are derived and applications to TEXT data are discussed. The effects depend critically on the ratio of the average fluctuation amplitude, n e , along the beam path to the local n e at the sample volume. Because the fluctuation amplitude is small in the core and rises sharply toward the plasma edge, the contamination effect is negligible in a radial zone near the edge but rises sharply to the interior of a critical radius. With increasing average plasma density, bar n e , the interior contamination increases strongly and the critical radius moves outward. 16 refs., 12 figs

  15. Numerical Study of Operating Pressure Effect on Carbon Nanotube Growth Rate and Length Uniformity

    Directory of Open Access Journals (Sweden)

    B. Zahed

    2014-01-01

    Full Text Available Chemical Vapor Deposition (CVD is one of the most popular methods for producing Carbon Nanotubes (CNTs. The growth rate of CNTs based on CVD technique is investigated by using a numerical model based on finite volume method. Inlet gas mixture, including xylene as carbon source and mixture of argon and hydrogen as carrier gas enters into a horizontal CVD reactor at atmospheric pressure. In this article the operating pressure variations are studied as the effective parameter on CNT growth rate and length uniformity.

  16. Effect of increasing length on the electronic transport of an armchair graphene nano-ribbons

    Directory of Open Access Journals (Sweden)

    Sh Aghamiri Esfahani

    2015-12-01

    Full Text Available In this research, we have investigated the effect of increasing length on the electronic transport of an armchair graphene nano-ribbons with nitrogen atom impurity and without impurity. The semi-infinite, one-dimensional molecular systems are connected to two electrodes and the electron-electron interaction is ignored. The system is described by a simple tight binding model. All calculations are based on the Green's function and Landauer–Buttiker approach, and the electrodes are described in a wide band approximation.

  17. Alkyl chain length impacts the antioxidative effect of lipophilized ferulic acid in fish oil enriched milk

    DEFF Research Database (Denmark)

    Sørensen, Ann-Dorit Moltke; Lyneborg, Karina Sieron; Villeneuve, Pierre

    2015-01-01

    Lipophilization of phenolics by esterification with fatty alcohols may alter their localization in an emulsion and thereby their antioxidant efficacy. In this study, synthesized unbranched alkyl ferulates were evaluated as antioxidants in fish oil enriched milk. Lipid oxidation was determined...... by peroxide values and concentration of volatile oxidation products. A cut-off effect in the antioxidant efficacy in relation to the alkyl chain length was observed. The most efficient alkyl ferulate was methyl ferulate followed by ferulic acid and butyl ferulate, whereas octyl ferulate was prooxidative...

  18. Isotope effects in complex scattering lengths for He collisions with molecular hydrogen

    International Nuclear Information System (INIS)

    Nolte, J. L.; Yang, B. H.; Stancil, P. C.; Lee, Teck-Ghee; Balakrishnan, N.; Forrey, R. C.; Dalgarno, A.

    2010-01-01

    We examine the effect of theoretically varying the collision-system reduced mass in collisions of He with vibrationally excited molecular hydrogen and observe zero-energy resonances for select atomic 'hydrogen' masses less than 1 u or a 'helium' mass of 1.95 u. Complex scattering lengths, state-to-state vibrational quenching cross sections, and a low-energy elastic scattering resonance are all studied as a function of collision-system reduced mass. Experimental observations of these phenomena in the cold and ultracold regimes for collisions of 3 He and 4 He with H 2 , HD, HT, and DT should be feasible in the near future.

  19. The effect of length, duration, and intensity of psychological therapy on CORE global distress scores.

    Science.gov (United States)

    Evans, Lauren Jayne; Beck, Alison; Burdett, Mark

    2017-09-01

    This study explores whether improvements, as measured by the CORE-OM/10, as a result of psychological therapy were related to length of treatment in weeks, number of treatment sessions, or treatment intensity, as well as any effect of diagnostic group. Pre- and post-therapy CORE-OM/10 scores were extracted from the clinical records of all secondary care adult psychological therapy team patients who undertook psychological therapy between 2010 and 2013 in one mental health trust. Of the 4,877 patients identified, 925 had complete records. Length of therapy was divided by the number of sessions to create 'treatment intensity' (sessions per week). Nonparametric analyses were used, initial score was controlled for, and diagnostic group was explored. No relationship was found between change in score and the number of sessions, therapy length, or treatment intensity; however, change in score was positively correlated with first-session score. Patients with higher initial scores had longer therapies; however, treatment intensity was similar for patients with lower pre-therapy distress. There were differences in treatment length (weeks) between diagnostic groups. Demographic differences were found between patients with and without complete records, prompting caution in terms of generalizability. These findings are consistent with the responsive regulation model (Barkham et al., 1996) which proposes that patients vary in their response to treatment, resulting in no associations between session numbers or treatment intensity and therapeutic gain with aggregated scores. Patients with higher CORE scores at the outset of psychological therapy had longer not more intensive therapy. There was variation in treatment intensity between diagnostic clusters. Number of sessions, length of therapy (in weeks), and treatment intensity (the number of sessions per week between the first and last therapy sessions) were not related to therapeutic gains. These results fit with a responsive

  20. Effects of π-conjugation attenuation on the photophysics and exciton dynamics of poly(p-phenylenevinylene) polymers incorporating 2,2'-bipyridines

    International Nuclear Information System (INIS)

    Chen, L. X.; Jager, W. J.; Niemczyk, M. P.; Wasielewski, M. R.

    1999-01-01

    The effect of π-conjugation attenuation on the photophysics and exciton dynamics of two conjugated polymers 1 and 2 are examined in solution. The structures of polymers 1 and 2 have 2,2'-bipyridyl-5-vinylene units that alternate with one and three 2,5-bis(n-decyloxy)-1,4-phenylenevinylene monomer units, respectively. The photophysics and exciton dynamics of polymers 1 and 2 were compared to those of the homopolymer, poly(2,5-bis(2'-ethylhexyloxy)-1,4-phenylenevinylene) (BEH-PPV). A series of changes in the photophysics of polymers 1 and 2 were found as a result of π-conjugation attenuation. These changes include blue shifts in absorption and emission spectra, spectral diffusion in stimulated emission, enhancement in photoluminescence quantum yields and lifetimes, and increases in photoinduced absorption intensities and lifetimes. These changes are systematically more pronounced in polymer 1 than in polymer 2 and are correlated with π-conjugation attenuation in the polymers due to twisting of the 2,2'-bipyridine groups about the 2,2' single bond. An exciton dynamics model involving an ensemble of initial exciton states localized on oligomeric segments within the polymer with different conjugation lengths is proposed to describe the observed differences between polymers 1 and 2 and BEH-PPV. When the electronic coupling between these segments is strong, the polymer displays characteristics that are close to those of a one-dimensional semiconductor. However, when these couplings are weakened by groups, such as the 2,2'-bipyridine that attenuate π-conjugation, the polymer displays properties of an ensemble of oligomers

  1. Flavanone silibinin treatment attenuates nitrogen mustard-induced toxic effects in mouse skin

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Anil K.; Tewari-Singh, Neera; Inturi, Swetha; Kumar, Dileep [Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 (United States); Orlicky, David J. [Department of Pathology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 (United States); Agarwal, Chapla [Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 (United States); White, Carl W. [Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045USA (United States); Agarwal, Rajesh, E-mail: Rajesh.Agarwal@UCDenver.edu [Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045 (United States)

    2015-05-15

    Currently, there is no effective antidote to prevent skin injuries by sulfur mustard (SM) and nitrogen mustard (NM), which are vesicating agents with potential relevance to chemical warfare, terrorist attacks, or industrial/laboratory accidents. Our earlier report has demonstrated the therapeutic efficacy of silibinin, a natural flavanone, in reversing monofunctional alkylating SM analog 2-chloroethyl ethyl sulfide-induced toxic effects in mouse skin. To translate this effect to a bifunctional alkylating vesicant, herein, efficacy studies were carried out with NM. Topical application of silibinin (1 or 2 mg) 30 min after NM exposure on the dorsal skin of male SKH-1 hairless mice significantly decreased NM-induced toxic lesions at 24, 72 or 120 h post-exposure. Specifically, silibinin treatment resulted in dose-dependent reduction of NM-induced increase in epidermal thickness, dead and denuded epidermis, parakeratosis and microvesication. Higher silibinin dose also caused a 79% and 51%reversal in NM-induced increases in myeloperoxidase activity and COX-2 levels, respectively. Furthermore, silibinin completely prevented NM-induced H2A.X phosphorylation, indicating reversal of DNA damage which could be an oxidative DNA damage as evidenced by high levels of 8-oxodG in NM-exposed mouse skin that was significantly reversed by silibinin. Together, these findings suggest that attenuation of NM-induced skin injury by silibinin is due to its effects on the pathways associated with DNA damage, inflammation, vesication and oxidative stress. In conclusion, results presented here support the optimization of silibinin as an effective treatment of skin injury by vesicants. - Highlights: • Silibinin treatment attenuated nitrogen mustard (NM)-induced skin injury. • Silibinin affects pathways associated with DNA damage, inflammation and vesication. • The efficacy of silibinin could also be associated with oxidative stress. • These results support testing and optimization of

  2. Analysis of source spectra, attenuation, and site effects from central and eastern United States earthquakes

    International Nuclear Information System (INIS)

    Lindley, G.

    1998-02-01

    This report describes the results from three studies of source spectra, attenuation, and site effects of central and eastern United States earthquakes. In the first study source parameter estimates taken from 27 previous studies were combined to test the assumption that the earthquake stress drop is roughly a constant, independent of earthquake size. 200 estimates of stress drop and seismic moment from eastern North American earthquakes were combined. It was found that the estimated stress drop from the 27 studies increases approximately as the square-root of the seismic moment, from about 3 bars at 10 20 dyne-cm to 690 bars at 10 25 dyne-cm. These results do not support the assumption of a constant stress drop when estimating ground motion parameters from eastern North American earthquakes. In the second study, broadband seismograms recorded by the United States National Seismograph Network and cooperating stations have been analysed to determine Q Lg as a function of frequency in five regions: the northeastern US, southeastern US, central US, northern Basin and Range, and California and western Nevada. In the third study, using spectral analysis, estimates have been made for the anelastic attenuation of four regional phases, and estimates have been made for the source parameters of 27 earthquakes, including the M b 5.6, 14 April, 1995, West Texas earthquake

  3. The effects of air pollution on length of hospital stay for adult patients with asthma.

    Science.gov (United States)

    Luo, Li; Ren, Jing; Zhang, Fengyi; Zhang, Wei; Li, Chunyang; Qiu, Zhixin; Huang, Debin

    2018-04-23

    Length of hospital stay (LOS) of asthma can be a reflection of the disease burden faced by patients, and it is also sensitive to air pollution. This study aims at estimating and validating the effects of air pollution and readmission on the LOS for those who have asthma, considering their readmission history, minimum temperature, and threshold effects of air pollutants. In addition, sex, age, and season were also constructed for stratification to achieve more precise and specific results. The results show that no significant effects of PM 2.5 and NO 2 on LOS were observed in any of the patients, but there were significant effects of PM 2.5 and NO 2 on LOS when a stratifying subgroup analysis was performed. The effect of PM 10 on LOS was found to be lower than that of PM 2.5 and higher than that of NO 2 . SO 2 did not have a significant effect on LOS for patients with asthma in our study. Our study confirmed that the adverse effects of air pollutants (such as PM 10 ) on LOS for patients with asthma existed; in addition, these effects vary for different stratifications. We measured the effects of air pollutants on the LOS for patients with asthma, and this study offers policy makers quantitative evidence that can support relevant policies for health care resource management and ambient air pollutants control. Copyright © 2018 John Wiley & Sons, Ltd.

  4. The small length scale effect for a non-local cantilever beam: a paradox solved.

    Science.gov (United States)

    Challamel, N; Wang, C M

    2008-08-27

    Non-local continuum mechanics allows one to account for the small length scale effect that becomes significant when dealing with microstructures or nanostructures. This paper presents some simplified non-local elastic beam models, for the bending analyses of small scale rods. Integral-type or gradient non-local models abandon the classical assumption of locality, and admit that stress depends not only on the strain value at that point but also on the strain values of all points on the body. There is a paradox still unresolved at this stage: some bending solutions of integral-based non-local elastic beams have been found to be identical to the classical (local) solution, i.e. the small scale effect is not present at all. One example is the Euler-Bernoulli cantilever nanobeam model with a point load which has application in microelectromechanical systems and nanoelectromechanical systems as an actuator. In this paper, it will be shown that this paradox may be overcome with a gradient elastic model as well as an integral non-local elastic model that is based on combining the local and the non-local curvatures in the constitutive elastic relation. The latter model comprises the classical gradient model and Eringen's integral model, and its application produces small length scale terms in the non-local elastic cantilever beam solution.

  5. Effects of energy chirp on bunch length measurement in linear accelerator beams

    Science.gov (United States)

    Sabato, L.; Arpaia, P.; Giribono, A.; Liccardo, A.; Mostacci, A.; Palumbo, L.; Vaccarezza, C.; Variola, A.

    2017-08-01

    The effects of assumptions about bunch properties on the accuracy of the measurement method of the bunch length based on radio frequency deflectors (RFDs) in electron linear accelerators (LINACs) are investigated. In particular, when the electron bunch at the RFD has a non-negligible energy chirp (i.e. a correlation between the longitudinal positions and energies of the particle), the measurement is affected by a deterministic intrinsic error, which is directly related to the RFD phase offset. A case study on this effect in the electron LINAC of a gamma beam source at the Extreme Light Infrastructure-Nuclear Physics (ELI-NP) is reported. The relative error is estimated by using an electron generation and tracking (ELEGANT) code to define the reference measurements of the bunch length. The relative error is proved to increase linearly with the RFD phase offset. In particular, for an offset of {{7}\\circ} , corresponding to a vertical centroid offset at a screen of about 1 mm, the relative error is 4.5%.

  6. Word skipping: effects of word length, predictability, spelling and reading skill.

    Science.gov (United States)

    Slattery, Timothy J; Yates, Mark

    2017-08-31

    Readers eyes often skip over words as they read. Skipping rates are largely determined by word length; short words are skipped more than long words. However, the predictability of a word in context also impacts skipping rates. Rayner, Slattery, Drieghe and Liversedge (2011) reported an effect of predictability on word skipping for even long words (10-13 characters) that extend beyond the word identification span. Recent research suggests that better readers and spellers have an enhanced perceptual span (Veldre & Andrews, 2014). We explored whether reading and spelling skill interact with word length and predictability to impact word skipping rates in a large sample (N=92) of average and poor adult readers. Participants read the items from Rayner et al. (2011) while their eye movements were recorded. Spelling skill (zSpell) was assessed using the dictation and recognition tasks developed by Sally Andrews and colleagues. Reading skill (zRead) was assessed from reading speed (words per minute) and accuracy of three 120 word passages each with 10 comprehension questions. We fit linear mixed models to the target gaze duration data and generalized linear mixed models to the target word skipping data. Target word gaze durations were significantly predicted by zRead while, the skipping likelihoods were significantly predicted by zSpell. Additionally, for gaze durations, zRead significantly interacted with word predictability as better readers relied less on context to support word processing. These effects are discussed in relation to the lexical quality hypothesis and eye movement models of reading.

  7. Effect of the Alkyl Chain Length on the Adsorption Properties of Malonamide Chelating Resins

    International Nuclear Information System (INIS)

    Ismail, I.M.; Nogami, M.; Suzuki, K.

    2004-01-01

    In order to investigate the effect of the alkyl chain length of malonamide chelating resins on the rate of uptake of U(VI) ions and Ce(III) Ions, lV,N,N',N'-tetraethyl malonamide (TEMA), N,N,N',N'-tetra-n-propyl malonamide (TPrMA), lV,lV,N',N'-tetra-n-butyl malonamide (TBMA) and N,l V,N',N'-tetra-n-pentyl malonamide (Tamp) chelating resins were synthesized by chemically bonding these function groups to CMS-DVB co-polymer beads. N,lV,N',N'-tetraphenyl malonamide (TPhMA) chelating resin was also investigated and the results of these resins were compared with those of N,lY,N',N-tetra methylmalonamide (TMMA) previously reported. The batch technique was used to study the thermodynamic equilibrium, in terms of distribution coefficient, and the kinetics of the adsorption U(VI) and Ce(III) ions from 3 M HNO 3 , Acid, and 3 M NaNO 3 + 0.05 M HNO 3 , Salt, media. The introduction ratio of the function group into the polymer base and the uptake of U(VI) ions and C(III) ions were found to decrease with the increase in the alkyl chain length. The uptake was found to diminish in case of TPhMA resin due to the decrease of the function group ratio and the steric-hinder effect

  8. Modeling of liquid–gas meniscus for textured surfaces: effects of curvature and local slip length

    International Nuclear Information System (INIS)

    Gaddam, Anvesh; Garg, Mayank; Agrawal, Amit; Joshi, Suhas S

    2015-01-01

    Surface texturing at the micro/nanolevel allows air to be trapped in sufficiently small cavities, thereby reducing the flow resistance over the surface in the laminar regime. The nature of the liquid–gas meniscus plays an important role in defining the boundary condition and it depends on the flow conditions and geometrical properties of textures. In the present work, we employ the unsteady volume of fluid model to investigate the behavior of the liquid–gas meniscus for ridges arranged normal to the flow direction to substantiate the frictional resistance of flow in a microchannel. It is found that the assumption of ‘zero shear stress’ at the liquid–gas interface grossly overpredicts the effective slip length with meniscus curvature and local partial slip length playing the dominant role. Numerical simulations performed in the laminar regime (20  <  Re  <  120) over single layered ridges normal to the flow direction revealed the effect of texture geometry on the reduction in pressure drop. In single layered structures, lotus-like geometries exhibited a greater reduction in drag (more than 30%) when compared to all other texture geometries. It is recognized that the flow experiences expansion and contraction cycles as it flows over the transverse ridges increasing the frictional resistance. Our findings will help to modify the boundary condition at the liquid–gas meniscus for accurate modeling in the laminar regime and to optimize the texture geometry to improve drag reduction. (paper)

  9. The effects of cavity length on nest size, sex ratio and mortality of Centris (Heterocentris) analis (Hymenoptera, Apidae, Centridini)

    OpenAIRE

    Alonso , Juliana; Silva , Janaina; Garófalo , Carlos

    2012-01-01

    International audience; This study investigated the effects of different cavity lengths in trap-nests on the number of cells constructed per nest, sex ratio and mortality of offspring of Centris analis at three sites in Ribeirão Preto, São Paulo, Brazil. Cavity length did not affect the occupation rates of the trap-nests, with the exception of a preference for the shortest trap-nests found at one site. The number of cells per nest increased with trap-nest length. Cavity length affected neithe...

  10. Effect of attenuation by the cranium on quantitative SPECT measurements of cerebral blood flow and a correction method

    International Nuclear Information System (INIS)

    Iwase, Mikio; Kurono, Kenji; Iida, Akihiko.

    1998-01-01

    Attenuation correction for cerebral blood flow SPECT image reconstruction is usually performed by considering the head as a whole to be equivalent to water, and the effects of differences in attenuation between subjects produced by the cranium have not been taken into account. We determined the differences in attenuation between subjects and assessed a method of correcting quantitative cerebral blood flow values. Attenuations by head on the right and left sides were measured before intravenous injection of 123 I-IMP, and water-converted diameters of both sides (Ta) were calculated from the measurements obtained. After acquiring SPECT images, attenuation correction was conducted according to the method of Sorenson, and images were reconstructed. The diameters of the right and left sides in the same position as the Ta (Tt) were calculated from the contours determined by threshold values. Using Ts given by 2 Ts=Ta-Tt, the correction factor λ=exp(μ 1 Ts) was calculated and multiplied as the correction factor when rCBF was determined. The results revealed significant differences between Tt and Ta. Although no gender differences were observed in Tt, they were seen in both Ta and Ts. Thus, interindividual differences in attenuation by the cranium were found to have an influence that cannot be ignored. Inter-subject correlation is needed to obtain accurate quantitative values. (author)

  11. Effects of brood size manipulation and common origin on phenotype and telomere length in nestling collared flycatchers

    Directory of Open Access Journals (Sweden)

    Voillemot Marie

    2012-08-01

    Full Text Available Abstract Background Evidence is accumulating that telomere length is a good predictor of life expectancy, especially early in life, thus calling for determining the factors that affect telomere length at this stage. Here, we investigated the relative influence of early growth conditions and origin (genetics and early maternal effects on telomere length of collared flycatchers (Ficedula albicollis at fledging. We experimentally transferred hatchlings among brood triplets to create reduced, control (i.e. unchanged final nestling number and enlarged broods. Results Although our treatment significantly affected body mass at fledging, we found no evidence that increased sibling competition affected nestling tarsus length and telomere length. However, mixed models showed that brood triplets explained a significant part of the variance in body mass (18% and telomere length (19%, but not tarsus length (13%, emphasizing that unmanipulated early environmental factors influenced telomere length. These models also revealed low, but significant, heritability of telomere length (h2 = 0.09. For comparison, the heritability of nestling body mass and tarsus length was 0.36 and 0.39, respectively, which was in the range of previously published estimates for those two traits in this species. Conclusion Those findings in a wild bird population demonstrate that telomere length at the end of the growth period is weakly, but significantly, determined by genetic and/or maternal factors taking place before hatching. However, we found no evidence that the brood size manipulation experiment, and by extension the early growth conditions, influenced nestling telomere length. The weak heritability of telomere length suggests a close association with fitness in natural populations.

  12. The evaluation of the effect of attenuation correction on lesion detectability in whole-body FDG-PET

    International Nuclear Information System (INIS)

    Tomemori, Takashi; Uno, Kimiichi; Oka, Takashi; Suzuki, Takayuki; Tomiyoshi, Katsumi; Jin Wu

    2004-01-01

    The aim of this study was to compare the attenuation corrected and non-corrected FDG-PET images in patients with malignant lesions and to evaluate the effect of attenuation correction on lesion detectability. A total of 71 persons with 112 malignant lesions was examined. All subjects fasted for at least 4 hours before PET study and whole-body PET imaging was performed 45 min after the intravenous administration of FDG (mean dose: 273.8 MBq). Emission scans of 6 min and post-injection transmission scans of 6 min per bed position were used. The intensity of lesion uptake in FDG-PET image was visually classified into 3 grades; grade 2=the lesion was clearly identified in the maximum intensity projection (MIP) image of FDG-PET, grade 1=the lesion was not identified in MIP image but it can be identified in coronal image, grade 0=there was no contrast between lesion and background in both MIP and coronal image. Ninety-eight lesions (87.5%) were classified into same grade in both attenuation corrected and non-corrected image, but in 11 lesions (9.8%) attenuation corrected image was better lesion visualization than non-corrected image. All lesions divided between the primary lesions and the metastatic lesions. In 50 primary lesions, 43 lesions were depicted in both attenuation corrected and non-corrected image and other 7 lesions were not in both image. In 62 metastatic lesions, 50 lesions (80.7%) were classified into same grade in both attenuation corrected and non-corrected image, but in 10 lesions (16.1%) attenuation corrected image were better lesion visualization than non-corrected image. In the most cases, the lesions were depicted in both attenuation corrected and non-corrected image. In the primary lesions, the lesion detectability between attenuation corrected and non-corrected image was similar. But in some cases with the metastatic lesions, attenuation corrected image were better lesion visualization than non-corrected image. For asymptomatic patients, non

  13. Possible involvement of caveolin in attenuation of cardioprotective effect of ischemic preconditioning in diabetic rat heart

    Directory of Open Access Journals (Sweden)

    Singh Manjeet

    2011-07-01

    Full Text Available Abstract Background Nitric oxide (NO has been noted to produce ischemic preconditioning (IPC-mediated cardioprotection. Caveolin is a negative regulator of NO, which inhibits endothelial nitric oxide synthase (eNOS by making caveolin-eNOS complex. The expression of caveolin is increased during diabetes mellitus (DM. The present study was designed to investigate the involvement of caveolin in attenuation of the cardioprotective effect of IPC during DM in rat. Methods Experimental DM was induced by single dose of streptozotocin (50 mg/Kg, i.p, and animals were used for experiments four weeks later. Isolated heart was mounted on Langendorff's apparatus, and was subjected to 30 min of global ischemia and 120 min of reperfusion. IPC was given by four cycles of 5 min of ischemia and 5 min of reperfusion with Kreb's-Henseleit solution (K-H. Extent of injury was measured in terms of infarct size by triphenyltetrazolium chloride (TTC staining, and release of lactate dehydrogenase (LDH and creatin kinase-MB (CK-MB in coronary effluent. The cardiac release of NO was noted by measuring the level of nitrite in coronary effluent. Results IPC- induced cardioprotection and release of NO was significantly decreased in diabetic rat heart. Pre-treatment of diabetic rat with daidzein (DDZ a caveolin inhibitor (0.2 mg/Kg/s.c, for one week, significantly increased the release of NO and restored the attenuated cardioprotective effect of IPC. Also perfusion of sodium nitrite (10 μM/L, a precursor of NO, significantly restored the lost effect of IPC, similar to daidzein in diabetic rat. Administration of 5-hydroxy deaconate (5-HD, a mito KATP channel blocker, significantly abolished the observed IPC-induced cardioprotection in normal rat or daidzein and sodium nitrite perfused diabetic rat heart alone or in combination. Conclusions Thus, it is suggested that attenuation of the cardioprotection in diabetic heart may be due to decrease the IPC mediated release of NO in

  14. Comparison of the Effects of the Different Methods for Computing the Slope Length Factor at a Watershed Scale

    Directory of Open Access Journals (Sweden)

    Fu Suhua

    2013-09-01

    Full Text Available The slope length factor is one of the parameters of the Universal Soil Loss Equation (USLE and the Revised Universal Soil Loss Equation (RUSLE and is sometimes calculated based on a digital elevation model (DEM. The methods for calculating the slope length factor are important because the values obtained may depend on the methods used for calculation. The purpose of this study was to compare the difference in spatial distribution of the slope length factor between the different methods at a watershed scale. One method used the uniform slope length factor equation (USLFE where the effects of slope irregularities (such as slope gradient, etc. on soil erosion by water were not considered. The other method used segmented slope length factor equation(SSLFE which considered the effects of slope irregularities on soil erosion by water. The Arc Macro Language (AML Version 4 program for the revised universal soil loss equation(RUSLE.which uses the USLFE, was chosen to calculate the slope length factor. In a parallel analysis, the AML code of RUSLE Version 4 was modified according to the SSLFE to calculate the slope length factor. Two watersheds with different slope and gully densities were chosen. The results show that the slope length factor and soil loss using the USLFE method were lower than those using the SSLFE method, especially on downslopes watershed with more frequent steep slopes and higher gully densities. In addition, the slope length factor and soil loss calculated by the USLFE showed less spatial variation.

  15. Effect of side chain length on charge transport, morphology, and photovoltaic performance of conjugated polymers in bulk heterojunction solar cells

    NARCIS (Netherlands)

    Duan, C.; Willems, R.E.M.; van Franeker, J.J.; Bruijnaers, B.J.; Wienk, M.M.; Janssen, R.A.J.

    2016-01-01

    The effect of side chain length on the photovoltaic properties of conjugated polymers is systematically investigated with two sets of polymers that bear different alkyl side chain lengths based on benzodithiophene and benzo[2,1,3]thiadiazole or 5,6-difluorobenzo[2,1,3]thiadiazole. Characterization

  16. Effects of Compost Type and Rootstock Length on Fruit and Vegetable Seedlings Growth in the Nursery

    Directory of Open Access Journals (Sweden)

    Dody Priadi

    2016-11-01

    Full Text Available The study was conducted to develop local fruit plants and to improve vegetable production at the Plant Germplasm Garden of RC for Biotechnology-LIPI. Carambola (Averrhoa carambola, durian (Durio zibethinus and guava (Psidium guajava were propagated vegetatively (grafting and budding and were grown on the media containing grass compost (K-1, spent compost of paddy straw mushroom (K-2 or oyster mushroom (K-3 in combination with rootstock length of 45-55 cm (TB-1, 65-75 cm (TB-2 and 75-90 cm (TB-3. Tomato (Lycopersicum esculentum and kangkung (Ipomoea reptans were grown on the same media in the screen house. The highest survival rate of grafted durian (71.56% was obtained from TB-3 grown on K-1 by budding technique. Meanwhile, the highest survival rate of carambola (68.89% was obtained from TB-1 by grafting technique. The budding technique was not appropriate for guava (0 % of survival. Application of K-3 of 3 kgs on tomato plants resulted in the highest fresh weight, length, and diameter of the fruit, and the highest of plant height, total leaves, and biomass of kangkung. The study is expected to be applied to improve fruit plant growth and survival rate as well as a high production of organic vegetable.How to CitePriadi, D., & Mulyaningsih, E. S. (2016. Effects of Compost Type and Rootstock Length on Fruit and Vegetable Seedlings Growth  in the Nursery. Biosaintifika: Journal of Biology & Biology Education, 8(3, 301-307. 

  17. Effect of nosocomial vancomycin-resistant enterococcal bacteremia on mortality, length of stay, and costs.

    Science.gov (United States)

    Song, Xiaoyan; Srinivasan, Arjun; Plaut, David; Perl, Trish M

    2003-04-01

    To determine the impact of vancomycin-resistant enterococcal bacteremia on patient outcomes and costs by assessing mortality, excess length of stay, and charges attributable to it. A population-based, matched, historical cohort study. A 1,025-bed, university-based teaching facility and referral hospital. Two hundred seventy-seven vancomycin-resistant enterococcal bacteremia case-patients and 277 matched control-patients identified between 1993 and 2000. The crude mortality rate was 50.2% and 19.9% for case-patients and control-patients, respectively, yielding a mortality rate of 30.3% attributable to vancomycin-resistant enterococcal bacteremia. The excess length of hospital stay attributable to vancomycin-resistant enterococcal bacteremia was 17 days, of which 12 days were spent in intensive care units. On average, dollars 77,558 in extra charges was attributable to each vancomycin-resistant enterococcal bacteremia. To adjust for severity of illness, 159 pairs of case-patients and control-patients, who had the same severity of illness (All Patient Refined-Diagnosis Related Group complexity level), were further analyzed. When patients were stratified by severity of illness, the crude mortality rate was 50.3% among case-patients compared with 27.7% among control-patients, accounting for an attributable mortality rate of 22.6%. Attributable excess length of stay and charges were 17 days and dollars 81,208, respectively. Vancomycin-resistant enterococcal bacteremia contributes significantly to excess mortality and economic loss, once severity of illness is considered. Efforts to prevent these infections will likely be cost-effective.

  18. Effects of size at birth, childhood growth patterns and growth hormone treatment on leukocyte telomere length.

    Directory of Open Access Journals (Sweden)

    Carolina C J Smeets

    Full Text Available Small size at birth and rapid growth in early life are associated with increased risk of cardiovascular disease in later life. Short children born small for gestational age (SGA are treated with growth hormone (GH, inducing catch-up in length. Leukocyte telomere length (LTL is a marker of biological age and shorter LTL is associated with increased risk of cardiovascular disease.To investigate whether LTL is influenced by birth size, childhood growth and long-term GH treatment.We analyzed LTL in 545 young adults with differences in birth size and childhood growth patterns. Previously GH-treated young adults born SGA (SGA-GH were compared to untreated short SGA (SGA-S, SGA with spontaneous catch-up to a normal body size (SGA-CU, and appropriate for gestational age with a normal body size (AGA-NS. LTL was measured using a quantitative PCR assay.We found a positive association between birth length and LTL (p = 0.04, and a trend towards a positive association between birth weight and LTL (p = 0.08, after adjustments for gender, age, gestational age and adult body size. Weight gain during infancy and childhood and fat mass percentage were not associated with LTL. Female gender and gestational age were positively associated with LTL, and smoking negatively. After adjustments for gender, age and gestational age, SGA-GH had a similar LTL as SGA-S (p = 0.11, SGA-CU (p = 0.80, and AGA-NS (p = 0.30.Larger size at birth is positively associated with LTL in young adulthood. Growth patterns during infancy and childhood are not associated with LTL. Previously GH-treated young adults born SGA have similar LTL as untreated short SGA, SGA with spontaneous catch-up and AGA born controls, indicating no adverse effects of GH-induced catch-up in height on LTL.

  19. Examination of Critical Length Effect in Copper Interconnects With Oxide and Low-k Dielectrics

    International Nuclear Information System (INIS)

    Thrasher, Stacye; Gall, Martin; Justison, Patrick; Hernandez, Richard; Kawasaki, Hisao; Capasso, Cristiano; Nguyen, Timothy

    2004-01-01

    As technology moves toward faster microelectronic devices with smaller feature sizes, copper is replacing aluminum-copper alloy and low-k dielectric is replacing oxide as the materials of choice for advanced interconnect integrations. Copper not only brings to the table the advantage of lower resistivity, but also exhibits better electromigration performance when compared to Al(Cu). Low-k dielectric materials are advantageous because they reduce power consumption and improve signal delay. Due to these advantages, the industry trend is moving towards integrating copper and low-k dielectric for high performance interconnects. The purpose of this study is to evaluate the critical length effect in single-inlaid copper interconnects and determine the critical product (jl)c, for a variety of integrations, examining the effect of ILD (oxide vs. low-k), geometry, and stress temperature

  20. Tree Diamter Effects on Cost and Productivity of Cut-to-Length Systems

    Science.gov (United States)

    Matthew A. Holtzscher; Bobby L. Lanford

    1997-01-01

    Currently, there is a lack of economic information concerning cut-to-length harvesting systems. This study examined and measured the different costs of operating cut-to-length logging equipment over a range of average stand diameters at breast height. Three different cut-to-length logging systems were examined in this study. Systems included: 1) felier-buncher/manual/...

  1. The effect of cutting length on the rooting and growth of subtropical ...

    African Journals Online (AJOL)

    The length of a cutting can affect both the rooting and plug colonisation of container-grown stock. Using hedges from conventional clonebanks established in the ground, four cutting length treatments (13, 10, 8 and 5 cm) were tested using five Eucalyptus grandis × E. urophylla clones. The smallest cutting length had the ...

  2. Effects of absorption on coherence domain path length resolved dynamic light scattering in the diffuse regime

    NARCIS (Netherlands)

    Petoukhova, A. L.; Steenbergen, W.; van Leeuwen, T. G.; de Mul, F. F. M.

    2002-01-01

    A low coherence Mach-Zehnder interferometer is developed for path length resolved dynamic light scattering in highly turbid media. The path length distribution of multiply scattered photons in Intralipid is changed by the addition of absorbing dyes. Path length distributions obtained for various

  3. Effects of absorption on coherence domain path length resolved dynamic light scattering in the diffuse regime

    NARCIS (Netherlands)

    Petoukhova, Anna; Steenbergen, Wiendelt; van Leeuwen, Ton; de Mul, F.F.M.

    2002-01-01

    A low coherence Mach–Zehnder interferometer is developed for path length resolved dynamic light scattering in highly turbid media. The path length distribution of multiply scatteredphotons in Intralipid is changed by the addition of absorbing dyes. Path length distributions obtained for various

  4. THERMAL EFFECTS ON CAMERA FOCAL LENGTH IN MESSENGER STAR CALIBRATION AND ORBITAL IMAGING

    Directory of Open Access Journals (Sweden)

    S. Burmeister

    2018-04-01

    Full Text Available We analyse images taken by the MErcury Surface, Space ENviorment, GEochemistry, and Ranging (MESSENGER spacecraft for the camera’s thermal response in the harsh thermal environment near Mercury. Specifically, we study thermally induced variations in focal length of the Mercury Dual Imaging System (MDIS. Within the several hundreds of images of star fields, the Wide Angle Camera (WAC typically captures up to 250 stars in one frame of the panchromatic channel. We measure star positions and relate these to the known star coordinates taken from the Tycho-2 catalogue. We solve for camera pointing, the focal length parameter and two non-symmetrical distortion parameters for each image. Using data from the temperature sensors on the camera focal plane we model a linear focal length function in the form of f(T = A0 + A1 T. Next, we use images from MESSENGER’s orbital mapping mission. We deal with large image blocks, typically used for the production of a high-resolution digital terrain models (DTM. We analyzed images from the combined quadrangles H03 and H07, a selected region, covered by approx. 10,600 images, in which we identified about 83,900 tiepoints. Using bundle block adjustments, we solved for the unknown coordinates of the control points, the pointing of the camera – as well as the camera’s focal length. We then fit the above linear function with respect to the focal plane temperature. As a result, we find a complex response of the camera to thermal conditions of the spacecraft. To first order, we see a linear increase by approx. 0.0107 mm per degree temperature for the Narrow-Angle Camera (NAC. This is in agreement with the observed thermal response seen in images of the panchromatic channel of the WAC. Unfortunately, further comparisons of results from the two methods, both of which use different portions of the available image data, are limited. If leaving uncorrected, these effects may pose significant difficulties in

  5. Effective atomic numbers in some food materials and medicines for γ -ray attenuation using ^{137}Cs γ -ray

    Science.gov (United States)

    Revathy, J. S.; Anooja, J.; Krishnaveni, R. B.; Gangadathan, M. P.; Varier, K. M.

    2018-06-01

    A light-weight multichannel analyser (MCA)-based γ -ray spectrometer, developed earlier at the Inter University Accelerator Centre, New Delhi, has been used as part of the PG curriculum, to determine the effective atomic numbers for γ attenuation of ^{137}Cs γ -ray in different types of samples. The samples used are mixtures of graphite, aluminum and selenium powders in different proportions, commercial and home-made edible powders, fruit and vegetable juices as well as certain allopathic and ayurvedic medications. A narrow beam good geometry set-up has been used in the experiments. The measured attenuation coefficients have been used to extract effective atomic numbers in the samples. The results are consistent with XCOM values wherever available. The present results suggest that the γ attenuation technique can be used as an effective non-destructive method for finding adulteration of food materials.

  6. Some effects of overall rate of earning reinforcers on run lengths and visit durations.

    Science.gov (United States)

    Macdonall, James S

    2006-07-01

    In a concurrent schedule, responding at each alternative is controlled by a pair of schedules that arrange reinforcers for staying at that alternative and reinforcers for switching to the other alternative. Each pair of schedules operates only while at the associated alternative. When only one pair of stay and switch schedules is presented, the rates of earning reinforcers for staying divided by the rates of earning reinforcers for switching controls the mean number responses in a visit and the mean duration of visits. The purpose of the present experiment was to see whether the sum of the rates of earning stay and switch reinforcers changed the way that run length and visit duration were affected by the ratio of the rates of stay to switch reinforcers. Rats were exposed to pairs of stay and switch schedules that varied both the ratio of the rates of earning stay and switch reinforcers and the sum of the rates of earning stay and switch reinforcers. Run lengths and visit durations were joint functions of the ratio of the rates of earning stay and switch reinforcers and the sum of the rates of earning stay and switch reinforcers. These results shows that the effect of the ratio of the sum of the rates of earning stay and switch reinforcers results from processes operating at the alternative, rather than from processes operating at both alternatives.

  7. Effect of minimal length uncertainty on the mass-radius relation of white dwarfs

    Science.gov (United States)

    Mathew, Arun; Nandy, Malay K.

    2018-06-01

    Generalized uncertainty relation that carries the imprint of quantum gravity introduces a minimal length scale into the description of space-time. It effectively changes the invariant measure of the phase space through a factor (1 + βp2) - 3 so that the equation of state for an electron gas undergoes a significant modification from the ideal case. It has been shown in the literature (Rashidi 2016) that the ideal Chandrasekhar limit ceases to exist when the modified equation of state due to the generalized uncertainty is taken into account. To assess the situation in a more complete fashion, we analyze in detail the mass-radius relation of Newtonian white dwarfs whose hydrostatic equilibria are governed by the equation of state of the degenerate relativistic electron gas subjected to the generalized uncertainty principle. As the constraint of minimal length imposes a severe restriction on the availability of high momentum states, it is speculated that the central Fermi momentum cannot have values arbitrarily higher than pmax ∼β - 1 / 2. When this restriction is imposed, it is found that the system approaches limiting mass values higher than the Chandrasekhar mass upon decreasing the parameter β to a value given by a legitimate upper bound. Instead, when the more realistic restriction due to inverse β-decay is considered, it is found that the mass and radius approach the values 1.4518 M⊙ and 601.18 km near the legitimate upper bound for the parameter β.

  8. Effect of Chain Length Compatibility of Alcohols on Muscovite Flotation by Dodecyl Amine

    Directory of Open Access Journals (Sweden)

    Li Wang

    2018-04-01

    Full Text Available A portion of dodecyl amine (DDA in a muscovite flotation system was replaced with alcohols with different carbon-chain lengths. These alcohols included octanol (OCT; decanol (DEC; dodecanol (DOD; and tetradecanol (TER. The muscovite adsorption behavior of the mixed DDA and alcohol systems were investigated through zeta potential; contact angle; and adsorption quantity tests. Single-mineral flotation tests showed that the muscovite-collecting power of the mixed DDA/alcohol (OCT, DEC, or DOD system was stronger than that of the pure DDA system. The muscovite-collecting power of the collector systems decreased in the following order: DDA/DEC > DDA/OCT > DDA/DEC > DDA > DDA/TER. Zeta potential and contact angle analysis indicated that when combined with DDA; alcohols physically adsorbed on the surfaces of muscovite. This behavior improved the hydrophobicity of muscovite. Furthermore, adsorption analysis revealed that synergy between DDA and alcohol enhanced the adsorption of alcohol on muscovite. DDA has a dominant role in synergistic adsorption; whereas alcohol has a supporting role. Among all tested alcohols; DDA and DOD exhibit the highest synergetic adsorption effect because of their similar carbon-chain lengths. This similarity promotes the formation of a compact adsorption layer on the muscovite surface.

  9. Word-length effect in verbal short-term memory in individuals with Down's syndrome.

    Science.gov (United States)

    Kanno, K; Ikeda, Y

    2002-11-01

    Many studies have indicated that individuals with Down's syndrome (DS) show a specific deficit in short-term memory for verbal information. The aim of the present study was to investigate the influence of the length of words on verbal short-term memory in individuals with DS. Twenty-eight children with DS and 10 control participants matched for memory span were tested on verbal serial recall and speech rate, which are thought to involve rehearsal and output speed. Although a significant word-length effect was observed in both groups for the recall of a larger number of items with a shorter spoken duration than for those with a longer spoken duration, the number of correct recalls in the group with DS was reduced compared to the control subjects. The results demonstrating poor short-term memory in children with DS were irrelevant to speech rate. In addition, the proportion of repetition-gained errors in serial recall was higher in children with DS than in control subjects. The present findings suggest that poor access to long-term lexical knowledge, rather than overt articulation speed, constrains verbal short-term memory functions in individuals with DS.

  10. Effects of hand gestures on auditory learning of second-language vowel length contrasts.

    Science.gov (United States)

    Hirata, Yukari; Kelly, Spencer D; Huang, Jessica; Manansala, Michael

    2014-12-01

    Research has shown that hand gestures affect comprehension and production of speech at semantic, syntactic, and pragmatic levels for both native language and second language (L2). This study investigated a relatively less explored question: Do hand gestures influence auditory learning of an L2 at the segmental phonology level? To examine auditory learning of phonemic vowel length contrasts in Japanese, 88 native English-speaking participants took an auditory test before and after one of the following 4 types of training in which they (a) observed an instructor in a video speaking Japanese words while she made syllabic-rhythm hand gesture, (b) produced this gesture with the instructor, (c) observed the instructor speaking those words and her moraic-rhythm hand gesture, or (d) produced the moraic-rhythm gesture with the instructor. All of the training types yielded similar auditory improvement in identifying vowel length contrast. However, observing the syllabic-rhythm hand gesture yielded the most balanced improvement between word-initial and word-final vowels and between slow and fast speaking rates. The overall effect of hand gesture on learning of segmental phonology is limited. Implications for theories of hand gesture are discussed in terms of the role it plays at different linguistic levels.

  11. Effect of dry period length on milk production in subsequent lactation

    DEFF Research Database (Denmark)

    Sørensen, J.T.; Enevoldsen, Carsten

    1991-01-01

    , two treatments were compared within herd. Compared with a 7-wk planned dry period, a 3-wk decrease lowered the level of milk production by 2.8 kg of 4% FCM/d in the first 84 d of the subsequent lactation, whereas a 3-wk increase raised the level of milk production by .5 kg/d. In the first 168 d......The effect of planned dry period lengths of 4, 7, and 10 wk on subsequent lactational yield was estimated with 366 cows in an experiment in which dry period was manipulated independently of milk yield prior to drying off. In two herds, all three treatments were compared within herd; in six herds...... of the subsequent lactation, the difference between 4-wk and 7-wk planned dry periods was 2.7 kg/d, and the difference between 7- and 10-wk periods was .4 kg/d. There was no indication of interaction among planned dry period length and lactation number, days open in previous lactation, previous milk yield, breed...

  12. Failure Mode and Effects Analysis (FMEA) of the solid state full length rod control system

    International Nuclear Information System (INIS)

    Shopsky, W.E.

