Sample records for e1 two-phonon strengths

  1. Isoscalar E0, E1, and E2 strength in Ca-40

    E-print Network

    Youngblood, David H.; Lui, YW; Clark, HL.

    2001-01-01

    The giant resonance region from 10 particles at small angles including 0 degrees. Strength corresponding to 97 +/- 11%, 108 +/- 12%, and 62 + 10-20 % of the isoscalar E0, E2, and E1 sum rules, respectively, was identified with centroids of 19...

  2. Giant two-phonon Raman scattering from nanoscale NbC precipitates in Nb

    NASA Astrophysics Data System (ADS)

    Cao, C.; Tao, R.; Ford, D. C.; Klie, R. F.; Proslier, T.; Cooley, L. D.; Dzyuba, A.; Zapol, P.; Warren, M.; Lind, H.; Zasadzinski, J. F.

    2015-03-01

    High-purity niobium (Nb), subjected to the processing methods used in the fabrication of superconducting rf cavities, displays micrometer-sized surface patches containing excess carbon. High-resolution transmission electron microscopy and electron energy-loss spectroscopy measurements are presented which reveal the presence of nanoscale NbC coherent precipitates in such regions. Raman backscatter spectroscopy on similar surface regions exhibit spectra consistent with the literature results on bulk NbC but with significantly enhanced two-phonon scattering. The unprecedented strength and sharpness of the two-phonon signal has prompted a theoretical analysis, using density functional theory (DFT), of phonon modes in NbC for two different interface models of the coherent precipitate. One model leads to overall compressive strain and a comparison to ab initio calculations of phonon dispersion curves under uniform compression of the NbC shows that the measured two-phonon peaks are linked directly to phonon anomalies arising from strong electron-phonon interaction. Another model of the extended interface between Nb and NbC, studied by DFT, gives insight into the frequency shifts of the acoustic and optical mode density of states measured by first-order Raman spectroscopy. The exact origin of the stronger two-phonon response is not known at present but it suggests the possibility of enhanced electron-phonon coupling in transition-metal carbides under strain found either in the bulk NbC inclusions or at their interfaces with Nb metal. Preliminary tunneling studies using a point contact method show some energy gaps larger than expected for bulk NbC.

  3. Two-phonon octupole excitation in {sup 146}Gd

    SciTech Connect

    Caballero, L.; Rubio, B.; Nacher, E. [Instituto de Fisica Corpuscular, CSIC-Universidad de Valencia, E-46071 Valencia (Spain); Kleinheinz, P. [Institut fuer Kernphysik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Yates, S. W. [Departments of Chemistry and Physics and Astronomy, University of Kentucky, Lexington, Kentucky, 40506-0055 (United States); Algora, A. [Instituto de Fisica Corpuscular, CSIC-Universidad de Valencia, E-46071 Valencia (Spain); Institute of Nuclear Research of the Hungarian Academy of Sciences, Debrecen H-4001 (Hungary); Dewald, A.; Fitzler, A.; Jolie, J.; Linnemann, A.; Moeller, O. [Institut fuer Kernphysik, Universitaet zu Koeln, D-50937 Koeln (Germany); Gadea, A. [Instituto de Fisica Corpuscular, CSIC-Universidad de Valencia, E-46071 Valencia (Spain); Laboratori Nazionali de Legnaro, INFN, I-35020 Legnaro (Italy); Julin, R.; Piiparinen, M. [Department of Physics, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland); Lunardi, S.; Menegazzo, R. [Laboratori Nazionali de Legnaro, INFN, I-35020 Legnaro (Italy); Blomqvist, J. [Research Institute of Physics, S-10405 Stockholm 50 (Sweden)

    2010-03-15

    Based on experimental evidence from the {sup 144}Sm({alpha},2n) reaction, the 3484.7-keV 6{sup +} state in {sup 146}Gd is identified as the highest-spin member of the 3{sup -} x 3{sup -} two-phonon octupole quartet. A previously unknown {gamma} line of 1905.8 keV and E3 character feeding the 3{sup -} octupole state has been observed. These results represent the first observation of a 6{sup +}->3{sup -}->0{sup +} cascade of two E3 transitions in an even-even nucleus and provide strong support for the interpretation of the 6{sup +} state as a two-phonon octupole excitation.

  4. Nonlinear Optomechanics: Two-phonon cooling and squeezing

    NASA Astrophysics Data System (ADS)

    Nunnenkamp, Andreas; Børkje, Kjetil; Harris, Jack; Girvin, Steven

    2010-03-01

    Motivated by recent optomechanics experiments using the membrane-in-the-middle geometry [Thompson et al., Nature 452, 06715 (2008)] we explore the physics of optomechanical systems where the mechanical oscillator is coupled quadratically rather than linearly to one mode of the optical cavity field. We derive an expression for the minimal phonon number achievable by two-phonon cooling, explain how to achieve mechanical squeezing by driving the cavity on both sidebands and calculate the squeezing spectrum of the output cavity field.