    1977-01-01

    The Full Length Rod Control System (FLRCS) controls the power to the rod drive mechanisms for rod movement in response to signals received from the Reactor Control System or from signals generated through Reactor Operator action. Rod movement is used to control reactivity of the reactor during plant operation. The Full Length Rod Control System is designed to perform its reactivity control function in conjunction with the Reactor Control and Protection System, to maintain the reactor core within design safety limits. By the use of a Failure Mode and Effects Analysis, it is shown that the FLRCS will perform its reactivity control functions considering the loss of single active components. That is, sufficient fault limiting control circuits are provided which blocks control rod movement and/or indicates presence of a fault condition at the Control Board. Reactor operator action or automatic reactor trip will thus mitigate the consequences of potential failure of the FLRCS. The analysis also qualitatively demonstrates the reliability of the FLRCS to perform its intended function

  13. Effect of length and diameter of fiber reinforced composite post (FRC on fracture resistance of remaining tooth structure

    Directory of Open Access Journals (Sweden)

    Mahdiyeh seifi

    2013-03-01

    Full Text Available Introduction: Post and core has been considered for endodontically treated tooth, especially in cases with severe damage crowns. Recently fiber reinforced composite posts (FRC post have been used in the treatment of endodontically treated teeth. Because the length and diameter of posts are effective in stress distribution, the purpose of this study is to evaluate the effect of length and diameter of FRC post on fracture resistance. Methods: In this experimental study, 36 glass fiber posts with combination of 7mm, 9mm, and 12mm length and 1.1mm, 1.3mm and 1.5mm diameter were divided into 9 groups of 4. These posts were cemented in root canals by Panavia. Samples were tested with 45° compressive forces for the evaluation of fracture resistance. Datas were analyzed using SPSS soft ware and One- way and Two-way ANOVA analyses. Results: Fracture resistance did not increase significantly with the effect of length and diameter simultaneously (P=0.85. Samples with 12mm length and 1.5mm diameter had the greatest fracture resistance (1023/33N±239/22. The minimum fracture resistance had occurred in post with 7mm length and 1.5mm diameter (503/13N ±69/18. Fracture resistance increased significantly by increasing the length and the same diameter. Conclusion: It can be concluded that fracture resistance is affected by the length and not the diameter of FRC post.

  14. Radio Frequency Interference: The Study of Rain Effect on Radio Signal Attenuation

    International Nuclear Information System (INIS)

    Roslan Umar; Roslan Umar; Shahirah Syafa Sulan; Atiq Wahidah Azlan; Zainol Abidin Ibrahim

    2015-01-01

    The intensity of radio waves received by radio telescopes is always not subject to human control. In the millimetre band, the propagation of the electromagnetic waves is severely affected by rain rate, dust particle size and drop size in the terms of attenuation, noise and depolarization. At the frequency above 10 GHz, the absorption and scattering by rain cause a reduction in the transmitted signal amplitude which will lead to the reducing of the availability, reliability and performance on the communications link. In this study, the rain effect on radio signal has been investigated. Spectrum analyzer and weather stations were used to obtain the RFI level and rain rate data respectively. The radio frequency interference (RFI) pattern due to rain factor was determined. This will benefit radio astronomer in managing sites for radio observation for radio astronomy purposes. (author)

  15. Recall of short word lists presented visually at fast rates: effects of phonological similarity and word length.

    Science.gov (United States)

    Coltheart, V; Langdon, R

    1998-03-01

    Phonological similarity of visually presented list items impairs short-term serial recall. Lists of long words are also recalled less accurately than are lists of short words. These results have been attributed to phonological recoding and rehearsal. If subjects articulate irrelevant words during list presentation, both phonological similarity and word length effects are abolished. Experiments 1 and 2 examined effects of phonological similarity and recall instructions on recall of lists shown at fast rates (from one item per 0.114-0.50 sec), which might not permit phonological encoding and rehearsal. In Experiment 3, recall instructions and word length were manipulated using fast presentation rates. Both phonological similarity and word length effects were observed, and they were not dependent on recall instructions. Experiments 4 and 5 investigated the effects of irrelevant concurrent articulation on lists shown at fast rates. Both phonological similarity and word length effects were removed by concurrent articulation, as they were with slow presentation rates.

  16. Cost Effectiveness of Influenza Vaccine for U.S. Children: Live Attenuated and Inactivated Influenza Vaccine.

    Science.gov (United States)

    Shim, Eunha; Brown, Shawn T; DePasse, Jay; Nowalk, Mary Patricia; Raviotta, Jonathan M; Smith, Kenneth J; Zimmerman, Richard K

    2016-09-01

    Prior studies showed that live attenuated influenza vaccine (LAIV) is more effective than inactivated influenza vaccine (IIV) in children aged 2-8 years, supporting the Centers for Disease Control and Prevention (CDC) recommendations in 2014 for preferential LAIV use in this age group. However, 2014-2015 U.S. effectiveness data indicated relatively poor effectiveness of both vaccines, leading CDC in 2015 to no longer prefer LAIV. An age-structured model of influenza transmission and vaccination was developed, which incorporated both direct and indirect protection induced by vaccination. Based on this model, the cost effectiveness of influenza vaccination strategies in children aged 2-8 years in the U.S. was estimated. The base case assumed a mixed vaccination strategy where 33.3% and 66.7% of vaccinated children aged 2-8 years receive LAIV and IIV, respectively. Analyses were performed in 2014-2015. Using published meta-analysis vaccine effectiveness data (83% LAIV and 64% IIV), exclusive LAIV use would be a cost-effective strategy when vaccinating children aged 2-8 years, whereas IIV would not be preferred. However, when 2014-2015 U.S. effectiveness data (0% LAIV and 15% IIV) were used, IIV was likely to be preferred. The cost effectiveness of influenza vaccination in children aged 2-8 years is highly dependent on vaccine effectiveness; the vaccine type with higher effectiveness is preferred. In general, exclusive IIV use is preferred over LAIV use, as long as vaccine effectiveness is higher for IIV than for LAIV. Copyright © 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  17. arXiv Strong reduction of the effective radiation length in an oriented PWO scintillator crystal

    CERN Document Server

    Bandiera, L.; Romagnoni, M.; Argiolas, N.; Bagli, E.; Ballerini, G.; Berra, A.; Brizzolani, C.; Camattari, R.; De Salvador, D.; Haurylavets, V.; Mascagna, V.; Mazzolari, A.; Prest, M.; Soldani, M.; Sytov, A.; Vallazza, E.

    We measured a considerable increase of the emitted radiation by 120 GeV/c electrons in an axially oriented lead tungstate scintillator crystal, if compared to the case in which the sample was not aligned with the beam direction. This enhancement resulted from the interaction of particles with the strong crystalline electromagnetic field. The data collected at the external lines of CERN SPS were critically compared to Monte Carlo simulations based on the Baier Katkov quasiclassical method, highlighting a reduction of the scintillator radiation length by a factor of five in case of beam alignment with the [001] crystal axes. The observed effect opens the way to the realization of compact electromagnetic calorimeters/detectors based on oriented scintillator crystals in which the amount of material can be strongly reduced with respect to the state of the art. These devices could have relevant applications in fixed-target experiments as well as in satellite-borne gamma-telescopes.

  18. Self-Assembly of Alkylammonium Chains on Montmorillonite: Effect of Interlayer Cations, CEC, and Chain Length

    Science.gov (United States)

    Chen, Hua; Li, Yingjun; Zhou, Yuanlin; Wang, Shanqiang; Zheng, Jian; He, Jiacai

    2017-12-01

    Recently, polymeric materials have been filled with synthetic or natural inorganic compounds in order to improve their properties. Especially, polymer clay nanocomposites have attracted both academic and industrial attention. Currently, the structure and physical phenomena of organoclays at molecular level are difficultly explained by existing experimental techniques. In this work, molecular dynamics (MD) simulation was executed using the CLAYFF and CHARMM force fields to evaluate the structural properties of organoclay such as basal spacing, interlayer density, energy and the arrangement of alkyl chains in the interlayer spacing. Our results are in good agreement with available experimental or other simulation data. The effects of interlayer cations (Na+, K+, Ca2+), the cation exchange capacity, and the alkyl chain length on the basal spacing and the structural properties are estimated. These simulations are expected to presage the microstructure of organo-montmorillonite and lead relevant engineering applications.

  19. Chain length effects on the vibrational structure and molecular interactions in the liquid normal alkyl alcohols

    Science.gov (United States)

    Kiefer, Johannes; Wagenfeld, Sabine; Kerlé, Daniela

    2018-01-01

    Alkyl alcohols are widely used in academia, industry, and our everyday lives, e.g. as cleaning agents and solvents. Vibrational spectroscopy is commonly used to identify and quantify these compounds, but also to study their structure and behavior. However, a comprehensive investigation and comparison of all normal alkanols that are liquid at room temperature has not been performed, surprisingly. This study aims at bridging this gap with a combined experimental and computational effort. For this purpose, the alkyl alcohols from methanol to undecan-1-ol have been analyzed using infrared and Raman spectroscopy. A detailed assignment of the individual peaks is presented and the influence of the alkyl chain length on the hydrogen bonding network is discussed. A 2D vibrational mapping allows a straightforward visualization of the effects. The conclusions drawn from the experimental data are backed up with results from Monte Carlo simulations using the simulation package Cassandra.

  20. Effect of dysphasia and dysphagia on inpatient mortality and hospital length of stay: a database study.

    Science.gov (United States)

    Guyomard, Veronique; Fulcher, Robert A; Redmayne, Oliver; Metcalf, Anthony K; Potter, John F; Myint, Phyo K

    2009-11-01

    To examine the effect of dysphasia and dysphagia on stroke outcome. Retrospective database study. Norfolk, United Kingdom. Two thousand nine hundred eighty-three men and women with stroke admitted to the hospital between 1997 and 2001. Inpatient mortality and likelihood of longer length of hospital stay, defined as longer than median length of stay (LOS). Dysphagia was defined as difficulty swallowing any liquid (including saliva) or solid material. Dysphasia was defined as speech disorders in which there was impairment of the power of expression by speech, writing, or signs or impairment of the power of comprehension of spoken or written language. An experienced team assessed dysphagia and dysphasia using explicit criteria. Two thousand nine hundred eighty-three patients (1,330 (44.6%) male), median age 78 (range 17-105), were included, of whom 77.7% had ischemic, 10.5% had hemorrhagic, and 11.8% had undetermined stroke types. Dysphasia was present in 41.2% (1,230) and dysphagia in 50.5% (1,506), and 27.7% (827) had both conditions. Having either or both conditions was associated with greater mortality and longer LOS (P<.001 for all). Using multiple logistic regression models controlling for age, sex, premorbid Rankin score, previous disabling stroke, and stroke type, corresponding odds ratios for death and longer LOS were 2.2 (95% confidence interval (CI)=1.8-2.7) and 1.4 (95% CI=1.2-1.6) for dysphasia; 12.5 (95% CI=8.9-17.3) and 3.9 (95% CI=3.3-4.6) for dysphagia, 5.5 (95% CI=3.7-8.2), 1.9 (95% CI=1.6-2.3) for either, and 13.8 (95% CI=9.4-20.4) and 3.7 (95% CI=3.1-4.6) if they had both, versus having no dysphasia, no dysphagia, or none of these conditions, respectively. Patients with dysphagia have worse outcome in terms of inpatient mortality and length of hospital stay than those with dysphasia. When both conditions are present, the presence of dysphagia appears to determine the likelihood of poor outcome. Whether this effect is related just to stroke severity

  1. Effect of surfactant chain length on drug release kinetics from microemulsion-laden contact lenses.

    Science.gov (United States)

    Maulvi, Furqan A; Desai, Ankita R; Choksi, Harsh H; Patil, Rahul J; Ranch, Ketan M; Vyas, Bhavin A; Shah, Dinesh O

    2017-05-30

    The effect of surfactant chain lengths [sodium caprylate (C 8 ), Tween 20 (C 12 ), Tween 80 (C 18 )] and the molecular weight of block copolymers [Pluronic F68 and Pluronic F 127] were studied to determine the stability of the microemulsion and its effect on release kinetics from cyclosporine-loaded microemulsion-laden hydrogel contact lenses in this work. Globule size and dilution tests (transmittance) suggested that the stability of the microemulsion increases with increase in the carbon chain lengths of surfactants and the molecular weight of pluronics. The optical transmittance of direct drug-laden contact lenses [DL-100] was low due to the precipitation of hydrophobic drugs in the lenses, while in microemulsion-laden lenses, the transmittance was improved when stability of the microemulsion was achieved. The results of in vitro release kinetics revealed that drug release was sustained to a greater extent as the stability of microemulsion was improved as well. This was evident in batch PF127-T80, which showed sustained release for 15days in comparison to batch DL-100, which showed release up to 7days. An in vivo drug release study in rabbit tear fluid showed significant increase in mean residence time (MRT) and area under curve (AUC) with PF-127-T80 lenses (stable microemulsion) in comparison to PF-68-SC lenses (unstable microemulsion) and DL-100 lenses. This study revealed the correlation between the stability of microemulsion and the release kinetics of drugs from contact lenses. Thus, it was inferred that the stable microemulsion batches sustained the release of hydrophobic drugs, such as cyclosporine from contact lenses for an extended period of time without altering critical lens properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. The effect of letter string length and report condition on letter recognition accuracy.

    Science.gov (United States)

    Raghunandan, Avesh; Karmazinaite, Berta; Rossow, Andrea S

    Letter sequence recognition accuracy has been postulated to be limited primarily by low-level visual factors. The influence of high level factors such as visual memory (load and decay) has been largely overlooked. This study provides insight into the role of these factors by investigating the interaction between letter sequence recognition accuracy, letter string length and report condition. Letter sequence recognition accuracy for trigrams and pentagrams were measured in 10 adult subjects for two report conditions. In the complete report condition subjects reported all 3 or all 5 letters comprising trigrams and pentagrams, respectively. In the partial report condition, subjects reported only a single letter in the trigram or pentagram. Letters were presented for 100ms and rendered in high contrast, using black lowercase Courier font that subtended 0.4° at the fixation distance of 0.57m. Letter sequence recognition accuracy was consistently higher for trigrams compared to pentagrams especially for letter positions away from fixation. While partial report increased recognition accuracy in both string length conditions, the effect was larger for pentagrams, and most evident for the final letter positions within trigrams and pentagrams. The effect of partial report on recognition accuracy for the final letter positions increased as eccentricity increased away from fixation, and was independent of the inner/outer position of a letter. Higher-level visual memory functions (memory load and decay) play a role in letter sequence recognition accuracy. There is also suggestion of additional delays imposed on memory encoding by crowded letter elements. Copyright © 2016 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

  3. Clinical presentation of Attenuated Psychosis Syndrome in children and adolescents: Is there an age effect?

    Science.gov (United States)

    Ribolsi, Michele; Lin, Ashleigh; Wardenaar, Klaas J; Pontillo, Maria; Mazzone, Luigi; Vicari, Stefano; Armando, Marco

    2017-06-01

    There is limited research on clinical features related to age of presentation of the Attenuated Psychosis Syndrome in children and adolescents (CAD). Based on findings in CAD with psychosis, we hypothesized that an older age at presentation of Attenuated Psychosis Syndrome would be associated with less severe symptoms and better psychosocial functioning than presentation in childhood or younger adolescence. Ninety-four CAD (age 9-18) meeting Attenuated Psychosis Syndrome criteria participated in the study. The sample was divided and compared according to the age of presentation of Attenuated Psychosis Syndrome (9-14 vs 15-18 years). The predictive value of age of Attenuated Psychosis Syndrome presentation was investigated using receiver operating characteristic (ROC)-curve calculations. The two Attenuated Psychosis Syndrome groups were homogeneous in terms of gender distribution, IQ scores and comorbid diagnoses. Older Attenuated Psychosis Syndrome patients showed better functioning and lower depressive scores. ROC curves revealed that severity of functional impairment was best predicted using an age of presentation cut-off of 14.9 years for social functioning and 15.9 years for role functioning. This study partially confirmed our hypothesis; older age at presentation of Attenuated Psychosis Syndrome was associated with less functional impairment, but age was not associated with psychotic symptoms. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  4. Effects of phosphodiesterase III inhibition on length-dependent regulation of myocardial function in coronary surgery patients

    NARCIS (Netherlands)

    de Hert, S. G.; ten Broecke, P. W.; Mertens, E.; Rodrigus, I. E.; Stockman, B. A.

    2002-01-01

    BACKGROUND: Phosphodiesterase III inhibitors increase myocardial contractility and decrease left ventricular (LV) afterload. We studied whether these effects altered LV response to an increase in cardiac load and affected length-dependent regulation of myocardial function. METHODS: Before the start

  5. The interacting effects of temperature and food chain length on trophic abundance and ecosystem function.

    Science.gov (United States)

    Beveridge, Oliver S; Humphries, Stuart; Petchey, Owen L

    2010-05-01

    1. While much is known about the independent effects of trophic structure and temperature on density and ecosystem processes, less is known about the interaction(s) between the two. 2. We manipulated the temperature of laboratory-based bacteria-protist communities that contained communities with one, two, or three trophic levels, and recorded species' densities and bacterial decomposition. 3. Temperature, food chain length and their interaction produced significant responses in microbial density and bacterial decomposition. Prey and resource density expressed different patterns of temperature dependency during different phases of population dynamics. The addition of a predator altered the temperature-density relationship of prey, from a unimodal trend to a negative one. Bacterial decomposition was greatest in the presence of consumers at higher temperatures. 4. These results are qualitatively consistent with a recent model of direct and indirect temperature effects on resource-consumer population dynamics. Results highlight and reinforce the importance of indirect effects of temperature mediated through trophic interactions. Understanding and predicting the consequences of environmental change will require that indirect effects, trophic structure, and individual species' tolerances be incorporated into theory and models.

  6. Word frequency influences on the list length effect and associative memory in young and older adults.

    Science.gov (United States)

    Badham, Stephen P; Whitney, Cora; Sanghera, Sumeet; Maylor, Elizabeth A

    2017-07-01

    Many studies show that age deficits in memory are smaller for information supported by pre-experimental experience. Many studies also find dissociations in memory tasks between words that occur with high and low frequencies in language, but the literature is mixed regarding the extent of word frequency effects in normal ageing. We examined whether age deficits in episodic memory could be influenced by manipulations of word frequency. In Experiment 1, young and older adults studied short and long lists of high- and low-frequency words for free recall. The list length effect (the drop in proportion recalled for longer lists) was larger in young compared to older adults and for high- compared to low-frequency words. In Experiment 2, young and older adults completed item and associative recognition memory tests with high- and low-frequency words. Age deficits were greater for associative memory than for item memory, demonstrating an age-related associative deficit. High-frequency words led to better associative memory performance whilst low-frequency words resulted in better item memory performance. In neither experiment was there any evidence for age deficits to be smaller for high- relative to low-frequency words, suggesting that word frequency effects on memory operate independently from effects due to cognitive ageing.

  7. Length-controlled few-walled carbon nanotubes and their effect on the electrical property of flexible transparent conductive films

    Science.gov (United States)

    Lee, Byeong-Joo; Shin, Eui-Chul; Jeong, Goo-Hwan

    2012-06-01

    We investigated the effect of the length of carbon nanotubes (CNTs) on the electrical property of CNT-based flexible, transparent, and conductive films (TCFs). We grew vertically aligned CNTs with controlled lengths, dispersed them in ethanol by ultrasonication, and spray coated them onto polyethylene terephthalate (PET) sheets. We focused on the variation in the sheet resistance and transmittance of the above-mentioned films as a function of the CNT length, and we found that the optimum CNT length was 200 μm. We concluded that the CNT length should be carefully optimized because a shorter tube affords the advantage of efficient dispersion, while a longer tube helps in reducing the number of contact points between tubes along the electrical conduction path.

  8. Effect of e-learning on quality of cervical-length measurements.

    Science.gov (United States)

    van Os, M A; van der Ven, A J; Bloemendaal, P M; Pajkrt, E; de Groot, C J M; Mol, B W J; Haak, M C

    2015-09-01

    To assess the effect of implementation of a newly developed e-learning module on the quality of cervical-length measurements. With the introduction of cervical-length (CL) measurement in a research setting, a CL measurement e-learning module (CLEM) was developed with the purpose to enhance the knowledge and skills of experienced ultrasonographers. CLEM was designed specifically for ultrasonographers who perform ultrasound in a general obstetrical practice but who do not regularly perform CL measurements. CLEM consists of five theoretical questions and three caliper-placement tests to learn the CL measurement technique. The quality of the CL measurements of CLEM participants was compared with images of non-participants using a CL measurement image score (CIS), defined as the sum of six items which assess the quality of the image. Each CLEM participant submitted five CL images and the images of non-CLEM participants were selected randomly from an ultrasound database. The CIS of the CLEM participants (n = 61) were significantly higher than those of non-CLEM participants (n = 23) (164.9 vs 155.6, respectively; P = 0.03). Visualization of the internal os and positioning of the calipers on the internal and external ora were found to have significantly higher CIS among the CLEM participants than among the non-CLEM participants (P = 0.001 and P < 0.001, respectively). Introducing CLEM may improve the quality of CL measurements obtained by trained and untrained sonographers. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

  9. Effect of shoulder stabilization on career length in national football league athletes.

    Science.gov (United States)

    Brophy, Robert H; Gill, Corey S; Lyman, Stephen; Barnes, Ronnie P; Rodeo, Scott A; Warren, Russell F

    2011-04-01

    Shoulder instability and surgical stabilization are common in college football athletes. The effect of shoulder stabilization during college on the length of an athlete's career in the National Football League (NFL) has not been well examined. Athletes with a history of shoulder stabilization before the NFL combine have a shorter career than do matched controls. Cohort study; Level of evidence, 3. A database containing the injury history and career NFL statistics of athletes from 1987 to 2000 was used to match athletes with a history of shoulder stabilization and no other surgery or significant injury to controls without a history of any previous surgery or significant injury. Athletes were matched by position, year drafted, round drafted, and additional minor injury history. Forty-two athletes with a history of shoulder stabilization were identified and matched with controls. A history of shoulder stabilization significantly reduced the length of career in terms of years (5.2 ± 3.9 vs 6.9 ± 3.6 years; P = .01) and games played (56 ± 53 vs 77 ± 50, P = .03) as compared with controls. By position, linemen and linebackers (20 athletes) with a history of shoulder stabilization had a significantly shorter career in years (4.7 ± 3.8 vs 6.7 ± 3.4 years; P = .049) and games played (51 ± 58 vs 81 ± 48; P = .046) than did controls. Among the other positions (22 athletes), the difference was not statistically significant in this small cohort. A history of shoulder stabilization shortens the expected career of a professional football player, particularly for linemen and linebackers. Further research is warranted to better understand how these injuries and surgeries affect an athlete's career and what can be done to improve the long-term outcome after treatment.

  10. Effects of length of abstinence on decision-making and craving in methamphetamine abusers.

    Directory of Open Access Journals (Sweden)

    Guibin Wang

    Full Text Available RATIONALE: The majority of drug abusers are incapable of sustaining abstinence over any length of time. Accumulating evidence has linked intense and involuntary craving, Impulsive decision-making and mood disturbances to risk for relapse. However, little is known about temporal changes of these neuropsychological functions in methamphetamine (METH-dependent individuals. OBJECTIVES: To investigate the effect of length of abstinence on decision-making, craving (baseline and cue-induced, and emotional state in METH-addicted individuals. METHODS: In this cross-sectional study, 183 adult METH-dependent patients at an addiction rehabilitation center who were abstinent for 6 days (n = 37, 14 days (n = 33, 1 month (n = 31, 3 months (n = 30, 6 months (n = 26, or 1 year (n = 30 and 39 healthy subjects were administered the Iowa Gambling Task (IGT to assess decision-making performance. Depression, anxiety, and impulsivity were also examined. One hundred thirty-nine METH abusers who were abstinent for the aforementioned times then underwent a cue session, and subjective and physiological measures were assessed. RESULTS: METH dependent individuals who were abstinent for longer periods of time exhibited better decision-making than those who were abstinent for shorter periods of time. And self-reported emotional symptoms improved with abstinence. METH abusers' ratings of craving decreased with the duration of abstinence, while cue-induced craving increased until 3 months of abstinence and decreased at 6 months and 1 year of abstinence. CONCLUSIONS: We present time-dependent alterations in decision-making, emotional state, and the incubation of cue-induced craving in METH-dependent individuals, which might have significant clinical implications for the prevention of relapse.

  11. The effect of span length and girder type on bridge costs

    Directory of Open Access Journals (Sweden)

    Batikha Mustafa

    2017-01-01

    Full Text Available Bridges have an important role in impacting the civilization, growth and economy of cities from ancient time until these days due to their function in reducing transportation cost and time. Therefore, development of bridges has been a knowledge domain in civil engineering studies in terms of their types and construction materials to confirm a reliable, safe, economic design and construction. Girder-bridge of concrete deck and I-beam girder has been used widely for short and medium span bridges because of ease and low-cost of fabrication. However, many theoretical and practical investigations are still undertaken regarding the type of beam girder; i.e steel composite or prestressed concrete. This paper evaluates the effect of bridge span and the type of girder on the capital cost and life cycle costs of bridges. Three types of girders were investigated in this research: steel composite, pre-tensioned pre-stressed concrete and post-tensioned pre-stressed concrete. The structural design was analyzed for 5 span lengths: 20, 25, 30, 35 and 40m. Then, the capital construction cost was accounted for 15 bridges according to each span and construction materials. Moreover, the maintenance required for 50 years of bridge life was evaluated and built up as whole life costs for each bridge. As a result of this study, the influence of both span length and type of girder on initial construction cost and maintenance whole life costs were assessed to support the decision makers and designers in the selection process for the optimum solution of girder bridges.

  12. Effect of practice and span length on the dual-task coordination executive test

    Directory of Open Access Journals (Sweden)

    Sylwan R.P.

    1999-01-01

    Full Text Available The measure "mu", proposed as an index of the ability to coordinate concurrent box-crossing (BC and digit-span (DS tasks in the dual task (DT, should reflect the capacity of the executive component of the working memory system. We investigated the effect of practice in BC and of a change in the digit span on mu by adding previous practice trials in BC and diminishing, maintaining or increasing the digit sequence length. The mu behavior was evaluated throughout three trials of the test. Reported strategies in digit tasks were also analyzed. Subjects with diminished span showed the best performance in DT due to a stable performance in DS and BC in the single- and dual-task conditions. These subjects also showed a more stable performance throughout trials. Subjects with diminished span tended to employ effortless strategies, whereas subjects with increased span employed effort-requiring strategies and showed the lowest means of mu. Subjects with initial practice trials showed the best performance in BC and the most differentiated performance between the single- and dual-task conditions in BC. The correlation coefficient between the mu values obtained in the first and second trials was 0.814 for subjects with diminished span and practice trials in BC. It seems that the within-session practice in BC and the performance variability in DS affect the reliability of the index mu. To control these factors we propose the introduction of previous practice trials in BC and a modification of the current method to determine the digit sequence length. This proposal should contribute to the development of a more reliable method to evaluate the executive capacity of coordination in the dual-task paradigm.

  13. The Effect of Various Waste Materials' Contents on the Attenuation Level of Anti-Radiation Shielding Concrete.

    Science.gov (United States)

    Azeez, Ali Basheer; Mohammed, Kahtan S; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Sandu, Andrei Victor; Razak, Rafiza Abdul

    2013-10-23

    Samples of concrete contain various waste materials, such as iron particulates, steel balls of used ball bearings and slags from steel industry were assessed for their anti-radiation attenuation coefficient properties. The attenuation measurements were performed using gamma spectrometer of NaI (Tl) detector. The utilized radiation sources comprised 137 Cs and ⁶⁰Co radioactive elements with photon energies of 0.662 MeV for 137 Cs and two energy levels of 1.17 and 1.33 MeV for the ⁶⁰Co. Likewise the mean free paths for the tested samples were obtained. The aim of this work is to investigate the effect of the waste loading rates and the particulate dispersive manner within the concrete matrix on the attenuation coefficients. The maximum linear attenuation coefficient (μ) was attained for concrete incorporates iron filling wastes of 30 wt %. They were of 1.12 ± 1.31×10 -3 for 137 Cs and 0.92 ± 1.57 × 10 -3 for ⁶⁰Co. Substantial improvement in attenuation performance by 20%-25% was achieved for concrete samples incorporate iron fillings as opposed to that of steel ball samples at different (5%-30%) loading rates. The steel balls and the steel slags gave much inferior values. The microstructure, concrete-metal composite density, the homogeneity and particulate dispersion were examined and evaluated using different metallographic, microscopic and measurement facilities.

  14. The Effect of Various Waste Materials’ Contents on the Attenuation Level of Anti-Radiation Shielding Concrete

    Science.gov (United States)

    Azeez, Ali Basheer; Mohammed, Kahtan S.; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Sandu, Andrei Victor; Razak, Rafiza Abdul

    2013-01-01

    Samples of concrete contain various waste materials, such as iron particulates, steel balls of used ball bearings and slags from steel industry were assessed for their anti-radiation attenuation coefficient properties. The attenuation measurements were performed using gamma spectrometer of NaI (Tl) detector. The utilized radiation sources comprised 137Cs and 60Co radioactive elements with photon energies of 0.662 MeV for 137Cs and two energy levels of 1.17 and 1.33 MeV for the 60Co. Likewise the mean free paths for the tested samples were obtained. The aim of this work is to investigate the effect of the waste loading rates and the particulate dispersive manner within the concrete matrix on the attenuation coefficients. The maximum linear attenuation coefficient (μ) was attained for concrete incorporates iron filling wastes of 30 wt %. They were of 1.12 ± 1.31×10−3 for 137Cs and 0.92 ± 1.57 × 10−3 for 60Co. Substantial improvement in attenuation performance by 20%–25% was achieved for concrete samples incorporate iron fillings as opposed to that of steel ball samples at different (5%–30%) loading rates. The steel balls and the steel slags gave much inferior values. The microstructure, concrete-metal composite density, the homogeneity and particulate dispersion were examined and evaluated using different metallographic, microscopic and measurement facilities. PMID:28788363

  15. Effects of Mental Fatigue on Physical Endurance Performance and Muscle Activation Are Attenuated by Monetary Incentives.

    Science.gov (United States)

    Brown, Denver M Y; Bray, Steven R

    2017-12-01

    Physical performance is impaired following cognitive control exertion. Incentives can ameliorate adverse carryover effects of cognitive control exertion but have not been investigated for physical endurance. This study examined the effect of monetary incentives on physical performance and muscle activation following exposure to a mentally fatiguing, cognitive control task. Participants (N = 82) performed two isometric endurance handgrip trials separated by a 12-min cognitive control manipulation using a 2 (high cognitive control [HCC]/low cognitive control [LCC]) × 2 (incentive/no incentive) design. Mental fatigue was significantly higher in the HCC conditions. Performance decreased in the HCC/no incentive condition but was unaffected in the HCC/incentive condition, which did not differ from the low cognitive control conditions. Electromyography data revealed increased muscle activation in the HCC/no incentive condition, which was also attenuated in the HCC/incentive condition. Findings show that incentives counteract the negative effects of HCC on physical endurance and alter central drive to motor units.

  16. SPECT quantification: a review of the different correction methods with compton scatter, attenuation and spatial deterioration effects

    International Nuclear Information System (INIS)

    Groiselle, C.; Rocchisani, J.M.; Moretti, J.L.; Dreuille, O. de; Gaillard, J.F.; Bendriem, B.

    1997-01-01

    SPECT quantification: a review of the different correction methods with Compton scatter attenuation and spatial deterioration effects. The improvement of gamma-cameras, acquisition and reconstruction software opens new perspectives in term of image quantification in nuclear medicine. In order to meet the challenge, numerous works have been undertaken in recent years to correct for the different physical phenomena that prevent an exact estimation of the radioactivity distribution. The main phenomena that have to betaken into account are scatter, attenuation and resolution. In this work, authors present the physical basis of each issue, its consequences on quantification and the main methods proposed to correct them. (authors)

  17. Effects of the concentration of emulsion of oil-in-water on the propagation velocity and attenuation

    International Nuclear Information System (INIS)

    Silva, L S F; Bibiano, D S; Figueiredo, M K K; Costa-Félix, R P B

    2015-01-01

    Soybean oil is an important feedstock for production of biodiesel that generates about 20 % of oily effluents. This paper studied the effect of concentration of soybean oil-inwater emulsions, in the range from 6 000 to 14 000 ppm, on the propagation velocity and ultrasonic attenuation. The Emission-Reception method has shown that the propagation velocity depends linearly on the concentration. The behavior of attenuation is similar to the velocity. Thus, both parameters can be used to measure oils and greases content in water

  18. Effects of the Length of Stay on the Cost of Total Knee and Total Hip Arthroplasty from 2002 to 2013.

    Science.gov (United States)

    Molloy, Ilda B; Martin, Brook I; Moschetti, Wayne E; Jevsevar, David S

    2017-03-01

    Utilization of total knee and hip arthroplasty has greatly increased in the past decade in the United States; these are among the most expensive procedures in patients with Medicare. Advances in surgical techniques, anesthesia, and care pathways decrease hospital length of stay. We examined how trends in hospital cost were altered by decreases in length of stay. Procedure, demographic, and economic data were collected on 6.4 million admissions for total knee arthroplasty and 2.8 million admissions for total hip arthroplasty from 2002 to 2013 using the National (Nationwide) Inpatient Sample, a component of the Healthcare Cost and Utilization Project. Trends in mean hospital costs and their association with length of stay were estimated using inflation-adjusted, survey-weighted generalized linear regression models, controlling for patient demographic characteristics and comorbidity. From 2002 to 2013, the length of stay decreased from a mean time of 4.06 to 2.97 days for total knee arthroplasty and from 4.06 to 2.75 days for total hip arthroplasty. During the same time period, the mean hospital cost for total knee arthroplasty increased from $14,988 (95% confidence interval [CI], $14,927 to $15,049) in 2002 to $22,837 (95% CI, $22,765 to $22,910) in 2013 (an overall increase of $7,849 or 52.4%). The mean hospital cost for total hip arthroplasty increased from $15,792 (95% CI, $15,706 to $15,878) in 2002 to $23,650 (95% CI, $23,544 to $23,755) in 2013 (an increase of $7,858 or 49.8%). If length of stay were set at the 2002 mean, the growth in cost for total knee arthroplasty would have been 70.8% instead of 52.4% as observed, and the growth in cost for total hip arthroplasty would have been 67.4% instead of 49.8% as observed. Hospital costs for joint replacement increased from 2002 to 2013, but were attenuated by reducing inpatient length of stay. With demographic characteristics showing an upward trend in the utilization of joint arthroplasty, including a shift

  19. The effects of session length on demand functions generated using FR schedules.

    Science.gov (United States)

    Foster, T Mary; Kinloch, Jennifer; Poling, Alan

    2011-05-01

    In comparing open and closed economies, researchers often arrange shorter sessions under the former condition than under the latter. Several studies indicate that session length per se can affect performance and there are some data that indicate that this variable can influence demand functions. To provide further data, the present study exposed domestic hens to series of increasing fixed-ratio schedules with the length of the open-economy sessions varied over 10, 40, 60, and 120 min. Session time affected the total-session response rates and pause lengths. The shortest session gave the greatest response rates and shortest pauses and the longest gave the lowest response rates and longest pauses. The total-session demand functions also changed with session length: The shortest session gave steeper initial slopes (i.e., the functions were more elastic at small ratios) and smaller rates of change of elasticity than the longest session. Response rates, pauses, and demand functions were, however, similar for equivalent periods of responding taken from within sessions of different overall lengths (e.g., total-session data for 10-min sessions and the data for the first 10 min of 120-min sessions). These findings suggest that differences in session length can confound the results of studies comparing open and closed economies when those economies are arranged in sessions that differ substantially in length, hence data for equivalent-length periods of responding, rather than total-session data, should be of primary interest under these conditions.

  20. The effects of different pot length and growing media on seedling ...

    African Journals Online (AJOL)

    The aim of this study was to determine appropriate pot length and growing medium for Crimean Juniper seedlings (Juniperus excelsa Bieb.), which will be used for afforestation of extreme areas. For this purpose, polyethylene pots of 11 cm width and 20, 25 and 30 cm lengths were used. As growing medium, 13 different ...

  1. Effect of temperature and cycle length on microbial competition in PHB-producing sequencing batch reactor

    NARCIS (Netherlands)

    Jiang, Y.; Marang, L.; Kleerebezem, R.; Muyzer, G.; van Loosdrecht, M.C.M.

    2011-01-01

    The impact of temperature and cycle length on microbial competition between polyhydroxybutyrate (PHB)-producing populations enriched in feast-famine sequencing batch reactors (SBRs) was investigated at temperatures of 20 °C and 30 °C, and in a cycle length range of 1-18 h. In this study, the

  2. The Effects of Iodine Attenuation on Pulmonary Nodule Volumetry using Novel Dual-Layer Computed Tomography Reconstructions

    NARCIS (Netherlands)

    den Harder, A M; Bangert, F; van Hamersvelt, R W; Leiner, T; Milles, Julien; Schilham, A M R; Willemink, M J; de Jong, P A

    2017-01-01

    OBJECTIVES: To assess the effect of iodine attenuation on pulmonary nodule volumetry using virtual non-contrast (VNC) and mono-energetic reconstructions. METHODS: A consecutive series of patients who underwent a contrast-enhanced chest CT scan were included. Images were acquired on a novel

  3. Effective attenuation of macroseismic intensity with distance according to data on the Racha earthquake of April 29, 1991

    International Nuclear Information System (INIS)

    Jibladze, E.; Butikashvili, N.; Glonti, E.

    2004-01-01

    The effective coefficient of attenuation of macroseismic intensity with distance is studied for the Racha earthquake region. The study is based on macroseismic data on the Racha earthquake of April 29, 1991. The Blake-Shebalin formula for macroseismic field was used. Proceeding from the energy model of the earthquake focus, we consider the intensity for point, linear and volumetric foci. (authors)

  4. Effect of temperature on atom-atom collision chain length in metals

    International Nuclear Information System (INIS)

    Makarov, A.A.; Demkin, N.A.; Lyashchenko, B.G.

    1981-01-01

    Focused atom-atom collision chain lengths are calculated for fcc-crystals with account of thermal oscillations. The model of solid spheres with the Born-Merier potential has been used in the calculations. The dependence of chain lengths on the temperature, energy and movement direction of the first chain atom for Cu, Au, Ag, Pb, Ni is considered. The plot presented shows that the chain lengths strongly decrease with temperature growth, for example, for the gold at T=100 K the chain length equals up to 37 interatomic spacings, whereas at T=1000 K their length decreases down to 5 interatomic distances. The dependence of the energy loss by the chain atoms on the atom number in the chain is obtained in a wide range of crystal temperature and the primary chain atom energy [ru

  5. Effects of G-CSF on telomere lengths in PBMCs from human immunodeficiency virus-infected patients

    DEFF Research Database (Denmark)

    Aladdin, H; Ullum, H; Schjerling, P

    2000-01-01

    , and not in CD4+ T cells. In this double-blind placebo-controlled study, we investigated the effect of granulocyte colony stimulating factor (G-CSF) treatment combined with highly active antiretroviral therapy (HAART) on mean telomere length in peripheral blood mononuclear cells (PBMC). The terminal restriction...... fragment (TRF) length showed no changes during G-CSF treatment although the number of lymphocytes increased significantly. The mean TRF length correlated positively (R = 0.552, P = 0.009) and negatively (R = -0.503, P = 0.02) to the proportion of CD4+ memory and naïve cells, respectively. Our data suggest...

  6. Coulomb corrections to nuclear scattering lengths and effective ranges for weakly bound systems

    International Nuclear Information System (INIS)

    Mur, V.D.; Popov, V.S.; Sergeev, A.V.

    1996-01-01

    A procedure is considered for extracting the purely nuclear scattering length as and effective range rs (which correspond to a strong-interaction potential Vs with disregarded Coulomb interaction) from the experimentally determined nuclear quantities acs and rcs, which are modified by Coulomb interaction. The Coulomb renormalization of as and rs is especially strong if the system under study involves a level with energy close to zero (on the nuclear scale). This applies to formulas that determine the Coulomb renormalization of the low-energy parameters of s scattering (l=0). Detailed numerical calculations are performed for coefficients appearing in the equations that determine Coulomb corrections for various models of the potential Vs(r). This makes it possible to draw qualitative conclusions that the dependence of Coulomb corrections on the form of the strong-interaction potential and, in particular, on its small-distance behavior. A considerable enhancement of Coulomb corrections to the effective range rs is found for potentials with a barrier

  7. Effect of ultrasonic stimulation on particle transport and fate over different lengths of porous media

    Science.gov (United States)

    Chen, Xingxin; Wu, Zhonghan; Cai, Qipeng; Cao, Wei

    2018-04-01

    It is well established that seismic waves traveling through porous media stimulate fluid flow and accelerate particle transport. However, the mechanism remains poorly understood. To quantify the coupling effect of hydrodynamic force, transportation distance, and ultrasonic stimulation on particle transport and fate in porous media, laboratory experiments were conducted using custom-built ultrasonic-controlled soil column equipment. Three column lengths (23 cm, 33 cm, and 43 cm) were selected to examine the influence of transportation distance. Transport experiments were performed with 0 W, 600 W, 1000 W, 1400 W, and 1800 W of applied ultrasound, and flow rates of 0.065 cm/s, 0.130 cm/s, and 0.195 cm/s, to establish the roles of ultrasonic stimulation and hydrodynamic force. The laboratory results suggest that whilst ultrasonic stimulation does inhibit suspended-particle deposition and accelerate deposited-particle release, both hydrodynamic force and transportation distance are the principal controlling factors. The median particle diameter for the peak concentration was approximately 50% of that retained in the soil column. Simulated particle-breakthrough curves using extended traditional filtration theory effectively described the experimental curves, particularly the curves that exhibited a higher tailing concentration.

  8. Caspase-3 Inhibition Attenuates the Cytopathic Effects of EV71 Infection

    Directory of Open Access Journals (Sweden)

    Fengmei Song

    2018-04-01

    Full Text Available Previous studies demonstrate that human enterovirus 71 (EV71, a primary causative agent for hand, foot, and mouth disease, activates caspase-3 through the non-structural viral 3C protein to induce host cell apoptosis; however, until now it was unclear how 3C activates caspase-3 and how caspase-3 activation affects viral production. Our results demonstrate that 3C binds caspase-8 and caspase-9 but does not directly bind caspase-3 to activate them, and that the proteolytic activity of 3C is required by the activation of caspase-8, caspase-9, and caspase-3. Inhibition of caspase-3 activity attenuates apoptosis in 3C-transfected cells. Furthermore, caspase-3 inhibitor protects host cells from the cytopathic effect of EV71 infection and prevents cell cycle arrest, which is known to be favored for EV71 viral replication. Inhibition of caspase-3 activity decreases EV71 viral protein expression and viral production, but has no effect on viral entry, replication, even polyprotein translation. Therefore, caspase-3 is exploited functionally by EV71 to facilitate its production, which suggests a novel therapeutic approach for the treatment and prevention of hand, foot, and mouth disease.

  9. The power of exercise: buffering the effect of chronic stress on telomere length.

    Directory of Open Access Journals (Sweden)

    Eli Puterman

    2010-05-01

    Full Text Available Chronic psychological stress is associated with detrimental effects on physical health, and may operate in part through accelerated cell aging, as indexed by shorter telomeres at the ends of chromosomes. However, not all people under stress have distinctly short telomeres, and we examined whether exercise can serve a stress-buffering function. We predicted that chronic stress would be related to short telomere length (TL in sedentary individuals, whereas in those who exercise, stress would not have measurable effects on telomere shortening.63 healthy post-menopausal women underwent a fasting morning blood draw for whole blood TL analysis by a quantitative polymerase chain reaction method. Participants completed the Perceived Stress Scale (Cohen et al., 1983, and for three successive days reported daily minutes of vigorous activity. Participants were categorized into two groups-sedentary and active (those getting Centers for Disease Control-recommended daily amount of activity. The likelihood of having short versus long telomeres was calculated as a function of stress and exercise group, covarying age, BMI and education. Logistic regression analyses revealed a significant moderating effect of exercise. As predicted, among non-exercisers a one unit increase in the Perceived Stress Scale was related to a 15-fold increase in the odds of having short telomeres (p<.05, whereas in exercisers, perceived stress appears to be unrelated to TL (B = -.59, SE = .78, p = .45.Vigorous physical activity appears to protect those experiencing high stress by buffering its relationship with TL. We propose pathways through which physical activity acts to buffer stress effects.

  10. Diffusion effects on volume-selective NMR at small length scales

    International Nuclear Information System (INIS)

    Gaedke, Achim

    2009-01-01

    In this thesis, the interplay between diffusion and relaxation effects in spatially selective NMR experiments at short length scales is explored. This is especially relevant in the context of both conventional and mechanically detected MRI at (sub)micron resolution in biological specimens. Recent results on selectively excited very thin slices showed an in-slice-magnetization recovery orders of magnitude faster than the longitudinal relaxation time T1. However, those experiments were run on fully relaxed samples while MRI and especially mechanically detected NMR experiments are typically run in a periodic fashion with repetition times far below T1. The main purpose of this work therefore was to extend the study of the interplay between diffusion and longitudinal relaxation to periodic excitations. In some way, this is inverse phenomenon to the DESIRE (Diffusive Enhancement of SIgnal and REsolution) approach, proposed 1992 by Lauterbur. Experiments on periodically excited thin slices were carried out at a dedicated static field gradient cryomagnet with magnetic field gradients up to 180 T/m. In order to obtain plane slices, an appropriate isosurface of the gradient magnet had to be identified. It was found at a field of 3.8 T with a gradient of 73 T/m. In this field, slices down to a thickness of 3.2 μm could be excited. The detection of the NMR signal was done using FIDs instead of echoes as the excitation bandwidth of those thin slices is sufficiently small to observe FIDs which are usually considered to be elusive to detection in such strong static field gradients. A simulation toolbox based on the full Bloch-Torrey-equation was developed to describe the excitation and the formation of NMR signals under those unusual conditions as well as the interplay of diffusion and magnetization recovery. Both the experiments and the simulations indicate that diffusion effects lead to a strongly enhanced magnetization modulation signal also under periodic excitation

  11. Effects of scatter and attenuation corrections on phantom and clinical brain SPECT

    International Nuclear Information System (INIS)

    Prando, S.; Robilotta, C.C.R.; Oliveira, M.A.; Alves, T.C.; Busatto Filho, G.