  5. Two-Phonon Octupole Excitation in 146Gd

    SciTech Connect

    Caballero, L.; Rubio, B.; Algora, A.; Nacher, E. [Instituto de Fisica Corpuscular, CSIC-Univ. de Valencia, E-46071 Valencia (Spain); Kleinheinz, P. [Institut fuer Kernphysik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Dewald, A.; Fitzler, A.; Jolie, J.; Linnemann, A.; Moeller, O. [Institut fuer Kernphysik, University of Cologne, Cologne (Germany); Gadea, A. [Laboratori Nazionali di Legnaro, INFN, Legnaro (Italy); Julin, R.; Piiparinen, M. [Department of Physics, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland); Lunardi, S.; Menegazzo, R. [Dipartimento di Fisica, Sezione di Padova, Padova (Italy); INFN, Sezione di Padova, Padova (Italy); Yates, S.W. [Department of Chemistry, Univ. of Kentucky, Lexington, KY 40506-0055 (United States); Department of Physics and Astronomy, Univ. of Kentucky, Lexington, KY 40506-0055 (United States)

    2005-11-21

    The excited states in 146Gd have been re-investigated with the 144Sm({alpha},2n) reaction using a modern Ge {gamma}-ray array including a polarimeter. Amongst the non-yrast states populated in this reaction we have identified the aligned 6+ member of the two-phonon octupole quartet from the observation of the E3 branching to the one phonon 3- state. Our results represent the first observation of a 6+{yields}3-{yields}0+ E3 cascade in an even-even nucleus.

  6. Two-Phonon Octupole Excitation in 146Gd

    SciTech Connect

    Caballero, L.; Rubio, B.; Nacher, E. [Instituto de Fisica Corpuscular, CSIC-Univ. de Valencia, E-46071 Valencia (Spain); Kleinheinz, P. [Institut fuer Kernphysik, Forschungszentrum Juelich, D-52425 Juelich (Germany); Algora, A. [Instituto de Fisica Corpuscular, CSIC-Univ. de Valencia, E-46071 Valencia (Spain); Institute of Nuclear Research, Debrecen (Hungary); Blomqvist, J. [Department of Physics, Royal Institute of Technology, Stockholm (Sweden); Dewald, A.; Fitzler, A.; Jolie, J.; Linnemann, A.; Moeller, O. [Institut fuer Kernphysik, University of Cologne, Cologne (Germany); Gadea, A. [Laboratori Nazionali di Legnaro, INFN, Legnaro (Italy); Julin, R.; Piiparinen, M. [Department of Physics, University of Jyvaeskylae, FIN-40014 Jyvaeskylae (Finland); Lunardi, S.; Menegazzo, R. [Dipartimento di Fisica, Padova (Italy); INFN, Sezione di Padova, Padova (Italy); Yates, S. W. [Department of Chemistry, Univ. of Kentucky, Lexington, KY 40506-0055 (United States); Department of Physics and Astronomy, Univ. of Kentucky, Lexington, KY 40506-0055 (United States)

    2006-04-26

    The excited states in 146Gd have been re-investigated with the 144Sm({alpha},2n) reaction using a modern Ge {gamma}-ray array including a polarimeter. Amongst the non-yrast states populated in this reaction we have identified the aligned 6+ member of the two-phonon octupole quartet from the observation of the E3 branching to the one phonon 3- state. Our results represent the first observation of a 6+{yields}3-{yields}0+ E3 cascade in an even-even nucleus.

  7. Search for E1 strength in 62,64Fe around the threshold

    NASA Astrophysics Data System (ADS)

    Wieland, O.; Bracco, A.; Camera, F.; affil="1, R.; pre="for ">the PRESPEC,

    2015-02-01

    The structure and nature of the pygmy dipole resonance (PDR) states below and above the neutron threshold is a recent open problem, particularly in exotic, neutron rich nuclei. Present experimental observations give only limited information on this subject. New experiments using different methods are needed. A recent measurement at the GSI laboratories on 62,64Fe with the PRESPEC (2014) setup, following a past experiment with the RISING (2005) setup on 68Ni, will contribute to solve the open questions. The setup located at GSI consists of the segmented HPGe detector array AGATA, scintillators (HECTOR), an Energy Loss / Total Energy time of flight measuring detector system called LYCCA and the fragment separator (FRS) apparatus. The experiment is based on relativistic Coulomb excitation together with the detection of the incoming and outgoing particles event by event. The detection of the produced y-rays in the reactions, provides insight into the problem of the electric dipole response and E1 strength distribution around particle separation threshold.

  8. Relativistic effects in E1 transition oscillator strengths along the Yb+ isoelectronic sequence

    NASA Astrophysics Data System (ADS)

    Migdalek, J.; Siegel, W.

    2014-04-01

    Electric dipole transition oscillator strengths have been computed for low-lying transitions in the Yb+ isoelectronic sequence (through Ra19 +) in fully relativistic and non-relativistic-limit approximations. Relativistic effects were carefully investigated and efforts were undertaken to establish systematic trends in relativistic contributions to oscillator strengths along the Yb+ isoelectronic sequence.

  9. New probe of M1 and E1 strengths in GDR regions

    SciTech Connect

    Hayakawa, T. [Japan Atomic Energy Agency and National Astronomical Observatory in Japan (Japan); Ogata, K. [RCNP, Osaka University (Japan); Miyamoto, S.; Mochizuki, T.; Horikawa, K.; Amano, S. [University of Hyogo (Japan); Imazaki, K.; Li, D.; Izawa, Y. [Institute for Laser Technology (Japan); Chiba, S. [Tokyo Institute of Technology (Japan)

    2014-05-02

    The M1 strengths (or level density of 1{sup +} states) are of importance for estimation of interaction strengths between neutrinos and nuclei for the study of the supernova neutrino-process. In 1957, Agodi predicted theoretically angular distribution of neutrons emitted from states excited via dipole transitions with linearly polarized gamma-ray beam at the polar angle of ?=90° should be followed by a simple function, a + b cos(2?), where ?, is azimuthal angel. However, this theoretical prediction has not been verified over the wide mass region except for light nuclei as deuteron. We have measured neutron angular distributions with (polarized gamma, n) reactions on Au, Nal, and Cu. We have verified the Agodi's prediction for the first time over the wide mass region. This suggests that (polarized gamma, n) reactions may be useful tools to study M1 strengths in giant resonance regions.