    2002-01-01

    Aim: The present work evaluated the effects of combinations of scatter and attenuation corrections on the analysis of brain SPECT. Materials and Methods: We studied images of the 3D Hoffman brain phantom and from a group of 20 depressive patients with confirmed cardiac insufficiency (CI) and 14 matched healthy controls (HC). Data were acquired with a Sophy-DST/SMV-GE dual-head camera after venous injection of 1110MBq 99m Tc-HMPAO. Two energy windows, 15% on 140keV and 30% centered on 108keV of the Compton distribution, were used to obtain corresponding sets of 128x128x128 projections. Tomograms were reconstructed using OSEM (2 iterations, 8 sub-sets) and Metz filter (order 8, 4 pixels FWHM psf) and FBP with Butterworth filter (order 10, frequency 0.7 Nyquist). Ten combinations of Jaszczak correction (factors 0.3, 0.4 and 0.5) and the 1st order Chang correction (u=0.12cm -1 and 0.159cm -1 ) were applied on the phantom data. In all the phantom images, contrast and signal-noise ratio between 3 ROIs (ventricle, occipital and thalamus) and cerebellum, as well as the ratio between activities in gray and white matters, were calculated and compared with the expected values. The patients images were corrected with k=0.5 and u=0.159cm -1 and reconstructed with OSEM and Metz filter. The images were inspected visually and blood flow comparisons between the CI and the HC groups were performed using Statistical Parametric Mapping (SPM). Results: The best results in the analysis of the contrast and activities ratio were obtained with k=0.5 and u=0.159cm -1 . The results of the activities ratio obtained with OSEM e Metz filter are similar to those published by Laere et al.[J.Nucl.Med 2000;41:2051-2062]. The method of correction using effective attenuation coefficient produced results visually acceptable, but inadequate for the quantitative evaluation. The results of signal-noise ratio are better with OSEM than FBP reconstruction method. The corrections in the CI patients studies

  12. Effect of Air Pollution on Menstrual Cycle Length-A Prognostic Factor of Women's Reproductive Health.

    Science.gov (United States)

    Merklinger-Gruchala, Anna; Jasienska, Grazyna; Kapiszewska, Maria

    2017-07-20

    Air pollution can influence women's reproductive health, specifically menstrual cycle characteristics, oocyte quality, and risk of miscarriage. The aim of the study was to assess whether air pollution can affect the length of the overall menstrual cycle and the length of its phases (follicular and luteal). Municipal ecological monitoring data was used to assess the air pollution exposure during the monitored menstrual cycle of each of 133 woman of reproductive age. Principal component analyses were used to group pollutants (PM 10 , SO₂, CO, and NO x ) to represent a source-related mixture. PM 10 and SO₂ assessed separately negatively affected the length of the luteal phase after standardization (b = -0.02; p = 0.03; b = -0.06; p = 0.02, respectively). Representing a fossil fuel combustion emission, they were also associated with luteal phase shortening (b = -0.32; p = 0.02). These pollutants did not affect the follicular phase length and overall cycle length, neither in single- nor in multi-pollutant models. CO and NO x assessed either separately or together as a traffic emission were not associated with overall cycle length or the length of cycle phases. Luteal phase shortening, a possible manifestation of luteal phase deficiency, can result from fossil fuel combustion. This suggests that air pollution may contribute to fertility problems in women.

  13. Effects of light attenuation on the sponge holobiont-implications for dredging management

    DEFF Research Database (Denmark)

    Pineda, Mari Carmen; Strehlow, Brian; Duckworth, Alan

    2016-01-01

    Dredging and natural sediment resuspension events can cause high levels of turbidity, reducing the amount of light available for photosynthetic benthic biota. To determine how marine sponges respond to light attenuation, five species were experimentally exposed to a range of light treatments......, indicating that light attenuation poses a risk to photosynthetic marine sponges. Examining benthic light levels over temporal scales would enable dredging proponents to be aware of conditions that could impact on sponge physiology....

  14. The effect of carbon chain length of starting materials on the formation of carbon dots and their optical properties

    Science.gov (United States)

    Pan, Xiaohua; Zhang, Yan; Sun, Xiaobo; Pan, Wei; Yu, Guifeng; Si, Shuxin; Wang, Jinping

    2018-04-01

    Carbon dots (CDs) have attracted increasing attention due to their high performances and potential applications in wide range of areas. However, their emission mechanism is not clear so far. In order to reveal more factors contributing to the emission of CDs, the effect of carbon chain length of starting materials on the formation of CDs and their optical properties was experimentally investigated in this work. In order to focus on the effect of carbon chain length, the starting materials with C, O, N in fully identical forms and only carbon chain lengths being different were selected for synthesizing CDs, including citric acid (CA) and adipic acid (AA) as carbon sources, and diamines with different carbon chain lengths (H2N(CH2)nNH2, n = 2, 4, 6) as nitrogen sources, as well as ethylenediamine (EDA) as nitrogen source and diacids with different carbon chain lengths (HOOC(CH2)nCOOH, n = 0, 2, 4, 6) as carbon sources. Therefore, the effect of carbon chain length of starting materials on the formation and optical properties of CDs can be systematically investigated by characterizing and comparing the structures and optical properties of as-prepared nine types of CDs. Moreover, the density of –NH2 on the surface of the CDs was quantitatively detected by a spectrophotometry so as to elucidate the relationship between the –NH2 related surface state and the optical properties.

  15. The effects of age and step length on joint kinematics and kinetics of large out-and-back steps.

    Science.gov (United States)

    Schulz, Brian W; Ashton-Miller, James A; Alexander, Neil B

    2008-06-01

    Maximum step length (MSL) is a clinical test that has been shown to correlate with age, various measures of fall risk, and knee and hip joint extension speed, strength, and power capacities, but little is known about the kinematics and kinetics of the large out-and-back step utilized. Body motions and ground reaction forces were recorded for 11 unimpaired younger and 10 older women while attaining maximum step length. Joint kinematics and kinetics were calculated using inverse dynamics. The effects of age group and step length on the biomechanics of these large out-and-back steps were determined. Maximum step length was 40% greater in the younger than in the older women (P<0.0001). Peak knee and hip, but not ankle, angle, velocity, moment, and power were generally greater for younger women and longer steps. After controlling for age group, step length generally explained significant additional variance in hip and torso kinematics and kinetics (incremental R2=0.09-0.37). The young reached their peak knee extension moment immediately after landing of the step out, while the old reached their peak knee extension moment just before the return step liftoff (P=0.03). Maximum step length is strongly associated with hip kinematics and kinetics. Delays in peak knee extension moment that appear to be unrelated to step length, may indicate a reduced ability of older women to rapidly apply force to the ground with the stepping leg and thus arrest the momentum of a fall.

  16. Journey length and high temperatures: effects on rabbit welfare and meat quality.

    Science.gov (United States)

    Liste, G; María, G A; Buil, T; García-Belenguer, S; Chacón, G; Olleta, J L; Sañudo, C; Villarroel, M

    2006-02-01

    The transport of domestic animals by road can increase levels of stress and decrease meat quality, especially in unfavourable climates. The purpose of this study was to investigate the effect of journey duration and vertical position on the transport truck on some physiological indicators of stress and on instrumental meat quality parameters in commercial rabbits. In the summer months (June and July, 2003), 78 rabbits were subjected to either long (7 h) (LJ) or short (1 h) (SJ) journeys (3 replicates each, n = 6) between the farm and an abattoir in northern Spain. The position (top, middle, or bottom) occupied by the rabbits on the Multi-Floor cage Rolling Stand (MFRS) of the transport truck was recorded. Blood samples were collected at sticking and meat pH was measured at 24 h post-mortem (pH24). At 48 h post-mortem, samples of the M. longissimus dorsi were used to determine water-holding capacity (WHC) and instrumental tenderness using an INSTRON machine. The levels of corticosterone, glucose, lactate, and creatine kinase were slightly higher in LJ than in SJ samples, but the difference was not statistically significant (p MFRS showed higher levels (p < or = 0.05) of glucose and creatine kinase (middle), and corticosterone (bottom) than the rabbits located at the top floor. The pH 24 and WHC values of the SJ and LJ rabbits did not differ significantly. Journey length had a significant effect (p < or = 0.01) on meat tenderness. The meat from rabbits subjected to LJ had higher values of maximum stress and total toughness than did the SJ rabbits (p < or = 0.05). There were similar differences (p < or = 0.05) between LJ and SJ rabbits in their stress values of compression at 20% and 40% (measures of the tenderness of raw meat). In hot weather, the position on the transport truck appeared to have a greater effect on rabbit welfare than the duration of the journey.

  17. Dose titration of BAF312 attenuates the initial heart rate reducing effect in healthy subjects.

    Science.gov (United States)

    Legangneux, Eric; Gardin, Anne; Johns, Donald

    2013-03-01

    Previous studies have shown transient decreases in heart rate (HR) following administration of sphingosine 1-phosphate (S1P) receptor modulators including BAF312. This study was conducted to determine whether dose titration of BAF312 reduces or eliminates these effects. Fifty-six healthy subjects were randomized 1:1:1:1 to receive BAF312 in one of two dose titration (DT) regimens (DT1 and DT2: 0.25-10 mg over 9-10 days), no titration (10 mg starting dose) or placebo. Pharmacodynamic and pharmacokinetic parameters were assessed. Neither DT1 nor DT2 resulted in clinically significant bradycardia or atrioventricular conduction effects. Both titration regimens showed a favourable difference on each of days 1-12 vs. the non-titration regimen on day 1 for HR effects (P titration was 1.18 (95% confidence interval [CI] 1.13, 1.23) and 1.14 (95% CI 1.09, 1.18) for DT2 (both P titration HRs showed considerable separation from placebo throughout the study. There was no statistically significant reduction in HR vs. placebo on day 1 in either titration regimen. On days 3-7 subjects in DT1 and DT2 experienced minor reductions in HR vs. placebo (approximately 5 beats min⁻¹; P ≤ 0.0001). From days 9-12, HRs in both titration regimens were comparable with placebo. Both titration regimens effectively attenuated the initial bradyarrhythmia observed on day 1 of treatment with BAF312 10 mg. © 2012 Novartis Institutes for BioMedical Research (NIBIR). British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

  18. Urtica dioica attenuate effect of Doxorobicin‐Induced changes on sperm parameters in the mice

    Directory of Open Access Journals (Sweden)

    Zahra Baninameh

    2016-11-01

    Full Text Available Doxorubicin (DXR is used as an antitumor agent for the treatment of human neoplasm. The use of DXR has adverse effect on reproductive system including testicular toxicity and alteration in semen quality. The aim of this study was to evaluate the protective effects of Urtica dioica against Doxorobicin‐Induced changes on sperm parameters. 24 male mice were randomly divided into 4 groups. Control group received normal saline solution throughout the course of the study. Urtica dioica (UD control group, received UD (100 mg/kg body weight thrice in a week and DOX (3 mg/kg body weight once in a week injected intraperitoneally in Doxorubicin (DXR control group and Urtica dioica- Doxorubicin (UD-DXR group, received Urtica dioica (100 mg/kg body weight three times in a week and DOX (3 mg/kg body weight once in a week through the route for a period of 2 weeks. At the end of experimental period, all animal were sacrificed by cervical dislocation, their epididymes were removed and sperm analysis were done. In mice with DXR administration, epididymal sperm motility, progressive motility, sperm count and viability significantly decrease while sperm cells with abnormal morphology significantly increase when compared with control groups. Co-treatment with UD attenuate toxicity effect of DXR and improve sperm parameters. Results of our study showed that UD diminished DXR-induced testicular toxicity and improve semen parameters, thus suggesting its co-administration as a protective agent during doxorubicin treatment. Further studies should be aimed to determine protective effect of UD against chemotherapeutic agents such as DXR.

  19. Effects of pulse-length and emitter area on virtual cathode formation in electron guns

    International Nuclear Information System (INIS)

    Valfells, Agust; Feldman, D.W.; Virgo, M.; O'Shea, P.G.; Lau, Y.Y.

    2002-01-01

    Recent experiments at the University of Maryland using photoemission from a dispenser cathode have yielded some interesting results regarding the effects of the area of emission and of the ratio between the pulse length and the gap transit time on the amount of current that may be drawn from an electron gun before a virtual cathode forms. The experiments show that a much higher current density may be drawn from a short pulse or limited emitter area than is anticipated by the Child-Langmuir limiting current. There is also evidence that the current may be increased even after virtual cathode formation, which leads a distinction between a limiting current density and a current density critical for virtual cathode formation. The experiments have also yielded some interesting results on the longitudinal structure of the current pulse passed through the anode. Some empirical and theoretical scaling laws regarding the formation of virtual cathodes in an electron gun will be presented. This work was motivated by the needs of the University of Maryland Electron Ring (UMER) [P. G. O'Shea, M. Reiser, R. A. Kishek et al., Nucl. Instrum. Methods Phys. Res. A 464, 646 (2001)] where the goal is to generate pulses that are well-localized in time and space

  20. Effect of length of dental resident clinical rotations on patient behavior.

    Science.gov (United States)

    Lau, Agnes

    2018-01-01

    The purpose of this retrospective chart review study was to determine if the length of residents' comprehensive dental care rotations in a general practice residency affected late cancellations, broken appointments, completion of treatment, timeliness of recall visits, emergency visits, and the need for redo of restorations and prostheses. Patients who presented for comprehensive care from 2010 to 2013, during which residents had 3- to 4-month dental clinic rotations, comprised Group 1, and patients who presented for comprehensive care from 2013 to 2016, during which residents had 11-month dental clinic rotations, comprised Group 2. Subjects were excluded if they only presented for emergency care, they had only one visit, or their care was delivered in both time periods. There were 105 patients in Group 1 and 55 patients in Group 2. The statistically significant results were that Group 1 patients had more late cancellations and broken appointments and failed to reach recall status more often than Group 2 patients, and that Group 1 patients had fewer emergency visits. Within the limitations of this retrospective study, the results suggest that short block rotations have an adverse effect on resident experience and outcomes of patient care in a hospital outpatient setting. © 2018 Special Care Dentistry Association and Wiley Periodicals, Inc.

  1. Colorimetric detection with aptamer–gold nanoparticle conjugates: effect of aptamer length on response

    International Nuclear Information System (INIS)

    Chávez, Jorge L.; MacCuspie, Robert I.; Stone, Morley O.; Kelley-Loughnane, Nancy

    2012-01-01

    A riboflavin binding aptamer (RBA) was used in combination with gold nanoparticles (AuNPs) to detect riboflavin in vitro. The RBA–AuNP conjugates (RBA–AuNPs) responded colorimetrically to the presence of riboflavin and this response could be followed by the naked eye. This system was used as a model to study how modifications on the aptamer sequence affect the RBA–AuNPs’ stability and their response to their target. To mimic primers and other sequence modifications typically used in aptamer work, the RBA was extended by adding extra bases to its 5′ end. These extra bases were designed to avoid interactions with the RBA binding site. The response of these RBA–AuNPs was evaluated and compared. Dynamic light scattering and UV-aggregation kinetics studies showed that the length of the aptamer significantly affected the RBA–AuNPs’ stability and, as a consequence, the magnitude of the detection response to riboflavin. The addition of thymine nucleotides instead of random tails to the RBA showed that the effects observed were not specific to the sequence used. This study shows that modifications of the aptamer sequence provide a means to improve the stability of aptamer–AuNPs conjugates and their sensing response.

  2. Colorimetric detection with aptamer-gold nanoparticle conjugates: effect of aptamer length on response

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, Jorge L. [Wright-Patterson Air Force Base, 711th Human Performance Wing, Human Effectiveness Directorate, Air Force Research Laboratory (United States); MacCuspie, Robert I. [National Institute of Standards and Technology, Ceramics Division (United States); Stone, Morley O.; Kelley-Loughnane, Nancy, E-mail: Nancy.Kelley-Loughnane@wpafb.af.mil [Wright-Patterson Air Force Base, 711th Human Performance Wing, Human Effectiveness Directorate, Air Force Research Laboratory (United States)

    2012-10-15

    A riboflavin binding aptamer (RBA) was used in combination with gold nanoparticles (AuNPs) to detect riboflavin in vitro. The RBA-AuNP conjugates (RBA-AuNPs) responded colorimetrically to the presence of riboflavin and this response could be followed by the naked eye. This system was used as a model to study how modifications on the aptamer sequence affect the RBA-AuNPs' stability and their response to their target. To mimic primers and other sequence modifications typically used in aptamer work, the RBA was extended by adding extra bases to its 5 Prime end. These extra bases were designed to avoid interactions with the RBA binding site. The response of these RBA-AuNPs was evaluated and compared. Dynamic light scattering and UV-aggregation kinetics studies showed that the length of the aptamer significantly affected the RBA-AuNPs' stability and, as a consequence, the magnitude of the detection response to riboflavin. The addition of thymine nucleotides instead of random tails to the RBA showed that the effects observed were not specific to the sequence used. This study shows that modifications of the aptamer sequence provide a means to improve the stability of aptamer-AuNPs conjugates and their sensing response.

  3. The Effect of Culture Type on the Length of Persian Proverbs Compared to their English Equivalents

    Directory of Open Access Journals (Sweden)

    Amir Mohammadian

    2017-05-01

    Full Text Available The interrelation of culture and language is to the extent that many classifications of culture are based on linguistic factors. In this article, high and low context cultures division is assessed on English and Persian as they belong to different cultural types. Forty Persian proverbs are contrasted with their equivalents in English to investigate whether there is a difference in the number of word forms used in each. In order to avoid linguistic differences which are effective in enumerating word forms, the second lines in linguistic glosses provided for Persian proverbs including a one to one correspondence of each word in English are used to count word forms. Results show that 70 percent of the Persian proverbs in the data are longer than their English counterparts. This shows that relative length of proverbs can be a distinguishing factor reflecting cultural types. The results not only confirm the applicability of this cultural division in the field of proverbs, but also a matter of tendency rather than a dichotomy in belonging to a high or low context culture is proposed. At the end, there are suggestions for further relevant investigations.

  4. Effects of solid-liquid separation and storage on monensin attenuation in dairy waste management systems

    Science.gov (United States)

    Hafner, Sarah C.; Watanabe, Naoko; Harter, Thomas; Bergamaschi, Brian; Parikh, Sanjai J.

    2017-01-01

    Environmental release of veterinary pharmaceuticals has been of regulatory concern for more than a decade. Monensin is a feed additive antibiotic that is prevalent throughout the dairy industry and is excreted in dairy waste. This study investigates the potential of dairy waste management practices to alter the amount of monensin available for release into the environment. Analysis of wastewater and groundwater from two dairy farms in California consistently concluded that monensin is most present in lagoon water and groundwater downgradient of lagoons. Since the lagoons represent a direct source of monensin to groundwater, the effect of waste management, by mechanical screen separation and lagoon aeration, on aqueous monensin concentration was investigated through construction of lagoon microcosms. The results indicate that monensin attenuation is not improved by increased solid-liquid separation prior to storage in lagoons, as monensin is rapidly desorbed after dilution with water. Monensin is also shown to be easily degraded in lagoon microcosms receiving aeration, but is relatively stable and available for leaching under typical anaerobic lagoon conditions.

  5. Effect of alkyl length of cationic surfactants on desorption of Cs from contaminated clay

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bo Hyun; Park, Chan Woo; Yang, Hee Man; Seo, Bum Kyoung; Lee, Kune Woo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, So Jin [Chungnam National University, Daejeon (Korea, Republic of)

    2017-03-15

    In this study, desorption characteristics of Cs from clay according to the hydrophobic alkyl chain length of the cationic surfactant were investigated. Alkyltrimethylammonium bromide was used as a cationic surfactant, and the length of the hydrophobic alkyl chain of the cationic surfactant was varied from –octyl to –cetyl. The adsorbed amount of the cationic surfactant on montmorillonite increased with the length of the hydrophobic alkyl chain, and intercalation of the cationic surfactant into the clay interlayer increased the interlayer distances. The Cs removal efficiency was also enhanced with increasing alkyl chain length, and the cationic surfactant with the cetyl group showed a maximum Cs removal efficiency of 99±2.9%.

  6. Effect of Nanopore Length on the Translocation Process of a Biopolymer: Numerical Study

    Directory of Open Access Journals (Sweden)

    Yong Kweon Suh

    2013-09-01

    Full Text Available In this study, we simulate the electrophoretic motion of a bio-polymer through a synthetic nanopore in the presence of an external bias voltage by considering the hydrodynamic interactions between the polymer and the fluid explicitly. The motion of the polymer is simulated by 3D Langevin dynamics technique by modeling the polymer as a worm-like-chain, while the hydrodynamic interactions are incorporated by the lattice Boltzmann equation. We report the simulation results for three different lengths of the nanopore. The translocation time increases with the pore length even though the electrophoretic force on the polymer is the same irrespective of the pore length. This is attributed to the fact that the translocation velocity of each bead inside the nanopore decreases with the pore length due to the increased fluid resistance force caused by the increase in the straightened portion of the polymer. We confirmed this using a theoretical formula.

  7. Thermal Conductivity of Nanotubes Revisited: Effects of Chirality, Isotope Impurity, Tube Length, and Temperature

    OpenAIRE

    Zhang, Gang; Li, Baowen

    2004-01-01

    We study the dependence of thermal conductivity of single walled nanotubes (SWNT) on chirality, isotope impurity, tube length and temperature by nonequilibrium molecular dynamics method with accurate potentials. It is found that, contrary to electronic conductivity, the thermal conductivity is insensitive to the chirality. The isotope impurity, however, can reduce the thermal conductivity up to 60% and change the temperature dependence behavior. We also found that the tube length dependence o...

  8. Effects of Foodstuffs on Intestinal Length in Larvae of Rhacophorus arboreus (Anura: Rhacophoridae) : Developmental Biology

    OpenAIRE

    SHINRI, HORIUCHI; YUTAKA, KOSHIDA; Department of Biology, College of General Education, Osaka University; Department of Biology, College of General Education, Osaka University

    1989-01-01

    Correlation between foodstuffs and intestinal length was examined in larvae of Rhacophorus arboreus (Anura: Rhacophoridae). The larva, being heterophagous, has a tube-like intestine provided with neither epithelial outfoldings nor villi, and intestinal length is found to be a good morphological index of digestive and absorptive functions of the intestine. The results obtained were summarized as follows: The grown larva fed on boiled spinach had an intestine more than 1.5 times as long as that...

  9. The Long-Term Effect on Children of Increasing the Length of Parents' Birth-Related Leave

    DEFF Research Database (Denmark)

    Wurtz, Astrid

    The length of parents' birth-related leave varies across countries and has been subject of some debate. In this paper, I will focus on some potential benefits of leave. I investigate the long-term effects on children of increasing the length of parents' birth-related leave using a natural...... experiment from 1984 in Denmark when the leave length was increased quite suddenly by almost 50% from 14 to 20 weeks. Regression discontinuity design is used to identify the causal effect of the leave reform and to estimate whether there is a measurable, persistent effect on children's cognitive...... and educational outcomes at ages 15 and 21. A population sample of Danish children born in the months around implementation of the reform and a dataset with Danish PISA-2000 scores are used for the analysis. Results indicate that increasing parents' access to birth-related leave has no measurable effect...

  10. Effects of footwear and stride length on metatarsal strains and failure in running.

    Science.gov (United States)

    Firminger, Colin R; Fung, Anita; Loundagin, Lindsay L; Edwards, W Brent

    2017-11-01

    The metatarsal bones of the foot are particularly susceptible to stress fracture owing to the high strains they experience during the stance phase of running. Shoe cushioning and stride length reduction represent two potential interventions to decrease metatarsal strain and thus stress fracture risk. Fourteen male recreational runners ran overground at a 5-km pace while motion capture and plantar pressure data were collected during four experimental conditions: traditional shoe at preferred and 90% preferred stride length, and minimalist shoe at preferred and 90% preferred stride length. Combined musculoskeletal - finite element modeling based on motion analysis and computed tomography data were used to quantify metatarsal strains and the probability of failure was determined using stress-life predictions. No significant interactions between footwear and stride length were observed. Running in minimalist shoes increased strains for all metatarsals by 28.7% (SD 6.4%; pRunning at 90% preferred stride length decreased strains for metatarsal 4 by 4.2% (SD 2.0%; p≤0.007), and no differences in probability of failure were observed. Significant increases in metatarsal strains and the probability of failure were observed for recreational runners acutely transitioning to minimalist shoes. Running with a 10% reduction in stride length did not appear to be a beneficial technique for reducing the risk of metatarsal stress fracture, however the increased number of loading cycles for a given distance was not detrimental either. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. A Monte Carlo simulation method for assessing biotransformation effects on groundwater fuel hydrocarbon plume lengths

    International Nuclear Information System (INIS)

    McNab, W.W. Jr.

    2000-01-01

    Biotransformation of dissolved groundwater hydrocarbon plumes emanating from leaking underground fuel tanks should, in principle, result in plume length stabilization over relatively short distances, thus diminishing the environmental risk. However, because the behavior of hydrocarbon plumes is usually poorly constrained at most leaking underground fuel tank sites in terms of release history, groundwater velocity, dispersion, as well as the biotransformation rate, demonstrating such a limitation in plume length is problematic. Biotransformation signatures in the aquifer geochemistry, most notably elevated bicarbonate, may offer a means of constraining the relationship between plume length and the mean biotransformation rate. In this study, modeled plume lengths and spatial bicarbonate differences among a population of synthetic hydrocarbon plumes, generated through Monte Carlo simulation of an analytical solute transport model, are compared to field observations from six underground storage tank (UST) sites at military bases in California. Simulation results indicate that the relationship between plume length and the distribution of bicarbonate is best explained by biotransformation rates that are consistent with ranges commonly reported in the literature. This finding suggests that bicarbonate can indeed provide an independent means for evaluating limitations in hydrocarbon plume length resulting from biotransformation. (Author)

  12. Effects of the Length of Jet Grouted Columns and Soil Profile on the Settlement of Shallow Foundations

    Directory of Open Access Journals (Sweden)

    Zaheer Ahmed Almani

    2012-07-01

    Full Text Available In this paper, the effect of length of jet grouted columns and varying soil profile under shallow foundations of buildings constructed on the liquefiable ground was studied. The isolated shallow footing pad which supports a typical simple frame structure was constructed on the liquefiable ground. This ground was reinforced with jet grouted column rows under the shallow foundations of structure. The system was modeled as plane-strain using the FLAC 2D (Fast Lagrangian Analysis of Continua dynamic modelling and analysis code. This case focuses on the length of jet grouted columns in a soil profile and the effect of soil profiles of varying thickness on the settlements of building structure when the soil is liquefied during an earthquake. The results show that liquefaction-induced large settlements of shallow foundation of building decrease to tolerable limits with the increase in the length of columns. For soil profiles, with a relatively thinner liquefiable layer, a certain minimum length of columns (extended in base non liquefiable layer is required to meet the settlement tolerable limits. For soil profiles, with a relatively thicker liquefiable layer, this length should be equal to the thickness of the liquefiable layer from the footing base plus some extension in the base non liquefiable dense layer. In the soil profile with the base liquefiable layer underlying the non liquefiable layer, settlements could not be reduced to the tolerable limits even with columns of relatively larger length which may be critical.

  13. Phonological short-term memory impairment and the word length effect in children with intellectual disabilities.

    Science.gov (United States)

    Poloczek, Sebastian; Büttner, Gerhard; Hasselhorn, Marcus

    2014-02-01

    There is mounting evidence that children and adolescents with intellectual disabilities (ID) of nonspecific aetiology perform poorer on phonological short-term memory tasks than children matched for mental age indicating a structural deficit in a process contributing to short-term recall of verbal material. One explanation is that children with ID of nonspecific aetiology do not activate subvocal rehearsal to refresh degrading memory traces. However, existing research concerning this explanation is inconclusive since studies focussing on the word length effect (WLE) as indicator of rehearsal have revealed inconsistent results for samples with ID and because in several existing studies, it is unclear whether the WLE was caused by rehearsal or merely appeared during output of the responses. We assumed that in children with ID only output delays produce a small WLE while in typically developing 6- to 8-year-olds rehearsal and output contribute to the WLE. From this assumption we derived several predictions that were tested in an experiment including 34 children with mild or borderline ID and 34 typically developing children matched for mental age (MA). As predicted, results revealed a small but significant WLE for children with ID that was significantly smaller than the WLE in the control group. Additionally, for children with ID, a WLE was not found for the first word of each trial but the effect emerged only in later serial positions. The findings corroborate the notion that in children with ID subvocal rehearsal does not develop in line with their mental age and provide a potential explanation for the inconsistent results on the WLE in children with ID. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Maximizing effectiveness of adaptation action in Pacific Island communities using coastal wave attenuation models

    Science.gov (United States)

    Jung, H.; Carruthers, T.; Allison, M. A.; Weathers, D.; Moss, L.; Timmermans, H.

    2017-12-01

    Pacific Island communities are highly vulnerable to the effects of climate change, specifically accelerating rates of sea level rise, changes to storm intensity and associated rainfall patterns resulting in flooding and shoreline erosion. Nature-based adaptation is being planned not only to reduce the risk from shoreline erosion, but also to support benefits of a healthy ecosystem (e.g., supporting fisheries or coral reefs). In order to assess potential effectiveness of the nature-based actions to dissipate wave energy, two-dimensional X-Beach models were developed to predict the wave attenuation effect of coastal adaptation actions at the pilot sites—the villages of Naselesele and Somosomo on Taveuni island, Fiji. Both sites are experiencing serious shoreline erosion due to sea level rise and storm wave. The water depth (single-beam bathymetry), land elevation (truck-based LiDAR), and vegetation data including stem density and height were collected in both locations in a June 2017 field experiment. Wave height and water velocity were also measured for the model setup and calibration using a series of bottom-mounted instruments deployed in the 0-15 m water depth portions of the study grid. The calibrated model will be used to evaluate a range of possible adaptation actions identified by the community members of Naselesele and Somosomo. Particularly, multiple storm scenario runs with management-relevant shoreline restoration/adaptation options will be implemented to evaluate efficiencies of each adaptation action (e.g., no action, with additional planted trees, with sand mining, with seawalls constructed with natural materials, etc.). These model results will help to better understand how proposed adaption actions may influence future shoreline change and maximize benefits to communities in island nations across the SW Pacific.

  15. Fundamental length and relativistic length

    International Nuclear Information System (INIS)

    Strel'tsov, V.N.

    1988-01-01

    It si noted that the introduction of fundamental length contradicts the conventional representations concerning the contraction of the longitudinal size of fast-moving objects. The use of the concept of relativistic length and the following ''elongation formula'' permits one to solve this problem

  16. Accumulative effects of indoor air pollution exposure on leukocyte telomere length among non-smokers

    International Nuclear Information System (INIS)

    Lin, Nan; Mu, Xinlin; Wang, Guilian; Ren, Yu'ang; Su, Shu; Li, Zhiwen; Wang, Bin; Tao, Shu

    2017-01-01

    Indoor air pollution is an important environmental factor that contributes to the burden of various diseases. Long-term exposure to ambient air pollution is associated with telomere shortening. However, the association between chronic indoor air pollution from household fuel combustion and leukocyte telomere length has not been studied. In our study, 137 cancer-free non-smokers were recruited. Their exposure levels to indoor air pollution from 1985 to 2014 were assessed using a face-to-face interview questionnaire, and leukocyte telomere length (LTL) was measured using a monochrome multiplex quantitative PCR method. Accumulative exposure to solid fuel usage for cooking was negatively correlated with LTL. The LTL of residents who were exposed to solid fuel combustion for three decades (LTL = 0.70 ± 0.17) was significantly shorter than that of other populations. In addition, education and occupation were related to both exposure to solid fuel and LTL. Sociodemographic factors may play a mediating role in the correlation between leukocyte telomere length and environmental exposure to indoor air pollution. In conclusion, long-term exposure to indoor air pollution may cause LTL dysfunction. - Highlights: • This is the first study to investigate a clear association between indoor air pollution and leukocyte telomere length. • Chronic exposure to household solid fuel combustion and leukocyte telomere length presented a negative correlation. • Shortest leukocyte telomere length belonged to population cooking for longest time. • Education and occupation were remarkably associated with leukocyte telomere length via relating with indoor air pollution. - Long-term exposure to household solid fuel combustion is negatively associated with LTL.

  17. Flame Length

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — Flame length was modeled using FlamMap, an interagency fire behavior mapping and analysis program that computes potential fire behavior characteristics. The tool...

  18. Beam hardening: Analytical considerations of the effective attenuation coefficient of x-ray tomography

    International Nuclear Information System (INIS)

    Alles, J.; Mudde, R. F.

    2007-01-01

    Polychromatic x-ray beams traveling though material are prone to beam hardening, i.e., the high energy part of the incident spectrum gets over represented when traveling farther into the material. This study discusses the concept of a mean attenuation coefficient in a formal way. The total energy fluence is one-to-one related to the traveled distance in case of a polychromatic beam moving through a given, inhomogeneous material. On the basis of this one-to-one relation, it is useful to define a mean attenuation coefficient and study its decrease with depth. Our results are based on a novel parametrization of the energy dependence of the attenuation coefficient that allows for closed form evaluation of certain spectral integrals. This approach underpins the ad hoc semianalytical expressions given in the literature. An analytical model for the average attenuation coefficient is proposed that uses a simple fit of the attenuation coefficient as a function of the photon energy as input. It is shown that a simple extension of this model gives a rather good description of beam hardening for x-rays traveling through water

  19. Exercise attenuates negative effects of abstinence during 72 hours of smoking deprivation.

    Science.gov (United States)

    Conklin, Cynthia A; Soreca, Isabella; Kupfer, David J; Cheng, Yu; Salkeld, Ronald P; Mumma, Joel M; Jakicic, John M; Joyce, Christopher J

    2017-08-01

    Exercise is presumed to be a potentially helpful smoking cessation adjunct reputed to attenuate the negative effects of deprivation. The present study examined the effectiveness of moderate within-session exercise to reduce 4 key symptoms of smoking deprivation during 3 72-hr nicotine abstinence blocks in both male and female smokers. Forty-nine (25 male, 24 female) sedentary smokers abstained from smoking for 3 consecutive days on 3 separate occasions. At each session, smokers' abstinence-induced craving, cue-induced craving, negative mood, and withdrawal symptom severity were assessed prior to and after either exercise (a.m. exercise, p.m. exercise) or a sedentary control activity (magazine reading). Abstinence-induced craving and negative mood differed as a function of condition, F(2, 385) = 21, p exercise, but exercise overall led to greater pre-post reduction in abstinence-induced craving, t(385) = 6.23, p exercise also led to a larger pre-post reduction in cue-induced craving in response to smoking cues, F(2, 387) = 8.94, p = .0002; and withdrawal severity, F(2, 385) = 3.8, p = .02. Unlike the other 3 measures, p.m. exercise reduced withdrawal severity over control, t(385) = 2.64, p = .009, d = 0.27, whereas a.m. exercise did not. The results support the clinical potential of exercise to assist smokers in managing common and robust negative symptoms experienced during the first 3 days of abstinence. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  20. Effect of digital noise reduction on the accuracy of endodontic file length determination

    International Nuclear Information System (INIS)

    Mehdizadeh, Mojdeh; Khademi, Abbas Ali; Shokraneh, Ali; Farhadi, Nastaran

    2013-01-01

    The aim of the present study was to evaluate the measurement accuracy of endodontic file length on periapical digital radiography after application of noise reduction digital enhancement. Thirty-five human single-rooted permanent teeth with canals measuring 20-24 mm in length were selected. ISO no.08 endodontic files were placed in the root canals of the teeth. The file lengths were measured with a digital caliper as the standard value. Standard periapical digital images were obtained using the Digora digital radiographic system and a dental X-ray unit. In order to produce the enhanced images, the noise reduction option was applied. Two blinded radiologists measured the file lengths on the original and enhanced images. The measurements were compared by repeated measures ANOVA and the Bonferroni test (a=0.05). Both the original and enhanced digital images provided significantly longer measurements compared with the standard value (P 0.05). Noise reduction digital enhancement did not influence the measurement accuracy of the length of the thin endodontic files on the digital periapical radiographs despite the fact that noise reduction could result in the elimination of fine details of the images.

  1. Effects of Huge Earthquakes on Earth Rotation and the length of Day

    Directory of Open Access Journals (Sweden)

    Changyi Xu

    2013-01-01

    Full Text Available We calculated the co-seismic Earth rotation changes for several typical great earthquakes since 1960 based on Dahlen¡¦s analytical expression of Earth inertia moment change, the excitation functions of polar motion and, variation in the length of a day (ΔLOD. Then, we derived a mathematical relation between polar motion and earthquake parameters, to prove that the amplitude of polar motion is independent of longitude. Because the analytical expression of Dahlen¡¦s theory is useful to theoretically estimate rotation changes by earthquakes having different seismic parameters, we show results for polar motion and ΔLOD for various types of earthquakes in a comprehensive manner. The modeled results show that the seismic effect on the Earth¡¦s rotation decreases gradually with increased latitude if other parameters are unchanged. The Earth¡¦s rotational change is symmetrical for a 45° dip angle and the maximum changes appear at the equator and poles. Earthquakes at a medium dip angle and low latitudes produce large rotation changes. As an example, we calculate the polar motion and ΔLOD caused by the 2011 Tohoku-Oki Earthquake using two different fault models. Results show that a fine slip fault model is useful to compute co-seismic Earth rotation change. The obtained results indicate Dahlen¡¦s method gives good approximations for computation of co-seismic rotation changes, but there are some differences if one considers detailed fault slip distributions. Finally we analyze and discuss the co-seismic Earth rotation change signal using GRACE data, showing that such a signal is hard to be detected at present, but it might be detected under some conditions. Numerical results of this study will serve as a good indicator to check if satellite observations such as GRACE can detect a seismic rotation change when a great earthquake occur.

  2. Time for actions in lucid dreams: Effects of task modality, length, and complexity

    Directory of Open Access Journals (Sweden)

    Daniel eErlacher

    2014-01-01

    Full Text Available The relationship between time in dreams and real time has intrigued scientists for centuries. The question if actions in dreams take the same time as in wakefulness can be tested by using lucid dreams where the dreamer is able to mark time intervals with prearranged eye movements that can be objectively identified in EOG recordings. Previous research showed an equivalence of time for counting in lucid dreams and in wakefulness (Erlacher & Schredl, 2004; LaBerge, 1985, but Erlacher and Schredl (2004 found that performing squats required about 40 % more time in lucid dreams than in the waking state. To find out if the task modality, the task length, or the task complexity results in prolonged times in lucid dreams, an experiment with three different conditions was conducted.In the first condition, five proficient lucid dreamers spent one to three non-consecutive nights in the sleep laboratory. Participants counted to 10, 20 and 30 in wakefulness and in their lucid dreams. Lucidity and task intervals were time stamped with left-right-left-right eye movements. The same procedure was used for the second condition where eight lucid dreamers had to walk 10, 20 or 30 steps. In the third condition, eight lucid dreamers performed a gymnastics routine, which in the waking state lasted the same time as walking 10 steps.Again, we found that performing a motor task in a lucid dream requires more time than in wakefulness. Longer durations in the dream state were present for all three tasks, but significant differences were found only for the tasks with motor activity (walking and gymnastics. However, no difference was found for relative times (no disproportional time effects and a more complex motor task did not result in more prolonged times. Longer durations in lucid dreams might be related to the lack of muscular feedback or slower neural processing during REM sleep. Future studies should explore factors that might be associated with prolonged durations.

  3. Time for actions in lucid dreams: effects of task modality, length, and complexity.

    Science.gov (United States)

    Erlacher, Daniel; Schädlich, Melanie; Stumbrys, Tadas; Schredl, Michael

    2013-01-01

    The relationship between time in dreams and real time has intrigued scientists for centuries. The question if actions in dreams take the same time as in wakefulness can be tested by using lucid dreams where the dreamer is able to mark time intervals with prearranged eye movements that can be objectively identified in EOG recordings. Previous research showed an equivalence of time for counting in lucid dreams and in wakefulness (LaBerge, 1985; Erlacher and Schredl, 2004), but Erlacher and Schredl (2004) found that performing squats required about 40% more time in lucid dreams than in the waking state. To find out if the task modality, the task length, or the task complexity results in prolonged times in lucid dreams, an experiment with three different conditions was conducted. In the first condition, five proficient lucid dreamers spent one to three non-consecutive nights in the sleep laboratory. Participants counted to 10, 20, and 30 in wakefulness and in their lucid dreams. Lucidity and task intervals were time stamped with left-right-left-right eye movements. The same procedure was used for the second condition where eight lucid dreamers had to walk 10, 20, or 30 steps. In the third condition, eight lucid dreamers performed a gymnastics routine, which in the waking state lasted the same time as walking 10 steps. Again, we found that performing a motor task in a lucid dream requires more time than in wakefulness. Longer durations in the dream state were present for all three tasks, but significant differences were found only for the tasks with motor activity (walking and gymnastics). However, no difference was found for relative times (no disproportional time effects) and a more complex motor task did not result in more prolonged times. Longer durations in lucid dreams might be related to the lack of muscular feedback or slower neural processing during REM sleep. Future studies should explore factors that might be associated with prolonged durations.

  4. Taylor-plasticity-based analysis of length scale effects in void growth

    KAUST Repository

    Liu, Junxian

    2014-09-25

    We have studied the void growth problem by employing the Taylor-based strain gradient plasticity theories, from which we have chosen the following three, namely, the mechanism-based strain gradient (MSG) plasticity (Gao et al 1999 J. Mech. Phys. Solids 47 1239, Huang et al 2000 J. Mech. Phys. Solids 48 99-128), the Taylor-based nonlocal theory (TNT; 2001 Gao and Huang 2001 Int. J. Solids Struct. 38 2615) and the conventional theory of MSG (CMSG; Huang et al 2004 Int. J. Plast. 20 753). We have addressed the following three issues which occur when plastic deformation at the void surface is unconstrained. (1) Effects of elastic deformation. Elasticity is essential for cavitation instability. It is therefore important to guarantee that the gradient term entering the Taylor model is the effective plastic strain gradient instead of the total strain gradient. We propose a simple elastic-plastic decomposition method. When the void size approaches the minimum allowable initial void size related to the maximum allowable geometrically necessary dislocation density, overestimation of the flow stress due to the negligence of the elastic strain gradient is on the order of lεY/R0 near the void surface, where l, εY and R0 are, respectively, the intrinsic material length scale, the yield strain and the initial void radius. (2) MSG intrinsic inconsistency, which was initially mentioned in Gao et al (1999 J. Mech. Phys. Solids 47 1239) but has not been the topic of follow-up studies. We realize that MSG higher-order stress arises due to the linear-strain-field approximation within the mesoscale cell with a nonzero size, lε. Simple analysis shows that within an MSG mesoscale cell near the void surface, the difference between microscale and mesoscale strains is on the order of (lε/R0)2, indicating that when lε/R0 ∼ 1.0, the higher-order stress effect can make the MSG result considerably different from the TNT or CMSG results. (3) Critical condition for cavitation instability

  5. Effects of the Utterance length on Fluency of Conversational Speech in Stuttering Persian-Speaker Children and Adults

    Directory of Open Access Journals (Sweden)

    Tabassom A'zimi

    2013-10-01

    Full Text Available Objective: recently, researchers have increasingly turned to study the relation between stuttering and utterance length. This study investigates the effect of utterance length on the amount of speech dysfluency in stuttering Persian-speaking children and adults in conversational speech. The obtained results can pave the way to reach a better understanding of stuttering of child and adults, as well as finding more appropriate treatments. Materials & Methods: in this descriptive- analysis study, the participants were 15 stuttering Persian- speaker adults, upper from 15 years old, and 15 stuttering Persian- speaker children in the age range of 4-6. In this study, first 30 minutes sample of adults and child's spontaneous speech was provided and then utterances of each person studied for the amount of dysfluency and utterance length. The obtained information intered to computer via spss software and analyzed using paired T test. Results: In both groups of stuttering children and adults, with increase of utterance length, there was a significant increase in the amount of dysfluency. Conclusion: The results of this study showed that by increase of utterance length at the spontaneous speech level, stuttering children and adults had more dysfluency amount. Also, by increase of utterance length, dysfluency amount of stuttering children and adults increased samely.