  10. New probe of M1 and E1 strengths in GDR regions

    NASA Astrophysics Data System (ADS)

    Hayakawa, T.; Ogata, K.; Miyamoto, S.; Mochizuki, T.; Horikawa, K.; Amano, S.; Imazaki, K.; Li, D.; Izawa, Y.; Chiba, S.

    2014-05-01

    The M1 strengths (or level density of 1+ states) are of importance for estimation of interaction strengths between neutrinos and nuclei for the study of the supernova neutrino-process. In 1957, Agodi predicted theoretically angular distribution of neutrons emitted from states excited via dipole transitions with linearly polarized gamma-ray beam at the polar angle of ?=90° should be followed by a simple function, a + b cos(2?), where ?, is azimuthal angel. However, this theoretical prediction has not been verified over the wide mass region except for light nuclei as deuteron. We have measured neutron angular distributions with (polarized gamma, n) reactions on Au, Nal, and Cu. We have verified the Agodi's prediction for the first time over the wide mass region. This suggests that (polarized gamma, n) reactions may be useful tools to study M1 strengths in giant resonance regions.

  11. Distribution of E1 spin flip strength in /sup 12/C

    SciTech Connect

    Castel, B.; van Hees, A.G.M.

    1983-12-01

    A very recent pion inelastic scattering experiment has revealed the existence of strong spin flip E1 resonances in light nuclei. The data are particularly impressive in /sup 12/C where two strong peaks are observed in the vicinity of the giant dipole resonance. We present here the first large scale shell model calculation of such electric spin excitations in /sup 12/C and discuss their admixture and influence on other S = 0 states.

  12. Distribution of E1 spin flip strength in /sup 12/C

    SciTech Connect

    Castel, B.; van Hees, A.G.M.

    1983-12-01

    A very recent pion inelastic scattering experiment has revealed the existence of strong spin-flip E1 resonance in light nuclei. The data particulary impressive in /sup 12/C where two strong peaks are observed in the vicinity of the giant dipole resonance. We present here the first large scale shell model calculation of such electric spin excitations in /sup 12/C and discuss their admixture and influence on other S = 0 states.

  13. Stokes suppression and supercontinuum generation by differential two-phonon excitation.

    PubMed

    Nishioka, Hajime

    2014-11-01

    Stimulated Raman scattering driven by differential coupling of two phonon modes has been demonstrated. These phonon modes are coherently and strongly coupled by external fields via two-phonon excitation at the first Brillouin zone boundary. Up to 11th order of sidebands and a supercontinuum covering entire visible region have been observed. The original Stokes and anti-Stokes lines by the single-phonon stimulated Raman scattering were significantly suppressed. PMID:25401797

  14. Changes in rotational characters of one- and two-phonon $?$-vibrational bands in $^{105}$Mo

    E-print Network

    Masayuki Matsuzaki

    2014-12-19

    The $\\gamma$ vibration is the most typical low-lying collective motion prevailing the nuclear chart. But only few one-phonon rotational bands in odd-$A$ nuclei have been known. Furthermore, two-phonon states, even the band head, have been observed in a very limited number of nuclides not only of odd-$A$ but even-even. Among them, that in $^{105}$Mo is unique in that Coriolis effects are expected to be stronger than in $^{103}$Nb and $^{105}$Nb on which theoretical studies were reported. Then the purpose of the present work is to study $^{105}$Mo paying attention to rotational character change of the one-phonon and two-phonon bands. The particle-vibration coupling model based on the cranking model and the random-phase approximation is used to calculate the vibrational states in rotating odd-$A$ nuclei. The present model reproduces the observed yrast zero-phonon and one-phonon bands well. Emerging general features of the rotational character change from low spin to high spin are elucidated. In particular, the reason why the one-phonon band does not exhibit signature splitting is clarified. The calculated collectivity of the two-phonon states, however, is located higher than observed.

  15. Coherent anti-Stokes Raman scattering of two-phonon complexes in diamond.

    PubMed

    Kuroda, Takashi; Zhokhov, Peter A; Watanabe, Kenji; Zheltikov, Aleksey M; Sakoda, Kazuaki

    2009-11-01

    Coherent anti-Stokes Raman scattering (CARS) associated with the second-order Raman process has been confirmed in diamond. Frequency dependence of CARS was analyzed using two-color synchronously-generated picosecond pulses. Resonance enhancement of chi((3)) was observed at an energy shift corresponding to the overtone Sigma branch (K point) phonon, as well as the fundamental Raman-active Gamma((25+)) phonon. The excitation spectrum of CARS at the two-phonon resonance region showed dispersive dependence, reflecting the interference of resonant CARS and nonresonant four-wave mixing scattering. PMID:19997312

  16. PHYSICAL REVIE% B VOLUME 17, NUMBER 6 15 MARCH 1978 Two-phonon scattemig in solid neon

    E-print Network

    Glyde, Henry R.

    PHYSICAL REVIE% B VOLUME 17, NUMBER 6 15 MARCH 1978 Two-phonon scattemig in solid neon %. M neutron scattering from phonons in solid neon at 5 K, is calculated using the self-consistent phonon that the unusually shaped phonon groups they found for high-frequency phonons in neon is due to an unusually large

  17. Identification of band structures and proposed one- and two-phonon {gamma}-vibrational bands in {sup 105}Mo

    SciTech Connect

    Ding, H. B.; Che, X. L.; Chen, Y. J.; Li, M. L. [Department of Physics, Tsinghua University, Beijing 100084 (China); Zhu, S. J. [Department of Physics, Tsinghua University, Beijing 100084 (China); Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Hamilton, J. H.; Ramayya, A. V.; Hwang, J. K.; Li, K.; Goodin, C. T. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Luo, Y. X. [Department of Physics, Vanderbilt University, Nashville, Tennessee 37235 (United States); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Rasmussen, J. O.; Lee, I. Y. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2006-11-15

    High-spin band structures in neutron-rich {sup 105}Mo have been investigated by measuring prompt {gamma} rays emitted by the spontaneous fission fragments of {sup 252}Cf with the Gammasphere detector array. The yrast band has been confirmed and five new collective bands are observed. The three bands based on the 246.3-, 332.0-, and 310.0-keV levels are proposed as the single-neutron excitation bands built on the 3/2{sup +}[411], 1/2{sup +}[411], and 5/2{sup +}[413] Nilsson orbitals, respectively. The other two bands with band head levels at 870.5 and 1534.6 keV are candidates for one-phonon K=9/2 and two-phonon K=13/2 {gamma}-vibrational bands, respectively. Systematic comparison of these bands with bands in neighboring nuclei are discussed.

  18. SEARCH FOR TWO-PHONON OCTUPOLE VIBRATIONAL BANDS IN 88, 89, 92, 93, 94, 96Sr AND 95, 96, 97, 98Zr

    NASA Astrophysics Data System (ADS)

    Hwang, J. K.; Hamilton, J. H.; Ramayya, A. V.; Brewer, N. T.; Wang, E. H.; Luo, Y. X.; Zhu, S. J.

    2012-09-01

    Several new gamma transitions were identified in 94Sr, 93Sr, 92Sr, 96Zr and 97Zr from the spontaneous fission of 252Cf. Excited states in 88, 89, 92, 94, 96Sr and 95, 96, 97, 98Zr were reanalyzed and reorganized to propose the new two-phonon octupole vibrational states and bands. The spin and parity of 6+ are assigned to a 4034.5 keV state in 94Sr and 3576.4 keV state in 98Zr. These states are proposed as the two-phonon octupole vibrational states along with the 6+ states at 3483.4 keV in 96Zr, at 3786.0 keV in 92Sr and 3604.2 keV in 96Sr. The positive parity bands in 88, 94, 96Sr and 96, 98Zr are the first two-phonon octupole vibrational bands based on a 6+ state assigned in spherical nuclei. It is thought that in 94, 96Sr and 96, 98Zr a 3- octupole vibrational phonon is weakly coupled to an one-phonon octupole vibrational band to make the two-phonon octupole vibrational band. Also, the high spin states of odd-A95Zr and 97Zr are interpreted to be generated by the neutron 2d5/2 hole and neutron 1g7/2 particle, respectively, weakly coupled to one- and two-phonon octupole vibrational bands of 96Zr. The high spin states of odd-A87Sr are interpreted to be caused by the neutron 1g9/2 hole weakly coupled to 3- and 5- states of 88Sr. New one- and two-POV bands in 95, 97Zr and 87, 89Sr are proposed, for the first time, in the present work.

  19. Two-Phonon Absorption

    ERIC Educational Resources Information Center

    Hamilton, M. W.

    2007-01-01

    A nonlinear aspect of the acousto-optic interaction that is analogous to multi-photon absorption is discussed. An experiment is described in which the second-order acousto-optically scattered intensity is measured and found to scale with the square of the acoustic intensity. This experiment using a commercially available acousto-optic modulator is…

  20. Weighted f-values, A-values, and line strengths for the E1 transitions among 3d{sup 6}, 3d{sup 5}4s, and 3d{sup 5}4p levels of Fe III

    SciTech Connect

    Deb, Narayan C. [School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland (United Kingdom); Hibbert, Alan [School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland (United Kingdom)], E-mail: a.hibbert@qub.ac.uk

    2009-03-15

    Weighted oscillator strengths, weighted radiative rates, and line strengths for all the E1 transitions between 285 fine-structure levels belonging to the 3d{sup 6}, 3d{sup 5}4s, and 3d{sup 5}4p configurations of Fe III are presented, in ascending order of wavelength. Calculations have been undertaken using the general configuration interaction (CI) code CIV3. The large configuration set is constructed by allowing single and double replacements from any of 3d{sup 6}, 3d{sup 5}4s, 3d{sup 5}4p, and 3d{sup 5}4d configurations to nl orbitals with n{<=}5,l{<=}3 as well as 6p. Additional selective promotions from 3s and 3p subshells are also included in the CI expansions to incorporate the important correlation effects in the n=3 shell. Results of some strong transitions between levels of 3d{sup 6}, 3d{sup 5}4s, and 3d{sup 5}4p configurations are also presented and compared with other available calculations. It is found that large disagreements occur in many transitions among the existing calculations.

  1. Analog E1 transitions and isospin mixing

    SciTech Connect

    Pattabiraman, N. S.; Jenkins, D. G.; Bentley, M. A.; Wadsworth, R.; Lister, C. J.; Carpenter, M. P.; Janssens, R. V. F.; Khoo, T. L.; Lauritsen, T.; Seweryniak, D.; Zhu, S.; Lotay, G.; Woods, P. J.; Krishichayan,; Isacker, P. Van [Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom); Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); UGC-DAE CSR, Kolkata 700 098 (India); Grand Accelerateur National d'Ions Lourds, CEA/DSM-CNRS/IN2P3, BP 55027, F-14076 Caen Cedex 5 (France)

    2008-08-15

    We investigate whether isospin mixing can be determined in a model-independent way from the relative strength of E1 transitions in mirror nuclei. The specific examples considered are the A=31 and A=35 mirror pairs, where a serious discrepancy between the strengths of 7/2{sup -}{yields}5/2{sup +} transitions in the respective mirror nuclei has been observed. A theoretical analysis of the problem suggests that it ought to be possible to disentangle the isospin mixing in the initial and final states given sufficient information on experimental matrix elements. With this in mind, we obtain a lifetime for the relevant 7/2{sup -} state in {sup 31}S using the Doppler-shift attenuation method. We then collate the available information on matrix elements to examine the level of isospin mixing for both A=31 and A=35 mirror pairs.