  6. Effect of crosslinker length on the elastic and compression modulus of poly(acrylamide) nanocomposite hydrogels

    International Nuclear Information System (INIS)

    Zaragoza, J; Chang, A; Asuri, P

    2017-01-01

    Polymer hydrogelshave shown to exhibit improved properties upon the addition of nanoparticles; however, the mechanical underpinnings behind these enhancements have not been fully elucidated. Moreover, fewer studies have focused on developing an understanding of how polymer parameters affect the nanoparticle-mediated enhancements. In this study, we investigated the elastic properties of silica nanoparticle-reinforced poly(acrylamide) hydrogels synthesized using crosslinkers of various lengths. Crosslinker length positively affected the mechanical properties of hydrogels that were synthesized with or without nanoparticles. However the degree of nanoparticle enhancement was negatively correlated to crosslinker length. Our findings enable the understanding of the respective roles of nanoparticle and polymer properties on nanoparticle-mediated enhancement of hydrogels and thereby the development of next-generation nanocomposite materials. (paper)

  7. The Effect of Length in Employment Sites’ Web Form Design on User Preferences

    Directory of Open Access Journals (Sweden)

    Yu-Ching Wang

    2014-06-01

    Full Text Available Web form has become a critical component for many Web applications and services. Previous research has investigated into the general design of web form layout without examining the impact of variations in format, length and structure on user experience. This study explores users’ preference and performance over Web forms of different lengths deployed on an employment site. Three types of design of Web forms were developed as the experiment instruments for 48 participants to test and evaluate. Results show that participants’ preferences and satisfaction varied by the length of Web forms. Participants’ preferences were also affected by their previous Internet experiences with job websites. In the end, recommendations for design principles for Web forms used for job sites were presented. [Article content in Chinese

  8. Mutation-specific effects on thin filament length in thin filament myopathy.

    Science.gov (United States)

    Winter, Josine M de; Joureau, Barbara; Lee, Eun-Jeong; Kiss, Balázs; Yuen, Michaela; Gupta, Vandana A; Pappas, Christopher T; Gregorio, Carol C; Stienen, Ger J M; Edvardson, Simon; Wallgren-Pettersson, Carina; Lehtokari, Vilma-Lotta; Pelin, Katarina; Malfatti, Edoardo; Romero, Norma B; Engelen, Baziel G van; Voermans, Nicol C; Donkervoort, Sandra; Bönnemann, C G; Clarke, Nigel F; Beggs, Alan H; Granzier, Henk; Ottenheijm, Coen A C

    2016-06-01

    Thin filament myopathies are among the most common nondystrophic congenital muscular disorders, and are caused by mutations in genes encoding proteins that are associated with the skeletal muscle thin filament. Mechanisms underlying muscle weakness are poorly understood, but might involve the length of the thin filament, an important determinant of force generation. We investigated the sarcomere length-dependence of force, a functional assay that provides insights into the contractile strength of muscle fibers as well as the length of the thin filaments, in muscle fibers from 51 patients with thin filament myopathy caused by mutations in NEB, ACTA1, TPM2, TPM3, TNNT1, KBTBD13, KLHL40, and KLHL41. Lower force generation was observed in muscle fibers from patients of all genotypes. In a subset of patients who harbor mutations in NEB and ACTA1, the lower force was associated with downward shifted force-sarcomere length relations, indicative of shorter thin filaments. Confocal microscopy confirmed shorter thin filaments in muscle fibers of these patients. A conditional Neb knockout mouse model, which recapitulates thin filament myopathy, revealed a compensatory mechanism; the lower force generation that was associated with shorter thin filaments was compensated for by increasing the number of sarcomeres in series. This allowed muscle fibers to operate at a shorter sarcomere length and maintain optimal thin-thick filament overlap. These findings might provide a novel direction for the development of therapeutic strategies for thin filament myopathy patients with shortened thin filament lengths. Ann Neurol 2016;79:959-969. © 2016 American Neurological Association.

  9. Attenuation correction for SPECT

    International Nuclear Information System (INIS)

    Hosoba, Minoru

    1986-01-01

    Attenuation correction is required for the reconstruction of a quantitative SPECT image. A new method for detecting body contours, which are important for the correction of tissue attenuation, is presented. The effect of body contours, detected by the newly developed method, on the reconstructed images was evaluated using various techniques for attenuation correction. The count rates in the specified region of interest in the phantom image by the Radial Post Correction (RPC) method, the Weighted Back Projection (WBP) method, Chang's method were strongly affected by the accuracy of the contours, as compared to those by Sorenson's method. To evaluate the effect of non-uniform attenuators on the cardiac SPECT, computer simulation experiments were performed using two types of models, the uniform attenuator model (UAM) and the non-uniform attenuator model (NUAM). The RPC method showed the lowest relative percent error (%ERROR) in UAM (11 %). However, 20 to 30 percent increase in %ERROR was observed for NUAM reconstructed with the RPC, WBP, and Chang's methods. Introducing an average attenuation coefficient (0.12/cm for Tc-99m and 0.14/cm for Tl-201) in the RPC method decreased %ERROR to the levels for UAM. Finally, a comparison between images, which were obtained by 180 deg and 360 deg scans and reconstructed from the RPC method, showed that the degree of the distortion of the contour of the simulated ventricles in the 180 deg scan was 15 % higher than that in the 360 deg scan. (Namekawa, K.)

  10. Effect of the Length of Traffic Flow Records on the Estimate of a Bridge Service Life

    Directory of Open Access Journals (Sweden)

    Krejsa Jan

    2016-12-01

    Full Text Available The service life of bridges is significantly affected by fatigue of used material induced by heavy vehicles. Therefore, precise determination of the vehicle weight is of crucial importance for the calculation of fatigue damage and the prediction of the bridge serviceability. This paper investigates accuracy of the determination of fatigue depending on the length of traffic flow recording. The presented data were obtained from the measurements carried out on a bridge of the Prague Highway Ring. The analysis reveals that the optimal length of traffic recording is about 30 days.

  11. Effect of hydrocarbon chain length of aliphatic diluents on hydrodynamic properties of irradiated solutions of extractant

    International Nuclear Information System (INIS)

    Gumenyuk, V.E.; Pribush, A.G.; Egorov, G.F.

    1990-01-01

    To optimize the composition of n-paraffin mixtures with different molecular weight, used as a diluent (D) of extractant during extraction reprocessing of spent fuel, interrelation between D hydrocarbon chain length and change in hydrodynamic properties of extraction mixture on D basis depending on the dose has been considered. It is shown that the value of threshold dose loading (D crit ), at which a sharp change in hydrodynamic properties of tri-n-butyl phosphate solutions in D is observed, decreases with hydrocarbon chain length growth. Empiric ratio relating D crit value and the number of carbon atoms of D is obtained

  12. Interferon-Inducible CD169/Siglec1 Attenuates Anti-HIV-1 Effects of Alpha Interferon

    Science.gov (United States)

    Akiyama, Hisashi; Ramirez, Nora-Guadalupe Pina; Gibson, Gregory; Kline, Christopher; Watkins, Simon; Ambrose, Zandrea

    2017-01-01

    ABSTRACT A hallmark of human immunodeficiency virus type 1 (HIV-1) infection in vivo is chronic immune activation concomitant with type I interferon (IFN) production. Although type I IFN induces an antiviral state in many cell types, HIV-1 can replicate in vivo via mechanisms that have remained unclear. We have recently identified a type I IFN-inducible protein, CD169, as the HIV-1 attachment factor on dendritic cells (DCs) that can mediate robust infection of CD4+ T cells in trans. Since CD169 expression on macrophages is also induced by type I IFN, we hypothesized that type I IFN-inducible CD169 could facilitate productive HIV-1 infection in myeloid cells in cis and CD4+ T cells in trans and thus offset antiviral effects of type I IFN. In support of this hypothesis, infection of HIV-1 or murine leukemia virus Env (MLV-Env)-pseudotyped HIV-1 particles was enhanced in IFN-α-treated THP-1 monocytoid cells, and this enhancement was primarily dependent on CD169-mediated enhancement at the virus entry step, a phenomenon phenocopied in HIV-1 infections of IFN-α-treated primary monocyte-derived macrophages (MDMs). Furthermore, expression of CD169, a marker of type I IFN-induced immune activation in vivo, was enhanced in lymph nodes from pigtailed macaques infected with simian immunodeficiency virus (SIV) carrying HIV-1 reverse transcriptase (RT-SHIV), compared to uninfected macaques, and interestingly, there was extensive colocalization of p27gag and CD169, suggesting productive infection of CD169+ myeloid cells in vivo. While cell-free HIV-1 infection of IFN-α-treated CD4+ T cells was robustly decreased, initiation of infection in trans via coculture with CD169+ IFN-α-treated DCs restored infection, suggesting that HIV-1 exploits CD169 in cis and in trans to attenuate a type I IFN-induced antiviral state. IMPORTANCE HIV-1 infection in humans causes immune activation characterized by elevated levels of proinflammatory cytokines, including type I interferons (IFN

  13. Effectiveness of transfixation and length of instrumentation on titanium and stainless steel transpedicular spine implants.

    Science.gov (United States)

    Korovessis, P; Baikousis, A; Deligianni, D; Mysirlis, Y; Soucacos, P

    2001-04-01

    This study compares the effectiveness of transfixation on the stiffness of two pedicle screw-rod constructs of different manufacture, implant design, and alloy, applied in one-and two-level instability. Four screws composed of either stainless steel or Titanium were assembled in pairs to two polymethylmethacrylate blocks to resemble one-and two-level corpectomy models and the construct underwent nondestructive torsional, extension, and flexion loading. In every loading test, each construct was tested using stainless steel or titanium rods of 4.9-mm diameter in two different lengths (short, 10 cm; long, 15 cm), not augmented or augmented with different transfixation devices or a pair of devices. The authors compared the stiffness of stainless steel and titanium constructs without cross-link with the stiffness of that reinforced with single or double Texas Scottish Rite Hospital (TSRH) cross-link, closed new-type cross-link (closed NTC), or open new-type cross-link (open NTC). The results showed that augmentation or no augmentation of short rods conferred significantly more stiffness than that of long rods of the same material in all three loading modes. The closed NTC provided the greatest increase of torsional, extension, and flexion stiffness, and single TSRH provided the least amount of stiffness. Torsional stiffness of short stainless steel rods augmented or not augmented was significantly greater than that of their titanium counterparts. Torsional stiffness of long titanium rods was always greater than that of their stainless steel counterparts. Extension stiffness of short nonaugmented titanium rods was superior to that of long titanium rods, whereas extension stiffness of nonaugmented short and long stainless steel rods was similar. Nonaugmented short titanium rods showed greater flexion stiffness than that of long titanium rods. Long stainless steel rods displayed significantly greater flexion stiffness than did their titanium counterparts. This

  14. Influence of arm positioning on tomographic thallium-201 myocardial perfusion imaging and the effect of attenuation correction

    International Nuclear Information System (INIS)

    Prvulovich, E.M.; Jarritt, P.H.; Vorontsova, E.; Bomanji, J.B.; Ell, P.J.

    2000-01-01

    Lateral attenuation in single-photon emission tomography (SPET) myocardial perfusion imaging (MPI) has been attributed to the left arm if it is held by the patient's side during data acquisition. As a result MPI data are conventionally acquired with the arms held above the head. The aims of this study were to determine the effect of imaging arms down on reconstructed tomographic images depicting regional myocardial thallium-201 distribution and to assess whether attenuation-corrected (AC) myocardial perfusion images acquired arms down could replace uncorrected (NC) images acquired arms up for routine clinical service. Twenty-eight patients referred for routine MPI underwent sequential 180 emission/transmission imaging for attenuation correction using an L-shaped dual-headed gamma camera (GE Optima) fitted with two gadolinium-153 scanning line sources. Delay data were acquired twice: once supine with the arms up and then supine with the arms down. Detector radius of rotation (ROR) for arms up and arms-down studies was recorded. For each data set, count density was measured in 17 segments of a polar plot and segmental uptake expressed relative to study maximum. Oblique images were assessed qualitatively by two observers blinded to study type for tracer distribution and overall quality. Transmission maps were assessed for truncation. Mean detector ROR was 190 mm for arms-up studies and 232 mm for arms-down studies (P 201 Tl distribution, particularly anterolaterally. There is lateral undercorrection in approximately 10% of AC arms-down studies, possibly because of attenuation map truncation. Image quality is reduced in about one-third of AC arms-down studies compared with NC arms-up studies. These data suggest that this attenuation correction method is not sufficiently robust to allow routine acquisition of MPI data with the arms down. (orig.)

  15. Determination of attenuation factors for mortar of barite in terms of environmental dose equivalent and effective dose

    International Nuclear Information System (INIS)

    Almeida Junior, Airton T.; Campos, L.L.R.; Araujo, F.G.S.; Santos, M.A.P.; Nogueira, M.S.

    2014-01-01

    This work addresses the characterization of barite mortars used as Xray shielding materials through the following quantities: mass attenuation coefficient, air kerma, effective dose and ambient dose - H⁎(10). The experiment was carried out with the use of the following reference qualities: RQR4, RQR6, RQR9 e RQR10, specified in accordance with norm IEC 61267: Medical diagnostic Xray equipment - radiation conditions for use in the determination of characteristics. In this study values was determined experimentally for the attenuation of the Cream barite (density 2.99g/cm 3 , collected in the state of Sao Paulo), Purple barite (density 2.95g/cm 3 , collected in the state of Bahia) and White barite (density 3.10g/cm 3 , collected in the state of Paraiba). These materials, in the form of mortar, were disposed in the form of squares namely poof bodies, whose dimensions were 10 x 10 cm and thickness ranging from 3 to 15 mm approximately. In the experimental procedure, these proof bodies were irradiated with a Pantak, model HF320 industrial X-ray apparatus. The potentials applied to the respective X-ray tube were: 60kV, 80kV, 120kV and 150kV at a constant current of 1mA. The attenuation responses in function of thickness, for each of the materials analyzed, were used to draw the attenuation and transmission curves. The efficiency of the barite studied concerning the capacity to attenuate X-ray radiation for X-ray beams ranging from 60 to 150 kV indicated

  16. Chronic Nicotine Treatment During Adolescence Attenuates the Effects of Acute Nicotine in Adult Contextual Fear Learning.

    Science.gov (United States)

    Holliday, Erica D; Gould, Thomas J

    2017-01-01

    Adolescent onset of nicotine abuse is correlated with worse chances at successful abstinence in adulthood. One reason for this may be due to enduring learning deficits resulting from nicotine use during adolescence. Previous work has indicated that chronic nicotine administration beginning in late adolescence (PND38) caused learning deficits in contextual fear when tested in adulthood. The purpose of this study was to determine if chronic nicotine treatment during adolescence would alter sensitivity to nicotine's cognitive enhancing properties in adulthood. C57BL/6J mice received saline or chronic nicotine (12.6mg/kg/day) during adolescence (postnatal day 38) or adulthood (postnatal day 54) for a period of 12 days. Following a 30-day protracted abstinence, mice received either an acute injection of saline or nicotine (0.045, 0.18, and 0.36mg/kg) prior to training and testing a mouse model of contextual fear. It was found that chronic nicotine administration in adult mice did not alter sensitivity to acute nicotine following a protracted abstinence. In adolescent mice, chronic nicotine administration disrupted adult learning and decreased sensitivity to acute nicotine in adulthood as only the highest dose tested (0.36mg/kg) was able to enhance contextual fear learning. These results suggest that adolescent nicotine exposure impairs learning in adulthood, which could increase the risk for continued nicotine use in adulthood by requiring administration of higher doses of nicotine to reverse learning impairments caused by adolescent nicotine exposure. Results from this study add to the growing body of literature suggesting chronic nicotine exposure during adolescence leads to impaired learning in adulthood and demonstrates that nicotine exposure during adolescence attenuates the cognitive enhancing effects of acute nicotine in adulthood, which suggests altered cholinergic function. © The Author 2016. Published by Oxford University Press on behalf of the Society for

  17. Edible bird’s nest attenuates procoagulation effects of high-fat diet in rats

    Directory of Open Access Journals (Sweden)

    Yida Z

    2015-07-01

    Full Text Available Zhang Yida,1,2 Mustapha Umar Imam,1 Maznah Ismail,1,3 Norsharina Ismail,1 Zhiping Hou1 1Laboratory of Molecular Biomedicine, Institute of Bioscience, Universiti Putra Malaysia, Serdang, Selangor, Malaysia; 2Cardiology Department, Affiliated Hospital of Chengde Medical University, Chengde, Hebei, People’s Republic of China; 3Faculty of Medicine and Health Sciences, Department of Nutrition and Dietetics, Universiti Putra Malaysia, Serdang, Selangor, Malaysia Abstract: Edible bird’s nest (EBN is popular in Asia, and has long been used traditionally as a supplement. There are, however, limited evidence-based studies on its efficacy. EBN has been reported to improve dyslipidemia, which is closely linked to hypercoagulation states. In the present study, the effects of EBN on high-fat diet- (HFD- induced coagulation in rats were evaluated. Rats were fed for 12 weeks with HFD alone or in combination with simvastatin or EBN. Food intake was estimated, and weight measurements were made during the experimental period. After sacrifice, serum oxidized low-density lipo­protein (oxLDL, adiponectin, leptin, von willibrand factor, prostacyclin, thromboxane and lipid profile, and whole blood coagulation indices (bleeding time, prothrombin time, activated partial thromboplastin time, red blood count count, and platelet count were estimated. Furthermore, hepatic expression of coagulation-related genes was evaluated using multiplex polymerase chain reaction. The results indicated that EBN could attenuate HFD-induced hypercholesterolemia and coagulation similar to simvastatin, partly through transcriptional regulation of coagulation-related genes. The results suggested that EBN has the potential for lowering the risk of cardiovascular disease-related hypercoagulation due to hypercholesterolemia. Keywords: edible bird’s nest, coagulation, high-fat diet, hypercholesterolemia, nutrigeno­mics

  18. Diffusion of responsibility attenuates altruistic punishment: A functional magnetic resonance imaging effective connectivity study.

    Science.gov (United States)

    Feng, Chunliang; Deshpande, Gopikrishna; Liu, Chao; Gu, Ruolei; Luo, Yue-Jia; Krueger, Frank

    2016-02-01

    Humans altruistically punish violators of social norms to enforce cooperation and pro-social behaviors. However, such altruistic behaviors diminish when others are present, due to a diffusion of responsibility. We investigated the neural signatures underlying the modulations of diffusion of responsibility on altruistic punishment, conjoining a third-party punishment task with event-related functional magnetic resonance imaging and multivariate Granger causality mapping. In our study, participants acted as impartial third-party decision-makers and decided how to punish norm violations under two different social contexts: alone (i.e., full responsibility) or in the presence of putative other third-party decision makers (i.e., diffused responsibility). Our behavioral results demonstrated that the diffusion of responsibility served as a mediator of context-dependent punishment. In the presence of putative others, participants who felt less responsible also punished less severely in response to norm violations. Our neural results revealed that underlying this behavioral effect was a network of interconnected brain regions. For unfair relative to fair splits, the presence of others led to attenuated responses in brain regions implicated in signaling norm violations (e.g., AI) and to increased responses in brain regions implicated in calculating values of norm violations (e.g., vmPFC, precuneus) and mentalizing about others (dmPFC). The dmPFC acted as the driver of the punishment network, modulating target regions, such as AI, vmPFC, and precuneus, to adjust altruistic punishment behavior. Our results uncovered the neural basis of the influence of diffusion of responsibility on altruistic punishment and highlighted the role of the mentalizing network in this important phenomenon. Hum Brain Mapp 37:663-677, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  19. Effect of fiber post length and abutment height on fracture resistance of endodontically treated premolars prepared for zirconia crowns.

    Science.gov (United States)

    Lin, Jie; Matinlinna, Jukka Pekka; Shinya, Akikazu; Botelho, Michael George; Zheng, Zhiqiang

    2018-04-01

    The purpose of this study was to compare the fracture resistance, mode of fracture, and stress distribution of endodontically treated teeth prepared with three different fiber post lengths and two different abutment heights, using both experimental and finite element (FE) approaches. Forty-eight human maxillary premolars with two roots were selected and endodontically treated. The teeth were randomly distributed into six equally sized groups (n = 8) with different combinations of post lengths (7.5, 11, and 15 mm) and abutment heights (3 and 5 mm). All the teeth restored with glass fiber post (Rely X Fiber Post, 3M ESPE, USA) and a full zirconia crown. All the specimens were thermocycled and then loaded to failure at an oblique angle of 135°. Statistical analysis was performed for the effects of post length and abutment height on failure loads using ANOVA and Tukey's honestly significant difference test. In addition, corresponding FE models of a premolar restored with a glass fiber post were developed to examine mechanical responses. The factor of post length (P abutment height (P > 0.05) did not have a significant effect on failure load. The highest mean fracture resistance was recorded for the 15 mm post length and 5 mm abutment height test group, which was significantly more resistant to fracture than the 7.5 mm post and 5 mm abutment height group (P abutment heights.

  20. Effects of tubing length and coupling method on hearing threshold and real-ear to coupler difference measures.

    Science.gov (United States)

    Gustafson, Samantha; Pittman, Andrea; Fanning, Robert

    2013-06-01

    This tutorial demonstrates the effects of tubing length and coupling type (i.e., foam tip or personal earmold) on hearing threshold and real-ear-to-coupler difference (RECD) measures. Hearing thresholds from 0.25 kHz through 8 kHz are reported at various tubing lengths for 28 normal-hearing adults between the ages of 22 and 31 years. RECD values are reported for 14 of the adults. All measures were made with an insert earphone coupled to a standard foam tip and with an insert earphone coupled to each participant's personal earmold. Threshold and RECD measures obtained with a personal earmold were significantly different from those obtained with a foam tip on repeated measures analyses of variance. One-sample t tests showed these differences to vary systematically with increasing tubing length, with the largest average differences (7-8 dB) occurring at 4 kHz. This systematic examination demonstrates the equal and opposite effects of tubing length on threshold and acoustic measures. Specifically, as tubing length increased, sound pressure level in the ear canal decreased, affecting both hearing thresholds and the real-ear portion of the RECDs. This demonstration shows that when the same coupling method is used to obtain the hearing thresholds and RECD, equal and accurate estimates of real-ear sound pressure level are obtained.

  1. Effect of length of thinning area on the failure behavior of carbon steel pipe containing a defect of wall thinning

    International Nuclear Information System (INIS)

    Kim, Jin Weon; Park, Chi Yong

    2003-01-01

    The present study performed pipe failure tests using 102 mm-Sch. 80 carbon steel pipe with various simulated wall thinning defects, to investigate the effect of axial length of wall thinning and internal pressure on the failure behavior of pipe thinned by flow accelerated corrosion (FAC). The tests were conducted under loading conditions of four-point bending with and without internal pressure. The results showed that a failure mode of pipe with a defect depended on the magnitude of internal pressure and axial thinning length as well as stress type and thinning depth and circumferential angle. Both load carrying capability (LCC) and deformation capability (DC) were depended on stress type in the thinning area and dimensions of thinning defect. For applying tensile stress to the thinned area, the dependence of LCC on the axial length of wall thinning was determined by circumferential thinning angle, and the DC was proportionally increased with increase in axial length of wall thinning regardless of the circumferential angle. For applying compressive stress to thinned area, however, the LCC was decreased with increase in axial length of the thinned area. Also, the effect of internal pressure on failure behavior was characterized by failure mode of thinned pipe, and it promoted crack occurrence and mitigated a local buckling of the thinned area

  2. Effects of Increased Nitrogen Deposition and Rotation Length on Long-Term Productivity of Cunninghamia lanceolata Plantation in Southern China

    Science.gov (United States)

    Zhao, Meifang; Xiang, Wenhua; Tian, Dalun; Deng, Xiangwen; Huang, Zhihong; Zhou, Xiaolu; Peng, Changhui

    2013-01-01

    Cunninghamia lanceolata (Lamb.) Hook. has been widely planted in subtropical China to meet increasing timber demands, leading to short-rotation practices that deplete soil nutrients. However, increased nitrogen (N) deposition offsets soil N depletion. While long-term experimental data investigating the coupled effects related to short rotation practices and increasing N deposition are scarce, applying model simulations may yield insights. In this study, the CenW3.1 model was validated and parameterized using data from pure C. lanceolata plantations. The model was then used to simulate various changes in long-term productivity. Results indicated that responses of productivity of C. lanceolata plantation to increased N deposition were more related to stand age than N addition, depending on the proportion and age of growing forests. Our results have also shown a rapid peak in growth and N dynamics. The peak is reached sooner and is higher under higher level of N deposition. Short rotation lengths had a greater effect on productivity and N dynamics than high N deposition levels. Productivity and N dynamics decreased as the rotation length decreased. Total productivity levels suggest that a 30-year rotation length maximizes productivity at the 4.9 kg N ha−1 year−1 deposition level. For a specific rotation length, higher N deposition levels resulted in greater overall ecosystem C and N storage, but this positive correlation tendency gradually slowed down with increasing N deposition levels. More pronounced differences in N deposition levels occurred as rotation length decreased. To sustain C. lanceolata plantation productivity without offsite detrimental N effects, the appropriate rotation length is about 20–30 years for N deposition levels below 50 kg N ha−1 year−1 and about 15–20 years for N deposition levels above 50 kg N ha−1 year−1. These results highlight the importance of assessing N effects on carbon management and the long-term productivity of

  3. Effects of tail docking and docking length on neuroanatomical changes in healed tail tips of pigs

    DEFF Research Database (Denmark)

    Herskin, M S; Thodberg, K; Jensen, Henrik Elvang

    2015-01-01

    % (n=19); or leaving 25% (n=11) of the tail length on the pigs. The piglets were docked between day 2 and 4 after birth using a gas-heated apparatus, and were kept under conventional conditions until slaughter at 22 weeks of age, where tails were removed and examined macroscopically and histologically...

  4. Rheological Properties of Associative Star Polymers in Aqueous Solutions: Effect of Hydrophobe Length and Polymer Topology

    DEFF Research Database (Denmark)

    Hietala, Sami; Strandman, Satu; Jarvi, Paula

    2009-01-01

    triblock copolymer. These polymers, synthesized by atom transfer radical polymerization (ATRP), were found to form hydrogels due to intermolecular association originating from the PS blocks. The increasing length of the PS block was observed to lead to more elastic networks due to increased hydrophobic...

  5. Effect of length of productive life on genetic trend of milk production ...

    African Journals Online (AJOL)

    Longevity is an important economic trait in dairy cattle. Including this trait in a breeding scheme, increases profit. The aim of this study was to evaluate the relationship between length of productive life (LPL), genetic trend of milk production and profitability of herds. LPL has been defined as time from first calving to culling.

  6. The effect of chain length and lipid phase transitions on the selective permeability properties of liposomes

    NARCIS (Netherlands)

    Blok, M.C.; Neut-Kok, E.C.M. van der; Deenen, L.L.M. van; Gier, J. de

    1975-01-01

    This paper describes experiments showing the importance of the fatty acid chain length on the barrier properties of liposomal bilayers, prepared from saturated lecithins, under conditions of lateral phase separation. 1. 1.|Above the gel to liquid crystalline phase transition temperature,

  7. The Effect of Gestational Age on Axial Length of the Eyes of Premature Infants

    Directory of Open Access Journals (Sweden)

    Mehmet Ali Sekeroglu

    2016-01-01

    Full Text Available Aim: The aim of the present study is to evaluate the axial length of the eyes of premature infants without retinopathy of prematurity and to document the relationship with gestational age and changes as infants grew-up. Material and Method: The axial length of the eyes were measured by using a mobile A-scan ultrasonographic biometry device just before the first retinopathy of prematurity screening examination and 4-weeks thereafter. Results: One-hundred and thirty-six infants with a mean gestational age of 31,7±2,7 weeks and a birth-weight of 1561.0±379.3 g were included in the study. Axial length measurements were done at a mean postconceptional age of 35.8 ±2.6 (31-40 and 39.8±2.7 (35-44 weeks, consecutively. The mean axial length at first and second visits were 16.43±0.42 mm (15.28-17.13 and 16.69±0.41 mm (15.60-17.70, consecutively (p

  8. Investigation into the effects of steel wire rope specimen length on breaking force

    CSIR Research Space (South Africa)

    O'Brien, TM

    2004-03-01

    Full Text Available (2000). The methodology employed was to test different length of triangular strand and non-spin rope to destruction, and to evaluate these results against SABS 0293:1996. For each rope construction, specimens were prepared both with and without cut wires...

  9. Effect of temperature and cycle length on microbial competition in PHB-producing sequencing batch reactor.

    Science.gov (United States)

    Jiang, Yang; Marang, Leonie; Kleerebezem, Robbert; Muyzer, Gerard; van Loosdrecht, Mark C M

    2011-05-01

    The impact of temperature and cycle length on microbial competition between polyhydroxybutyrate (PHB)-producing populations enriched in feast-famine sequencing batch reactors (SBRs) was investigated at temperatures of 20 °C and 30 °C, and in a cycle length range of 1-18 h. In this study, the microbial community structure of the PHB-producing enrichments was found to be strongly dependent on temperature, but not on cycle length. Zoogloea and Plasticicumulans acidivorans dominated the SBRs operated at 20 °C and 30 °C, respectively. Both enrichments accumulated PHB more than 75% of cell dry weight. Short-term temperature change experiments revealed that P. acidivorans was more temperature sensitive as compared with Zoogloea. This is particularly true for the PHB degradation, resulting in incomplete PHB degradation in P. acidivorans at 20 °C. Incomplete PHB degradation limited biomass growth and allowed Zoogloea to outcompete P. acidivorans. The PHB content at the end of the feast phase correlated well with the cycle length at a constant solid retention time (SRT). These results suggest that to establish enrichment with the capacity to store a high fraction of PHB, the number of cycles per SRT should be minimized independent of the temperature.

  10. Effect of length of productive life on genetic trend of milk ... - AJOL

    African Journals Online (AJOL)

    USER

    2010-05-17

    May 17, 2010 ... Longevity is an important economic trait in dairy cattle. Including this trait in a breeding scheme, increases profit. The aim of this study was to evaluate the relationship between length of productive life. (LPL), genetic trend of milk production and profitability of herds. LPL has been defined as time from.

  11. The processing of spatial information in short-term memory: insights from eye tracking the path length effect.

    Science.gov (United States)

    Guérard, Katherine; Tremblay, Sébastien; Saint-Aubin, Jean

    2009-10-01

    Serial memory for spatial locations increases as the distance between successive stimuli locations decreases. This effect, known as the path length effect [Parmentier, F. B. R., Elford, G., & Maybery, M. T. (2005). Transitional information in spatial serial memory: Path characteristics affect recall performance. Journal of Experimental Psychology: Learning, Memory & Cognition, 31, 412-427], was investigated in a systematic manner using eye tracking and interference procedures to explore the mechanisms responsible for the processing of spatial information. In Experiment 1, eye movements were monitored during a spatial serial recall task--in which the participants have to remember the location of spatially and temporally separated dots on the screen. In the experimental conditions, eye movements were suppressed by requiring participants to incessantly move their eyes between irrelevant locations. Ocular suppression abolished the path length effect whether eye movements were prevented during item presentation or during a 7s retention interval. In Experiment 2, articulatory suppression was combined with a spatial serial recall task. Although articulatory suppression impaired performance, it did not alter the path length effect. Our results suggest that rehearsal plays a key role in serial memory for spatial information, though the effect of path length seems to involve other processes located at encoding, such as the time spent fixating each location and perceptual organization.

  12. Effect of repetitive pecking at working length for glide path preparation using G-file

    Directory of Open Access Journals (Sweden)

    Jung-Hong Ha

    2015-05-01

    Full Text Available Objectives Glide path preparation is recommended to reduce torsional failure of nickel-titanium (NiTi rotary instruments and to prevent root canal transportation. This study evaluated whether the repetitive insertions of G-files to the working length maintain the apical size as well as provide sufficient lumen as a glide path for subsequent instrumentation. Materials and Methods The G-file system (Micro-Mega composed of G1 and G2 files for glide path preparation was used with the J-shaped, simulated resin canals. After inserting a G1 file twice, a G2 file was inserted to the working length 1, 4, 7, or 10 times for four each experimental group, respectively (n = 10. Then the canals were cleaned by copious irrigation, and lubricated with a separating gel medium. Canal replicas were made using silicone impression material, and the diameter of the replicas was measured at working length (D0 and 1 mm level (D1 under a scanning electron microscope. Data was analysed by one-way ANOVA and post-hoc tests (p = 0.05. Results The diameter at D0 level did not show any significant difference between the 1, 2, 4, and 10 times of repetitive pecking insertions of G2 files at working length. However, 10 times of pecking motion with G2 file resulted in significantly larger canal diameter at D1 (p < 0.05. Conclusions Under the limitations of this study, the repetitive insertion of a G2 file up to 10 times at working length created an adequate lumen for subsequent apical shaping with other rotary files bigger than International Organization for Standardization (ISO size 20, without apical transportation at D0 level.

  13. Repeated Excessive Exercise Attenuates the Anti-Inflammatory Effects of Exercise in Older Men

    Directory of Open Access Journals (Sweden)

    Ronni E. Sahl

    2017-06-01

    increased insulin resistance as estimated by the Quicki Index.Conclusion: The regular prolonged exercise did not influence abdominal adipose tissue inflammation, but the higher plasma IL-6 concentration concurrent with a trend toward higher insulin resistance and decreased VO2peak implies that the excessive amount of exercise probably attenuated the possible potential anti-inflammatory effects of exercise.

  14. Evaluation of live attenuated S79 mumps vaccine effectiveness in mumps outbreaks: a matched case-control study.

    Science.gov (United States)

    Fu, Chuan-xi; Nie, Jun; Liang, Jian-hua; Wang, Ming

    2009-02-05

    Mumps virus infection is a potentially serious viral infection of childhood and early adulthood. In China, live attenuated S(79) mumps vaccine has been licensed for pediatric use since 1990. The objective of this study was to determine the effectiveness of live attenuated S(79) mumps vaccine against clinical mumps in outbreaks. Cases were selected from mumps outbreaks in schools in Guangzhou between 2004 and 2005. Each case was matched by gender, age and classroom. Vaccination information was obtained from Children's EPI Administrative Computerized System. Vaccine effectiveness (VE) was calculated for 1 or 2 doses of S(79) vaccine with 95% confidence intervals (CI). One hundred and ninety-four cases and 194 controls were enrolled into the study. VE of the S(79) mumps vaccine for 1 dose versus 0 confer protection 80.4% (95% CI, 60.0%-90.4%) and VEs against mumps in outbreaks for 1 dose of mumps vaccine are similar among those children aged 4-9 years and aged over 10 years old. The live attenuated S(79) mumps vaccine can be effective in preventing clinical mumps outbreaks.

  15. Enzyme-treated Asparagus officinalis extract shows neuroprotective effects and attenuates cognitive impairment in senescence-accelerated mice.

    Science.gov (United States)

    Sakurai, Takuya; Ito, Tomohiro; Wakame, Koji; Kitadate, Kentaro; Arai, Takashi; Ogasawara, Junetsu; Kizaki, Takako; Sato, Shogo; Ishibashi, Yoshinaga; Fujiwara, Tomonori; Akagawa, Kimio; Ishida, Hitoshi; Ohno, Hideki

    2014-01-01

    Increases in the number of patients with dementia involving Alzheimer's disease (AD) are seen as a grave public health problem. In neurodegenerative disorders involving AD, biological stresses, such as oxidative and inflammatory stress, induce neural cell damage. Asparagus (Asparagus officinalis) is a popular vegetable, and an extract prepared from this reportedly possesses various beneficial biological activities. In the present study, we investigated the effects of enzyme-treated asparagus extract (ETAS) on neuronal cells and early cognitive impairment of senescence-accelerated mouse prone 8 (SAMP8) mice. The expression of mRNAs for factors that exert cytoprotective and anti-apoptotic functions, such as heat-shock protein 70 and heme oxygenase-1, was upregulated in NG108-15 neuronal cells by treatment with ETAS. Moreover, when release of lactate dehydrogenase from damaged NG108-15 cells was increased for cells cultured in medium containing either the nitric oxide donor sodium nitroprusside or the hypoxia mimic reagent cobalt chloride, ETAS significantly attenuated this cell damage. Also, when contextual fear memory, which is considered to be a hippocampus-dependent memory, was significantly impaired in SAMP8 mice, ETAS attenuated the cognitive impairment. These results suggest that ETAS produces cytoprotective effects in neuronal cells and attenuates the effects on the cognitive impairment of SAMP8 mice.

  16. Modeling the relative impact of capsular tissue effects on implanted glucose sensor time lag and signal attenuation.

    Science.gov (United States)

    Novak, Matthew T; Yuan, Fan; Reichert, William M

    2010-10-01

    Little is known mechanistically about why implanted glucose sensors lag behind blood glucose levels in both the time to peak sensor response and the magnitude of peak sensor response. A mathematical model of glucose transport from capillaries through surrounding tissue to the sensor surface was constructed to address how different aspects of the tissue affect glucose transport to an implanted sensor. Physiologically relevant values of capsule diffusion coefficient, capsule porosity, cellular glucose consumption, capsule thickness, and subcutaneous vessel density were used as inputs to create simulated sensor traces that mimic experimental instances of time lag and concentration attenuation relative to a given blood glucose profile. Using logarithmic sensitivity analysis, each parameter was analyzed to study the effect of these variables on both lag and attenuation. Results identify capsule thickness as the strongest determinant of sensor time lag, while subcutaneous vessel density and capsule porosity had the largest effects on attenuation of glucose that reaches the sensor surface. These findings provide mechanistic insight for the rational design of sensor modifications that may alleviate the deleterious consequences of tissue effects on implanted sensor performance.

  17. Attenuation correction of myocardial SPECT images with X-ray CT. Effects of registration errors between X-ray CT and SPECT

    International Nuclear Information System (INIS)

    Takahashi, Yasuyuki; Murase, Kenya; Mochizuki, Teruhito; Motomura, Nobutoku

    2002-01-01

    Attenuation correction with an X-ray CT image is a new method to correct attenuation on SPECT imaging, but the effect of the registration errors between CT and SPECT images is unclear. In this study, we investigated the effects of the registration errors on myocardial SPECT, analyzing data from a phantom and a human volunteer. Registerion (fusion) of the X-ray CT and SPECT images was done with standard packaged software in three dimensional fashion, by using linked transaxial, coronal and sagittal images. In the phantom study, and X-ray CT image was shifted 1 to 3 pixels on the x, y and z axes, and rotated 6 degrees clockwise. Attenuation correction maps generated from each misaligned X-ray CT image were used to reconstruct misaligned SPECT images of the phantom filled with 201 Tl. In a human volunteer, X-ray CT was acquired in different conditions (during inspiration vs. expiration). CT values were transferred to an attenuation constant by using straight lines; an attenuation constant of 0/cm in the air (CT value=-1,000 HU) and that of 0.150/cm in water (CT value=0 HU). For comparison, attenuation correction with transmission CT (TCT) data and an external γ-ray source ( 99m Tc) was also applied to reconstruct SPECT images. Simulated breast attenuation with a breast attachment, and inferior wall attenuation were properly corrected by means of the attenuation correction map generated from X-ray CT. As pixel shift increased, deviation of the SPECT images increased in misaligned images in the phantom study. In the human study, SPECT images were affected by the scan conditions of the X-ray CT. Attenuation correction of myocardial SPECT with an X-ray CT image is a simple and potentially beneficial method for clinical use, but accurate registration of the X-ray CT to SPECT image is essential for satisfactory attenuation correction. (author)

  18. An EMA Analysis of the Effect of Increasing Word Length on Consonant Production in Apraxia of Speech: A Case Study

    Science.gov (United States)

    Bartle, Carly J.; Goozee, Justine V.; Murdoch, Bruce E.

    2007-01-01

    The effect of increasing word length on the articulatory dynamics (i.e. duration, distance, maximum acceleration, maximum deceleration, and maximum velocity) of consonant production in acquired apraxia of speech was investigated using electromagnetic articulography (EMA). Tongue-tip and tongue-back movement of one apraxic patient was recorded…

  19. The Effect of Physiotherapy on Ventilatory Dependency and the Length of Stay in an Intensive Care Unit

    Science.gov (United States)

    Malkoc, Mehtap; Karadibak, Didem; Yldrm, Yucel

    2009-01-01

    The aim of this study was to assess the effect of physiotherapy on ventilator dependency and lengths of intensive care unit (ICU) stay. Patients were divided into two groups. The control group, which received standard nursing care, was a retrospective chart review. The data of control patients who were not receiving physiotherapy were obtained…

  20. Does working memory change with age? The interactions of concurrent articulation with the effects of word length and acoustic confusion.

    Science.gov (United States)

    Bireta, Tamra J; Fine, Hope C; Vanwormer, Lisa A

    2013-01-01

    The effects of acoustic confusion (phonological similarity), word length, and concurrent articulation (articulatory suppression) are cited as support for Working Memory's phonological loop component (e.g., Baddeley, 2000 , Psychonomic Bulletin and Review, 7, 544). Research has focused on younger adults, with no studies examining whether concurrent articulation reduces the word length and acoustic confusion effects among older adults. In the current study, younger and older adults were given lists of similar and dissimilar letters (Experiment 1) or long and short words (Experiment 2) for immediate serial reconstruction of order. Items were presented visually or auditorily, with or without concurrent articulation. As expected, younger and older adults demonstrated effects of acoustic confusion, word length, and concurrent articulation. Further, concurrent articulation reduced the effects of acoustic confusion and word length equally for younger and older adults. This suggests that age-related differences occur in overall performance, but do not reflect an age-related deficiency in the functioning of the phonological loop component of working memory.

  1. Finite element modeling of aponeurotomy: altered intramuscular myofascial force transmission yields complex sarcomere length distributions determining acute effects

    NARCIS (Netherlands)

    Yucesoy, C.A.; Koopman, Hubertus F.J.M.; Grootenboer, H.J.; Huijing, P.A.J.B.M.

    2007-01-01

    Finite element modeling of aponeurotomized rat extensor digitorium longus muscle was performed to investigate the acute effects of proximal aponeurotomy. The specific goal was to assess the changes in lengths of sarcomeres within aponeurotomized muscle and to explain how the intervention leads to

  2. The Effects of Input Enhancement and Text Length on Adult L2 Readers' Comprehension and Intake in Second Language Acquisition.

    Science.gov (United States)

    Leow, Ronald P.

    1997-01-01

    Investigated the effects of written input enhancement and text length on college students' second-language comprehension and intake. First-year Spanish students were exposed to one of four conditions with enhanced and non-enhanced short and long text. Exposing students to short authentic reading materials facilitated reading comprehension but not…

  3. Effect of maternal dry period length on colostrum immunoglobulin content and natural and specific antibody titers in calves

    NARCIS (Netherlands)

    Mayasari, N.; Vries Reilingh, de G.; Nieuwland, M.G.B.; Remmelink, G.J.; Parmentier, H.K.; Kemp, B.; Knegsel, van A.T.M.

    2015-01-01

    The objective was to study the effect of dry period length in dairy cows on immunoglobulin content and natural antibodies (NAb) titers in colostrum, growth, and plasma natural and specific antibody titers in plasma of calves. Holstein-Friesian dairy cows (n = 167) were randomly assigned to 3 dry

  4. Disentangling behavior in early child development : Interpretability of early child language and its effect on utterance length measures

    NARCIS (Netherlands)

    Van Dijk, M.W.G.; Van Geert, P. L. C.

    Early child speech is often difficult to understand and interpret. Usually, these unintelligible units are not included in quantitative measures, such as MLU. In this paper, we claim that these interpretation problems have an unknown effect on utterance length measures (such as MLU), since we have

  5. Effect of dry period length and dietary energy source on energy balance, milk yield, and milk composition of dairy cows

    NARCIS (Netherlands)

    Knegsel, van A.T.M.; Remmelink, G.J.; Jorjong, S.; Fievez, V.; Kemp, B.

    2014-01-01

    The objective of this study was to evaluate the effects of dry period length and dietary energy source in early lactation on milk production, feed intake, and energy balance (EB) of dairy cows. Holstein-Friesian dairy cows (60 primiparous and 108 multiparous) were randomly assigned to dry period

  6. Effects of dry period length and dietary energy source on inflammatory biomarkers and oxidative stress in dairy cows

    NARCIS (Netherlands)

    Mayasari, N.; Chen, J.; Ferrari, A.; Bruckmaier, R.M.; Kemp, B.; Parmentier, H.K.; Knegsel, van A.T.M.; Trevisi, E.

    2017-01-01

    Negative energy balance in dairy cows in early lactation has been associated with increased inflammation and oxidative stress in these cows. The objective of this study was to evaluate the effects of dry period (DP) length and dietary energy source on inflammatory biomarkers and oxidative stress

  7. Effect of taurine on attenuating chemotherapy-induced adverse effects in acute lymphoblastic leukemia

    Directory of Open Access Journals (Sweden)

    Mina Islambulchilar

    2015-01-01

    Conclusion: In conclusion our results indicated that taurine supplementation could be a protection against chemotherapy-induced toxicities probably by its antioxidant capacity. Present study showed effectiveness of taurineon the chemotherapy-related toxicities and some of the complications during the maintenance period of treatment following coadministration in young adults with ALL.

  8. Effects of cellulose fiber with different fiber length on rheological properties of wheat dough and quality of baked rolls.

    Science.gov (United States)

    Lauková, Michaela; Kohajdová, Zlatica; Karovičová, Jolana; Kuchtová, Veronika; Minarovičová, Lucia; Tomášiková, Lenka

    2017-09-01

    Powdered cellulose is often used in cereal processing industry. The effects of partial replacement (0.5%, 1%, 2% and 5%) of wheat flour by cellulose fiber with different fiber length (80, 120 and 220 µm) on rheological properties of wheat dough and qualitative parameters of baked rolls were studied. Sensory evaluation of baked products was also performed. Mixing and pasting properties of dough were determined by Mixolab. Generally, cellulose-enriched dough was characterized with higher water absorption, dough stability and parameters C2 and C3. Moreover, it was found that parameters C4 and C5 increased with increasing cellulose fiber length. From the results, it was also concluded that the physical parameters of baked rolls containing cellulose were reduced. It was also observed that the incorporation of cellulose fiber with shorter fiber length concluded in lower rolls volume compared to cellulose fiber with long fiber length. Texture analyses showed that the firmness of rolls containing cellulose at the substitution level 5% was significantly higher than those of the control, whereas the springiness of wheat rolls was not significantly affected. It was also recorded that the firmness and cohesiveness of baked rolls were higher after the addition of cellulose fiber with shorter fiber length. Sensory evaluation indicated that baked rolls with cellulose addition up to 1% were comparable with control rolls. Results also showed that higher levels of cellulose significantly decreased crust, taste, color and porosity of rolls.

  9. Dissolution Behavior of Cellulose in IL + DMSO Solvent: Effect of Alkyl Length in Imidazolium Cation on Cellulose Dissolution

    Directory of Open Access Journals (Sweden)

    Airong Xu

    2015-01-01

    Full Text Available Four cellulose solvents including [C2mim][CH3COO] + DMSO, [C4mim][CH3COO] + DMSO, [C6mim][CH3COO] + DMSO, and [C8mim][CH3COO] + DMSO were prepared by adding dimethyl sulfoxide DMSO in 1-ethyl-3-methylimidazolium acetate [C2mim][CH3COO], 1-butyl-3-methylimidazolium acetate [C4mim][CH3COO], 1-hexyl-3-methylimidazolium acetate [C6mim][CH3COO], and 1-octyl-3-methylimidazolium acetate [C8mim][CH3COO], respectively. The solubilities of cellulose in these solvents were determined at 25°C. The effect of the alkyl chain length in imidazolium cation on cellulose solubility was investigated. With increasing alkyl chain length in imidazolium cation, the solubility of cellulose increases, but further increase in alkyl chain length results in decreases in cellulose.