  2. Strength Training

    MedlinePLUS

    ... comfortably perform the exercise for 8 to 15 repetitions. Before you begin any type of strength training ... added weight. Perform three sets of 8-15 repetitions (or reps) of each exercise, starting out with ...

  3. Spaghetti Strength

    NSDL National Science Digital Library

    American Chemical Society

    2011-01-01

    In this activity on page 7 of the PDF, learners explore how engineers characterize building materials. Learners test the strength of spaghetti and determine how the number of spaghetti strands affects the strength of a bundle of spaghetti. Use this activity to chemical bonds, mechanical testing, and engineering. Note: The pasta strands can be dipped in water and stuck together to more closely mimic the layers within a piece of plywood. More information about this can be found at the top of page 7, directly underneath the cartoon image. Safety note: Do not eat or drink any of the materials in this activity.

  4. Isoscalar giant resonance strength in (24)Mg

    E-print Network

    Youngblood, David H.; Lui, Y. -W; Chen, X. F.; Clark, H. L.

    2009-01-01

    The giant resonance region from 9 MeV < E(x)< 60 MeV in (24)Mg has been studied with inelastic scattering of 240-MeV alpha particles at small angles, including 0(degrees). Isoscalar E0, E1, E2, and E3 strength was identified from 9 MeV < E(x)< 40 Me...

  5. Gene coding for the E1 endoglucanase

    DOEpatents

    Thomas, Steven R. (Denver, CO); Laymon, Robert A. (Littleton, CO); Himmel, Michael E. (Littleton, CO)

    1996-01-01

    The gene encoding Acidothermus cellulolyticus E1 endoglucanase is cloned and expressed in heterologous microorganisms. A new modified E1 endoglucanase enzyme is produced along with variants of the gene and enzyme. The E1 endoglucanase is useful for hydrolyzing cellulose to sugars for simultaneous or later fermentation into alcohol.

  6. Gene coding for the E1 endoglucanase

    DOEpatents

    Thomas, S.R.; Laymon, R.A.; Himmel, M.E.

    1996-07-16

    The gene encoding Acidothermus cellulolyticus E1 endoglucanase is cloned and expressed in heterologous microorganisms. A new modified E1 endoglucanase enzyme is produced along with variants of the gene and enzyme. The E1 endoglucanase is useful for hydrolyzing cellulose to sugars for simultaneous or later fermentation into alcohol. 6 figs.

  7. Energy-dependence of skin-mode fraction in $E1$ excitations of neutron-rich nuclei

    E-print Network

    Nakada, H; Sawai, H

    2015-01-01

    We have extensively investigated characters of the low-energy $E1$ strengths in $N>Z$ nuclei, by analyzing the transition densities obtained by the HF+RPA calculations with several effective interactions. Crossover behavior has been confirmed, from the skin mode at low energy to the $pn$ mode at higher energy. Decomposing the $E1$ strengths into the skin-mode, $pn$-mode and interference fractions, we show that the ratio of the skin-mode strength to the full strength may be regarded as a generic function of the excitation energy, insensitive to nuclides and effective interactions, particularly beyond Ni.

  8. Energy-dependence of skin-mode fraction in $E1$ excitations of neutron-rich nuclei

    E-print Network

    H. Nakada; T. Inakura; H. Sawai

    2015-02-17

    We have extensively investigated characters of the low-energy $E1$ strengths in $N>Z$ nuclei, by analyzing the transition densities obtained by the HF+RPA calculations with several effective interactions. Crossover behavior has been confirmed, from the skin mode at low energy to the $pn$ mode at higher energy. Decomposing the $E1$ strengths into the skin-mode, $pn$-mode and interference fractions, we show that the ratio of the skin-mode strength to the full strength may be regarded as a generic function of the excitation energy, insensitive to nuclides and effective interactions, particularly beyond Ni.

  9. "Bi-modal'' Isoscalar Giant Dipole Strength in $^{58}$Ni

    E-print Network

    Nayak, B K; Fujimura, H; Fujiwara, M; Garg, U; Hara, K; Harakeh, M N; Hedden, M; Itoh, M; Kawabata, T; Koss, M; Li, T; Liu, Y; Rao, P V M; Sakaguchi, H; Takeda, H; Uchida, M; Yasuda, Y; Yosoi, M; Zhu, S

    2006-01-01

    The strength distribution of the isoscalar giant dipole resonance (ISGDR) in $^{58}$Ni has been obtained over the energy range 10.5--49.5 MeV via extreme forward angle scattering (including 0$^{\\circ}$) of 386 MeV $\\alpha$ particles. We observe a ``bi-modal'' ${E1}$ strength distribution for the first time in an A $<$ 90 nucleus. The observed ISGDR strength distribution is in good agreement with the predictions of a recent QRPA calculation.

  10. Strength Training for Girls.

    ERIC Educational Resources Information Center

    Connaughton, Daniel; Connaughton, Angela; Poor, Linda

    2001-01-01

    Strength training can be fun, safe, and appropriate for young girls and women and is an important component of any fitness program when combined with appropriate cardiovascular and flexibility activities. Concerns and misconceptions regarding girls' strength training are discussed, presenting general principles of strength training for children…

  11. Do strengths measure up?

    Microsoft Academic Search

    Nicky Garcea; Stephen Isherwood; Alex Linley

    2011-01-01

    Purpose – This paper sets out to draw comparisons and make linkages between strengths and competency methodologies. Whereas some authors have seen the strengths approach as a revolution in human resources (HR), the authors of this paper see it more as a natural evolution. The paper aims to overview the strengths approach as well as presenting a case study of

  12. Strength Modeling Report

    NASA Technical Reports Server (NTRS)

    Badler, N. I.; Lee, P.; Wong, S.