  10. Effects of Surrounding Information and Line Length on Text Comprehension from the Web

    Directory of Open Access Journals (Sweden)

    Jess McMullin

    2002-02-01

    Full Text Available The World Wide Web (Web is becoming a popular medium for transmission of information and online learning. We need to understand how people comprehend information from the Web to design Web sites that maximize the acquisition of information. We examined two features of Web page design that are easily modified by developers, namely line length and the amount of surrounding information, or whitespace. Undergraduate university student participants read text and answered comprehension questions on the Web. Comprehension was affected by whitespace; participants had better comprehension for information surrounded by whitespace than for information surrounded by meaningless information. Participants were not affected by line length. These findings demonstrate that reading from the Web is not the same as reading print and have implications for instructional Web design.

  11. Tornado hazard model with the variation effects of tornado intensity along the path length

    International Nuclear Information System (INIS)

    Hirakuchi, Hiromaru; Nohara, Daisuke; Sugimoto, Soichiro; Eguchi, Yuzuru; Hattori, Yasuo

    2015-01-01

    Most of Japanese tornados have been reported near the coast line, where all of Japanese nuclear power plants are located. It is necessary for Japanese electric power companies to assess tornado risks on the plants according to a new regulation in 2013. The new regulatory guide exemplifies a tornado hazard model, which cannot consider the variation of tornado intensity along the path length and consequently produces conservative risk estimates. The guide also recommends the long narrow strip area along the coast line with the width of 5-10 km as a region of interest, although the model tends to estimate inadequate wind speeds due to the limit of application. The purpose of this study is to propose a new tornado hazard model which can be apply to the long narrow strip area. The new model can also consider the variation of tornado intensity along the path length and across the path width. (author)

  12. Bond length effects during the dissociation of O2 on Ni(1 1 1)

    International Nuclear Information System (INIS)

    Shuttleworth, I.G.

    2015-01-01

    Graphical abstract: - Highlights: • The dissociation of O 2 on Ni(1 1 1) has been investigated using the Nudged Elastic Band (NEB) technique. • An exceptional correlation has been identified between the O/Ni bond order and the O 2 bond length for a series of sterically different reaction paths. • Direct magnetic phenomena accompany these processes suggesting further mechanisms for experimental control. - Abstract: The interaction between O 2 and Ni(1 1 1) has been investigated using spin-polarised density functional theory. A series of low activation energy (E A = 103–315 meV) reaction pathways corresponding to precursor and non-precursor mediated adsorption have been identified. It has been seen that a predominantly pathway-independent correlation exists between O−Ni bond order and the O 2 bond length. This correlation demonstrates that the O−O interaction predominantly determines the bonding of this system

  13. Effect of operational cycle time length on nitrogen removal in an alternating oxidation ditch system.

    Science.gov (United States)

    Mantziaras, I D; Stamou, A; Katsiri, A

    2011-06-01

    This paper refers to nitrogen removal optimization of an alternating oxidation ditch system through the use of a mathematical model and pilot testing. The pilot system where measurements have been made has a total volume of 120 m(3) and consists of two ditches operating in four phases during one cycle and performs carbon oxidation, nitrification, denitrification and settling. The mathematical model consists of one-dimensional mass balance (convection-dispersion) equations based on the IAWPRC ASM 1 model. After the calibration and verification of the model, simulation system performance was made. Optimization is achieved by testing operational cycles and phases with different time lengths. The limits of EU directive 91/271 for nitrogen removal have been used for comparison. The findings show that operational cycles with smaller time lengths can achieve higher nitrogen removals and that an "equilibrium" between phase time percentages in the whole cycle, for a given inflow, must be achieved.

  14. Simulating the Effect of Modulated Tool-Path Chip Breaking On Surface Texture and Chip Length

    Energy Technology Data Exchange (ETDEWEB)

    Smith, K.S.; McFarland, J.T.; Tursky, D. A.; Assaid, T. S.; Barkman, W. E.; Babelay, Jr., E. F.

    2010-04-30

    One method for creating broken chips in turning processes involves oscillating the cutting tool in the feed direction utilizing the CNC machine axes. The University of North Carolina at Charlotte and the Y-12 National Security Complex have developed and are refining a method to reliably control surface finish and chip length based on a particular machine's dynamic performance. Using computer simulations it is possible to combine the motion of the machine axes with the geometry of the cutting tool to predict the surface characteristics and map the surface texture for a wide range of oscillation parameters. These data allow the selection of oscillation parameters to simultaneously ensure broken chips and acceptable surface characteristics. This paper describes the machine dynamic testing and characterization activities as well as the computational method used for evaluating and predicting chip length and surface texture.

  15. The Effects of Minimal Length, Maximal Momentum, and Minimal Momentum in Entropic Force

    Directory of Open Access Journals (Sweden)

    Zhong-Wen Feng

    2016-01-01

    Full Text Available The modified entropic force law is studied by using a new kind of generalized uncertainty principle which contains a minimal length, a minimal momentum, and a maximal momentum. Firstly, the quantum corrections to the thermodynamics of a black hole are investigated. Then, according to Verlinde’s theory, the generalized uncertainty principle (GUP corrected entropic force is obtained. The result shows that the GUP corrected entropic force is related not only to the properties of the black holes but also to the Planck length and the dimensionless constants α0 and β0. Moreover, based on the GUP corrected entropic force, we also derive the modified Einstein’s field equation (EFE and the modified Friedmann equation.

  16. Effect of in vitro gamma exposure on rat mesencephalic and striatal cellular types and processes length

    International Nuclear Information System (INIS)

    Coffigny, H.; Court, L.

    1994-01-01

    The isolated mesencephalic and striatal cells were irradiated in a dose-range of 0.25 to 3 Gy followed by 3 day of culture. The proportion of monopolar, bipolar, tripolar and multipolar cell population was not obviously modified by irradiation. The processes length was similar to controls, except after 3 Gy exposure, for monopolar and bipolar mesencephalic cells and the tripolar striatal cells where it was increased. In these populations, only cells with long processes seemed to survive. (author)

  17. Effect of hydrocarbon radical length of fatty acid collectors on flotation separation process of thorium ions

    International Nuclear Information System (INIS)

    Skrylev, L.D.; Perlova, O.V.; Sazonova, V.F.

    1991-01-01

    It is shown experimentally that the degree of flotation separation of thorium ions collected by their means increases firstly (potassium laurate), then decreases (potassium tridecanate) and after that increases again (potassium palminate) when increasing the length of the hydrocarbon radical of potassium soaps of saturated fatty acids. The first increase of the collector efficiency is due to the decrease of solubility of thorium-containing sublates, and drop and further increase is due to the change in colloidchemical properties of sublates

  18. State switching kinetics for quasi-one-dimensional nanosystems: Effects of Finite length and irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Petukhov, B. V., E-mail: petukhov@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics,” (Russian Federation)

    2017-01-15

    The state switching in an extended quasi-one-dimensional material is modeled by the stochastic formation of local new-state nuclei and their subsequent growth along the system axis. An analytical approach is developed to describe the influence of defects, dividing a sample into an ensemble of finite-length segments, on its state switching kinetics. As applied to magnetic systems, the method makes it possible to calculate magnetization curves for different defect concentrations and parameters of material.

  19. The Effect of the Chain Length on MMA Free Radicl Polymerization

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the polymerization process of methyl methacrylate (MMA), the Arrhenius parameters (activation energy and frequency factor) of propagating reaction monotonically decrease with increasing monomer conversion. At the beginning and middle stage of the propagating reaction, the increase of radical chain length is the main reason of above mentioned change. And at the end stage, the sharp decrease of kp indicates that the activation energy is approximately incline to zero and the propagating reaction is controlled by molecular diffusion motion.

  20. EFFECTS INDUCED BY DIETHYL SULPHATE ON SOME CYTOGENETICAL PARAMETERS AND LENGTH GROWTH OF HEMP PLANTLETS

    Directory of Open Access Journals (Sweden)

    Elena Truta

    2007-08-01

    Full Text Available The hemp seeds were treated with diethyl sulphate, in four concentrations (0.1%, 0.25%, 0.5%, and 1% and in two variants of alkylant exposure (3 and 6 hours. The length growth of plantlets, mitotic index and frequency of chromosomal aberrations were the analyzed parameters. Significant modifications were obtained at the level of parameters in variants treated with DES, comparatively with control.

  1. Effects of dietary protein levels on length-weight relationships and ...

    African Journals Online (AJOL)

    Feeding trial involving different protein levels on length–weight relationships and condition factor of Clarias gariepinus was conducted in floating hapa system. Fingerlings (average weight, 4.50± 0.01g and average length, 8.0±0.2 cm) were randomly stocked at 20 fish/1m3. Five diets with crude protein: 40.0, 42.5, 45.0, 47.5 ...

  2. EFFECT OF MUSIC EXPOSURE ON THE WEIGHT AND BODY-LENGTH OF RAT-LITTERS

    Directory of Open Access Journals (Sweden)

    Ria Puspitawati

    2015-06-01

    Full Text Available Music is related to stress reduction and increased levels of growth hormone. In rats, music exposure since prenatal period was found to increase body weight of 7-days-old litters and brain cells. Somatic growth was primarily influenced by growth hormone and supported by psycho-physic condition. The objective of this study was to analyze whether music exposure since prenatal until 35 days post-natal period could affect the weight and body-length of the rat-pups. Four pregnant Wistar rats were daily exposed to one hour classic music (Mozart every 17.30 pm since gestation period day one until the 22 litters were 35 days old. Controls were 5 pregnant rats and their 36 litters caged in a different room with no music. Weighing and measuring the body-length (the most anterior point of the nasal septum to the base of the tail were conducted at day 7, 25, and 35. Data were analyzed using Multivariate General-Linear-Modem (α = 0.05. It was revealed that the mean weight of the experimental litters was significantly higher than those of the controls either at day 7 (p = 0.00, day 25 (p = 0.012 or 35 (p = 0.006. Difference of the body-length of the experiment and control animals only significant at day 25 (p = 0.012. Conclusion: Music exposure since prenatal period has significant influences on the weight of the rat-litters aged 7, 25 and 35 days and on the body-length of the 25-days-old litters.

  3. Numerical analysis of finite Debye-length effects in induced-charge electro-osmosis.

    Science.gov (United States)

    Gregersen, Misha Marie; Andersen, Mathias Baekbo; Soni, Gaurav; Meinhart, Carl; Bruus, Henrik

    2009-06-01

    For a microchamber filled with a binary electrolyte and containing a flat unbiased center electrode at one wall, we employ three numerical models to study the strength of the resulting induced-charge electro-osmotic (ICEO) flow rolls: (i) a full nonlinear continuum model resolving the double layer, (ii) a linear slip-velocity model not resolving the double layer and without tangential charge transport inside this layer, and (iii) a nonlinear slip-velocity model extending the linear model by including the tangential charge transport inside the double layer. We show that, compared to the full model, the slip-velocity models significantly overestimate the ICEO flow. This provides a partial explanation of the quantitative discrepancy between observed and calculated ICEO velocities reported in the literature. The discrepancy increases significantly for increasing Debye length relative to the electrode size, i.e., for nanofluidic systems. However, even for electrode dimensions in the micrometer range, the discrepancies in velocity due to the finite Debye length can be more than 10% for an electrode of zero height and more than 100% for electrode heights comparable to the Debye length.

  4. Accumulative effects of indoor air pollution exposure on leukocyte telomere length among non-smokers.

    Science.gov (United States)

    Lin, Nan; Mu, Xinlin; Wang, Guilian; Ren, Yu'ang; Su, Shu; Li, Zhiwen; Wang, Bin; Tao, Shu

    2017-08-01

    Indoor air pollution is an important environmental factor that contributes to the burden of various diseases. Long-term exposure to ambient air pollution is associated with telomere shortening. However, the association between chronic indoor air pollution from household fuel combustion and leukocyte telomere length has not been studied. In our study, 137 cancer-free non-smokers were recruited. Their exposure levels to indoor air pollution from 1985 to 2014 were assessed using a face-to-face interview questionnaire, and leukocyte telomere length (LTL) was measured using a monochrome multiplex quantitative PCR method. Accumulative exposure to solid fuel usage for cooking was negatively correlated with LTL. The LTL of residents who were exposed to solid fuel combustion for three decades (LTL = 0.70 ± 0.17) was significantly shorter than that of other populations. In addition, education and occupation were related to both exposure to solid fuel and LTL. Sociodemographic factors may play a mediating role in the correlation between leukocyte telomere length and environmental exposure to indoor air pollution. In conclusion, long-term exposure to indoor air pollution may cause LTL dysfunction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Stability of measures from children's interviews: the effects of time, sample length, and topic.

    Science.gov (United States)

    Heilmann, John; DeBrock, Lindsay; Riley-Tillman, T Chris

    2013-08-01

    The purpose of this study was to examine the reliability of, and sources of variability in, language measures from interviews collected from young school-age children. Two 10-min interviews were collected from 20 at-risk kindergarten children by an examiner using a standardized set of questions. Test-retest reliability coefficients were calculated for 8 language measures. Generalizability theory (G-theory) analyses were completed to document the variability introduced into the measures from the child, session, sample length, and topic. Significant and strong reliability correlation coefficients were observed for most of the language sample measures. The G-theory analyses revealed that most of the variance in the language measures was attributed to the child. Session, sample length, and topic accounted for negligible amounts of variance in most of the language measures. Measures from interviews were reliable across sessions, and the sample length and topic did not have a substantial impact on the reliability of the language measures. Implications regarding the clinical feasibility of language sample analysis for assessment and progress monitoring are discussed.

  6. Capillary Versus Aspiration Biopsy: Effect of Needle Size and Length on the Cytopathological Specimen Quality

    International Nuclear Information System (INIS)

    Hopper, Kenneth D.; Grenko, Ronald T.; Fisher, Alicia I.; TenHave, Thomas R.

    1996-01-01

    Purpose: To test the value of the nonaspiration, or capillary, biopsy technique by experimental comparison with the conventional fine-needle aspiration technique using various needle gauges and lengths. Methods: On fresh hepatic and renal tissue from five autopsies, multiple biopsy specimens were taken with 20, 22, and 23-gauge Chiba needles of 5, 10, 15, and 20-cm length, using the aspiration technique and the capillary technique. The resultant specimens were graded on the basis of a grading scheme by a cytopathologist who was blinded to the biopsy technique. Results: The capillary technique obtained less background blood or clot which could obscure diagnostic tissue, although not significantly different from the aspiration technique (p= 0.2). However, for the amount of cellular material obtained, retention of appropriate architecture, and mean score, the capillary technique performed statistically worse than aspiration biopsy (p < 0.01). In addition, with decreasing needle caliber (increasing needle gauge) and increasing length, the capillary biopsy was inferior to the aspiration biopsy. Conclusion: The capillary biopsy technique is inferior to the aspiration technique according to our study. When the capillary technique is to be applied, preference should be given to larger caliber, shorter needles

  7. Effect of MK-801 on methamphetamine-induced dopaminergic neurotoxicity: long-term attenuation of methamphetamine-induced dopamine release

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sang Eun; Kim, Yu Ri; Hwang, Se Hwan [Sungkyunkwan Univ., School of Medicine, Seoul (Korea, Republic of)

    2001-08-01

    Repeated administration of methamphetamine (METH) produces high extracellular levels of dopamine (DA) and subsequent striatal DA terminal damage. The effect of MK-801, a noncompetitive N-methyl-D-aspartate receptor antagonist, on METH-induced changes in DA transporter (DAT) and DA release evoked by an acute METH challenge was evaluated in rodent striatum using [{sup 3}H] WIN 38,428 ex vivo auto-radiography and in vivo microdialysis. Four injections of METH (10 mg/kg, i.p.), each given 2 h apart, produced 71% decrease in DAT levels in mouse striatum 3 d after administration. Pretreatment with MK-801 (2.5 g/kg, i.p.) 15 min before each of the four METH injections protected completely against striatal DAT depletions. Four injections of MK-801 alone did not significantly change striatal DAT levels. Striatal DA release evoked by an acute METH challenge (4mg/kg, i.p.) at 3 d after repeated administration of METH in rats was decreased but significant compared with controls, which was attenuated by repeated pretreatment with MK-801. Also, repeated injections of MK-801 alone attenuated acute METH-induced striatal DA release 3 d after administration. These results suggest that repeated administration of MK-801 may exert a preventive effect against METH-induced DA terminal injury through long-term attenuation of DA release induced by METH and other stimuli.

  8. Effect of MK-801 on methamphetamine-induced dopaminergic neurotoxicity: long-term attenuation of methamphetamine-induced dopamine release

    International Nuclear Information System (INIS)

    Kim, Sang Eun; Kim, Yu Ri; Hwang, Se Hwan

    2001-01-01

    Repeated administration of methamphetamine (METH) produces high extracellular levels of dopamine (DA) and subsequent striatal DA terminal damage. The effect of MK-801, a noncompetitive N-methyl-D-aspartate receptor antagonist, on METH-induced changes in DA transporter (DAT) and DA release evoked by an acute METH challenge was evaluated in rodent striatum using [ 3 H] WIN 38,428 ex vivo auto-radiography and in vivo microdialysis. Four injections of METH (10 mg/kg, i.p.), each given 2 h apart, produced 71% decrease in DAT levels in mouse striatum 3 d after administration. Pretreatment with MK-801 (2.5 g/kg, i.p.) 15 min before each of the four METH injections protected completely against striatal DAT depletions. Four injections of MK-801 alone did not significantly change striatal DAT levels. Striatal DA release evoked by an acute METH challenge (4mg/kg, i.p.) at 3 d after repeated administration of METH in rats was decreased but significant compared with controls, which was attenuated by repeated pretreatment with MK-801. Also, repeated injections of MK-801 alone attenuated acute METH-induced striatal DA release 3 d after administration. These results suggest that repeated administration of MK-801 may exert a preventive effect against METH-induced DA terminal injury through long-term attenuation of DA release induced by METH and other stimuli

  9. Ameliorative effects of curcumin on the spermatozoon tail length, count, motility and testosterone serum level in metronidazole-treated mice.

    Science.gov (United States)

    Karbalay-Doust, S; Noorafshan, A

    2011-01-01

    Metronidazole (MTZ) is used as an antiparasitic drug. Curcumin is considered as anti-oxidant and anti-inflammatory agent. The ameliorative effects of curcumin on MTZ induced toxicity on mice spermatozoon tail length, count, motility and testosterone level were investigated. MTZ was administered in 500 and 165 (high and therapeutic doses) mg/kg/day, with and without curcumin (100 mg/kg/day). After 16 days the above parameters were assessed. Spermatozoon count and motility and serum testosterone level MTZ-treated (500 and 165) mice were reduced. In the mice treated with MTZ+curcumin these parameters decreased but in a lesser extent than the MTZ-treated animals. Mid-piece and total lengths of the spermatozoon tail in control animals were 31.6 ± 9.0 μm and 100.3 ± 15.0 μm and in the mice treated with high doses (500) of MTZ were reduced. The mid-piece and total spermatozoon tail length has been decreased in a lesser extent in the mice treated with high dose MTZ+curcumin than the mice treated with high dose MTZ (paverage increase in mid-piece and total lengths in comparison with the MTZ-treated (500) animals. Stereological estimation of the sperm tail length, including sampling of spermatozoa and also counting of the intersections of their tails with the stereological grids was a rapid technique and took only 5-10 minutes. It can be concluded that curcumin has an ameliorative effect on the spermatozoon, testosterone level and tail length in MTZ-treated mice.

  10. Relationship Between the Relative Age Effect and Lengths of Professional Careers in Male Japanese Baseball Players: a Retrospective Analysis.

    Science.gov (United States)

    Nakata, Hiroki

    2017-12-01

    The mechanisms underlying the relative age effect in sport events have been investigated for more than two decades. The present study focused on the relationship between the relative age effect and lengths of professional careers among professional male Japanese baseball players. The birth dates of players and lengths of professional careers were collected from an official publication, and data were divided into four quarters (Q1: April-June; Q2: July-September; Q3: October-December; Q4: January-March of the following year) grouped by 3 years. Based on the data for Q4, the expected numbers for the lengths of professional careers were calculated for Q1, Q2, and Q3. The number of players with professional careers of more than 19 years was significantly smaller in Q4 than in Q1, Q2, and Q3. The relative age effect among professional male Japanese baseball players was associated with the lengths of professional careers. Relative age appears to be a very important factor for the development of expertise among male Japanese baseball players and involves long-term disadvantages after becoming professional players.

  11. Combined effects of rainfall regime and plot length on runoff and soil loss in the Loess Plateau of China

    Science.gov (United States)

    Liu, J.; Gao, G.; Wang, S.; Fu, B.

    2017-12-01

    The purpose of this paper was to study the interaction effects of rainfall regime and slope length on runoff and soil loss under different land uses. Event runoff and soil loss of forest, shrub and grass were measured in plots with length of 5, 9, or 13 m in the Loess Plateau from 2008 to 2016. Fifty-nine erosive rainfall events were recorded and classified into three rainfall regimes. The results firstly showed that the runoff coefficient was grass > shrub > forest, and soil loss was grass > forest > shrub, but the differences between forest and shrub in runoff and between grass and forest in soil loss didn't reach significant level. Secondly, rainfall regimes had important effect on runoff and soil loss of different land uses. The lowest runoff coefficients and the highest soil loss in regime 2 were found in shrub and forest land, respectively, which differed from that of regime 1. In total, rainfall regime 1 had the highest runoff coefficient of 0.84-2.06%, followed by regime 3 with 0.33-0.88%, and regime 2 with 0.04-0.06%. Soil loss in forest and grass land had a different order of regime 3 > regime 1 > regime 2. Thirdly, both the runoff coefficient and soil loss decreased with increasing plot length, while the effect of slope length on runoff/soil loss were influenced by land use type and rainfall regimes.

  12. Effects of the length and timing of nighttime naps on task performance and physiological function

    Directory of Open Access Journals (Sweden)

    Hidemaro Takeyama

    2004-12-01

    Full Text Available OBJECTIVE: To examine the effects of the length and timing of nighttime naps on performance and physiological functions, an experimental study was carried out under simulated night shift schedules. METHODS: Six students were recruited for this study that was composed of 5 experiments. Each experiment involved 3 consecutive days with one night shift (22:00-8:00 followed by daytime sleep and night sleep. The experiments had 5 conditions in which the length and timing of naps were manipulated: 0:00-1:00 (E60, 0:00-2:00 (E120, 4:00-5:00 (L60, 4:00-6:00 (L120, and no nap (No-nap. During the night shifts, participants underwent performance tests. A questionnaire on subjective fatigue and a critical flicker fusion frequency test were administered after the performance tests. Heart rate variability and rectal temperature were recorded continuously during the experiments. Polysomnography was also recorded during the nap. RESULTS: Sleep latency was shorter and sleep efficiency was higher in the nap in L60 and L120 than that in E60 and E120. Slow wave sleep in the naps in E120 and L120 was longer than that in E60 and L60. The mean reaction time in L60 became longer after the nap, and faster in E60 and E120. Earlier naps serve to counteract the decrement in performance and physiological functions during night shifts. Performance was somewhat improved by taking a 2-hour nap later in the shift, but deteriorated after a one-hour nap. CONCLUSIONS: Naps in the latter half of the night shift were superior to earlier naps in terms of sleep quality. However performance declined after a 1-hour nap taken later in the night shift due to sleep inertia. This study suggests that appropriate timing of a short nap must be carefully considered, such as a 60-min nap during the night shift.OBJETIVO: Para investigar os efeitos da duração e horário de cochilos noturnos sobre o desempenho e as funções fisiológicas foi realizado um estudo experimental por meio do trabalho

  13. SPM and XPM crosstalk in WDM systems with DRA: Channel spacing and attenuation effects

    Science.gov (United States)

    Morsy, Emadeldeen; Fayed, Heba A.; Abd El Aziz, Ahmed; Aly, Moustafa H.

    2018-06-01

    This paper presents a theoretical analysis of a closed formula for nonlinear crosstalk due to self-phase modulation (SPM) and cross phase modulation (XPM) in wavelength division multiplexing (WDM) systems. The influence of channel spacing and attenuation on the system behavior is modeled and investigated. The system under consideration is a standard single-mode fiber (SSMF) with a single-span distributed Raman amplifier (DRA) and is operating at 100 Gbps.

  14. The effect of cushioning system on impact attenuation of athletic footwear

    Directory of Open Access Journals (Sweden)

    Maropoulos Stergios

    2017-01-01

    Full Text Available Several studies sought to determine impact attenuation of shoes through the evaluation of force platform or accelerometer measurements. Recent literature however points out methodological flaws of “subject inclusive” experimentation, as this approach is unable to evaluate neither the foot/ground interface nor the absorbed energy allocation. This study provides a holistic evaluation of the biomechanical response of athletic footwear to individual runner characteristics through advanced mechanical testing.

  15. In vitro cytotoxicity of Manville Code 100 glass fibers: Effect of fiber length on human alveolar macrophages

    Directory of Open Access Journals (Sweden)

    Jones William

    2006-03-01

    Full Text Available Abstract Background Synthetic vitreous fibers (SVFs are inorganic noncrystalline materials widely used in residential and industrial settings for insulation, filtration, and reinforcement purposes. SVFs conventionally include three major categories: fibrous glass, rock/slag/stone (mineral wool, and ceramic fibers. Previous in vitro studies from our laboratory demonstrated length-dependent cytotoxic effects of glass fibers on rat alveolar macrophages which were possibly associated with incomplete phagocytosis of fibers ≥ 17 μm in length. The purpose of this study was to examine the influence of fiber length on primary human alveolar macrophages, which are larger in diameter than rat macrophages, using length-classified Manville Code 100 glass fibers (8, 10, 16, and 20 μm. It was hypothesized that complete engulfment of fibers by human alveolar macrophages could decrease fiber cytotoxicity; i.e. shorter fibers that can be completely engulfed might not be as cytotoxic as longer fibers. Human alveolar macrophages, obtained by segmental bronchoalveolar lavage of healthy, non-smoking volunteers, were treated with three different concentrations (determined by fiber number of the sized fibers in vitro. Cytotoxicity was assessed by monitoring cytosolic lactate dehydrogenase release and loss of function as indicated by a decrease in zymosan-stimulated chemiluminescence. Results Microscopic analysis indicated that human alveolar macrophages completely engulfed glass fibers of the 20 μm length. All fiber length fractions tested exhibited equal cytotoxicity on a per fiber basis, i.e. increasing lactate dehydrogenase and decreasing chemiluminescence in the same concentration-dependent fashion. Conclusion The data suggest that due to the larger diameter of human alveolar macrophages, compared to rat alveolar macrophages, complete phagocytosis of longer fibers can occur with the human cells. Neither incomplete phagocytosis nor length-dependent toxicity was

  16. The effect of hydrate content on seismic attenuation: A case study for Mallik 2L-38 well data, Mackenzie delta, Canada

    Science.gov (United States)

    Chand, Shyam; Minshull, Tim A.

    2004-07-01

    Observations of velocities in sediments containing gas hydrates show that the strength of sediments increases with hydrate saturation. Hence it is expected that the attenuation of these sediments will decrease with increasing hydrate saturation. However, sonic log measurements in the Mallik 2L-38 well and cross hole tomography measurements in the Mallik field have shown that attenuation increases with hydrate saturation. We studied a range of mechanisms by which increasing hydrate saturation could cause increased attenuation. We found that a difference in permeability between the host sediment and the newly formed hydrate can produce the observed effect. We modelled attenuation in terms of Biot and squirt flow mechanisms in composite media. We have used our model to predict observed attenuations in the Mallik 2L-38 well, Mackenzie Delta, Canada.

  17. Effect of Different Concrete Grade on Radiation Linear Attenuation Coefficient (μ)

    International Nuclear Information System (INIS)

    Noor Azreen Masenwat; Mohammad Shahrizan Samsu; Mohamad Pauzi Ismail; Suhairy Sani; Ismail Mustapha; Nasharuddin Isa; Mohamad Haniza Mahmud

    2014-01-01

    In calculating the quantity of absorption of radiation and its relationship with the thickness of a material, linear attenuation coefficient (μ) of the material is one of the parameters to be taken into account. For normal concrete, the (μ) varies depending on the type of radiation used, 0.105 cm -1 for Co-60 and 0.123 cm -1 for Cs-137. Value (μ) is used in the calculation of the radiation absorption for concrete material does not take into account factors such concrete grades. In this research, concrete with different grades (Grade 15, Grade 20, Grade 25, Grade 30, Grade 35, Grade 40) are designed and manufactured with reference to the mixing method described in British Standard. Then, the linear attenuation (μ) for each grade are measured using the radiation from the source Co-60 and Cs-137 sources. This paper describes and discusses the impact of differences in concrete grade of linear attenuation (μ) for Co-60 source/ source Cs-137 and its relationship with the compressive strength. (author)

  18. The effect of regional variation of seismic wave attenuation on the strong ground motion from earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Chung, D H; Bernreuter, D L

    1981-10-01

    Attenuation is caused by geometric spreading and absorption. Geometric spreading is almost independent of crustal geology and physiographic region, but absorption depends strongly on crustal geology and the state of the earth's upper mantle. Except for very high frequency waves, absorption does not affect ground motion at distances less than about 25 to 50 km. Thus, in the near-field zone, the attenuation in the eastern United States is similar to that in the western United States. Beyond the near field, differences in ground motion can best be accounted for by differences in attenuation caused by differences in absorption. The stress drop of eastern earthquakes may be higher than for western earthquakes of the same seismic moment, which would affect the high-frequency spectral content. But we believe this factor is of much less significance than differences in absorption in explaining the differences in ground motion between the East and the West. The characteristics of strong ground motion in the conterminous United States are discussed in light of these considerations, and estimates are made of the epicentral ground motions in the central and eastern United States. (author)

  19. Effects of foot strike on low back posture, shock attenuation, and comfort in running.

    Science.gov (United States)

    Delgado, Traci L; Kubera-Shelton, Emilia; Robb, Robert R; Hickman, Robbin; Wallmann, Harvey W; Dufek, Janet S

    2013-03-01

    Barefoot running (BF) is gaining popularity in the running community. Biomechanical changes occur with BF, especially when initial contact changes from rearfoot strike (RFS) to forefoot strike (FFS). Changes in lumbar spine range of motion (ROM), particularly involving lumbar lordosis, have been associated with increased low back pain. However, it is not known if changing from RFS to FFS affects lumbar lordosis or low back pain. The purpose of this study was to determine whether a change from RFS to FFS would change lumbar lordosis, influence shock attenuation, or change comfort levels in healthy recreational/experienced runners. Forty-three subjects performed a warm-up on the treadmill where a self-selected foot strike pattern was determined. Instructions on running RFS/FFS were taught, and two conditions were examined. Each condition consisted of 90 s of BF with RFS or FFS, order randomly assigned. A comfort questionnaire was completed after both conditions. Fifteen consecutive strides from each condition were extracted for analyses. Statistically significant differences between FFS and RFS shock attenuation (P strike from RFS to FFS decreased overall ROM in the lumbar spine but did not make a difference in flexion or extension in which the lumbar spine is positioned. Shock attenuation was greater in RFS. RFS was perceived a more comfortable running pattern.

  20. The effect of halo-vest length on stability of the cervical spine. A study in normal subjects.

    Science.gov (United States)

    Wang, G J; Moskal, J T; Albert, T; Pritts, C; Schuch, C M; Stamp, W G

    1988-03-01

    In order to study how the efficiency of the halo vest is affected by different lengths of the vest, an experimental headband was devised that allowed the head of a normal person to be held securely in the halo attachment. The vest was then modified to allow it to be adjusted to three different lengths (Fig. 2): a full vest extended to the iliac crests, a short vest extended to the twelfth ribs, and a half vest extended to the level of the nipples. Twenty normal, healthy adult men participated in the study. For each vest length, radiographs were made of each subject demonstrating rotation, flexion-extension, and lateral bending of the cervical spine. There was no rotation of the cervical spine, regardless of the length of the vest. There was a variable degree of motion in flexion or extension of the upper part of the cervical spine with all vest lengths, but this was not statistically significant. There was definite increase of motion caudad to the level of the fifth cervical vertebra regardless of the length of the vest. We concluded that a lesion of the upper part of the cervical spine can be treated effectively by halo traction with a half vest. This will improve the comfort and care of the patient and avoid the necessity of removing the vest if emergency cardiovascular resuscitation is needed. In the treatment of lesions of the lower part of the cervical spine (caudad to the level of the fourth cervical vertebra), the use of a halo vest that extends caudad to the level of the twelfth ribs does provide additional stability.

  1. Voxel effects within digital images of trabecular bone and their consequences on chord-length distribution measurements

    International Nuclear Information System (INIS)

    Rajon, D.A.; Shah, A.P.; Watchman, C.J.; Bolch, W.E.; Jokisch, D.W.; Patton, P.W.

    2002-01-01

    Chord-length distributions through the trabecular regions of the skeleton have been investigated since the early 1960s. These distributions have become important features for bone marrow dosimetry; as such, current models rely on the accuracy of their measurements. Recent techniques utilize nuclear magnetic resonance (NMR) microscopy to acquire 3D images of trabecular bone that are then used to measure 3D chord-length distributions by Monte Carlo methods. Previous studies have shown that two voxel effects largely affect the acquisition of these distributions within digital images. One is particularly pertinent as it dramatically changes the shape of the distribution and reduces its mean. An attempt was made to reduce this undesirable effect and good results were obtained for a single-sphere model using minimum acceptable chord (MAC) methods (Jokisch et al 2001 Med. Phys. 28 1493-504). The goal of the present work is to extend the study of these methods to more general models in order to better quantify their consequences. First, a mathematical model of a trabecular bone sample was used to test the usefulness of the MAC methods. The results showed that these methods were not efficient for this simulated bone model. These methods were further tested on a single voxelized sphere over a large range of voxel sizes. The results showed that the MAC methods are voxel-size dependent and overestimate the mean chord length for typical resolutions used with NMR microscopy. The study further suggests that bone and marrow chord-length distributions currently utilized in skeletal dosimetry models are most likely affected by voxel effects that yield values of mean chord length lower than their true values. (author)

  2. Electropolishing effect on roughness metrics of ground stainless steel: a length scale study

    Science.gov (United States)

    Nakar, Doron; Harel, David; Hirsch, Baruch

    2018-03-01

    Electropolishing is a widely-used electrochemical surface finishing process for metals. The electropolishing of stainless steel has vast commercial application, such as improving corrosion resistance, improving cleanness, and brightening. The surface topography characterization is performed using several techniques with different lateral resolutions and length scales, from atomic force microscopy in the nano-scale (filter are adopted. While the commonly used roughness amplitude parameters (Ra, Rq and Rz) fail to characterize electropolished textures, the root mean square slope (RΔq) is found to better describe the electropolished surfaces and to be insensitive to scale.

  3. Effects of spatially varying slip length on friction drag reduction in wall turbulence

    International Nuclear Information System (INIS)

    Hasegawa, Yosuke; Frohnapfel, Bettina; Kasagi, Nobuhide

    2011-01-01

    A series of direct numerical simulation has been made of turbulent flow over hydrophobic surfaces, which are characterized by streamwise periodic micro-grooves. By assuming that the size of micro-grooves is much smaller than the typical length-scale of near-wall turbulent structures, the dynamical boundary condition is expressed by a mobility tensor, which relates the slip velocity and the surface shear stress. Based on the derived mathematical relationship between the friction drag and different dynamical contributions, it is shown how the turbulence contribution can be extracted and analyzed.

  4. Purcell effect for finite-length metal-coated and metal nanowires

    DEFF Research Database (Denmark)

    Filonenko, Konstantin V.; Willatzen, Morten; Bordo, Vladimir G.

    2014-01-01

    We investigate the modification (enhancement and suppression) of the spontaneous emission rate of a dipole emitter in two configurations: inside a finite-length semiconductor nanowire surrounded by bulk metal and in the vicinity of a finite metal nanowire. Our analysis is based on a first......-principle approach, which is reduced to a seminumeric one in the limit of large nanowire aspect ratios. The numerical calculations are carried out for an emitter in a GaAs nanowire embedded in Ag or Au and for that nearby an Ag or Au nanowire in vacuum or dielectric. We consider in detail the Purcell and β factors...

  5. The effects of iodine attenuation on pulmonary nodule volumetry using novel dual-layer computed tomography reconstructions

    Energy Technology Data Exchange (ETDEWEB)

    Harder, A.M. den; Hamersvelt, R.W. van; Leiner, T.; Schilham, A.M.R.; Willemink, M.J.; Jong, P.A. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Bangert, F. [Sint Antonius Ziekenhuis, Department of Radiology, Nieuwegein (Netherlands); Milles, Julien [Philips Healthcare, Best (Netherlands)

    2017-12-15

    To assess the effect of iodine attenuation on pulmonary nodule volumetry using virtual non-contrast (VNC) and mono-energetic reconstructions. A consecutive series of patients who underwent a contrast-enhanced chest CT scan were included. Images were acquired on a novel dual-layer spectral CT system. Conventional reconstructions as well as VNC and mono-energetic images at different keV levels were used for nodule volumetry. Twenty-four patients with a total of 63 nodules were included. Conventional reconstructions showed a median (interquartile range) volume and diameter of 174 (87 - 253) mm{sup 3} and 6.9 (5.4 - 9.9) mm, respectively. VNC reconstructions resulted in a significant volume reduction of 5.5% (2.6 - 11.2%; p<0.001). Mono-energetic reconstructions showed a correlation between nodule attenuation and nodule volume (Spearman correlation 0.77, (0.49 - 0.94)). Lowering the keV resulted in increased volumes while higher keV levels resulted in decreased pulmonary nodule volumes compared to conventional CT. Novel dual-layer spectral CT offers the possibility to reconstruct VNC and mono-energetic images. Those reconstructions show that higher pulmonary nodule attenuation results in larger nodule volumes. This may explain the reported underestimation in nodule volume on non-contrast enhanced compared to contrast-enhanced acquisitions. (orig.)

  6. The effects of iodine attenuation on pulmonary nodule volumetry using novel dual-layer computed tomography reconstructions

    International Nuclear Information System (INIS)

    Harder, A.M. den; Hamersvelt, R.W. van; Leiner, T.; Schilham, A.M.R.; Willemink, M.J.; Jong, P.A. de; Bangert, F.; Milles, Julien

    2017-01-01

    To assess the effect of iodine attenuation on pulmonary nodule volumetry using virtual non-contrast (VNC) and mono-energetic reconstructions. A consecutive series of patients who underwent a contrast-enhanced chest CT scan were included. Images were acquired on a novel dual-layer spectral CT system. Conventional reconstructions as well as VNC and mono-energetic images at different keV levels were used for nodule volumetry. Twenty-four patients with a total of 63 nodules were included. Conventional reconstructions showed a median (interquartile range) volume and diameter of 174 (87 - 253) mm 3 and 6.9 (5.4 - 9.9) mm, respectively. VNC reconstructions resulted in a significant volume reduction of 5.5% (2.6 - 11.2%; p<0.001). Mono-energetic reconstructions showed a correlation between nodule attenuation and nodule volume (Spearman correlation 0.77, (0.49 - 0.94)). Lowering the keV resulted in increased volumes while higher keV levels resulted in decreased pulmonary nodule volumes compared to conventional CT. Novel dual-layer spectral CT offers the possibility to reconstruct VNC and mono-energetic images. Those reconstructions show that higher pulmonary nodule attenuation results in larger nodule volumes. This may explain the reported underestimation in nodule volume on non-contrast enhanced compared to contrast-enhanced acquisitions. (orig.)

  7. The Effects of Iodine Attenuation on Pulmonary Nodule Volumetry using Novel Dual-Layer Computed Tomography Reconstructions.

    Science.gov (United States)

    den Harder, A M; Bangert, F; van Hamersvelt, R W; Leiner, T; Milles, Julien; Schilham, A M R; Willemink, M J; de Jong, P A

    2017-12-01

    To assess the effect of iodine attenuation on pulmonary nodule volumetry using virtual non-contrast (VNC) and mono-energetic reconstructions. A consecutive series of patients who underwent a contrast-enhanced chest CT scan were included. Images were acquired on a novel dual-layer spectral CT system. Conventional reconstructions as well as VNC and mono-energetic images at different keV levels were used for nodule volumetry. Twenty-four patients with a total of 63 nodules were included. Conventional reconstructions showed a median (interquartile range) volume and diameter of 174 (87 - 253) mm 3 and 6.9 (5.4 - 9.9) mm, respectively. VNC reconstructions resulted in a significant volume reduction of 5.5% (2.6 - 11.2%; p<0.001). Mono-energetic reconstructions showed a correlation between nodule attenuation and nodule volume (Spearman correlation 0.77, (0.49 - 0.94)). Lowering the keV resulted in increased volumes while higher keV levels resulted in decreased pulmonary nodule volumes compared to conventional CT. Novel dual-layer spectral CT offers the possibility to reconstruct VNC and mono-energetic images. Those reconstructions show that higher pulmonary nodule attenuation results in larger nodule volumes. This may explain the reported underestimation in nodule volume on non-contrast enhanced compared to contrast-enhanced acquisitions. • Pulmonary nodule volumes were measured on virtual non-contrast and mono-energetic reconstructions • Mono-energetic reconstructions showed that higher attenuation results in larger volumes • This may explain the reported nodule volume underestimation on non-contrast enhanced CT • Mostly metastatic pulmonary nodules were evaluated, results might differ for benign nodules.

  8. Attenuation data of point isotropic neutron sources up to 400MeV in water, ordinary concrete and iron

    Energy Technology Data Exchange (ETDEWEB)

    Kotegawa, Hiroshi; Tanaka, Shun-ichi; Sakamoto, Yukio; Nakane, Yoshihiro; Nakashima, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1994-08-01

    A comprehensive attenuation data of dose equivalent for point isotropic monoenergetic neutron sources up to 400MeV in infinite shields of water, ordinary concrete and iron has been calculated using the ANISN-JR code and a neutron-photon multigroup macroscopic cross section HIL086R. The attenuation factors were fitted to a 4th order polynomial exponent formula, making possible to use easily for point kernel codes. Additional data in finite shielding geometry was also calculated to correct the effect due to infinite medium, giving the maximum correction of 0.23 in the region for more 400 cm distance from neutron source of 400 MeV in iron shield. Effective attenuation length for monoenergetic neutrons have been studied in detail. Subsequently, it was shown that the attenuation length was strongly dependent upon the penetration length and the Moyer`s formula using a single attenuation length brought large error into the dose estimation behind thick shields for the intermediate energy neutrons up to 400 MeV. Furthermore, it was demonstrated that there was difference more than 50 % in the attenuation length of iron between the calculations with HIL086R and HIL086 because of the self-shielding effect. (author).

  9. Topoclimate effects on growing season length and montane conifer growth in complex terrain

    Science.gov (United States)

    Barnard, D. M.; Barnard, H. R.; Molotch, N. P.

    2017-05-01

    Spatial variability in the topoclimate-driven linkage between forest phenology and tree growth in complex terrain is poorly understood, limiting our understanding of how ecosystems function as a whole. To characterize the influence of topoclimate on phenology and growth, we determined the start, end, and length of the growing season (GSstart, GSend, and GSL, respectively) using the correlation between transpiration and evaporative demand, measured with sapflow. We then compared these metrics with stem relative basal area increment (relative BAI) at seven sites among elevation and aspects in a Colorado montane forest. As elevation increased, we found shorter GSL (-50 d km-1) due to later GSstart (40 d km-1) and earlier GSend (-10 d km-1). North-facing sites had a 21 d shorter GSL than south-facing sites at similar elevations (i.e. equal to 200 m elevation difference on a given aspect). Growing season length was positively correlated with relative BAI, explaining 83% of the variance. This study shows that topography exerts strong environmental controls on GSL and thus forest growth. Given the climate-related dependencies of these controls, the results presented here have important implications for ecosystem responses to changes in climate and highlight the need for improved phenology representation in complex terrain.

  10. Effect of length of measurement period on accuracy of predicted annual heating energy consumption of buildings

    International Nuclear Information System (INIS)

    Cho, Sung-Hwan; Kim, Won-Tae; Tae, Choon-Soeb; Zaheeruddin, M.

    2004-01-01

    This study examined the temperature dependent regression models of energy consumption as a function of the length of the measurement period. The methodology applied was to construct linear regression models of daily energy consumption from 1 day to 3 months data sets and compare the annual heating energy consumption predicted by these models with actual annual heating energy consumption. A commercial building in Daejon was selected, and the energy consumption was measured over a heating season. The results from the investigation show that the predicted energy consumption based on 1 day of measurements to build the regression model could lead to errors of 100% or more. The prediction error decreased to 30% when 1 week of data was used to build the regression model. Likewise, the regression model based on 3 months of measured data predicted the annual energy consumption within 6% of the measured energy consumption. These analyses show that the length of the measurement period has a significant impact on the accuracy of the predicted annual energy consumption of buildings

  11. Oriented particleboard made from tali bamboo (Gigantochloa Apus): effect of particle length on physical and mechanical properties

    Science.gov (United States)

    Iswanto, A. H.

    2018-02-01

    Strength properties are one of the problems of particleboard. The objective of this research was to analyze the effect of particle length on physical and mechanical properties oriented particleboard (OPB). The variation particle length size in this experiment namely 3, 5, and 7 cm. The width and thickness size of all bamboo particles were 1 and 0.1 cm respectively. 12% mixed resin of UF and MDI (70/30 %w/w) used for binding. Board size fabricated in 25 by 25 cm2 with thickness and density target of 1 cm and 0.75 gcm-3. The OPB layers for face and back layers aligned perpendicular to the core layer. The weight ratio of the face-to-core-to-back layers were set at 1:2:1. Mat was pressed at 160 °C under 30 kgcm-2 as the pressure for 10 minutes. The results showed that 7 cm length particle produced of the best strength and dimensional stability. The increase of particle length resulted in increasing of strength properties. Over all the parameters of physical and mechanical properties fulfill requirements of JIS A 5908 (2003) excepted of thickness swelling and modulus of elasticity.

  12. Effects of different frequencies of rhythmic auditory cueing on the stride length, cadence, and gait speed in healthy young females.

    Science.gov (United States)

    Yu, Lili; Zhang, Qi; Hu, Chunying; Huang, Qiuchen; Ye, Miao; Li, Desheng

    2015-02-01

    [Purpose] The aim of this study was to explore the effects of different frequencies of rhythmic auditory cueing (RAC) on stride length, cadence, and gait speed in healthy young females. The findings of this study might be used as clinical guidance of physical therapy for choosing the suitable frequency of RAC. [Subjects] Thirteen healthy young females were recruited in this study. [Methods] Ten meters walking tests were measured in all subjects under 4 conditions with each repeated 3 times and a 3-min seated rest period between repetitions. Subjects first walked as usual and then were asked to listen carefully to the rhythm of a metronome and walk with 3 kinds of RAC (90%, 100%, and 110% of the mean cadence). The three frequencies (90%, 100%, and 110%) of RAC were randomly assigned. Gait speed, stride length, and cadence were calculated, and a statistical analysis was performed using the SPSS (version 17.0) computer package. [Results] The gait speed and cadence of 90% RAC walking showed significant decreases compared with normal walking and 100% and 110% RAC walking. The stride length, cadence, and gait speed of 110% RAC walking showed significant increases compared with normal walking and 90% and 100% RAC walking. [Conclusion] Our results showed that 110% RAC was the best of the 3 cueing frequencies for improvement of stride length, cadence, and gait speed in healthy young females.

  13. Study of injection moulded long glass fibre-reinforced polypropylene and the effect on the fibre length and orientation distribution

    Science.gov (United States)

    Parveeen, B.; Caton-Rose, P.; Costa, F.; Jin, X.; Hine, P.

    2014-05-01

    Long glass fibre (LGF) composites are extensively used in manufacturing to produce components with enhanced mechanical properties. Long fibres with length 12 to 25mm are added to a thermoplastic matrix. However severe fibre breakage can occur in the injection moulding process resulting in shorter fibre length distribution (FLD). The majority of this breakage occurs due to the melt experiencing extreme shear stress during the preparation and injection stage. Care should be taken to ensure that the longer fibres make it through the injection moulding process without their length being significantly degraded. This study is based on commercial 12 mm long glass-fibre reinforced polypropylene (PP) and short glass fibre Nylon. Due to the semi-flexiable behaviour of long glass fibres, the fibre orientation distribution (FOD) will differ from the orientation distribution of short glass fibre in an injection molded part. In order to investigate the effect the change in fibre length has on the fibre orientation distribution or vice versa, FOD data was measured using the 2D section image analyser. The overall purpose of the research is to show how the orientation distribution chnages in an injection moulded centre gated disc and end gated plaque geometry and to compare this data against fibre orientation predictions obtained from Autodesk Moldflow Simulation Insight.

  14. Can job autonomy attenuate the effect of depression on employees' well-being? It may depend on culture.

    Science.gov (United States)

    Li, Liman Man Wai

    2018-04-26

    Depression is one of the leading causes of work disability. Thus, it is important to explore possible ways to reduce its impact on employees. The current research examined whether promoting job autonomy would attenuate the detrimental effect of depression on employees' well-being. Study 1 included the data from 5974 full-time employees from China. Full-time employees living in India, a collectivistic culture, and the United States, an individualistic culture, were recruited online in Study 2. Study 1 revealed that job autonomy moderated the influence of depression on job strain and perceived control mediated this interaction effect. Specifically, job autonomy weakened the detrimental effect of depression on job strain via weakening the association between depression and perceived control. The data from the 258 full-time employees in Study 2 replicated the findings and found that job autonomy had a stronger attenuating effect on the influence of depression in India than it had in the United States. Job autonomy was found to be an effective way to reduce the negative impact of depression on employees' well-being, a finding that should be considered when organizations develop their work policies.

  15. Effect of Beamstrahlung on Bunch Length and Emittance in Future Circular e+e- Colliders

    CERN Document Server

    Valdivia Garcia, Marco Alan

    2016-01-01

    In future circular e+e− colliders, beamstrahlung may limit the beam lifetime at high energies, and increase the energy spread and bunch length at low energies. If the dispersion or slope of the dispersion is not zero at the collision point, beamstrahlung will also affect the transverse emittance. In this paper, we first examine the beamstrahlung properties, and show that for the proposed FCC-ee, the radiation is fairly well modelled by the classical formulae describing synchrotron radiation in bending magnets. We then derive a set of equations determining the equilibrium emittances in the presence of a nonzero dispersion at the collision point. An example case from FCC-ee will serve as an illustration.

  16. List length and overlap effects in forced-choice associative recognition.

    Science.gov (United States)

    Clark, S E; Hori, A

    1995-07-01

    Two experiments examined forced-choice associative recognition for OLAP and NOLAP test conditions. OLAP test trials consist of pairs with overlapping items (e.g., AB vs. AD), whereas NOLAP test trials contain no overlapping items (e.g., AB vs. CF). Previous results show better performance for NOLAP than for OLAP tests, contrary to the predictions of global memory models. The present experiments varied list length to examine the hypothesis that the NOLAP advantage is produced by recall-like retrieval processes. The use of longer lists either eliminated (Experiment 1) or greatly reduced (Experiment 2) the NOLAP advantage. However, a reliable OLAP advantage was not obtained. Implications for models are discussed.

  17. Amplifying and attenuating the coffee-ring effect in drying sessile nanofluid droplets

    Science.gov (United States)

    Crivoi, A.; Duan, Fei

    2013-04-01

    Experiments and simulations to promote or attenuate the “coffee-ring effect” for pinned sessile nanofluid droplets are presented. The addition of surfactant inside a water suspension of aluminum oxide nanoparticles results in coffee-ring formation after the pinned sessile droplets are fully dried on a substrate, while droplets of the same suspension without the surfactant produce a fine uniform coverage. A mathematical model based on diffusion-limited cluster-cluster aggregation has been developed to explain the observed difference in the experiments. The simulations show that the particle sticking probability is a crucial factor on the morphology of finally dried structures.

  18. Effect of dietary protein level and length of fattening period on dressing percentage and carcass conformation in broiler chickens

    OpenAIRE

    Dosković, Vladimir; Bogosavljević-Bošković, Snežana; Škrbić, Zdenka; Đoković, Radojica; Rakonjac, Simeon; Petričević, Veselin

    2017-01-01

    This study analyses the effect of different protein levels in broiler feeds (supplemented with protease) and different lengths of fattening period on some parameters related to dressed carcass quality. Medium-growing Master Gris broiler chickens were used in a fattening trial lasting 63 days. At slaughter, dressing percentages and abdominal fat percentages were determined based on traditionally dressed carcass weights and abdominal fat weights of broilers at 49 and 63 days, and conformation i...

  19. Effectivity of Sugar-Apple (Annona squamosa) Seed Extract with a Different Length of Storage against Culec quinquefasciatus Larvae

    OpenAIRE

    Heni Prasetyowati; Wisnu Satria

    2012-01-01

    Synthetic insecticide have been used to control Culex quinquefasciatus, but the prolonged usage of synthetic insecticide has a bad impact on the environment and may caused resistance. Sugar apple’s (Annona squamosa) seeds which contain alkaloid can be used as an alternative insecticide that was safe for environment. This research aims is to know the effect of sugar apple’s seeds with different length of storage as C. quinquefasciatus larvacide. This research was an experimental study with a r...

  20. Low-dose memantine attenuated morphine addictive behavior through its anti-inflammation and neurotrophic effects in rats.

    Science.gov (United States)

    Chen, Shiou-Lan; Tao, Pao-Luh; Chu, Chun-Hsien; Chen, Shih-Heng; Wu, Hsiang-En; Tseng, Leon F; Hong, Jau-Shyong; Lu, Ru-Band

    2012-06-01

    Opioid abuse and dependency are international problems. Studies have shown that neuronal inflammation and degeneration might be related to the development of opioid addiction. Thus, using neuroprotective agents might be beneficial for treating opioid addiction. Memantine, an Alzheimer's disease medication, has neuroprotective effects in vitro and in vivo. In this study, we evaluated whether a low dose of memantine prevents opioid-induced drug-seeking behavior in rats and analyzed its mechanism. A conditioned-place-preference test was used to investigate the morphine-induced drug-seeking behaviors in rats. We found that a low-dose (0.2-1 mg/kg) of subcutaneous memantine significantly attenuated the chronic morphine-induced place-preference in rats. To clarify the effects of chronic morphine and low-dose memantine, serum and brain levels of cytokines and brain-derived neurotrophic factor (BDNF) were measured. After 6 days of morphine treatment, cytokine (IL-1β, IL-6) levels had significantly increased in serum; IL-1β and IL-6 mRNA levels had significantly increased in the nucleus accumbens and medial prefrontal cortex, both addiction-related brain areas; and BDNF levels had significantly decreased, both in serum and in addiction-related brain areas. Pretreatment with low-dose memantine significantly attenuated chronic morphine-induced increases in serum and brain cytokines. Low-dose memantine also significantly potentiated serum and brain BDNF levels. We hypothesize that neuronal inflammation and BDNF downregulation are related to the progression of opioid addiction. We hypothesize that the mechanism low-dose memantine uses to attenuate morphine-induced addiction behavior is its anti-inflammatory and neurotrophic effects.

  1. Assessment of the effectiveness of attenuation of leaded aprons through TLD dosimetry and Monte Carlo simulation method

    Energy Technology Data Exchange (ETDEWEB)

    Olaya D, H.; Diaz M, J. A.; Martinez O, S. A. [Universidad Pedagogica y Tecnologica de Colombia, Grupo de Fisica Nuclear Aplicada y Simulacion, 150003 Tunja, Boyaca (Colombia); Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico)

    2016-10-15

    Were performed experimental setups using an X-ray equipment continuous emission Pantak DXT-3000 and three types of leaded aprons with thickness of 0.25, 0.5 and 0.75 mm coated with Mylar Fiber coated Mylar on its surface. Apron was located at a distance of 2.5 m with respect focus in order to cover a radiation field size of a meter in diameter. At the beam output were added aluminum filtration in order to reproduce qualities of narrow beams N-40 (E{sub efective} = 33 keV), N-80 (E{sub efective} = 65 keV) and N-100 (E{sub efective} = 83 keV) according to the ISO standard 4037 (1-3). Each lead apron were fixed 10 TLD dosimeters over its surface, 5 dosimeters before and 5 dosimeters after with respect to X-ray beam and were calibrated for Harshaw 4500 thermoluminescent reader system order to assess the attenuation of each apron. Were performed dosimeters readings and were calculated the attenuation coefficients for each effective energy of X-ray quality. In order to confirm the method of effective energy of ISO-4037 and evaluate effectiveness of lead aprons based on energy range for each medical practice was made a Monte Carlo simulation using code GEANT-4, calculating the fluence and absorbed dose in each one of the dosimeters Monte Carlo, then coefficients of linear attenuation were calculated and compared with the experimental data and reported by the National Institute of Standards and Technology (Nist). Finally, results are consistent between theoretical calculation and experimental measures. This work will serve to make assessments for other personalized leaded protections. (Author)

  2. Assessment of the effectiveness of attenuation of leaded aprons through TLD dosimetry and Monte Carlo simulation method

    International Nuclear Information System (INIS)

    Olaya D, H.; Diaz M, J. A.; Martinez O, S. A.; Vega C, H. R.

    2016-10-01

    Were performed experimental setups using an X-ray equipment continuous emission Pantak DXT-3000 and three types of leaded aprons with thickness of 0.25, 0.5 and 0.75 mm coated with Mylar Fiber coated Mylar on its surface. Apron was located at a distance of 2.5 m with respect focus in order to cover a radiation field size of a meter in diameter. At the beam output were added aluminum filtration in order to reproduce qualities of narrow beams N-40 (E_e_f_e_c_t_i_v_e = 33 keV), N-80 (E_e_f_e_c_t_i_v_e = 65 keV) and N-100 (E_e_f_e_c_t_i_v_e = 83 keV) according to the ISO standard 4037 (1-3). Each lead apron were fixed 10 TLD dosimeters over its surface, 5 dosimeters before and 5 dosimeters after with respect to X-ray beam and were calibrated for Harshaw 4500 thermoluminescent reader system order to assess the attenuation of each apron. Were performed dosimeters readings and were calculated the attenuation coefficients for each effective energy of X-ray quality. In order to confirm the method of effective energy of ISO-4037 and evaluate effectiveness of lead aprons based on energy range for each medical practice was made a Monte Carlo simulation using code GEANT-4, calculating the fluence and absorbed dose in each one of the dosimeters Monte Carlo, then coefficients of linear attenuation were calculated and compared with the experimental data and reported by the National Institute of Standards and Technology (Nist). Finally, results are consistent between theoretical calculation and experimental measures. This work will serve to make assessments for other personalized leaded protections. (Author)

  3. Effect of Attenuation Correction on Regional Quantification Between PET/MR and PET/CT

    DEFF Research Database (Denmark)

    Teuho, Jarmo; Johansson, Jarkko; Linden, Jani

    2016-01-01

    UNLABELLED: A spatial bias in brain PET/MR exists compared with PET/CT, because of MR-based attenuation correction. We performed an evaluation among 4 institutions, 3 PET/MR systems, and 4 PET/CT systems using an anthropomorphic brain phantom, hypothesizing that the spatial bias would be minimized....../MR systems, CTAC was applied as the reference method for attenuation correction. RESULTS: With CTAC, visual and quantitative differences between PET/MR and PET/CT systems were minimized. Intersystem variation between institutions was +3.42% to -3.29% in all VOIs for PET/CT and +2.15% to -4.50% in all VOIs...... for PET/MR. PET/MR systems differed by +2.34% to -2.21%, +2.04% to -2.08%, and -1.77% to -5.37% when compared with a PET/CT system at each institution, and these differences were not significant (P ≥ 0.05). CONCLUSION: Visual and quantitative differences between PET/MR and PET/CT systems can be minimized...

  4. Study of mass attenuation coefficients and effective atomic numbers of bismuth-ground granulated blast furnace slag concretes

    International Nuclear Information System (INIS)

    Kumar, Sandeep; Singh, Sukhpal

    2016-01-01

    Five samples of Bismuth-Ground granulated blast furnace slag (Bi-GGBFS) concretes were prepared using composition (0.6 cement + x Bi_2O_3 + (0.4-x) GGBFS, x = 0.05, 0.10, 0.15, 0.20 and 0.25) by keeping constant water (W) cement (C) ratio. Mass attenuation coefficients (μ_m) of these prepared samples were calculated using a computer program winXCOM at different gamma ray energies, whereas effective atomic numbers (Z_e_f_f) is calculated using mathematical formulas. The radiation shielding properties of Bi-GGBFS concrete has been compared with standard radiation shielding concretes.

  5. Anatomic and functional leg-length inequality: A review and recommendation for clinical decision-making. Part I, anatomic leg-length inequality: prevalence, magnitude, effects and clinical significance

    Directory of Open Access Journals (Sweden)

    Knutson Gary A

    2005-07-01

    Full Text Available Abstract Background Leg-length inequality is most often divided into two groups: anatomic and functional. Part I of this review analyses data collected on anatomic leg-length inequality relative to prevalence, magnitude, effects and clinical significance. Part II examines the functional "short leg" including anatomic-functional relationships, and provides an outline for clinical decision-making. Methods Online database – Medline, CINAHL and MANTIS – and library searches for the time frame of 1970–2005 were done using the term "leg-length inequality". Results and Discussion Using data on leg-length inequality obtained by accurate and reliable x-ray methods, the prevalence of anatomic inequality was found to be 90%, the mean magnitude of anatomic inequality was 5.2 mm (SD 4.1. The evidence suggests that, for most people, anatomic leg-length inequality does not appear to be clinically significant until the magnitude reaches ~ 20 mm (~3/4". Conclusion Anatomic leg-length inequality is near universal, but the average magnitude is small and not likely to be clinically significant.

  6. Electromagnetic corrections to ππ scattering lengths: some lessons for the construction of effective hadronic field theories

    International Nuclear Information System (INIS)

    Maltman, K.

    1998-01-01

    Using the framework of effective chiral Lagrangians, we show that, in order to correctly implement electromagnetism (EM), as generated from the Standard Model, into effective hadronic theories (such as meson-exchange models) it is insufficient to consider only graphs in the low-energy effective theory containing explicit photon lines. The Standard Model requires the presence of contact interactions in the effective theory which are electromagnetic in origin, but which involve no photons in the effective theory. We illustrate the problems which can result from a ''standard'' EM subtraction: i.e., from assuming that removing all contributions in the effective theory generated by graphs with explicit photon lines fully removes EM effects, by considering the case of the s-wave ππ scattering lengths. In this case it is shown that such a subtraction procedure would lead to the incorrect conclusion that the strong interaction isospin-breaking contributions to these quantities were large when, in fact, they are known to vanish at leading order in m d -m u . The leading EM contact corrections for the channels employed in the extraction of the I=0,2 s-wave ππ scattering lengths from experiment are also evaluated. (orig.)

  7. The Effects of Health Coverage Schemes on Length of Stay and Preventable Hospitalization in Seoul

    Directory of Open Access Journals (Sweden)

    Jungah Kim

    2018-04-01

    Full Text Available The Medical Aid program is government’s medical benefit program to secure the minimum livelihood and medical services for low-income Korean households. In Seoul, the number of Medical Aid beneficiaries has grown, driving an increases in the length of stay (LOS and healthcare cost. Until now, studies have focused on quantity indicators, such as LOS, but only a few studies have been conducted on the service quality. We investigated both LOS and the preventable hospitalization (PH rate as proxy indicators for the quantity and quality of services provided to Medical Aid beneficiaries in Seoul. To understand the program’s impact, we extracted appropriate data of Medical Aid beneficiaries and data of the lower 20% of National Health Insurance (NHI enrollees, performed Propensity Score Matching (PSM, and controlled the variables related to disease severity. The differences between Medical Aid beneficiaries and NHI enrollees were estimated using multilevel analysis. The LOS of Medical Aid beneficiaries was longer, and the preventable hospitalization (PH rate was higher than that of NHI enrollees. It implies that these beneficiaries did not receive timely and adequate healthcare services, despite their high rate of service utilization. Thus, indicators such as patient’s visits and screening related to PHs should be included in management policies to improve primary care.

  8. The effect of the severity of obstructive sleep apnea syndrome on telomere length.

    Science.gov (United States)

    Tempaku, Priscila Farias; Mazzotti, Diego Robles; Hirotsu, Camila; Andersen, Monica Levy; Xavier, Gabriela; Maurya, Pawan Kumar; Rizzo, Lucas Bortolotto; Brietzke, Elisa; Belangero, Sintia Iole; Bittencourt, Lia; Tufik, Sergio

    2016-10-25

    Aging is associated with an increase in the prevalence of obstructive sleep apnea syndrome (OSAS) as well as the shortening of telomeres. It is known that OSAS-related factors are stimuli that can contribute to the acceleration of cellular senescence. Thus, the present study aimed to compare the leukocyte telomere length (LTL) between OSAS patients and controls, as well as to verify the correlation between LTL and sleep parameters. We used DNA extracted of 928 individuals from EPISONO to measure the LTL by the quantitative real-time polymerase chain reaction. All individuals were subjected to one full-night polysomnography. LTL was significantly shorter in OSAS patients compared to controls. The results showed negative correlations between LTL and the following variables: apnea-hypopnea index, respiratory disturbance index, desaturation index and wake after sleep onset. LTL was positively correlated with sleep efficiency, total sleep time, basal, minimum and maximum oxygen saturation. Lastly, it was observed that OSAS severity was associated with shorter LTL even after adjusting for sex, age, years of schooling, body mass index, diabetes, stroke and heart attack. In conclusion, our study indicates the presence of an association between LTL and OSAS and a significant impact of severity of OSAS in telomeres shortening.

  9. Leukocyte telomere length and mortality among U.S. adults: Effect modification by physical activity behaviour.

    Science.gov (United States)

    Loprinzi, Paul D; Loenneke, Jeremy P

    2018-01-01

    The purpose of this study was to examine the association between leukocyte telomere length (LTL) and mortality (outcome variable), with consideration by physical activity behaviour. Data from the 1999-2002 National Health and Nutrition Examination Survey were employed (N = 6,611; 20-85 yrs), with follow-up mortality assessment through 31 December 2006. DNA was extracted from whole blood to assess LTL via quantitative polymerase chain reaction. Compared to those in the first LTL tertile, the adjusted hazard ratio for all-cause mortality for those in the 2 nd and 3 rd LTL tertiles, respectively, was 0.82 (95% CI: 0.60-1.12; P = .22) and 0.76 (95% CI: 0.50-1.14; P = .18). However, after adjustments, LTL tertile 3 (vs. 1) was associated with all-cause mortality (HR = 0.37; 95% CI: 0.14-0.93; P = .03) for those who engaged in moderate-intensity exercise. Similarly, LTL was associated with CVD-specific mortality for those who engaged in moderate-intensity exercise (HR = 0.17; 95% CI: 0.04-0.73; P = .02). Longer telomeres are associated with increased survival, particularly among men and those who are active, underscoring the importance of promotion of physical activity behaviour.

  10. Effect of rest interval length on bench press performance in boys, teens, and men.

    Science.gov (United States)

    Faigenbaum, Avery D; Ratamess, Nicholas A; McFarland, Jim; Kaczmarek, Jon; Coraggio, Michael J; Kang, Jie; Hoffman, Jay R

    2008-11-01

    The purpose of this study was to assess the lifting performance of boys (N = 12; age 11.3 +/- 0.8 yr), teens (N = 13; age 13.6 +/- 0.6 yr), and men (N = 17; age 21.4 +/- 2.1 yr) to various rest interval (RI) lengths on the bench press exercise. Each subject performed 3 sets with a 10 repetition maximum load and a 1, 2, and 3 min RI between sets. Significant differences in lifting performance between age groups were observed within each RI for selected sets with boys and teens performing significantly more total repetitions than adults following protocols with 1 min (27.9 +/- 3.1, 26.9 +/- 3.9, and 18.2 +/- 4.1, respectively), 2 min (29.6 +/- 1.0, 27.8 +/- 3.5, and 21.4 +/- .1, respectively) and 3 min (30.0 +/- 0.0, 28.8 +/- 2.4, and 23.9 +/- 5.3, respectively) RIs. Significant differences in average velocity and average power between age groups were also observed. These findings indicate that boys and teens are better able to maintain muscle performance during intermittent moderate-intensity resistance exercise as compared with men.

  11. Intermittent search strategies revisited: effect of the jump length and biased motion

    Energy Technology Data Exchange (ETDEWEB)

    Rojo, F; Budde, C E [Fa.M.A.F., Universidad Nacional de Cordoba, Ciudad Universitaria, X5000HUA Cordoba (Argentina); Revelli, J; Wio, H S [Instituto de Fisica de Cantabria, Universidad de Cantabria and CSIC, E-39005 Santander (Spain); Oshanin, G [Laboratoire de Physique Theorique de la Matiere Condensee, Universite Pierre et Marie Curie, 4 place Jussieu, 75252 Paris Cedex 5 (France); Lindenberg, Katja [Department of Chemistry and Biochemistry and BioCircuits Institute, University of California, San Diego, La Jolla, CA 92093-0340 (United States)

    2010-08-27

    We study the kinetics of a search of a single fixed target by a large number of searchers performing an intermittent biased random walk in a homogeneous medium. Our searchers carry out their walks in one of two states between which they switch randomly. One of these states (search phase) is a nearest-neighbor walk characterized by the probability of stepping in a given direction (i.e. the walks in this state are not necessarily isotropic). The other (relocation phase) is characterized by the length of the jumps (i.e. when in this state a walker does not perform a nearest-neighbor walk). Within such a framework, we propose a model to describe the searchers' dynamics, generalizing results of our previous work. We have obtained, and numerically evaluated, analytic results for the mean number of distinct sites visited up to a maximum evolution time. We have studied the dependence of this quantity on both the transition probability between the states and the parameters that characterize each state. In addition to our theoretical approach, we have implemented Monte Carlo simulations, finding excellent agreement between the theoretical-numerical and simulations results.

  12. Intermittent search strategies revisited: effect of the jump length and biased motion

    International Nuclear Information System (INIS)

    Rojo, F; Budde, C E; Revelli, J; Wio, H S; Oshanin, G; Lindenberg, Katja

    2010-01-01

    We study the kinetics of a search of a single fixed target by a large number of searchers performing an intermittent biased random walk in a homogeneous medium. Our searchers carry out their walks in one of two states between which they switch randomly. One of these states (search phase) is a nearest-neighbor walk characterized by the probability of stepping in a given direction (i.e. the walks in this state are not necessarily isotropic). The other (relocation phase) is characterized by the length of the jumps (i.e. when in this state a walker does not perform a nearest-neighbor walk). Within such a framework, we propose a model to describe the searchers' dynamics, generalizing results of our previous work. We have obtained, and numerically evaluated, analytic results for the mean number of distinct sites visited up to a maximum evolution time. We have studied the dependence of this quantity on both the transition probability between the states and the parameters that characterize each state. In addition to our theoretical approach, we have implemented Monte Carlo simulations, finding excellent agreement between the theoretical-numerical and simulations results.

  13. Effects of epidural analgesia on labor length, instrumental delivery, and neonatal short-term outcome.

    Science.gov (United States)

    Hasegawa, Junichi; Farina, Antonio; Turchi, Giovanni; Hasegawa, Yuko; Zanello, Margherita; Baroncini, Simonetta

    2013-02-01

    We aimed to clarify whether the short-term adverse neonatal outcomes associated with epidural analgesia are due to the epidural analgesia itself or to the instrumental delivery. A retrospective case-control study was conducted to evaluate the relationship between epidural analgesia, labor length, and perinatal outcomes. A total of 350 pregnant women at term who delivered under epidural analgesia (cases) were compared with 1400 patients without epidural analgesia (controls). Vacuum extraction (6.5 vs. 2.9 %) and cesarean section (19.9 vs. 11.1 %) were more frequently performed in the cases than controls (p neonatal variables stratified by mode of delivery were not different in cases and controls, except for a slightly lower umbilical arterial pH in spontaneous delivery for the cases group. However, the Apgar scores and umbilical arterial pH were significantly lower in the neonates delivered by vacuum extraction compared with those in the neonates delivered by spontaneous delivery or cesarean section, regardless of whether epidural analgesia was performed. A multivariable analysis showed that vacuum extraction much more consistently affected the arterial pH than the analgesia itself (the β coefficients were -0.036 for epidural analgesia vs. -0.050 for vacuum extraction). Epidural analgesia was associated with slowly progressing labor, thus resulting in an increased rate of instrumental delivery. This instrumental delivery appears to adversely affect the neonatal outcomes more strongly than the analgesia itself.

  14. Biological phosphorus and nitrogen removal in sequencing batch reactors: effects of cycle length, dissolved oxygen concentration and influent particulate matter.

    Science.gov (United States)

    Ginige, Maneesha P; Kayaalp, Ahmet S; Cheng, Ka Yu; Wylie, Jason; Kaksonen, Anna H

    2013-01-01

    Removal of phosphorus (P) and nitrogen (N) from municipal wastewaters is required to mitigate eutrophication of receiving water bodies. While most treatment plants achieve good N removal using influent carbon (C), the use of influent C to facilitate enhanced biological phosphorus removal (EBPR) is poorly explored. A number of operational parameters can facilitate optimum use of influent C and this study investigated the effects of cycle length, dissolved oxygen (DO) concentration during aerobic period and influent solids on biological P and N removal in sequencing batch reactors (SRBs) using municipal wastewaters. Increasing cycle length from 3 to 6 h increased P removal efficiency, which was attributed to larger portion of N being removed via nitrite pathway and more biodegradable organic C becoming available for EBPR. Further increasing cycle length from 6 to 8 h decreased P removal efficiencies as the demand for biodegradable organic C for denitrification increased as a result of complete nitrification. Decreasing DO concentration in the aerobic period from 2 to 0.8 mg L(-1) increased P removal efficiency but decreased nitrification rates possibly due to oxygen limitation. Further, sedimented wastewater was proved to be a better influent stream than non-sedimented wastewater possibility due to the detrimental effect of particulate matter on biological nutrient removal.

  15. An investigation into kana reading development in normal and dyslexic Japanese children using length and lexicality effects.

    Science.gov (United States)

    Sambai, Ami; Uno, Akira; Kurokawa, Suzuko; Haruhara, Noriko; Kaneko, Masato; Awaya, Noriko; Kozuka, Junko; Goto, Takashi; Tsutamori, Eishi; Nakagawa, Kazumi; Wydell, Taeko N

    2012-06-01

    This is the first study to report differences between Japanese children with and without dyslexia in the way string-length and lexicality effects are manifested when reading Japanese kana. These children were asked to read kana words and non-words consisting of either two or five kana characters. The results showed that the error rates of the normal Preschoolers and Primary-School children with dyslexia were higher than those of the normal Primary-School children. Further, the reading latencies of the normal Preschoolers, First-graders and dyslexics were significantly longer than those of the normal Second, Third and Fifth/Sixth graders. Moreover, reading latencies became shorter as the age of the participants increased. Both normal and dyslexic children showed significant effects of length and lexicality on reading latencies. However, the interaction between the length and lexicality was only seen in normal children from the Second-grade onwards. These results suggest that (1) normal First-graders reach a ceiling in terms of reading accuracy and that (2) as Japanese normal children become older, they become better at lexical reading processes, which leads to fluent kana reading, but that (3) the dyslexics, even at Fifth/Sixth grades, have not developed sufficient lexical reading processes. Copyright © 2011 The Japanese Society of Child Neurology. All rights reserved.

  16. The effects of social status on biological aging as measured by white-blood-cell telomere length.

    Science.gov (United States)

    Cherkas, L F; Aviv, A; Valdes, A M; Hunkin, J L; Gardner, J P; Surdulescu, G L; Kimura, M; Spector, T D

    2006-10-01

    Low socio-economic status (SES) is associated with a shortened life expectancy, but its effect on aging is unknown. The rate of white-blood-cell (WBC) telomere attrition may be a biological indicator of human aging. We tested the hypothesis that SES is associated with telomere attrition independent of known risk factors influencing the aging process. We studied 1552 female twins. A venous blood sample was taken from each twin and isolated WBCs used for extraction of DNA. Terminal restriction fragment length (TRFL) was measured. Questionnaire data were collected on occupation, education, income, smoking, exercise, height and weight. Standard multiple linear regression and multivariate analyses of variance tested for associations between SES and TRFL, adjusting for covariates. A discordant twin analysis was conducted on a subset to verify findings. WBC telomere length was highly variable but significantly shorter in lower SES groups. The mean difference in TRFL between nonmanual and manual SES groups was 163.2 base pairs (bp) of which 22.9 bp (approximately 14%) was accounted for by body mass index, smoking and exercise. Comparison of TRFL in the 17 most discordant SES twin pairs confirmed this difference. Low SES, in addition to the harmful effects of smoking, obesity and lack of exercise, appears to have an impact on telomere length.

  17. Effects of fracture distribution and length scale on the equivalent continuum elastic compliance of fractured rock masses

    Directory of Open Access Journals (Sweden)

    Marte Gutierrez

    2015-12-01

    Full Text Available Fracture systems have strong influence on the overall mechanical behavior of fractured rock masses due to their relatively lower stiffness and shear strength than those of the rock matrix. Understanding the effects of fracture geometrical distribution, such as length, spacing, persistence and orientation, is important for quantifying the mechanical behavior of fractured rock masses. The relation between fracture geometry and the mechanical characteristics of the fractured rock mass is complicated due to the fact that the fracture geometry and mechanical behaviors of fractured rock mass are strongly dependent on the length scale. In this paper, a comprehensive study was conducted to determine the effects of fracture distribution on the equivalent continuum elastic compliance of fractured rock masses over a wide range of fracture lengths. To account for the stochastic nature of fracture distributions, three different simulation techniques involving Oda's elastic compliance tensor, Monte Carlo simulation (MCS, and suitable probability density functions (PDFs were employed to represent the elastic compliance of fractured rock masses. To yield geologically realistic results, parameters for defining fracture distributions were obtained from different geological fields. The influence of the key fracture parameters and their relations to the overall elastic behavior of the fractured rock mass were studied and discussed. A detailed study was also carried out to investigate the validity of the use of a representative element volume (REV in the equivalent continuum representation of fractured rock masses. A criterion was also proposed to determine the appropriate REV given the fracture distribution of the rock mass.

  18. Effects of rice husks and their chars from hydrothermal carbonization on the germination rate and root length of Lepidium sativum

    Science.gov (United States)

    Kern, Jürgen; Mukhina, Irina; Dicke, Christiane; Lanza, Giacomo; Kalderis, Dimitrios

    2015-04-01

    Currently, char substrates gain a lot of interest, since they are being discussed as a component in growing media, which may become one option for the replacement of peat. Among different thermal conversion processes of biomass hydrothermal carbonization (HTC) has been found to produce chars with similar acidic pH values like peat. The question however is, if these hydrochars, which may contain toxic phenolic compounds are suitable to be introduced as a new substitute for peat in horticulture. In this study rice husk were hydrothermally carbonized at 200° C for 6 hours, yielding in hydrochars containing organic contaminants such as phenols and furfurals, which may affect plants and soil organisms. We investigated potential toxic effects on the germination rate and the root length of cress salad (Lepidium sativum) in four fractions: i) soil control, ii) raw rice husk + soil, iii) unwashed rice char + soil and iv) acetone/water washed rice char + soil. It could be shown that phenols and furfurals, which were removed from the hydrochar after washing by 80 to 96% did not affect the germination rate and the root length of the cress plants. The lowest germination rate and root length were found in the soil control, the highest in the non-washed hydrochar treatment, indicating a fertilization effect and growth stimulation of cress salad by hydrochar. If this result can be confirmed for other target and non-target organisms in future studies, a new strategy for the production of growing media may be developed.

  19. Attenuation in Melting Layer of Precipitation

    NARCIS (Netherlands)

    Klaassen, W.

    1988-01-01

    A model of the melting layer is employed on radar measurements to simulate the attenuation of radio waves at 12, 20 and 30GHz. The attenuation in the melting layer is simulated to be slightly larger than that of rain with the same path length and precipitation intensity. The result appears to depend

  20. Scattering length and effective range for charged-particle scattering in a plane and in higher dimensions

    International Nuclear Information System (INIS)

    Verhaar, B.J.; de Goey, L.P.H.; Vredenbregt, E.J.D.

    1985-01-01

    The concepts of scattering length a and effective range r/sub e/ previously introduced for low-energy scattering from a potential V(r) in a plane and in higher dimensions are extended to include a 1/r potential (strength parameter γ). Both a and r/sub e/ have the physical significance of being equal to the radius of an equivalent hard sphere giving rise to the same O(k 0 ) and O(k 2 ) terms in the expression for the phase shift. The method used is based on the properties of the ''local scattering length'' a(r,γ) for the potential V(r) cut off at radius r and an ''equivalent hard-sphere radius'' a(r,k,γ) for wave number knot =0. It is shown that these quantities have a smooth behavior for γ→0 and for dimension n→2

  1. Effects of cloud-point grafting, chain length, and density of PEG layers on competitive adsorption of ocular proteins

    DEFF Research Database (Denmark)

    Kingshott, P.; Thissen, H.; Griesser, H.J.

    2002-01-01

    The effects of pinning density, chain length, and 'cloud point' (CP) versus non-CP grafting conditions have been studied on the ability of polyethylene glycol (PEG) layers to minimize adsorption from a multicomponent (lysozyme, human serum albumin (HSA), IgG and lactoferrin) protein solution...... density) r.f.g.d. polymer layers. The PEG graft density was varied also by increasing the temperature and salt (K2SO4) content of the grafting solution; it reached a maximum at the CP of the PEGs. The CP reaction conditions were critical for producing PEG layers capable of minimizing protein adsorption. X...... density and chain length are interrelated, but the key factor is optimization of PEG chain density by use of the CP conditions, provided that a sufficient density of pinning sites exists. (C) 2002 Elsevier Science Ltd. Al l rights reserved....

  2. Effect of the Channel Length on the Transport Characteristics of Transistors Based on Boron-Doped Graphene Ribbons

    Directory of Open Access Journals (Sweden)

    Paolo Marconcini

    2018-04-01

    Full Text Available Substitutional boron doping of devices based on graphene ribbons gives rise to a unipolar behavior, a mobility gap, and an increase of the I O N / I O F F ratio of the transistor. Here we study how this effect depends on the length of the doped channel. By means of self-consistent simulations based on a tight-binding description and a non-equilibrium Green’s function approach, we demonstrate a promising increase of the I O N / I O F F ratio with the length of the channel, as a consequence of the different transport regimes in the ON and OFF states. Therefore, the adoption of doped ribbons with longer aspect ratios could represent a significant step toward graphene-based transistors with an improved switching behavior.

  3. Effects of Organic Cation Length on Exciton Recombination in Two-Dimensional Layered Lead Iodide Hybrid Perovskite Crystals.

    Science.gov (United States)

    Gan, Lu; Li, Jing; Fang, Zhishan; He, Haiping; Ye, Zhizhen

    2017-10-19

    In recent years, 2D layered organic-inorganic lead halide perovskites have attracted considerable attention due to the distinctive quantum confinement effects as well as prominent excitonic luminescence. Herein, we show that the recombination dynamics and photoluminescence (PL) of the 2D layered perovskites can be tuned by the organic cation length. 2D lead iodide perovskite crystals with increased length of the organic chains reveal blue-shifted PL as well as enhanced relative internal quantum efficiency. Furthermore, we provide experimental evidence that the formation of face-sharing [PbI 6 ] 4- octahedron in perovskites with long alkyls induces additional confinement for the excitons, leading to 1D-like recombination. As a result, the PL spectra show enhanced inhomogeneous broadening at low temperature. Our work provides physical understanding of the role of organic cation in the optical properties of 2D layered perovskites, and would benefit the improvement of luminescence efficiency of such materials.

  4. Clonal Propagation of Khaya senegalensis: The Effects of Stem Length, Leaf Area, Auxins, Smoke Solution, and Stockplant Age

    Directory of Open Access Journals (Sweden)

    Catherine Ky-Dembele

    2011-01-01

    Full Text Available Khaya senegalensis is a multipurpose African timber species. The development of clonal propagation could improve plantation establishment, which is currently impeded by mahogany shoot borer. To examine its potential for clonal propagation, the effects of cutting length, leaf area, stockplant maturation, auxin, and smoke solution treatments were investigated. Leafy cuttings rooted well (up to 80% compared to leafless cuttings (0%. Cuttings taken from seedlings rooted well (at least 95%, but cuttings obtained from older trees rooted poorly (5% maximum. The rooting ability of cuttings collected from older trees was improved (16% maximum by pollarding. Auxin application enhanced root length and the number of roots while smoke solution did not improve cuttings' rooting ability. These results indicate that juvenile K. senegalensis is amenable to clonal propagation, but further work is required to improve the rooting of cuttings from mature trees.

  5. Attenuated, oncolytic, but not wild-type measles virus infection has pleiotropic effects on human neutrophil function.

    Science.gov (United States)

    Zhang, Yu; Patel, Bella; Dey, Aditi; Ghorani, Ehsan; Rai, Lena; Elham, Mohammed; Castleton, Anna Z; Fielding, Adele K

    2012-02-01

    We previously showed that neutrophils play a role in regression of human tumor xenografts in immunodeficient mice following oncolytic vaccine measles virus (MV-Vac) treatment. In this study, we sought, using normal human neutrophils, to identify potential neutrophil-mediated mechanisms for the attenuated MV-Vac induced effects seen in vivo, by comparison with those consequent on wild-type (WT-MV) infection. Both MV-Vac and WT-MV infected and replicated within neutrophils, despite lack of SLAM expression. In both cases, neutrophils survived longer ex vivo postinfection. Furthermore, MV-Vac (but not WT-MV) infection activated neutrophils and stimulated secretion of several specific antitumor cytokines (IL-8, TNF-α, MCP-1, and IFN-α) via induction of de novo RNA and protein synthesis. In addition, MV-Vac (but not WT-MV) infection caused TRAIL secretion in the absence of de novo synthesis by triggering release of prefabricated TRAIL, via a direct effect upon degranulation. The differences between the outcome of infection by MV-Vac and WT-MV were not entirely explained by differential infection and replication of the viruses within neutrophils. To our knowledge, this is the first demonstration of potential mechanisms of oncolytic activity of an attenuated MV as compared with its WT parent. Furthermore, our study suggests that neutrophils have an important role to play in the antitumor effects of oncolytic MV.

  6. Effect of span length and temperature on the 3-D confined flow around a vortex promoter

    International Nuclear Information System (INIS)

    Martin, E.; Velazquez, A.

    2011-01-01

    Highlights: ► The article deals with study of vortex promoter flow in a 3-D micro-channel. ► Aspects studied are: channel aspect ratio and prism surface temperature. ► Flow is classified into three different regimes depending on different parameters. ► Results could be used for practical engineering design purposes. - Abstract: This article presents a numerical study on the influence of span length and wall temperature on the 3-D flow pattern around a square section vortex promoter located inside a micro-channel in the low Reynolds number regime. The first objective of the work is to quantify the critical Reynolds number that defines the onset of vortex shedding and to identify the different regimes that appear as a function of the channel aspect ratio (span to height ratio). We found that the critical Reynolds number for the onset of the Karman street regime increases as the aspect ratio decreases. In particular, for the aspect ratio of 1/2 the critical Reynolds number is nearly six times the critical Reynolds number of the 2-D problem. An intermediate oscillating regime between the steady and the Karman street solutions was also found to exist within a rather wide range of Reynolds numbers for small channel aspect ratios. The second objective was to investigate the influence of the vortex promoter wall temperature on both vortex shedding and flow pattern. This has practical engineering implications because the working fluid considered in the article is water that has a viscosity that depends significantly on temperature and promotes a strong coupling between the momentum and energy equations that influences the system behaviour. Results indicate that high surface temperature on the prism promotes the onset of the Karman street, suggesting design guidelines for micro-channel based heat sinks that make use of vortex promoters.

  7. Effect of mitomycin-c-assisted sutureless trabeculectomy on keratometry and axial length

    Directory of Open Access Journals (Sweden)

    Anant Sharma

    2017-01-01

    Full Text Available Aim: Glaucoma is defined as chronic, progressive optic neuropathy caused by a group of ocular conditions, which leads to damage of the optic nerve with loss of visual function. This study was conducted to find out the changes in corneal curvature, axial length and intraocular pressure. Materials and Methods: The present study was conducted in the Department of Ophthalmology, S P Medical College and Associated Group of Hospitals, Bikaner. A total of fifty cases of either age- and sex-matched controls were selected for this study. These cases were divided into two groups: Group A (sutureless trabeculectomy with mitomycin-C [MMC] and Group B (sutureless trabeculectomy without MMC. Results: The mean post-operative intraocular pressure (IOP was lowered in MMC-treated eyes when compared to control at 1½ months. The IOP reduction was greater in the MMC-treated eyes (13.25 mmHg at 1½ months as compared to control Group B (16.9 mmHg at 1½ months. Comparing results with the present study, it was found that success rate in MMC-treated eyes was noted in 23 (92% individuals, in which complete success was in 22 (88% while qualified success in 1 (4% and qualified failure in 2 (8% with mean IOP of 13.2 mmHg at 1½ months, whereas in control group, success rate was noted in 19 (76% individuals, in which complete success was in 18 (72% and qualified success in 1 (4%, while qualified failure in 6 (24% with mean IOP of 16.9 mmHg at 1½ months after operation. Conclusion: Results of this study are in favour of intraoperative application of MMC during filtration surgery, especially in cases with high-risk failure.

  8. An effective AIDS vaccine based on live attenuated vesicular stomatitis virus recombinants.

    Science.gov (United States)

    Rose, N F; Marx, P A; Luckay, A; Nixon, D F; Moretto, W J; Donahoe, S M; Montefiori, D; Roberts, A; Buonocore, L; Rose, J K

    2001-09-07

    We developed an AIDS vaccine based on attenuated VSV vectors expressing env and gag genes and tested it in rhesus monkeys. Boosting was accomplished using vectors with glycoproteins from different VSV serotypes. Animals were challenged with a pathogenic AIDS virus (SHIV89.6P). Control monkeys showed a severe loss of CD4+ T cells and high viral loads, and 7/8 progressed to AIDS with an average time of 148 days. All seven vaccinees were initially infected with SHIV89.6P but have remained healthy for up to 14 months after challenge with low or undetectable viral loads. Protection from AIDS was highly significant (p = 0.001). VSV vectors are promising candidates for human AIDS vaccine trials because they propagate to high titers and can be delivered without injection.

  9. Molecular cloning, expression analysis, and potential food intake attenuation effect of peptide YY in grass carp (Ctenopharyngodon idellus).