    1985-01-01

    Strength modeling is a complex and multi-dimensional issue. There are numerous parameters to the problem of characterizing human strength, most notably: (1) position and orientation of body joints; (2) isometric versus dynamic strength; (3) effector force versus joint torque; (4) instantaneous versus steady force; (5) active force versus reactive force; (6) presence or absence of gravity; (7) body somatotype and composition; (8) body (segment) masses; (9) muscle group envolvement; (10) muscle size; (11) fatigue; and (12) practice (training) or familiarity. In surveying the available literature on strength measurement and modeling an attempt was made to examine as many of these parameters as possible. The conclusions reached at this point toward the feasibility of implementing computationally reasonable human strength models. The assessment of accuracy of any model against a specific individual, however, will probably not be possible on any realistic scale. Taken statistically, strength modeling may be an effective tool for general questions of task feasibility and strength requirements.

  13. Vector expression of adenovirus type 5 E1a proteins: evidence for E1a autoregulation.

    PubMed Central

    Smith, D H; Kegler, D M; Ziff, E B

    1985-01-01

    We transiently expressed adenovirus type C E1a proteins in wild-type or mutant form from plasmid vectors which have different combinations of E1a and simian virus 40 enhancer elements and which contain the DNA replication origin of SV40 and can replicate in COS 7 cells. We measured the levels of E1a mRNA encoded by the vectors and the transition regulation properties of the protein products. Three vectors encoded equivalent levels of E1a mRNA in COS 7 cells: (i) a plasmid encoding the wt 289-amino acid E1a protein (this complemented the E1a deletion mutant dl312 for early region E2a expression under both replicative and nonreplicative conditions); (ii) a vector for the wt 243-amino acid E1a protein (this complemented dl312 weakly and only under conditions of high multiplicities of dl312); (iii) a mutant, pSVXL105, in which amino acid residues-38 through 44 of the 289-amino acid E1a protein (which includes two highly conserved residues) are replaced by 3 novel amino acids (this also complemented dl312 efficiently). A fourth vector, mutant pSVXL3 with which linker substitution shifts the reading frame to encode a truncated 70-amino acid fragment from the amino terminus of the 289-amino acid protein, was unable to complement dl312. Surprisingly, pSVXL3 overexpressed E1a mRNA approximately 30-fold in COS 7 cells in comparison with the other vectors. The pSVXL3 overexpression could be reversed by cotransfection with a wt E1a vector. We suggest that wt E1a proteins regulate the levels of their own mRNAs through the recently described transcription repression functions of the 289- and 243-amino acid E1a protein products and that pSVXL3 fails to autoregulate negatively. Images PMID:2942761

  14. Why Strength Training?

    MedlinePLUS

    ... of heart disease and as a therapy for patients in cardiac rehabilitation programs. Research and Background About Strength Training Scientific research has shown that exercise can slow the physiological aging clock. While aerobic ...

  15. Fe II oscillator strengths

    Microsoft Academic Search

    S. Kroll; M. Kock

    1987-01-01

    Oscillator strengths of 124 Fe II lines in the wavelength range 220-540 nm were obtained from wall-stabilized arc and hollow-cathode measurements. By a combination of hook and emission measurements it was possible to determine a large set of relative oscillator strengths of Fe II lines without any assumptions concerning the plasma state of the light sources used. The relative f-values

  16. Apple Strength Issues

    SciTech Connect

    Syn, C

    2009-12-22

    Strength of the apple parts has been noticed to decrease, especially those installed by the new induction heating system since the LEP campaign started. Fig. 1 shows the ultimate tensile strength (UTS), yield strength (YS), and elongation of the installed or installation-simulated apples on various systems. One can clearly see the mean values of UTS and YS of the post-LEP parts decreased by about 8 ksi and 6 ksi respectively from those of the pre-LEP parts. The slight increase in elongation seen in Fig.1 can be understood from the weak inverse relationship between the strength and elongation in metals. Fig.2 shows the weak correlation between the YS and elongation of the parts listed in Fig. 1. Strength data listed in Figure 1 were re-plotted as histograms in Figs. 3 and 4. Figs. 3a and 4a show histograms of all UTS and YS data. Figs. 3b and 4b shows histograms of pre-LEP data and Figs. 3c and 4c of post-LEP data. Data on statistical scatter of tensile strengths have been rarely published by material suppliers. Instead, only the minimum 'guaranteed' strength data are typically presented. An example of strength distribution of aluminum 7075-T6 sheet material, listed in Fig. 5, show that its scatter width of both UTS and YS for a single sheet can be about 6 ksi and for multi-lot scatter can be as large as 11 ksi even though the sheets have been produced through well-controlled manufacturing process. By approximating the histograms shown in Figs. 3 and 4 by a Gaussian or similar type of distribution curves, one can plausibly see the strength reductions in the later or more recent apples. The pre-LEP data in Figs. 3b and 4b show wider scatter than the post-LEP data in Figs. 3c and 4c and seem to follow the binomial distribution of strength indicating that the apples might have been made from two different lots of material, either from two different vendors or from two different melts of perhaps slightly different chemical composition by a single vendor. The post-LEP apples seem to have been from a single batch of material. The pre-LEP apples of the weak strength and the post-LEP apples with even weaker strength could have been made of the same batch of material, and the small strength differential might be due to the difference in the induction heating system. If the pre-LEP apples with the lower strength and the post LEP apples are made from the same batch of material, their combined scatter of strength data would be wider and can be understood as a result of the additional processing steps of stress relief and induction heating as discussed.