    Science.gov (United States)

    Chen, Yong; Shen, Yubang; Pandit, Narayan Prasad; Fu, Jianjun; Li, Da; Li, Jiale

    2013-06-15

    The peptide YY (PYY) is a 36 amino acid peptide involved in the food intake control in vertebrates. We have cloned and characterized a PYY gene from grass carp Ctenopharyngodon idellus. The full-length cDNA encodes a precursor protein of grass carp PYY (gcPYY) that consists of a putative 28-amino acid signal peptide, a 36-amino acid mature peptide, an amidation-proteolytic site, and a 30-amino acid carboxy-terminal extension. The gcPYY gene is comprised of 4 exons interspaced by 3 introns as seen in PYYs from other species. Amino acid alignment and gene structure comparison indicate that the structure of PYY is well preserved throughout vertebrate phylogeny. The tissue distribution and postprandial changes in gcPYY mRNA expression were evaluated by real-time PCR, which showed that the gcPYY is expressed abundantly in the central nervous system, with significantly increased expression following a single meal. During embryogenesis, the presence of gcPYY mRNA was detected in early developing embryos, and high expression levels were observed when most larvae completed their switch from endogenous nourishment to exogenous feeding. Reduced food intake by juveniles during a single meal after giving perpheral injection of gcPYY1-36 suggests a potentially important role of PYY in the food intake attenuation in grass carp. Copyright © 2013 Elsevier Inc. All rights reserved.

  10. Effect of Process Parameters on Flow Length and Flash Formation in Injection Moulding of High Aspect Ratio Polymeric Micro Features

    Directory of Open Access Journals (Sweden)

    Abdelkhalik Eladl

    2018-01-01

    Full Text Available This paper reports an investigation of the effects of process parameters on the quality characteristics of polymeric parts produced by micro injection moulding (μIM with two different materials. Four injection moulding process parameters (injection velocity, holding pressure, melt temperature and mould temperature were investigated using Polypropylene (PP and Acrylonitrile Butadiene Styrene (ABS. Three key characteristics of the mouldings were evaluated with respect to process settings and the material employed: part mass, flow length and flash formation. The experimentation employs a test part with four micro fingers with different aspect ratios (from 21 up to 150 and was carried out according to the Design of Experiments (DOE statistical technique. The results show that holding pressure and injection velocity are the most influential parameters on part mass with a direct effect for both materials. Both parameters have a similar effect on flow length for both PP and ABS at all aspect ratios and have higher effects as the feature thickness decreased below 300 μm. The study shows that for the investigated materials the injection speed and packing pressure were the most influential parameters for increasing the amount of flash formation, with relative effects consistent for both materials. Higher melt and mould temperatures settings were less influential parameters for increasing the flash amount when moulding with both materials. Of the two investigated materials, PP was the one exhibiting more flash formation as compared with ABS, when corresponding injection moulding parameters settings for both materials were considered.

  11. Effects of the addition of remifentanil to propofol anesthesia on seizure length and postictal suppression index in electroconvulsive therapy.

    Science.gov (United States)

    Porter, Richard; Booth, David; Gray, Hamish; Frampton, Chris

    2008-09-01

    Propofol is a widely used anesthetic agent for electroconvulsive therapy (ECT). However, there are concerns that its anticonvulsant effect may interfere with the efficacy of ECT. We aimed to investigate the effects on seizure activity of the addition of the opiate remifentanil to propofol anesthesia for ECT. A retrospective analysis of 633 treatments in 73 patients was conducted. At each treatment, patients had received anesthesia with propofol alone or propofol plus remifentanil, depending on which anesthetist was providing anesthesia. Analysis of variance was performed to examine the effects of the anesthetic used, the electrode placement, the dose of electricity administered, and the stage in the course of treatment. Dependent variables were electroencephalogram seizure length and postictal suppression index (PSI). Addition of remifentanil resulted in a small but significantly lower dose of propofol being used to induce unconsciousness. Addition of remifentanil affected seizure length, mainly related to an effect when placement was right unilateral (F = 5.70; P = 0.017). There was also a significantly increased PSI (F = 4.3; P = 0.039), which was not dependent on dose or on placement. The data suggest that addition of remifentanil to propofol anesthesia significantly alters seizure indices. This may be secondary to a reduction in the amount of propofol required or to an independent effect of remifentanil. The increase in PSI in particular suggests that addition of remifentanil may improve clinical response. However, this can only be examined in a randomized controlled trial.

  12. Assessment of the effectiveness of onsite exsitu remediation by enhanced natural attenuation in the Niger Delta region, Nigeria.

    Science.gov (United States)

    Okparanma, Reuben N; Azuazu, Ikeabiama; Ayotamuno, Josiah M

    2017-12-15

    This study was conducted to quantify and rank the effectiveness of onsite exsitu remediation by enhanced natural attenuation using soil quality index. The investigation was conducted at three oil spill sites in the Niger Delta (5.317°N, 6.467°E), Nigeria with a predominance of Oxisols. Baseline assessment and a two-step post-remediation monitoring of the sites were conducted. Target contaminants including total petroleum hydrocarbon (TPH) and BTEX (benzene, toluene, ethylbenzene, and xylene) were analyzed by gas chromatography-mass spectrometry. Results of the baseline assessment showed that TPH concentrations across the study sites averaged between 5113 and 7640 mg/kg at 0- to 1-m depth, which was higher than the local regulatory value of 5000 mg/kg. The soil quality index across the sites ranged between 68 and 45, suggesting medium to high potential ecological health risks with medium to high priority for remediation. BTEX concentrations followed a similar trend. However, after remediation TPH degraded rapidly initially and then slowly but asymptotically during the post-remediation monitoring period. Then, soil quality index across the study sites ranged between 100 and 58, indicating very low to medium potential ecological health risks. This demonstrates the effectiveness of onsite exsitu remediation by enhanced natural attenuation as a remediation strategy for petroleum-contaminated soils, which holds great promise for the Niger Delta province. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Updated data on effective and safe immunizations with live-attenuated vaccines for children after living donor liver transplantation.

    Science.gov (United States)

    Shinjoh, Masayoshi; Hoshino, Ken; Takahashi, Takao; Nakayama, Tetsuo

    2015-01-29

    Although immunizations using live-attenuated vaccines are not recommended for children post-liver transplant due to their theoretical risks, they will inevitably encounter vaccine-preventable viral diseases upon returning to real-life situations. The window of opportunity for vaccination is usually limited prior to transplantation because these children often have unstable disease courses. Also, vaccine immunity does not always persist after transplantation. Beginning in 2002, subcutaneous immunizations with four individual live-attenuated vaccines (measles, rubella, varicella, and mumps) to pediatric patients following living donor liver transplantation (LDLT) were performed for those who fulfilled the clinical criteria, including humoral and cell-mediated immunity. Written informed consent was collected. We included the study on 70 immunizations for 18 cases that we reported in 2008 (Shinjoh et al., 2008). A total of 196 immunizations were administered to 48 pediatric post-LDLT recipients. Of these, 144 were first immunizations and 52 were repeated immunizations following LDLT. The seroconversion rates at the first dose for measles (AIK-C), rubella (TO-336), varicella (Oka), and mumps (Hoshino) were 100% (36/36), 100% (35/35), 70% (23/33), and 75% (24/32), respectively. Antibody levels did not fall over time in patients immunized with rubella vaccine. Three mild cases of breakthrough varicella were observed. Two cases with transient parotid gland swelling were observed after mumps immunization. Two admissions because of fever at 2-3 weeks after the measles vaccine were reported but the patients had no symptoms of measles. Immunizations using selected live-attenuated vaccines were safe and effective for post-LDLT children who were not severely immunosuppressed. However, with the exception of rubella, repeated immunization may be necessary. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Earth-Space Link Attenuation Estimation via Ground Radar Kdp

    Science.gov (United States)

    Bolen, Steven M.; Benjamin, Andrew L.; Chandrasekar, V.

    2003-01-01

    A method of predicting attenuation on microwave Earth/spacecraft communication links, over wide areas and under various atmospheric conditions, has been developed. In the area around the ground station locations, a nearly horizontally aimed polarimetric S-band ground radar measures the specific differential phase (Kdp) along the Earth-space path. The specific attenuation along a path of interest is then computed by use of a theoretical model of the relationship between the measured S-band specific differential phase and the specific attenuation at the frequency to be used on the communication link. The model includes effects of rain, wet ice, and other forms of precipitation. The attenuation on the path of interest is then computed by integrating the specific attenuation over the length of the path. This method can be used to determine statistics of signal degradation on Earth/spacecraft communication links. It can also be used to obtain real-time estimates of attenuation along multiple Earth/spacecraft links that are parts of a communication network operating within the radar coverage area, thereby enabling better management of the network through appropriate dynamic routing along the best combination of links.

  15. Self-consistent field theoretic simulations of amphiphilic triblock copolymer solutions: Polymer concentration and chain length effects

    Directory of Open Access Journals (Sweden)

    X.-G. Han

    2014-06-01

    Full Text Available Using the self-consistent field lattice model, polymer concentration φP and chain length N (keeping the length ratio of hydrophobic to hydrophilic blocks constant the effects on temperature-dependent behavior of micelles are studied, in amphiphilic symmetric ABA triblock copolymer solutions. When chain length is increased, at fixed φP, micelles occur at higher temperature. The variations of average volume fraction of stickers φcos and the lattice site numbers Ncols at the micellar cores with temperature are dependent on N and φP, which demonstrates that the aggregation of micelles depends on N and φP. Moreover, when φP is increased, firstly a peak appears on the curve of specific heat CV for unimer-micelle transition, and then in addition a primary peak, the secondary peak, which results from the remicellization, is observed on the curve of CV. For a long chain, in intermediate and high concentration regimes, the shape of specific heat peak markedly changes, and the peak tends to be a more broad peak. Finally, the aggregation behavior of micelles is explained by the aggregation way of amphiphilic triblock copolymer. The obtained results are helpful in understanding the micellar aggregation process.

  16. Effects of Unpredictable Variable Prenatal Stress (UVPS) on Bdnf DNA Methylation and Telomere Length in the Adult Rat Brain

    Science.gov (United States)

    Blaze, Jennifer; Asok, A.; Moyer, E. L.; Roth, T. L.; Ronca, A. E.

    2015-01-01

    In utero exposure to stress can shape neurobiological and behavioral outcomes in offspring, producing vulnerability to psychopathology later in life. Animal models of prenatal stress likewise have demonstrated long-­-term alterations in brain function and behavioral deficits in offspring. For example, using a rodent model of unpredictable variable prenatal stress (UVPS), in which dams are exposed to unpredictable, variable stress across pregnancy, we have found increased body weight and anxiety-­-like behavior in adult male, but not female, offspring. DNA methylation (addition of methyl groups to cytosines which normally represses gene transcription) and changes in telomere length (TTAGGG repeats on the ends of chromosomes) are two molecular modifications that result from stress and could be responsible for the long-­-term effects of UVPS. Here, we measured methylation of brain-­-derived neurotrophic factor (bdnf), a gene important in development and plasticity, and telomere length in the brains of adult offspring from the UVPS model. Results indicate that prenatally stressed adult males have greater methylation in the medial prefrontal cortex (mPFC) compared to non-­-stressed controls, while females have greater methylation in the ventral hippocampus compared to controls. Further, prenatally stressed males had shorter telomeres than controls in the mPFC. These findings demonstrate the ability of UVPS to produce epigenetic alterations and changes in telomere length across behaviorally-­-relevant brain regions, which may have linkages to the phenotypic outcomes.

  17. Effect of the length of inflation on angular TT and TE power spectra in power-law inflation

    International Nuclear Information System (INIS)

    Hirai, Shiro; Takami, Tomoyuki

    2006-01-01

    The effect of the length of inflation on the power spectra of scalar and tensor perturbations is estimated using the power-law inflation model with a scale factor of a(η) = (-η) p = t q . Considering various pre-inflation models with radiation-dominated or scalar matter-dominated periods before inflation in combination with two matching conditions, the temperature angular power spectrum (TT) and temperature-polarization cross-power spectrum (TE) are calculated and a likelihood analysis is performed. It is shown that the discrepancies between the Wilkinson microwave anisotropy probe (WMAP) data and the ΛCDM model, such as suppression of the spectrum at l = 2, 3 and oscillatory behaviour, may be explained by the finite length of inflation model if the length of inflation is near 60 e-folds and q ≥ 300. The proposed models retain similar values of χ 2 to that achieved by the ΛCDM model with respect to fit to the WMAP data, but display different characteristics of the angular TE power spectra at l ≤ 20

  18. Effect of gate length on breakdown voltage in AlGaN/GaN high-electron-mobility transistor

    International Nuclear Information System (INIS)

    Luo Jun; Zhao Sheng-Lei; Mi Min-Han; Zhang Jin-Cheng; Ma Xiao-Hua; Hao Yue; Chen Wei-Wei; Hou Bin

    2016-01-01

    The effects of gate length L G on breakdown voltage V BR are investigated in AlGaN/GaN high-electron-mobility transistors (HEMTs) with L G = 1 μm∼ 20 μm. With the increase of L G , V BR is first increased, and then saturated at L G = 3 μm. For the HEMT with L G = 1 μm, breakdown voltage V BR is 117 V, and it can be enhanced to 148 V for the HEMT with L G = 3 μm. The gate length of 3 μm can alleviate the buffer-leakage-induced impact ionization compared with the gate length of 1 μm, and the suppression of the impact ionization is the reason for improving the breakdown voltage. A similar suppression of the impact ionization exists in the HEMTs with L G > 3 μm. As a result, there is no obvious difference in breakdown voltage among the HEMTs with L G = 3 μm∼20 μm, and their breakdown voltages are in a range of 140 V–156 V. (paper)

  19. A neural signature of phonological access: distinguishing the effects of word frequency from familiarity and length in overt picture naming.

    Science.gov (United States)

    Graves, William W; Grabowski, Thomas J; Mehta, Sonya; Gordon, Jean K

    2007-04-01

    Cognitive models of word production correlate the word frequency effect (i.e., the fact that words which appear with less frequency take longer to produce) with an increased processing cost to activate the whole-word (lexical) phonological representation. We performed functional magnetic resonance imaging (fMRI) while subjects produced overt naming responses to photographs of animals and manipulable objects that had high name agreement but were of varying frequency, with the purpose of identifying neural structures participating specifically in activating whole-word phonological representations, as opposed to activating lexical semantic representations or articulatory-motor routines. Blood oxygen level-dependent responses were analyzed using a parametric approach based on the frequency with which each word produced appears in the language. Parallel analyses were performed for concept familiarity and word length, which provided indices of semantic and articulatory loads. These analyses permitted us to identify regions related to word frequency alone, and therefore, likely to be related specifically to activation of phonological word forms. We hypothesized that the increased processing cost of producing lower-frequency words would correlate with activation of the left posterior inferotemporal (IT) cortex, the left posterior superior temporal gyrus (pSTG), and the left inferior frontal gyrus (IFG). Scan-time response latencies demonstrated the expected word frequency effect. Analysis of the fMRI data revealed that activity in the pSTG was modulated by frequency but not word length or concept familiarity. In contrast, parts of IT and IFG demonstrated conjoint frequency and familiarity effects, and parts of both primary motor regions demonstrated conjoint effects of frequency and word length. The results are consistent with a model of word production in which lexical-semantic and lexical-phonological information are accessed by overlapping neural systems within

  20. Effect of Conjugation Length on Photoinduced Charge-Transfer in π-Conjugated Oligomer-Acceptor Dyads

    KAUST Repository

    Jiang, Junlin

    2017-05-25

    A series of -conjugated oligomer-acceptor dyads were synthesized that feature oligo(phenylene ethynylene) (OPE) conjugated backbones end-capped with a naphthalene diimide (NDI) acceptor. The OPE segments vary in length from 4 to 8 phenylene ethynene units (PEn-NDI, where n = 4, 6 and 8). Fluorescence and transient absorption spectroscopy reveals that intramolecular OPE NDI charge transfer dominates the deactivation of excited states of the PEn-NDI oligomers. Both charge separation (CS) and charge recombination (CR) are strongly exothermic (G0CS ~ -1.1 and G0CR ~ -2.0 eV), and the driving forces do not vary much across the series because the oxidation and reduction potentials and singlet energies of the OPEs do not vary much with their length. Bimolecular photoinduced charge transfer between model OPEs that do not contain the NDI acceptors with methyl viologen was studied, and the results reveal that the absorption of the cation radical state (OPE+•) remains approximately constant ( ~ 575 nm) regardless of oligomer length. This finding suggests that the cation radical (polaron) of the OPE is relatively localized, effectively occupying a confined segment of n 4 repeat units in the longer oligomers. Photoinduced intramolecular electron transfer dynamics in the PEn-NDI series was investigated by UV-visible femtosecond transient absorption spectroscopy with visible and mid-infrared probes. Charge separation occurs on the 1 – 10 ps timescale, with the rates decreasing slightly with increased oligomer length (βCS ~ 0.15 Å-1). The rate for charge-recombination decreases in the sequence PE4-NDI > PE6-NDI ~ PE8-NDI. The discontinuous distance dependence in the rate for charge recombination may be related to the spatial localization of the positive polaron state in the longer oligomers.

  1. The effect of the chain length distribution of free fatty acids on the mixing properties of stratum corneum model membranes.

    Science.gov (United States)

    Oguri, Masashi; Gooris, Gert S; Bito, Kotatsu; Bouwstra, Joke A

    2014-07-01

    The stratum corneum (SC) plays a fundamental role in the barrier function of the skin. The SC consists of corneocytes embedded in a lipid matrix. The main lipid classes in the lipid matrix are ceramides (CERs), cholesterol (CHOL) and free fatty acids (FFAs). The aim of this study was to examine the effect of the chain length of FFAs on the thermotropic phase behavior and mixing properties of SC lipids. Fourier transform infrared spectroscopy and Raman imaging spectroscopy were used to study the mixing properties using either protonated or deuterated FFAs. We selected SC model lipid mixtures containing only a single CER, CHOL and either a single FFA or a mixture of FFAs mimicking the FFA SC composition. The single CER consists of a sphingoid base with 18 carbon atoms and an acyl chain with a chain length of 24 carbon atoms. When using lignoceric acid (24 carbon atoms) or a mixture of FFAs, the CER and FFAs participated in mixed crystals, but hydration of the mixtures induced a slight phase separation between CER and FFA. The mixed crystalline structures did not phase separate during storage even up to a time period of 3months. When using palmitic acid (16 carbon atoms), a slight phase separation was observed between FFA and CER. This phase separation was clearly enhanced during hydration and storage. In conclusion, the thermotropic phase behavior and the mixing properties of the SC lipid mixtures were shown to strongly depend on the chain length and chain length distribution of FFAs, while hydration enhanced the phase separation. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Effect of Conjugation Length on Photoinduced Charge-Transfer in π-Conjugated Oligomer-Acceptor Dyads

    KAUST Repository

    Jiang, Junlin; Alsam, Amani Abdu; Wang, Shanshan; Aly, Shawkat Mohammede; Pan, Zhenxing; Mohammed, Omar F.; Schanze, Kirk S.

    2017-01-01

    A series of -conjugated oligomer-acceptor dyads were synthesized that feature oligo(phenylene ethynylene) (OPE) conjugated backbones end-capped with a naphthalene diimide (NDI) acceptor. The OPE segments vary in length from 4 to 8 phenylene ethynene units (PEn-NDI, where n = 4, 6 and 8). Fluorescence and transient absorption spectroscopy reveals that intramolecular OPE NDI charge transfer dominates the deactivation of excited states of the PEn-NDI oligomers. Both charge separation (CS) and charge recombination (CR) are strongly exothermic (G0CS ~ -1.1 and G0CR ~ -2.0 eV), and the driving forces do not vary much across the series because the oxidation and reduction potentials and singlet energies of the OPEs do not vary much with their length. Bimolecular photoinduced charge transfer between model OPEs that do not contain the NDI acceptors with methyl viologen was studied, and the results reveal that the absorption of the cation radical state (OPE+•) remains approximately constant ( ~ 575 nm) regardless of oligomer length. This finding suggests that the cation radical (polaron) of the OPE is relatively localized, effectively occupying a confined segment of n 4 repeat units in the longer oligomers. Photoinduced intramolecular electron transfer dynamics in the PEn-NDI series was investigated by UV-visible femtosecond transient absorption spectroscopy with visible and mid-infrared probes. Charge separation occurs on the 1 – 10 ps timescale, with the rates decreasing slightly with increased oligomer length (βCS ~ 0.15 Å-1). The rate for charge-recombination decreases in the sequence PE4-NDI > PE6-NDI ~ PE8-NDI. The discontinuous distance dependence in the rate for charge recombination may be related to the spatial localization of the positive polaron state in the longer oligomers.

  3. TO STUDY EFFECT OF GABAPENTIN ON ATTENUATION OF PRESSOR RESPONSE TO DIRECT LARYNGOSCOPY AND TRACHEAL INTUBATION AND ON PERIOPERATIVE PAIN

    Directory of Open Access Journals (Sweden)

    Sarita Chandapet

    2017-05-01

    Full Text Available BACKGROUND Endotracheal intubation was first described by Rowbotham and Magill in 1921. 1 In 1940 Reid and Brace first described hemodynamic response to Laryngoscopy and Intubation due to Noxious stimuli. 2 The circulatory responses to laryngeal and tracheal stimulation are due to sympathoadrenal stimulation. 3 Laryngoscopy and Tracheal Intubation induces changes in circulating Catecholamine levels significantly. Norepinephrine, Epinephrine and Dopamine levels rise, but the raise in Norepinephrine levels is consistently associated with elevation of Blood pressure and Heart rate. 4 Even though the elevation in Blood pressure and Heart rate due to Laryngoscopy and Intubation are brief, they may have detrimental effects in high risk patients including Myocardial Infarction, Cardiac failure, Intracranial haemorrhage and increases in Intracranial pressure. 5 Many strategies have been advocated to minimize these hemodynamic adverse responses and aimed at different levels of the reflex arc. 6 Block of the peripheral sensory receptors and afferent input is by topical application and infiltration of Local Anaesthetic to Superior laryngeal nerve. Block of central mechanism of integration and sensory input by drugs like Fentanyl, Morphine etc. Block of efferent pathway and effector sites IV Lignocaine, Beta blockers, Calcium channel blockers, Hydralazine etc. No single drug or technique is satisfactory. The aim of this study is to evaluate the efficacy of Gabapentin in attenuating hemodynamic response to laryngoscopy and intubation in a placebo controlled double blind study. MATERIALS AND METHODS A clinical comparative study of attenuation of sympathetic response to laryngoscopy and intubation was done in 150 patients posted for elective surgery divided into two groups and were randomly allocated Group 1 – placebo capsules with sugar and Group 2 – Gabapentin 300 mg capsules. Heart rate, systolic, diastolic blood pressure, mean arterial pressure were

  4. Study of optical non-linear properties of a constant total effective length multiple quantum wells system

    International Nuclear Information System (INIS)

    Solaimani, M.; Morteza, Izadifard; Arabshahi, H.; Reza, Sarkardehi Mohammad

    2013-01-01

    In this work, we have studied the effect of the number of the wells, in a multiple quantum wells structure with constant total effective length, on the optical properties of multiple quantum wells like the absorption coefficient and the refractive index by means of compact density matrix approach. GaAs/Al x Ga (1−x) As multiple quantum wells systems was selected as an example. Besides, the effect of varying number of wells on the subband energies, wave functions, number of bound states, and the Fermi energy have been also investigated. Our calculation revealed that the number of wells in a multiple quantum well is a criterion with which we can control the amount of nonlinearity. This study showed that for the third order refractive index change there is two regimes of variations and the critical well number was six. In our calculations, we have used the same wells and barrier thicknesses to construct the multiple quantum wells system. - Highlights: ► OptiOptical Non-Linear. ► Total Effective Length. ► Multiple Quantum Wells System - genetic algorithm ► Schrödinger equation solution. ► Nanostructure.

  5. Controlled trial of the effect of length, incentives, and follow-up techniques on response to a mailed questionnaire.

    Science.gov (United States)

    Hoffman, S C; Burke, A E; Helzlsouer, K J; Comstock, G W

    1998-11-15

    Mailed questionnaires are an economical method of data collection for epidemiologic studies, but response tends to be lower than for telephone or personal interviews. As part of a follow-up study of volunteers who provided a brief health history and blood sample for a blood specimen bank in 1989, the authors conducted a controlled trial of the effect of length, incentives, and follow-up techniques on response to a mailed questionnaire. Interventions tested included variations on length of the questionnaire, effect of a monetary incentive, and effect of a postcard reminder versus a letter accompanied by a second questionnaire. Response was similar for the short (16-item, 4-page) and long (76-item, 16-page) questionnaire groups. The non-monetary [corrected] incentive did not improve the frequency of response. The second mailing of a questionnaire was significantly better than a postcard reminder in improving responses (23% vs. 10%). It is important to systematically test marketing principles to determine which techniques are effective in increasing response to mailed questionnaires for epidemiologic studies.

  6. A Comparison of Intrathecal and Epidural Analgesia and Its Effect on Length of Labor

    Science.gov (United States)

    1997-09-10

    differences were found between agents, lidocaine with epinephrine or bupivacaine with epinephrine, in depression of uterine activity (Willdeck-Lund et al...effects. Also, all parturients except for three reported pain relief lasting throughout labor. Local infiltration of lidocaine was performed for...are not reached. In response to the relative ineffectiveness of epidural morphine and the high incidence of side effects with morphine injected

  7. 3D Microstructure Effects in Ni-YSZ Anodes: Influence of TPB Lengths on the Electrochemical Performance

    Directory of Open Access Journals (Sweden)

    Omar M. Pecho

    2015-10-01

    Full Text Available 3D microstructure-performance relationships in Ni-YSZ anodes for electrolyte-supported cells are investigated in terms of the correlation between the triple phase boundary (TPB length and polarization resistance (Rpol. Three different Ni-YSZ anodes of varying microstructure are subjected to eight reduction-oxidation (redox cycles at 950 °C. In general the TPB lengths correlate with anode performance. However, the quantitative results also show that there is no simplistic relationship between TPB and Rpol. The degradation mechanism strongly depends on the initial microstructure. Finer microstructures exhibit lower degradation rates of TPB and Rpol. In fine microstructures, TPB loss is found to be due to Ni coarsening, while in coarse microstructures reduction of active TPB results mainly from loss of YSZ percolation. The latter is attributed to weak bottlenecks associated with lower sintering activity of the coarse YSZ. The coarse anode suffers from complete loss of YSZ connectivity and associated drop of TPBactive by 93%. Surprisingly, this severe microstructure degradation did not lead to electrochemical failure. Mechanistic scenarios are discussed for different anode microstructures. These scenarios are based on a model for coupled charge transfer and transport, which allows using TPB and effective properties as input. The mechanistic scenarios describe the microstructure influence on current distributions, which explains the observed complex relationship between TPB lengths and anode performances. The observed loss of YSZ percolation in the coarse anode is not detrimental because the electrochemical activity is concentrated in a narrow active layer. The anode performance can be predicted reliably if the volume-averaged properties (TPBactive, effective ionic conductivity are corrected for the so-called short-range effect, which is particularly important in cases with a narrow active layer.

  8. 3D Microstructure Effects in Ni-YSZ Anodes: Influence of TPB Lengths on the Electrochemical Performance.

    Science.gov (United States)

    Pecho, Omar M; Mai, Andreas; Münch, Beat; Hocker, Thomas; Flatt, Robert J; Holzer, Lorenz

    2015-10-21

    3D microstructure-performance relationships in Ni-YSZ anodes for electrolyte-supported cells are investigated in terms of the correlation between the triple phase boundary (TPB) length and polarization resistance ( R pol ). Three different Ni-YSZ anodes of varying microstructure are subjected to eight reduction-oxidation (redox) cycles at 950 °C. In general the TPB lengths correlate with anode performance . However, the quantitative results also show that there is no simplistic relationship between TPB and R pol . The degradation mechanism strongly depends on the initial microstructure. Finer microstructures exhibit lower degradation rates of TPB and R pol . In fine microstructures, TPB loss is found to be due to Ni coarsening, while in coarse microstructures reduction of active TPB results mainly from loss of YSZ percolation. The latter is attributed to weak bottlenecks associated with lower sintering activity of the coarse YSZ. The coarse anode suffers from complete loss of YSZ connectivity and associated drop of TPB active by 93%. Surprisingly, this severe microstructure degradation did not lead to electrochemical failure. Mechanistic scenarios are discussed for different anode microstructures. These scenarios are based on a model for coupled charge transfer and transport, which allows using TPB and effective properties as input. The mechanistic scenarios describe the microstructure influence on current distributions, which explains the observed complex relationship between TPB lengths and anode performances. The observed loss of YSZ percolation in the coarse anode is not detrimental because the electrochemical activity is concentrated in a narrow active layer. The anode performance can be predicted reliably if the volume-averaged properties (TPB active , effective ionic conductivity) are corrected for the so-called short-range effect, which is particularly important in cases with a narrow active layer.

  9. Salient stimuli in advertising: the effect of contrast interval length and type on recall.

    Science.gov (United States)

    Olsen, G Douglas

    2002-09-01

    Salient auditory stimuli (e.g., music or sound effects) are commonly used in advertising to elicit attention. However, issues related to the effectiveness of such stimuli are not well understood. This research examines the ability of a salient auditory stimulus, in the form of a contrast interval (CI), to enhance recall of message-related information. Researchers have argued that the effectiveness of the CI is a function of the temporal duration between the onset and offset of the change in the background stimulus and the nature of this stimulus. Three experiments investigate these propositions and indicate that recall is enhanced, providing the CI is 3 s or less. Information highlighted with silence is recalled better than information highlighted with music.

  10. Effects of dry period length on clinical mastitis and other major clinical health disorders

    DEFF Research Database (Denmark)

    Enevoldsen, Carsten; Sørensen, J.T.

    1992-01-01

    Four, 7-, and 10-wk dry periods were randomly assigned to 366 dairy cows in eight herds. A multiple polytomous logistic regression analysis was conducted with the objective to reveal possible important effects of the dry period on the risk of contracting major clinical health disorders. Several...... complex statistical interactions were revealed. Complications around and after drying off occurred least frequently at 7-wk dry periods. There was little evidence of an effect of the dry period on the risk of clinical mastitis and other severe clinical disorders around and after calving. With short...... like milk yield at drying off and previous mastitis are much more important predisposing factors....

  11. The effect of different temperature profiles upon the length and crystallinity of vertically-aligned multi-walled carbon nanotubes.

    Science.gov (United States)

    Yun, Jongju; Lee, Cheesung; Zheng, Qing; Baik, Seunghyun

    2012-08-01

    We synthesized vertically-aligned multi-walled carbon nanotubes with an inner diameter of 1.6-7.5 nm and stack height of 80-28600 microm by chemical vapor deposition. The effects of synthesis conditions such as substrate position in the tube furnace, maximum temperature, temperature increasing rate and synthesis duration on the structure of nanotubes were investigated. It was found that slightly faster temperature increase rate resulted in significantly longer length, larger diameter and more defects of nanotubes. Structural parameters such as inner, outer diameters, wall thickness and defects were investigated using transmission electron microscopy and Raman spectroscopy.

  12. Effectiveness of Sand-Therapy on the Attenuation of Separation anxiety Signs in Pre-School Children

    Directory of Open Access Journals (Sweden)

    Arghavan Shariat

    2015-01-01

    Full Text Available Background and Objective: The present research was conducted with the aim of determining effect of Sand-therapy on the attenuation of separation anxiety signs among pre-school children in Isfahan, Iran. Methods: The statistical society consists of all pre-school children who had separation anxiety disorder and Among100 children, 30 persons were selected using available sampling. The method of this research is quasi-experimental with one group and pre-test and post-test plan. After performing pre-test of separation anxiety disorder scale, the experimental group were trained under sand-therapy training in 10 sessions of 60 minutes for a period of two months and after that, post-test of separation anxiety disorder scale was performed. The research tool consists of the questionnaire CSI-4 of child’s morbid signs. Wilcoxon method was used to analysis the results. Results: The research findings showed that there was a meaningful different (P=0.008 between pre- test & post-test scores of anxiety signs for study group.Conclusion: As a practical message, we can mention that sand therapy is as an interesting and practical playing for the children and it is a meaningful therapy related to attenuation of separation anxious signs. Keywords: Sand therapy, separation anxiety, pre-school-children

  13. Effect of collimator size and absorber thickness on soil bulk density evaluation by gamma-ray attenuation

    International Nuclear Information System (INIS)

    Costa, J.C.; Borges, J.A.R.; Pires, L.F.

    2014-01-01

    Representative measurements of the soil bulk density (ρ s ) can be affected depending on the geometry selected for gamma-ray attenuation (GRA) measurements. In this study, the effect of collimator size (2–4 mm diameters) and absorber thickness (2–15 cm) on ρ s measurements of sandy and clayey soils was investigated. In summary, the results obtained for the 137 Cs show that ρ s remained fairly constant for values of thickness larger than 7 cm (both soils). The very same result was observed for collimator sizes 2–4 mm. Regarding the 241 Am source, ρ s values presented variations with the collimator size (both soils) for the different thicknesses. The best values of ρ s were obtained for samples smaller than 5 cm and also for the small collimator diameters. - Highlights: ► Representative measurements of the soil bulk density by gamma-ray attenuation. ► For 137 Cs the best bulk density values were obtained for samples larger than 7 cm. ► For 241 Am the best bulk density values were obtained for samples smaller than 5 cm

  14. Experimental Study of the Effect of Water Mist Location On Blast Overpressure Attenuation in A Shock Tube

    Science.gov (United States)

    Mataradze, Edgar; Chikhradze, Nikoloz; Bochorishvili, Nika; Akhvlediani, Irakli; Tatishvili, Dimitri

    2017-12-01

    Explosion protection technologies are based on the formation of a shock wave mitigation barrier between the protection site and the explosion site. Contemporary protective systems use water mist as an extinguishing barrier. To achieve high effectiveness of the protective system, proper selection of water mist characteristics is important. The main factors defining shock wave attenuation in water mist include droplet size distribution, water concentration in the mist, droplet velocity and geometric properties of mist. This paper examines the process of attenuation of shock waves in mist with droplets ranging from 25 to 400 microns under different conditions of water mist location. Experiments were conducted at the Mining Institute with the use of a shock tube to study the processes of explosion suppression by a water mist barrier. The shock tube consists of a blast chamber, a tube, a system for the dosed supply of water, sensors, data recording equipment, and a process control module. Shock wave overpressure reduction coefficient was studied in the shock tube under two different locations of water mist: a) when water mist is created in direct contact with blast chamber and b) the blast chamber and the mist are separated by air space. It is established that in conditions when the air space distance between the blast chamber and the mist is 1 meter, overpressure reduction coefficient is 1.5-1.6 times higher than in conditions when water mist is created in direct contact with blast chamber.

  15. Silencing effect of shRNA expression vectors with stem length of 21 ...

    African Journals Online (AJOL)

    Then, the recombinant plasmids were transfected into mouse embryonic fibroblast with lipofection and injected into leg muscle of mouse. The mRNA expression level of the green fluorescent protein gene was checked by real-time quantitative polymerase chain reaction (RT-PCR). The silencing effect of the 29 bp shRNA ...

  16. Effects of Personalization and Invitation Email Length on Web-Based Survey Response Rates

    Science.gov (United States)

    Trespalacios, Jesús H.; Perkins, Ross A.

    2016-01-01

    Individual strategies to increase response rate and survey completion have been extensively researched. Recently, efforts have been made to investigate a combination of interventions to yield better response rates for web-based surveys. This study examined the effects of four different survey invitation conditions on response rate. From a large…

  17. Diversity effects on root length production and loss in an experimental grassland community

    NARCIS (Netherlands)

    Mommer, L.; Padilla, F.M.; Ruijven, van J.; Caluwe, de H.; Smit-Tiekstra, A.E.; Berendse, F.; Kroon, de H.

    2015-01-01

    Advances in root ecology have revealed that root standing biomass is higher in species-rich plant communities than in species-poor communities. Currently, we do not know whether this below-ground diversity effect is the result of enhanced root production or reduced root mortality or both, which is

  18. Velocity overshoot decay mechanisms in compound semiconductor field-effect transistors with a submicron characteristic length

    International Nuclear Information System (INIS)

    Jyegal, Jang

    2015-01-01

    Velocity overshoot is a critically important nonstationary effect utilized for the enhanced performance of submicron field-effect devices fabricated with high-electron-mobility compound semiconductors. However, the physical mechanisms of velocity overshoot decay dynamics in the devices are not known in detail. Therefore, a numerical analysis is conducted typically for a submicron GaAs metal-semiconductor field-effect transistor in order to elucidate the physical mechanisms. It is found that there exist three different mechanisms, depending on device bias conditions. Specifically, at large drain biases corresponding to the saturation drain current (dc) region, the velocity overshoot suddenly begins to drop very sensitively due to the onset of a rapid decrease of the momentum relaxation time, not the mobility, arising from the effect of velocity-randomizing intervalley scattering. It then continues to drop rapidly and decays completely by severe mobility reduction due to intervalley scattering. On the other hand, at small drain biases corresponding to the linear dc region, the velocity overshoot suddenly begins to drop very sensitively due to the onset of a rapid increase of thermal energy diffusion by electrons in the channel of the gate. It then continues to drop rapidly for a certain channel distance due to the increasing thermal energy diffusion effect, and later completely decays by a sharply decreasing electric field. Moreover, at drain biases close to a dc saturation voltage, the mechanism is a mixture of the above two bias conditions. It is suggested that a large secondary-valley energy separation is essential to increase the performance of submicron devices

  19. On the thermal analysis of a plate-fin heat sink considering the thermal-entry length effect

    International Nuclear Information System (INIS)

    Bassiouny, Ramadan; Maher, Hisham; Hegazy, Adel A.

    2016-01-01

    Highlights: • Dissipated convective heat strongly depends on convection coefficient. Two correlations were developed for so and validated. • A clear error in air temperature distribution along the heat sink was seen if coefficient were not properly selected. • The error decreases when thermal-entry length effect is considered, as for thermal flow through short conduits as Pr <1. - Abstract: Cooling electric and electronic components is very imperative to keep these components functioning properly. The heat sink is a device used to dissipate generated heat and accordingly cool these components. Airflow through heat sinks experiences velocity and thermal boundary layer variation that significantly affects the heat transfer process and heat sink performance as a result. The present study aims at developing an analytical model that compares the effect of adopting fully-developed or thermally-developing flow on convective heat transfer coefficient and accordingly longitudinal predicted air temperature distribution. Experiments on plate-fin heat sinks were carried out to validate the developed model. The results quantitatively showed a noticeable overprediction in the air temperature distribution when the heat transfer coefficient was estimated based on a fully-developed assumption. On the other hand, a close agreement between predicted and measured values was noticed when the thermal-entry length effect was considered.

  20. An Expanded UV Irradiance Database from TOMS Including the Effects of Ozone, Clouds, and Aerosol Attenuation

    Science.gov (United States)

    Herman, J.; Krotkov, N.

    2003-01-01

    The TOMS UV irradiance database (1978 to 2003) has been expanded to include five new products (noon irradiance at 305,310,324, and 380 nm, and noon erythemal-weighted irradiance), in addition to the existing erythemal daily exposure, that permit direct comparisons with ground-based measurements from spectrometers and broadband instruments. The new data are available on http://toms.gsfc.nasa.gov/>http://toms.gsfc.nasa.gov. Comparisons of the TOMS estimated irradiances with ground-based instruments are given along with a review of the sources of known errors, especially the recent improvements in accounting for aerosol attenuation. Trend estimations from the new TOMS irradiances permit the clear separation of changes caused by ozone and those caused by aerosols and clouds. Systematic differences in cloud cover are shown to be the most important factor in determining regional differences in UV radiation reaching the ground for locations at the same latitude (e.g., the summertime differences between Australia and the US southwest).

  1. Phosphate attenuates the anti-proteinuric effect of very low-protein diet in CKD patients.

    Science.gov (United States)

    Di Iorio, Biagio R; Bellizzi, Vincenzo; Bellasi, Antonio; Torraca, Serena; D'Arrigo, Graziella; Tripepi, Giovanni; Zoccali, Carmine

    2013-03-01

    High phosphate levels attenuate nephroprotection through angiotensin-converting enzyme inhibition in patients with proteinuric chronic kidney disease (CKD). Whether this phenomenon holds true for other nephroprotective interventions like very-low-protein diet (VLPD) is unknown. We tested the hypothesis that phosphate interferes with the anti-proteinuric response to VLPD in a non-randomized, sequential study in 99 proteinuric CKD patients who sequentially underwent low-protein diet (LPD; 0.6 g/kg) and VLPD (0.3 g/kg) supplemented with keto-analogues, each for periods longer than 1 year. Serum phosphate significantly reduced during VLPD (3.2 ± 0.6 mg/dL) when compared with LPD (3.7 ± 0.6 mg/dL, P diet periods. In linear mixed models including the diagnosis of renal disease, eGFR, 24-h urine sodium and urea and other potential confounders, there was a strong interaction between serum phosphate (P = 0.04) and phosphaturia (P < 0.001) with the anti-proteinuric response to VLPD. Accordingly, 24-h proteinuria reduced modestly in patients who maintained relatively higher serum phosphate levels or relatively higher phosphaturia to be maximal in those who achieved the lowest level of serum and urine phosphate. Phosphate is an important modifier of the anti-proteinuric response to VLPD. Reducing phosphate burden may decrease proteinuria and slow the progression of renal disease in CKD patients, an issue that remains to be tested in specific clinical trials.

  2. Radiation-induced attenuation in polarization maintaining fibers: low dose rate response, stress, and materials effects

    International Nuclear Information System (INIS)

    Gingerich, M.E.; Friebele, E.J.; Hickey, S.J.; Brambani, L.A.; Onstott, J.R.

    1989-01-01

    The loss induced in polarization-maintaining (PM) fibers by low dose rate <0.01 Gy/h, where 1 Gy = 100 rads(Si) radiation exposure has been found to vary from <0.4 to ∼6 dB/km-10 Gy, depending on the wavelength of measurement and the fiber. Correlations have been established between low dose rate response and the ''permanent'' induced loss determined by fitting the recovery of the induced loss following high dose rate exposure to nth-order kinetics. Using this technique, both 0.85- and 1.3-μm PM fibers have been found which show virtually no permanent incremental loss and would therefore appear to be resistant to low dose rate radiation environments. The asymmetric stress inherent in PM fibers has been shown to reduce the permanent induced loss, while the recovery of the radiation-induced attenuation was found to be enhanced in fibers with Ge-F-doped silica clads

  3. Effect of metal ions on de novo aggregation of full-length prion protein

    International Nuclear Information System (INIS)

    Giese, Armin; Levin, Johannes; Bertsch, Uwe; Kretzschmar, Hans

    2004-01-01

    It is well established that the prion protein (PrP) contains metal ion binding sites with specificity for copper. Changes in copper levels have been suggested to influence incubation time in experimental prion disease. Therefore, we studied the effect of heavy metal ions (Cu 2+ , Mn 2+ , Ni 2+ , Co 2+ , and Zn 2+ ) in vitro in a model system that utilizes changes in the concentration of SDS to induce structural conversion and aggregation of recombinant PrP. To quantify and characterize PrP aggregates, we used fluorescently labelled PrP and cross-correlation analysis as well as scanning for intensely fluorescent targets in a confocal single molecule detection system. We found a specific strong pro-aggregatory effect of Mn 2+ at low micromolar concentrations that could be blocked by nanomolar concentration of Cu 2+ . These findings suggest that metal ions such as copper and manganese may also affect PrP conversion in vivo

  4. Effective calculation algorithm for nuclear chains of arbitrary length and branching

    International Nuclear Information System (INIS)

    Chirkov, V.A.; Mishanin, B.V.

    1994-01-01

    An effective algorithm for calculation of the isotope concentration in the spent nuclear fuel when it is kept in storage, is presented. Using the superposition principle and representing the transfer function in a rather compact form it becomes possible achieve high calculation speed and a moderate computer code size. The algorithm is applied for the calculation of activity, energy release and toxicity of heavy nuclides and products of their decay when the fuel is kept in storage. (authors). 1 ref., 4 tabs

  5. Word frequency influences on the list length effect and associative memory in young and older adults

    OpenAIRE

    Badham, SP; Whitney, C; Sanghera, S; Maylor, EA

    2016-01-01

    Many studies show that age deficits in memory are smaller for information supported by pre-experimental experience. Many studies also find dissociations in memory tasks between words that occur with high and low frequencies in language, but the literature is mixed regarding the extent of word frequency effects in normal ageing. We examined whether age deficits in episodic memory could be influenced by manipulations of word frequency. In Experiment 1, young and older adults studied short and l...

  6. Effects of hydrophobic helix length and side chain chemistry on biomimicry in peptoid analogues of SP-C.

    Science.gov (United States)

    Brown, Nathan J; Wu, Cindy W; Seurynck-Servoss, Shannon L; Barron, Annelise E

    2008-02-12

    The hydrophobic proteins of lung surfactant (LS), SP-B and SP-C, are critical constituents of an effective surfactant replacement therapy for the treatment of respiratory distress syndrome. Because of concerns and difficulties associated with animal-derived surfactants, recent investigations have focused on the creation of synthetic analogues of the LS proteins. However, creating an accurate mimic of SP-C that retains its biophysical surface activity is extraordinarily challenging given the lipopeptide's extreme hydrophobicity and propensity to misfold and aggregate. One successful approach that overcomes these difficulties is the use of poly-N-substituted glycines, or peptoids, to mimic SP-C. To develop a non-natural, bioactive mimic of SP-C and to investigate the effects of side chain chemistry and length of the helical hydrophobic region, we synthesized, purified, and performed in vitro testing of two classes of peptoid SP-C mimics: those having a rigid alpha-chiral aromatic helix and those having a biomimetic alpha-chiral aliphatic helix. The length of the two classes of mimics was also systematically altered. Circular dichroism spectroscopy gave evidence that all of the peptoid-based mimics studied here emulated SP-C's secondary structure, forming stable helical structures in solution. Langmuir-Wilhelmy surface balance, fluorescence microscopy, and pulsating bubble surfactometry experiments provide evidence that the aromatic-based SP-C peptoid mimics, in conjunction with a synthetic lipid mixture, have superior surface activity and biomimetic film morphology in comparison to the aliphatic-based mimics and that there is an increase in surface activity corresponding to increasing helical length.

  7. PAD WELDING EFFECT ON CRANKSHAFT LENGTH WHILE MAKING BUILD-UP PROCESS

    Directory of Open Access Journals (Sweden)

    T. V. Vigerina

    2011-01-01

    Full Text Available The paper reveals a pad welding effect on axial sizes of a crankshaft to be built-up and a dependence of axial deformation of built-up element on an elasticity modulus, a heating temperature and thermal coefficient of linear expansion of an element and a plating, weave bead sizes. This dependence enables to forecast tensile stresses in the plating. The paper contains justification on limitation of axial deformation of the built crank due to decrease of pad welding numbers up to only one during the whole period of its lifetime and carrying out  resource-saving measures.

  8. Finite Word-Length Effects in Digital State-Space Filters

    Directory of Open Access Journals (Sweden)

    B. Psenicka

    1999-12-01

    Full Text Available The state-space description of digital filters involves except the relationship between input and output signals an additional set of state variables. The state-space structures of digital filters have many positive properties compared with direct canonical structures. The main advantage of digital filter structures developed using state-space technique is a smaller sensitivity to quantization effects by fixed-point implementation. In our presentation, the emphasis is on the analysis of coefficient quantization and on existence of zero-input limit cycles in state-space digital filters. The comparison with direct form II structure is presented.

  9. Date fruit consumption at term: Effect on length of gestation, labour and delivery.

    Science.gov (United States)

    Razali, Nuguelis; Mohd Nahwari, Siti Hayati; Sulaiman, Sofiah; Hassan, Jamiyah

    2017-07-01

    Labour induction and augmentation with Prostaglandin and Oxytocin are well established as standard practice worldwide. They are safe when used judiciously, but may be associated with maternal and neonatal morbidities. Other safer alternatives have been studied including dates consumption during late pregnancy with various outcomes. The aim of this randomised controlled trial was to investigate the effect of date fruit consumption during late pregnancy on the onset of labour and need for induction or augmentation of labour. A total of 154 nulliparous women with an uncomplicated singleton pregnancy were randomly allocated to either dates-consumer (77) or control group (77). The women in the dates-consumer group had significantly less need for augmentation of labour and longer intervention to delivery interval. There was no significant difference in the onset of spontaneous labour. Dates consumption reduces the need for labour augmentation but does not expedite the onset of labour. Impact statement • Dates fruit consumption during late pregnancy has been shown to positively affect the outcome of labour and delivery. In this study, date consumption reduced the need for labour augmentation with oxytocin but did not expedite the onset of labour. Therefore, dates consumption in late pregnancy is a safe supplement to be considered as it reduced the need for labour intervention without any adverse effect on the mother and child. This further supports the finding of earlier studies.

  10. Effects of trawl selectivity and genetic parameters on fish body length under long-term trawling

    Science.gov (United States)

    Yu, Yang; Sun, Peng; Cui, He; Sheng, Huaxiang; Zhao, Fenfang; Tang, Yanli; Chen, Zelin

    2015-10-01

    Long-term fishing pressure affects the biological characteristics of exploited fish stocks. The biological characteristics of hairtail ( Trichiurus lepturus) in the East China Sea are unable to recover because of long-term trawling. Fishing induces evolutionary effects on the fish's biological characteristics. Evidence of these changes includes small size at age, a shift to earlier age structure, and early maturation. Natural and artificial selection usually affect the fish's life history. Selection can induce different chances of reproduction, and individual fish can give a different genetic contribution to the next generation. In this study, analysis of time-dependent probability of significance and test of sensitivity were used to explore the effects of fish exploitation rate, mesh size, and heritability with long-term trawling. Results showed that fishing parameters were important drivers to exploited fish population. However, genetic traits altered by fishing were slow, and the changes in biological characteristics were weaker than those caused by fishing selection. Exploitation rate and mesh size exhibited similar evolutionary trend tendency under long-term fishing. The time-dependent probability of significance trend showed a gradual growth and tended to be stable. Therefore, the direction of fishing-induced evolution and successful management of fish species require considerable attention to contribute to sustainable fisheries in China.

  11. Effects of chain length, chlorination degree, and structure on the octanol-water partition coefficients of polychlorinated n-alkanes.

    Science.gov (United States)

    Hilger, Bettina; Fromme, Hermann; Völkel, Wolfgang; Coelhan, Mehmet

    2011-04-01

    Log octanol-water partition coefficients (log Kow) of 40 synthesized polychlorinated n-alkanes (PCAs) with different chlorination degrees were determined using reversed-phase high performance liquid chromatography (RP-HPLC). In addition, log Kow values of a technical mixture namely Cereclor 63L as well as 15 individual in house synthesized C10, C11, and C12 chloroalkanes with known chlorine positions were estimated. Based on these results, the effects of chain length, chlorination degree, and structure were explored. The estimated log Kow values ranged from 4.10 (polychlorinated n-decanes with 50.2% chlorine content) to 11.34 (polychlorinated n-octacosanes with 54.8% chlorine content) for PCAs and from 3.82 (1,2,5,6,9,10-hexachlorodecane) to 7.75 (1,1,1,3,9,11,11,11-octachlorododecane) for the individual chloroalkanes studied. The results showed that log Kow value was influenced linearly at a given chlorine content by chain length, while a polynominal effect was observed in dependence on the chlorination degree of an alkane chain. Chlorine substitution pattern influenced markedly the log Kow value of chloroalkanes.

  12. Predicting permeability of regular tissue engineering scaffolds: scaling analysis of pore architecture, scaffold length, and fluid flow rate effects.

    Science.gov (United States)

    Rahbari, A; Montazerian, H; Davoodi, E; Homayoonfar, S

    2017-02-01

    The main aim of this research is to numerically obtain the permeability coefficient in the cylindrical scaffolds. For this purpose, a mathematical analysis was performed to derive an equation for desired porosity in terms of morphological parameters. Then, the considered cylindrical geometries were modeled and the permeability coefficient was calculated according to the velocity and pressure drop values based on the Darcy's law. In order to validate the accuracy of the present numerical solution, the obtained permeability coefficient was compared with the published experimental data. It was observed that this model can predict permeability with the utmost accuracy. Then, the effect of geometrical parameters including porosity, scaffold pore structure, unit cell size, and length of the scaffolds as well as entrance mass flow rate on the permeability of porous structures was studied. Furthermore, a parametric study with scaling laws analysis of sample length and mass flow rate effects on the permeability showed good fit to the obtained data. It can be concluded that the sensitivity of permeability is more noticeable at higher porosities. The present approach can be used to characterize and optimize the scaffold microstructure due to the necessity of cell growth and transferring considerations.

  13. Effects of statistical distribution of joint trace length on the stability of tunnel excavated in jointed rock mass

    Directory of Open Access Journals (Sweden)

    Kayvan Ghorbani

    2015-12-01

    Full Text Available The rock masses in a construction site of underground cavern are generally not continuous, due to the presence of discontinuities, such as bedding, joints, faults, and fractures. The performance of an underground cavern is principally ruled by the mechanical behaviors of the discontinuities in the vicinity of the cavern. During underground excavation, many surrounding rock failures have close relationship with joints. The stability study on tunnel in jointed rock mass is of importance to rock engineering, especially tunneling and underground space development. In this study, using the probability density distribution functions of negative exponential, log-normal and normal, we investigated the effect of joint trace length on the stability parameters such as stress and displacement of tunnel constructed in rock mass using UDEC (Universal Distinct Element Code. It was obtained that normal distribution function of joint trace length is more critical on the stability of tunnel, and exponential distribution function has less effect on the tunnel stability compared to the two other distribution functions.

  14. Allopregnanolone's attenuation of the lordosis-inhibiting effects of restraint is blocked by the antiprogestin, CDB-4124.

    Science.gov (United States)

    Uphouse, Lynda; Hiegel, Cindy

    2014-07-01

    A brief restraint experience reduces lordosis behavior in ovariectomized females that have been hormonally primed with estradiol benzoate. The addition of progesterone to the priming prevents the lordosis inhibition. Based on prior studies with an inhibitor of progesterone metabolism, we have implicated the intracellular progesterone receptor, rather than progesterone metabolites, as responsible for this protection. However, the progesterone metabolite, allopregnanolone (3α-hydroxy-5α-pregnan-20-one), also prevents lordosis inhibition after restraint. In a prior study, we reported that the progestin receptor antagonist, RU486 (11β-(4-dimethylamino)phenyl-17β-hydroxy-17-(1-propynyl)estra-4,9-dien-3-one), attenuated the effect of allopregnanolone. Because RU486 can also block the glucocorticoid receptor, in the current studies, we evaluated the effect of the progestin receptor antagonist, CDB-4124 (17α-acetoxy-21-methoxy-11β-[4-N,N-dimethyaminopheny]-19-norpregna-4,9-dione-3,20-dione), which is relatively devoid of antiglucocorticoid activity. Ovariectomized, Fischer rats were injected with 10 μg estradiol benzoate. Two days later, rats received either 60 mg/kg CDB-4124 or 20% DMSO/propylene glycol vehicle 1 h before injection with 4 mg/kg allopregnanolone. After a pretest to confirm sexual receptivity, rats were restrained for 5min and immediately tested for sexual behavior. Lordosis behavior was reduced by the restraint and attenuated by allopregnanolone. Pretreatment with CDB-4124 reduced allopregnanolone's effect. These findings support prior suggestions that allopreganolone reduces the response to restraint by mechanisms that require activation of the intracellular progesterone receptor. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. ALLOPREGNANOLONE’S ATTENUATION OF THE LORDOSIS-INHIBITNG EFFECTS OF RESTRAINT IS BLOCKED BY THE ANTIPROGESTIN, CDB-4124

    Science.gov (United States)

    Uphouse, Lynda; Hiegel, Cindy

    2014-01-01

    A brief restraint experience reduces lordosis behavior in ovariectomized females that have been hormonally primed with estradiol benzoate. The addition of progesterone to the priming prevents the lordosis inhibition. Based on prior studies with an inhibitor of progesterone metabolism, we have implicated the intracellular progesterone receptor, rather than progesterone metabolites, as responsible for this protection. However, the progesterone metabolite, allopregnanolone (3α-hydroxy-5α-pregnan-20-one), also prevents lordosis inhibition after restraint. In a prior study, we reported that the progestin receptor antagonist, RU486 (11β-(4-dimethylamino)phenyl-17β-hydroxy-17-(1-propynyl)estra-4,9-dien-3-one), attenuated the effect of allopregnanolone. Because RU486 can also block the glucocorticoid receptor, in the current studies, we evaluated the effect of the progestin receptor antagonist, CDB-4124 (17 α-acetoxy-21-methoxy-11β-[4-N,N-dimethyaminopheny]-19-norpregna-4,9-dione-3,20-dione), which is relatively devoid of antiglucocorticoid activity. Ovariectomized, Fischer rats were injected with 10 μg estradiol benzoate. Two days later, rats received either 60 mg/kg CDB-4124 or the 20% DMSO/propylene glycol vehicle 1 hr before injection with 4 mg/kg allopregnanolone. After a pretest to confirm sexual receptivity, rats were restrained for 5 min and immediately tested for sexual behavior. Lordosis behavior was reduced by the restraint and attenuated by allopregnanolone. Pretreatment with CDB-4124 reduced allopregnanolone’s effect. These findings support prior suggestions that allopreganolone reduces the response to restraint by mechanisms that require activation of the intracellular progesterone receptor. PMID:24650591

  16. Live-attenuated tetravalent dengue vaccines: The needs and challenges of post-licensure evaluation of vaccine safety and effectiveness.

    Science.gov (United States)

    Wichmann, Ole; Vannice, Kirsten; Asturias, Edwin J; de Albuquerque Luna, Expedito José; Longini, Ira; Lopez, Anna Lena; Smith, Peter G; Tissera, Hasitha; Yoon, In-Kyu; Hombach, Joachim

    2017-10-09

    Since December 2015, the first dengue vaccine has been licensed in several Asian and Latin American countries for protection against disease from all four dengue virus serotypes. While the vaccine demonstrated an overall good safety and efficacy profile in clinical trials, some key research questions remain which make risk-benefit-assessment for some populations difficult. As for any new vaccine, several questions, such as very rare adverse events following immunization, duration of vaccine-induced protection and effectiveness when used in public health programs, will be addressed by post-licensure studies and by data from national surveillance systems after the vaccine has been introduced. However, the complexity of dengue epidemiology, pathogenesis and population immunity, as well as some characteristics of the currently licensed vaccine, and potentially also future, live-attenuated dengue vaccines, poses a challenge for evaluation through existing monitoring systems, especially in low and middle-income countries. Most notable are the different efficacies of the currently licensed vaccine by dengue serostatus at time of first vaccination and by dengue virus serotype, as well as the increased risk of dengue hospitalization among young vaccinated children observed three years after the start of vaccination in one of the trials. Currently, it is unknown if the last phenomenon is restricted to younger ages or could affect also seronegative individuals aged 9years and older, who are included in the group for whom the vaccine has been licensed. In this paper, we summarize scientific and methodological considerations for public health surveillance and targeted post-licensure studies to address some key research questions related to live-attenuated dengue vaccines. Countries intending to introduce a dengue vaccine should assess their capacities to monitor and evaluate the vaccine's effectiveness and safety and, where appropriate and possible, enhance their surveillance

  17. Effect of length/width ratio of tapered beams on the performance of piezoelectric energy harvesters

    International Nuclear Information System (INIS)

    Matova, S P; Renaud, M; Jambunathan, M; Goedbloed, M; Van Schaijk, R

    2013-01-01

    Tapering of the beams as a way to increase the generated output power of cantilever piezoelectric energy harvesters has gained popularity in recent years. The tapering increases the average strain in the beam and consequently the charge generated by the piezoelectric material. Different authors claim an improvement of up to 30% in the generated output power. We have investigated the possibility of using tapered beams in MEMS piezoelectric energy harvesters. Numerical simulations did not suggest any increase in the generated output power and the lack of improvement was confirmed in practice. With the help of the numerical simulations it was further found that the tapering does work but only for certain design configurations, namely for cantilevers with long slender beams. For cantilevers with short wide beams, the tapering has no significant effect on the output power of the harvester. (paper)

  18. Sonoporation at Small and Large Length Scales: Effect of Cavitation Bubble Collapse on Membranes.

    Science.gov (United States)

    Fu, Haohao; Comer, Jeffrey; Cai, Wensheng; Chipot, Christophe

    2015-02-05

    Ultrasound has emerged as a promising means to effect controlled delivery of therapeutic agents through cell membranes. One possible mechanism that explains the enhanced permeability of lipid bilayers is the fast contraction of cavitation bubbles produced on the membrane surface, thereby generating large impulses, which, in turn, enhance the permeability of the bilayer to small molecules. In the present contribution, we investigate the collapse of bubbles of different diameters, using atomistic and coarse-grained molecular dynamics simulations to calculate the force exerted on the membrane. The total impulse can be computed rigorously in numerical simulations, revealing a superlinear dependence of the impulse on the radius of the bubble. The collapse affects the structure of a nearby immobilized membrane, and leads to partial membrane invagination and increased water permeation. The results of the present study are envisioned to help optimize the use of ultrasound, notably for the delivery of drugs.

  19. Electron attenuation in free, neutral ethane clusters.

    Science.gov (United States)

    Winkler, M; Myrseth, V; Harnes, J; Børve, K J

    2014-10-28

    The electron effective attenuation length (EAL) in free, neutral ethane clusters has been determined at 40 eV kinetic energy by combining carbon 1s x-ray photoelectron spectroscopy and theoretical lineshape modeling. More specifically, theory is employed to form model spectra on a grid in cluster size (N) and EAL (λ), allowing N and λ to be determined by optimizing the goodness-of-fit χ(2)(N, λ) between model and observed spectra. Experimentally, the clusters were produced in an adiabatic-expansion setup using helium as the driving gas, spanning a range of 100-600 molecules in mean cluster size. The effective attenuation length was determined to be 8.4 ± 1.9 Å, in good agreement with an independent estimate of 10 Å formed on the basis of molecular electron-scattering data and Monte Carlo simulations. The aggregation state of the clusters as well as the cluster temperature and its importance to the derived EAL value are discussed in some depth.

  20. Effect of methylphenidate on ICU and hospital length of stay in patients with severe and moderate traumatic brain injury.

    Science.gov (United States)

    Moein, Houshang; Khalili, Hossein A; Keramatian, Kamyar

    2006-09-01

    Traumatic brain injury is one of the major causes of death and disability among young people. Methylphenidate, a neural stimulant and protective drug, which has been mainly used for childhood attention deficit/hyperactivity disorder, has shown some benefits in late psychosocial problems in patients with traumatic brain injury. Its effect on arousal and consciousness has been also revealed in the sub-acute phase of traumatic brain injury. We studied its effect on the acute phase of moderate and severe traumatic brain injury (TBI) in relation to the length of ICU and hospital admission. Severely and moderately TBI patients (according to inclusion and exclusion criteria) were randomized to treatment and control groups. The treatment group received methylphenidate 0.3mg/kg per dose PO BID by the second day of admission until the time of discharge, and the control group received a placebo. Admission information and daily Glasgow Coma Scale (GCS) were recorded. Medical, surgical, and discharge plans for patients were determined by the attending physician, blinded to the study. Forty patients with severe TBI (GCS = 5-8) and 40 moderately TBI patients (GCS = 9-12) were randomly divided into treatment and control groups on the day of admission. In the severely TBI patients, both hospital and ICU length of stay, on average, were shorter in the treatment group compared with the control group. In the moderately TBI patients while ICU stay was shorter in the treatment group, there was no significant reduction of the period of hospitalization. There were no significant differences between the treatment and control groups in terms of age, sex, post resuscitation GCS, or brain CT scan findings, in either severely or moderately TBI patients. Methylphenidate was associated with reductions in ICU and hospital length of stay by 23% in severely TBI patients (P = 0.06 for ICU and P = 0.029 for hospital stay time). However, in the moderately TBI patients who received methylphenidate

  1. Proton irradiation effects on optical attenuation in doped- and pure-silica fibers

    International Nuclear Information System (INIS)

    Sakasai, Kaoru; Bueker, H.; Haesing, F.W.; Pfeiffer, F.

    1999-05-01

    Optical attenuation in doped- and pure-silica fibers was measured at wavelengths of 470 nm, 660 nm, and 850 nm during and after 20 MeV proton irradiation. In the experiment the fibers were arranged on a holder to make one layer' so that uniform proton irradiation can be achieved to them. The induced loss of the doped-silica fiber increased strongly at the beginning of the first irradiation, and decreased slowly after stopping of the beam. In the second irradiation, however, the developed loss was not so large. On the other hand, the loss of the pure-silica fiber increased gradually in the first irradiation, and decreased very quickly after the beam stopped. The loss increased stepwise at the very beginning of the second irradiation. Small luminescence from the fibers during irradiation was observed also. The luminescence of the pure-silica fiber was slightly larger than that of the doped-silica fiber. The induced loss of HCP fibers was also measured when a SiO 2 plate was set in front of the fibers. It may be possible to estimate the proton dose in materials using fiber-optic technique. Proton sensitivities of doped- and pure-silica fibers were, respectively, 1.0 x 10 -10 at 660 nm and 5.5 x 10 -12 at 470 nm in units of (dB/m)/(protons/cm 2 ), where the values were estimated from the slope of the loss growth curves at the beginning of the first irradiation. (author)

  2. Streptozotocin diabetes attenuates the effects of nondepolarizing neuromuscular relaxants on rat muscles.

    Science.gov (United States)

    Huang, Lina; Chen, Dan; Li, Shitong

    2014-12-01

    The hypothesis of this study was that diabetes-induced desensitization of rat soleus (SOL) and extensor digitorum longus (EDL) to non-depolarizing muscle relaxants (NDMRs) depends on the stage of diabetes and on the kind of NDMRs. We tested the different magnitude of resistance to vecuronium, cisatracurium, and rocuronium at different stages of streptozotocin (STZ)-induced diabetes by the EDL sciatic nerve-muscle preparations, and the SOL sciatic nerve-muscle preparations from rats after 4 and 16 weeks of STZ treatment. The concentration-twitch tension curves were significantly shifted from those of the control group to the right in the diabetic groups. Concentration giving 50% of maximal inhibition (IC50) was larger in the diabetic groups for all the NDMRs. For rocuronium and cisatracurium in both SOL and EDL, IC50 was significantly larger in diabetic 16 weeks group than those in the diabetic 4 weeks group. For SOL/EDL, the IC50 ratios were significantly largest in the diabetic 16 weeks group, second largest in the diabetic 4 weeks group, and smallest for the control group. Diabetes-induced desensitization to NDMRs depended on the stage of diabetes and on the different kind of muscles observed while was independent on different kind of NDMRs. The resistance to NDMRs was stronger in the later stage of diabetes (16 versus 4 weeks after STZ treatment). Additionally, when monitoring in SOL, diabetes attenuated the actions of neuromuscular blockade more intensely than that in EDL. Nonetheless, the hyposensitivity to NDMRs in diabetes was not relevant for the kind of NDMRs.

  3. Effect of photoperiod length and light intensity on some welfare criteria, carcass, and meat quality characteristics in broilers

    Directory of Open Access Journals (Sweden)

    Evrim Dereli Fidan

    Full Text Available ABSTRACT The objective of this study was to investigate the effects of photoperiod length and light intensity on leg and eye health, tonic immobility, some blood parameters, carcass, and meat quality characteristics in broilers. A total of 272 one-day-old male broiler chicks (Ross 308 were randomly assigned to four treatment groups based on the photoperiod length (23L:1D or increasing duration of light and light intensity (20 lux vs. dim light with four replicates. In this study, photoperiod lenght had no effect on incidence of foot pad and hock burn. On the other hand, the effect of photoperiod lenght had significant influence on the gait score. The incidences of gait score (3 + 4 + 5 in bright and dim light groups was found as 21.4 and 41.0% in broilers, respectively. In addition, the effect of light intensity had statistical significance on gait score. The tonic immobility duration in 20 lux and dim light groups were 271.53 and 226.78 s, respectively, and tonic immobility duration was unaffected by light intensity. All the blood parameters, except for triglyceride, were not affected by light intensity. The dim light had a negative effect on broiler welfare as demonstrated by increased eye weight and dimensions. Cold carcass yield and whole breast and wing yields were lower in the dim light group than in 20 lux light intensity. The broilers kept with dim light had lower breast meat ultimate pH (6.19 and L* values (54.30 than those reared with 20 lux. These findings have a lot of implications on the use of increasing photoperiod and bright light to improve leg an eye health benefits for the broiler welfare in broilers.

  4. Effective Electrostatic Interactions Between Two Overall Neutral Surfaces with Quenched Charge Heterogeneity Over Atomic Length Scale

    Science.gov (United States)

    Zhou, S.

    2017-12-01

    Using Monte Carlo results as a reference, a classical density functional theory ( CDFT) is shown to reliably predict the forces between two heterogeneously charged surfaces immersed in an electrolyte solution, whereas the Poisson-Boltzmann ( PB) theory is demonstrated to deteriorate obviously for the same system even if the system parameters considered fall within the validity range of the PB theory in the homogeneously charged surfaces. By applying the tested CDFT, we study the effective electrostatic potential of mean force ( EPMF) between two face-face planar and hard surfaces of zero net charge on which positive and negative charges are separated and considered to present as discontinuous spots on the inside edges of the two surfaces. Main conclusions are summarized as follows: (i) strength of the EPMF in the surface charge separation case is very sensitively and positively correlated with the surface charge separation level and valency of the salt ion. Particularly, the charge separation level and the salt ion valency have a synergistic effect, which makes high limit of the EPMF strength in the surface charge separation case significantly go beyond that of the ideal homogeneously charged surface counterpart at average surface charge density similar to the average surface positive or negative charge density in the charge separation case. (ii) The surface charge distribution patterns mainly influence sign of the EPMF: symmetrical and asymmetrical patterns induce repulsive and attractive (at small distances) EPMF, respectively; but with low valency salt ions and low charge separation level the opposite may be the case. With simultaneous presence of both higher valency cation and anion, the EPMF can be repulsive at intermediate distances for asymmetrical patterns. (iii) Salt ion size has a significant impact, which makes the EPMF tend to become more and more repulsive with the ion diameter regardless of the surface charge distribution patterns and the valency of

  5. Dopamine attenuates the chemoattractant effect of interleukin-8: a novel role in the systemic inflammatory response syndrome.

    LENUS (Irish Health Repository)

    Sookhai, S

    2012-02-03

    Activated neutrophil (PMN) adherence to vascular endothelium comprises a key step for both transendothelial migration and initiation of potentially deleterious release of PMN products. The biogenic amine, dopamine (DA), has been used for several decades in patients to maintain hemodynamic stability. The effect of dopamine on PMN transendothelial migration and adhesion receptor expression and on the endothelial molecules, E-selectin and ICAM-1, was evaluated. PMN were isolated from healthy controls, stimulated with lipopolysaccharide (LPS), and tumor necrosis factor-alpha (TNF-alpha) and treated with dopamine. CD 11b and CD 18 PMN adhesion receptor expression were assessed flow cytometrically. In a separate experiment, the chemoattractant peptide, IL-8, was placed in the lower chamber of transwells, and PMN migration was assessed. Human umbilical vein endothelial cells (HUVEC) were stimulated with LPS\\/TNF-alpha and incubated with dopamine. ICAM-1 and E-selectin endothelial molecule expression were assessed flow cytometrically. There was a significant increase in transendothelial migration in stimulated PMN compared with normal PMN (40 vs. 14%, P < 0.001). In addition, PMN CD11b\\/CD18 was significantly upregulated in stimulated PMN compared with normal PMN (252.4\\/352.4 vs. 76.7\\/139.4, P < 0.001) as were endothelial E-selectin\\/ICAM-1 expression compared with normal EC (8.1\\/9 vs. 3.9\\/3.8, P < 0.05). After treatment with dopamine, PMN transmigration was significantly decreased compared with stimulated PMN (8% vs. 40%, P < 0.001). Furthermore, dopamine also attenuated PMN CD11b\\/CD18 and the endothelial molecules E-selectin and ICAM-1 compared with stimulated PMN\\/EC that were not treated dopamine (174\\/240 vs. 252\\/352, P < 0.05 and 4\\/4.4 vs. 8.1\\/9, P < 0.05. respectively). The chemoattractant effect of IL-8 was also attenuated. These results identify for the first time that dopamine attenuates the initial interaction between PMN and the endothelium

  6. X-ray Pulse Length Characterization using the Surface Magneto Optic Kerr Effect

    International Nuclear Information System (INIS)

    Krejcik, P.; SLAC

    2006-01-01

    It will be challenging to measure the temporal profile of the hard X-ray SASE beam independently from the electron beam in the LCLS and other 4th generation light sources. A fast interaction mechanism is needed that can be probed by an ultrafast laser pulse in a pump-probe experiment. It is proposed to exploit the rotation in polarization of light reflected from a thin magnetized film, known as the surface magneto optic Kerr effect (SMOKE), to witness the absorption of the x-ray pulse in the thin film. The change in spin orbit coupling induced by the x-ray pulse occurs on the subfemtosecond time scale and changes the polarization of the probe beam. The limitation to the technique lies with the bandwidth of the probe laser pulse and how short the optical pulse can be made. The SMOKE mechanism will be described and the choices of materials for use with 1.5 (angstrom) x-rays. A schematic description of the pump-probe geometry for x-ray diagnosis is also described

  7. PEGylation of Phytantriol-Based Lyotropic Liquid Crystalline Particles-The Effect of Lipid Composition, PEG Chain Length, and Temperature on the Internal Nanostructure

    DEFF Research Database (Denmark)

    Nilsson, Christa; Ostergaard, Jesper; Larsen, Susan Weng

    2014-01-01

    of these lipidic nonlamellar liquid crystalline particles by using DSPE-mPEGs with three different block lengths of the hydrophilic PEG segment. The effects of lipid composition, PEG chain length, and temperature on the morphology and internal nanostructure of these self-assembled lipidic aqueous dispersions based...

  8. The Effect of the Length of To-Be-Remembered Lists and Intervening Lists on Free Recall: A Reexamination Using Overt Rehearsal

    Science.gov (United States)

    Ward, Geoff; Tan, Lydia

    2004-01-01

    In 3 experiments, the authors investigated the effects of to-be-remembered (TBR) and intervening list length on free recall to determine whether selective rehearsal could explain the previous finding that recall was affected only by TBR list length. In Experiments 1 (covert rehearsal) and 2 (overt rehearsal), participants saw 5- and 20-word lists…

  9. Effect of abutment screw length and cyclic loading on removal torque in external and internal hex implants.

    Science.gov (United States)

    Mohammed, Hnd Hadi; Lee, Jin-Han; Bae, Ji-Myung; Cho, Hye-Won

    2016-02-01

    The purpose of this study was to evaluate the effects of abutment screw length and cyclic loading on the removal torque (RTV) in external hex (EH) and internal hex (IH) implants. Forty screw-retained single crowns were connected to external and internal hex implants. The prepared titanium abutment screws were classified into 8 groups based on the number of threads (n = 5 per group): EH 12.5, 6.5, 3.5, 2.5 and IH 6.5, 5, 3.5, 2.5 threads. The abutment screws were tightened with 20 Ncm torque twice with 10-minute intervals. After 5 minutes, the initial RTVs of the abutment screws were measured with a digital torque gauge (MGT12). A customized jig was constructed to apply a load along the implant long axis at the central fossa of the maxillary first molar. The post-loading RTVs were measured after 16,000 cycles of mechanical loading with 50 N at a 1-Hz frequency. Statistical analysis included one-way analysis of variance and paired t-tests. The post-loading RTVs were significantly lower than the initial RTVs in the EH 2.5 thread and IH 2.5 thread groups (P<.05). The initial RTVs exhibited no significant differences among the 8 groups, whereas the post-loading RTVs of the EH 6.5 and EH 3.5 thread groups were higher than those of the IH 3.5 thread group (P<.05). Within the limitations of this study, the external hex implants with short screw lengths were more advantageous than internal hex implants with short screw lengths in torque maintenance after cyclic loading.

  10. Maternal and ambient environmental effects of light on germination in Plantago lanceolata: correlated responses to selection on leaf length

    International Nuclear Information System (INIS)

    Hinsberg, A. van

    1998-01-01

    1. Seeds from artificial selection lines were exposed to different maternal and ambient conditions, simulating sunlight and vegetation shade. 2. Lines selected for longer leaves also produced larger seeds, indicating a positive genetic correlation between leaf length and seed size. 3. Light conditions during maturation had no large effect on seed size. 4. Seed germination was reduced by a low ratio of red to far-red light (R/FR ratio) in the ambient environment. 5. Seeds maturated under simulated vegetation shade germinated less readily and were more inhibited by a low ambient R/FR ratio than seeds maturated under full sunlight or R/FR-neutral shade. Thus, low R/FR-ratios in the maternal and ambient environment operated synergistically. 6. Large genotypic variation in the germination responses to both maternal and ambient light conditions was found among and within selection lines, indicating that such responses might have the potential to evolve in response to natural selection. 7. Artificial selection for leaf length had affected seed germination characteristics but correlated responses and thus genetic correlations largely depended on light conditions in the selective environment. Selection for longer leaves under a low R/FR ratio increased seed dormancy and plasticity of germination in response to the R/FR ratio. However, in the opposite selective environment selection for longer leaves reduced seed dormancy and plasticity to the R/FR ratio. It is argued that leaf length and seed germination characteristics are somehow linked by shared physiological mechanisms, which may facilitate concerted changes in shade avoidance responses

  11. Effect of the Length of Side Group Substitution on Optical and Electroluminescene Properties

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Hwan Gyu; Kang, Hyeon Mi; Kim, Beom Jin; Park, Young Il [The Catholic University, Bucheon (Korea, Republic of); Yu, Young Jun [Korea Research Institute of Chemical Technology, Ulsan (Korea, Republic of); Park, Jong Wook [LG display Co., Gyeonggi (Korea, Republic of)

    2014-09-15

    Blue emitting materials, 9,10-bis-biphenyl-4-yl-anthracene (AC-P), 9,10-bis-[1,1';4',1'']terphenyl-4-yl-anthracene (AC-DP), and 9,10-bis[3'',5''-deiphenyltriphenyl-4'-yl]anthracene (AC-TP) were synthesized through boration and Suzuki aryl-aryl coupling reaction. EL performance of blue light-emitters was optimized and improved by varying the chemical structures of the side groups. In the thin film state, the three materials exhibit PLmax values in the range of 442-456 nm. EL device with the synthesized compounds in the following configuration was fabricated: ITO/4,4',4''-tris(N-(2-naphthyl)-N-phenylamino)triphenylamine (2-TNATA) 60nm/N,N'-bis (naphthalene-1-yl)-N,N'-bis(phenyl)benzidine (NPB) 15nm/synthesized blue emitting materials (30nm)/1,3,5- tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl (TPBi) 20nm/LiF 1nm/Al 200nm. The current efficiency and C.I.E. value of AC-TP were 3.87 cd/A and (0.15, 0.12). A bulky and non-planar side group helps to prevent π-π* stacking interaction, which should lead to the formation of more reliable amorphous film. This is expected to have a positive effect on the high efficiency of the operating OLED device.

  12. Effects of chemical modifications on photophysics and exciton dynamics on {pi}-conjugation attenuated and metal-chelated photoconducting polymers

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L. X.; Jager, W. J. H.; Gosztola, D. J.; Niemczyk, M. P.; Wasielewski, M. R.

    2000-03-11

    Effects of two types of chemical modifications on photoconducting polymers consisting of polyphenylenevinylene (PPV) derivatives are studied by static and ultrafast transient optical spectroscopy as well as semi-empirical ZINDO calculations. The first type of modification inserts 2,2{prime}-bipyridyl-5-vinylene units (bpy V) in the PPV backbone, and the second type involves metal-chelation with the bpy sites. Photoluminescence and exciton dynamics of polymers 1 and 2 with PV:bpyV ratios of 1 and 3 were examined in solution, and compared to those of the homopolymer, poly(2,5-bis(2{prime}-ethylhexyloxy)-1,4-phenylenevinylene) (BEH-PPV). Similar studies were carried out for several metal-chelated polymers. These results can be explained by changes in {pi}-conjugation throughout the polymer backbone. The attenuation in {pi}-conjugation by the chemical modifications transforms a conducting polymer from one-dimensional semiconductor to molecular aggregates.

  13. Mass attenuation coefficients, effective atomic and electron numbers of stainless steel and carbon steels with different energies

    International Nuclear Information System (INIS)

    Mohd Fakarudin Abdul Rahman; Mohd Iqbal Saripan; Nor Paiza Mohamad Hasan; Ismail Mustapha

    2011-01-01

    The total mass attenuation coefficients (μ/ ρ) of stainless steel (SS316L) and carbon steel (A516) that are widely used as petrochemical plant components, such as distillation column, heat exchanger, boiler and storage tank were measured at 662, 1073 and 1332 keV of photon energies. Measurements of radiation intensity for various thicknesses of steel were made by using transmission method. The γ-ray intensity were counted by using a Gamma spectrometer that contains a Hyper-pure Germanium (HPGe) detector connected with Multi Channel Analyzer (MCA). The effective numbers of atomic (Z eff ) and electron (N eff ) obtained experimentally were compared by those obtained through theoretical calculation. Both experimental and calculated values of Z eff and N eff were in good agreement. (author)

  14. Self-attenuation factors in gamma-ray spectrometry

    International Nuclear Information System (INIS)

    Korun, M.

    1999-01-01

    The relation between the self-attenuation factors and the distribution function describing the number of photons detected in the full-energy peaks, as a function of their path length in the sample is presented. The relations between the self-attenuation factor and the moments of the distribution function, the average path length and the variance are also presented. The use of these relations is illustrated by applying them to self-attenuation factors describing attenuation in cylindrical samples. The results of the calculations are compared with the measured average path lengths and discussed in terms of the properties of the distribution function. (author)

  15. Cell therapy attenuates cardiac dysfunction post myocardial infarction: effect of timing, routes of injection and a fibrin scaffold.

    Directory of Open Access Journals (Sweden)

    Juliana S Nakamuta

    Full Text Available BACKGROUND: Cell therapy approaches for biologic cardiac repair hold great promises, although basic fundamental issues remain poorly understood. In the present study we examined the effects of timing and routes of administration of bone marrow cells (BMC post-myocardial infarction (MI and the efficacy of an injectable biopolymer scaffold to improve cardiac cell retention and function. METHODOLOGY/PRINCIPAL FINDINGS: (99mTc-labeled BMC (6 x 10(6 cells were injected by 4 different routes in adult rats: intravenous (IV, left ventricular cavity (LV, left ventricular cavity with temporal aorta occlusion (LV(+ to mimic coronary injection, and intramyocardial (IM. The injections were performed 1, 2, 3, or 7 days post-MI and cell retention was estimated by gamma-emission counting of the organs excised 24 hs after cell injection. IM injection improved cell retention and attenuated cardiac dysfunction, whereas IV, LV or LV* routes were somewhat inefficient (<1%. Cardiac BMC retention was not influenced by timing except for the IM injection that showed greater cell retention at 7 (16% vs. 1, 2 or 3 (average of 7% days post-MI. Cardiac cell retention was further improved by an injectable fibrin scaffold at day 3 post-MI (17 vs. 7%, even though morphometric and function parameters evaluated 4 weeks later displayed similar improvements. CONCLUSIONS/SIGNIFICANCE: These results show that cells injected post-MI display comparable tissue distribution profile regardless of the route of injection and that there is no time effect for cardiac cell accumulation for injections performed 1 to 3 days post-MI. As expected the IM injection is the most efficient for cardiac cell retention, it can be further improved by co-injection with a fibrin scaffold and it significantly attenuates cardiac dysfunction evaluated 4 weeks post myocardial infarction. These pharmacokinetic data obtained under similar experimental conditions are essential for further development of these

  16. The effect of shape, length and diameter of implants on primary stability based on resonance frequency analysis

    Directory of Open Access Journals (Sweden)

    Hamidreza Barikani

    2014-01-01

    Full Text Available Background: The aim of this in vitro study was to evaluate the effect of shape, diameter and length of implants on their primary stability based on resonance frequency analysis. Materials and Methods: Replace select tapered and Branemark MK III implants were selected. Each of these two selected groups was divided into nine subgroups based on the implant length (IL (short, medium and long and the implant diameter (ID (narrow platform [NP], regular platform [RP] and wide platform [WP]. Five implants were assigned to each of the nine subgroups. Implants were placed in artificial bone blocks with bone quality similar to D3 bone. Immediately after the implant placement, its primary stability was measured using Osstell Mentor equipment. T-test and Tukey′s honest significant difference Post hoc were performed for data analysis. Statistical significance was defined at P < 0.05. Results: Replace select system showed significantly higher primary stability compared to the Branemark system, when using the short implants for all three diameters (P ≤ 0.004. However, in medium length implants there were no significant differences between the two implant systems (P ≥ 0.31. In long implants, only when the NP and RP implants were used, the Replace Select system showed significantly higher primary stability compared to the Branemark system (P = 0.000. In the replace select system, long implants had a significantly higher primary stability compared to medium and short length implants (P ≤ 0.003. In the NP and RP Branemark implants, short implants showed significantly lower primary stability compared to medium and long implants (P ≤ 0.002. However, in WP Branemark implants, primary stability increased significantly with increasing the IL from short to medium and from medium to long (P = 0.000. There were also significant differences between NP and the two other wider implants in both systems (P = 0.000. Conclusion: The use of tapered implants is

  17. Acquisition session length modulates consolidation effects produced by 5-HT2C ligands in a mouse autoshaping-operant procedure.

    Science.gov (United States)

    Walker, Ellen A; Foley, John J

    2010-03-01

    Although the neurotransmitter, 5-hydroxytryptamine (serotonin, 5-HT), has been implicated as a mediator of learning and memory, the specific role of 5-HT receptors in rodents requires further delineation. In this study, 5-HT2C receptor ligands of varying relative intrinsic efficacies were tested in a mouse learning and memory model called autoshaping-operant. On day 1, mice were placed in experimental chambers and presented with a tone on a variable interval schedule. The tone remained on for 6 s or until a nose-poke response occurred to produce a dipper with Ensure solution. Mice were then injected with saline, MK212 (full agonist), m-chlorophenylpiperazine (partial agonist), mianserin, and SB206 553 (inverse agonists), and methysergide and (+)-2-bromo lysergic acid diethylamide (+)-hydrogen tartrate (neutral antagonists). Each compound was injected after either 1 or 2-h acquisition sessions on day 1 to investigate the role of acquisition session length on consolidation. Day 1 injection of the 5-HT2C inverse agonist mianserin produced greater retrieval impairments of the autoshaped operant response on day 2 than any other agent tested. Furthermore, decreasing the length of the acquisition session to 1h significantly increased the difficulty of the autoshaping task further modulating the consolidation effects produced by the 5-HT2C ligands tested.

  18. Effect of Full-Length Carbon Fiber Insoles on Lower Limb Kinetics in Patients With Midfoot Osteoarthritis: A Pilot Study.

    Science.gov (United States)

    Yi, Taeim; Kim, Jung Hyun; Oh-Park, Mooyeon; Hwang, Ji Hye

    2018-03-01

    We investigated the effects of full-length carbon fiber (FCF) insoles on gait, muscle activity, kinetics, and pain in patients with midfoot osteoarthritis (OA). We enrolled 13 patients with unilateral midfoot OA (mild: Visual Analog Scale [VAS] range, 1-3; moderate, VAS range, 4-7) and healthy controls. All participants were asked to walk under two conditions: with and without FCF insole. The outcome measures were ground reaction force, quantitative gait parameters, electromyography activities and pain severity (VAS). In the patients with moderate midfoot OA, significantly longer gait cycle and higher muscle activity of lower limb during loading-response phase were observed while walking without FCF insoles. In the mild midfoot OA group, there was no significant difference in VAS score (without, 2.0 ± 1.0 vs. with, 2.0 ± 0.5) with FCF insole use. However, significantly reduced VAS score (without, 5.5 ± 1.4 vs. with, 2.0 ± 0.5) and muscle activity of the tibialis anterior and increased muscle activity of gastrocnemius were observed in the moderate midfoot OA group by using an FCF insole (P < 0.05). Full-length carbon fiber insoles can improve pain in individuals with moderate midfoot OA, which might be associated with changes in the kinetics and muscle activities of the lower limb. Taken together, the results of the present study suggest that FCF insoles may be used as a helpful option for midfoot OA.

  19. Effect of tubing length on the dispersion correction of an arterially sampled input function for kinetic modeling in PET.

    Science.gov (United States)

    O'Doherty, Jim; Chilcott, Anna; Dunn, Joel

    2015-11-01

    Arterial sampling with dispersion correction is routinely performed for kinetic analysis of PET studies. Because of the the advent of PET-MRI systems, non-MR safe instrumentation will be required to be kept outside the scan room, which requires the length of the tubing between the patient and detector to increase, thus worsening the effects of dispersion. We examined the effects of dispersion in idealized radioactive blood studies using various lengths of tubing (1.5, 3, and 4.5 m) and applied a well-known transmission-dispersion model to attempt to correct the resulting traces. A simulation study was also carried out to examine noise characteristics of the model. The model was applied to patient traces using a 1.5 m acquisition tubing and extended to its use at 3 m. Satisfactory dispersion correction of the blood traces was achieved in the 1.5 m line. Predictions on the basis of experimental measurements, numerical simulations and noise analysis of resulting traces show that corrections of blood data can also be achieved using the 3 m tubing. The effects of dispersion could not be corrected for the 4.5 m line by the selected transmission-dispersion model. On the basis of our setup, correction of dispersion in arterial sampling tubing up to 3 m by the transmission-dispersion model can be performed. The model could not dispersion correct data acquired using a 4.5 m arterial tubing.

  20. Ischemic preconditioning effect of prodromal angina is attenuated in acute myocardial infarction patients with hypertensive left ventricular hypertrophy

    International Nuclear Information System (INIS)

    Takeuchi, Toshiharu; Kikuchi, Kenjiro; Hasebe, Naoyuki; Ishii, Yoshinao

    2011-01-01

    Several animal experiments on acute myocardial infarction (AMI) have shown that the cardioprotective effects of ischemic preconditioning are more significant in hypertensive subjects. However, because there are no clinical data on the impact of hypertension on ischemic preconditioning in patients with AMI, whether clinical ischemic preconditioning of prodromal angina was beneficial in AMI patients with hypertension was investigated in the present study. 125 patients with a first anterior AMI who had undergone successful reperfusion therapy were divided into 2 groups, with or without hypertension, and into 2 further subgroups based on the presence or absence of prodromal angina. Dual-isotope (thallium-201(TL)/Tc-99m pyrophosphate) single-photon emission computed tomography (SPECT) was performed within 1 week of reperfusion therapy. Left ventricular (LV) function and LV mass index (LVMI) were measured by left ventriculography and echocardiography, respectively. In patients without hypertension, prodromal angina resulted in significantly less myocardial damage on TL-SPECT, better LV ejection fraction and a greater myocardial blush grade compared to patients without prodromal angina. However, these cardioprotective effects of prodromal angina were significantly diminished in hypertensive patients. Importantly, the myocardial salvage effects of prodromal angina showed a significant negative correlation with LVMI, which was significantly greater in hypertensive patients. The cardioprotective effects of prodromal angina were attenuated in patients with hypertension. Hypertensive LV hypertrophy may crucially limit the effects of ischemic preconditioning in AMI. (author)