  17. Crossover from skin-mode to proton-neutron-mode in $E1$ excitations of neutron-rich nuclei

    E-print Network

    H. Nakada; T. Inakura; H. Sawai

    2013-02-06

    Character of the low-energy $E1$ excitations is investigated by analyzing transition densities obtained from the RPA calculations in the doubly-magic nuclei. We propose a decomposition method of the $E1$ excitations into the $pn$ mode (i.e. oscillation between protons and neutrons) and the skin mode (oscillation of the neutron skin against the inner core) via the transition densities, by which their mixing is handled in a straightforward manner. Crossover behavior of the $E1$ excitations is found, from the skin mode at low energy to the $pn$ mode at higher energy. The ratio of the skin-mode strength to the full strength turns out to be insensitive to nuclide and to effective interactions in the energy region of the crossover. Depending on the excitation energy, the observed low-energy $E1$ excitations are not necessarily dominated by the skin mode, as exemplified for $^{90}$Zr. fied for $^{90}$Zr.

  18. High strength alloys

    DOEpatents

    Maziasz, Phillip James [Oak Ridge, TN; Shingledecker, John Paul [Knoxville, TN; Santella, Michael Leonard [Knoxville, TN; Schneibel, Joachim Hugo [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Vinegar, Harold J [Bellaire, TX; John, Randy Carl [Houston, TX; Kim, Dong Sub [Sugar Land, TX

    2010-08-31

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tubular that is at least partially made from a material containing at least one of the metal alloys.

  19. High strength alloys

    DOEpatents

    Maziasz, Phillip James; Shingledecker, John Paul; Santella, Michael Leonard; Schneibel, Joachim Hugo; Sikka, Vinod Kumar; Vinegar, Harold J.; John, Randy Carl; Kim, Dong Sub

    2012-06-05

    High strength metal alloys are described herein. At least one composition of a metal alloy includes chromium, nickel, copper, manganese, silicon, niobium, tungsten and iron. System, methods, and heaters that include the high strength metal alloys are described herein. At least one heater system may include a canister at least partially made from material containing at least one of the metal alloys. At least one system for heating a subterranean formation may include a tublar that is at least partially made from a material containing at least one of the metal alloys.

  20. Time-dependent density-functional studies on strength functions in neutron-rich nuclei

    E-print Network

    Shuichiro Ebata; Tsunenori Inakura; Takashi Nakatsukasa

    2013-02-08

    The electric dipole (E1) strength functions have been systematically calculated based on the time-dependent density functional theory (TDDFT), using the finite amplitude method and the real-time approach to the TDDFT with pairing correlations. The low-energy E1 strengths in neutron-rich isotopes show peculiar behaviors, such as sudden enhancement and reduction, as functions of the neutron numbers.They seem to be due to the interplay between the neutron shell effect and the deformation effect.

  1. 'Dirac Fock + core-polarization' calculations of E1 transitions in the francium isoelectronic sequence

    Microsoft Academic Search

    Jacek Migdalek; Agnieszka Glowacz-Proszkiewicz

    2007-01-01

    Some E1 transitions in the francium isoelectronic sequence are computed in the 'Dirac-Fock + core-polarization' approximation, where core-valence electron correlation is treated in a semiclassical core-polarization picture. The obtained ionization energies and oscillator strengths are tested versus very accurate many-body perturbation treatment (MBPT) theoretical results published recently as well as versus available experimental data. The role of core-valence correlation (core

  2. Electron impact collision strengths in Sn XXIII

    SciTech Connect

    Liang, Y.Q. [School of Logistics, Beijing Wuzi University, Beijing 101149 (China)], E-mail: yaqiongliang@hotmail.com; Zhong, J.Y. [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

    2008-11-15

    The energy levels, multipole (E1, M1, E2, and M2) transition rates, and electron-impact collision strengths are calculated for Sn XXIII. The data refer to 107 fine-structure levels belonging to the configurations (1s{sup 2}2s{sup 2}2p{sup 6})3s{sup 2}3p{sup 6}3d{sup 10}, 3s{sup 2}3p{sup 6}3d{sup 9}4l, 3s{sup 2}3p{sup 5}3d{sup 10}4l, and 3s3p{sup 6}3d{sup 10}4l(l = s, p, d, and f). The collision strengths are calculated with a 20-collision-energy grid in terms of the energy of the scattered electron between 37.5 and 8436 eV by using the distorted-wave approximation. Effective collision strengths are obtained at five electron temperatures, T{sub e} (eV) = 193.89, 387.78, 581.67, 775.57, and 969.46, by integrating the collision strengths over a Maxwellian electron distribution.

  3. INDUSTRIAL STRENGTH GENETIC PROGRAMMING

    E-print Network

    Fernandez, Thomas

    Chapter 15 INDUSTRIAL STRENGTH GENETIC PROGRAMMING Empirical Modeling and Symbolic Regression via and Arthur Kordon3 1Dow Chemical, Midland, MI USA 2Dow Benelux, Terneuzen, NV 3Dow Chemical, Freeport, TX USA of a multi-disciplinary approach to empir- ical modeling at Dow Chemical. Herein we review the role

  4. Corium crust strength measurements.

    SciTech Connect

    Lomperski, S.; Nuclear Engineering Division

    2009-11-01

    Corium strength is of interest in the context of a severe reactor accident in which molten core material melts through the reactor vessel and collects on the containment basemat. Some accident management strategies involve pouring water over the melt to solidify it and halt corium/concrete interactions. The effectiveness of this method could be influenced by the strength of the corium crust at the interface between the melt and coolant. A strong, coherent crust anchored to the containment walls could allow the yet-molten corium to fall away from the crust as it erodes the basemat, thereby thermally decoupling the melt from the coolant and sharply reducing the cooling rate. This paper presents a diverse collection of measurements of the mechanical strength of corium. The data is based on load tests of corium samples in three different contexts: (1) small blocks cut from the debris of the large-scale MACE experiments, (2) 30 cm-diameter, 75 kg ingots produced by SSWICS quench tests, and (3) high temperature crusts loaded during large-scale corium/concrete interaction (CCI) tests. In every case the corium consisted of varying proportions of UO{sub 2}, ZrO{sub 2}, and the constituents of concrete to represent a LWR melt at different stages of a molten core/concrete interaction. The collection of data was used to assess the strength and stability of an anchored, plant-scale crust. The results indicate that such a crust is likely to be too weak to support itself above the melt. It is therefore improbable that an anchored crust configuration could persist and the melt become thermally decoupled from the water layer to restrict cooling and prolong an attack of the reactor cavity concrete.

  5. Radiative strength in the compound nucleus 157Gd

    NASA Astrophysics Data System (ADS)

    Kopecky, J.; Uhl, M.; Chrien, R. E.

    1993-01-01

    The distribution of E1 and M1 strength in 157Gd compound nucleus has been studied. An investigation of capture of 2 and 24 keV neutrons in a 156Gd target resulted in resonance-averaged intensities of primary gamma rays between 3.7 and 6.4 MeV. From these intensities the gamma-ray strength functions have been derived for E1 and M1 radiation. We compare several formulations of strength functions to these resonance capture and/or photoabsorption data. Further we use these prescriptions in calculations of the total average radiation width, radiative capture cross sections, and gamma-ray spectra, and compare them to available experimental information. By analyzing these results strong evidence was found for an E1 strength function which is based on a generalized Lorentzian, enhanced compared to spherical nuclei, with an energy-dependent spreading width and a nonzero limit as the energy tends to zero. For M1 radiation the giant resonance spin-flip mode is favored.

  6. Pygmy dipole strength in 90Zr

    E-print Network

    R. Schwengner; G. Rusev; N. Tsoneva; N. Benouaret; R. Beyer; M. Erhard; E. Grosse; A. R. Junghans; J. Klug; K. Kosev; H. Lenske; C. Nair; K. D. Schilling; A. Wagner

    2008-11-27

    The dipole response of the N=50 nucleus 90Zr was studied in photon-scattering experiments at the electron linear accelerator ELBE with bremsstrahlung produced at kinetic electron energies of 7.9, 9.0, and 13.2 MeV. We identified 189 levels up to an excitation energy of 12.9 MeV. Statistical methods were applied to estimate intensities of inelastic transitions and to correct the intensities of the ground-state transitions for their branching ratios. In this way we derived the photoabsorption cross section up to the neutron-separation energy. This cross section matches well the photoabsorption cross section obtained from (gamma,n) data and thus provides information about the extension of the dipole-strength distribution toward energies below the neutron-separation energy. An enhancement of E1 strength has been found in the range of 6 MeV to 11 MeV. Calculations within the framework of the quasiparticle-phonon model ascribe this strength to a vibration of the excessive neutrons against the N = Z neutron-proton core, giving rise to a pygmy dipole resonance.

  7. Pygmy dipole strength in {sup 90}Zr

    SciTech Connect

    Schwengner, R.; Rusev, G.; Benouaret, N.; Beyer, R.; Erhard, M.; Junghans, A. R.; Klug, J.; Kosev, K.; Nair, C.; Schilling, K. D.; Wagner, A. [Institut fuer Strahlenphysik, Forschungszentrum Dresden-Rossendorf, D-01314 Dresden (Germany); Tsoneva, N. [Institut fuer Theoretische Physik, Universitaet Giessen, D-35392 Giessen (Germany); Institute for Nuclear Research and Nuclear Energy, BAS, BG-1784 Sofia (Bulgaria); Grosse, E. [Institut fuer Strahlenphysik, Forschungszentrum Dresden-Rossendorf, D-01314 Dresden (Germany); Institut fuer Kern- und Teilchenphysik, Technische Universitaet Dresden, D-01062 Dresden (Germany); Lenske, H. [Institut fuer Theoretische Physik, Universitaet Giessen, D-35392 Giessen (Germany)

    2008-12-15

    The dipole response of the N=50 nucleus {sup 90}Zr was studied in photon-scattering experiments at the electron linear accelerator ELBE with bremsstrahlung produced at kinetic electron energies of 7.9, 9.0, and 13.2 MeV. We identified 189 levels up to an excitation energy of 12.9 MeV. Statistical methods were applied to estimate intensities of inelastic transitions and to correct the intensities of the ground-state transitions for their branching ratios. In this way we derived the photoabsorption cross section up to the neutron-separation energy. This cross section matches well the photoabsorption cross section obtained from ({gamma}, n) data and thus provides information about the extension of the dipole-strength distribution toward energies below the neutron-separation energy. An enhancement of E1 strength has been found in the range of 6 to 11 MeV. Calculations within the framework of the quasiparticle-phonon model ascribe this strength to a vibration of the excessive neutrons against the N=Z neutron-proton core, giving rise to a pygmy dipole resonance.

  8. Bone strength and its determinants

    Microsoft Academic Search

    P. Ammann; R. Rizzoli

    2003-01-01

    Osteoporosis is a disease defined by decreased bone mass and alteration of microarchitecture which results in increased bone fragility and increased risk of fracture. The major complication of osteoporosis, i.e., fracture, is due to a lower bone strength. Thus, any treatment of osteoporosis implies an improvement in bone strength. Bone strength is determined by bone geometry, cortical thickness and porosity,

  9. Strength of Rewelded Inconel 718

    NASA Technical Reports Server (NTRS)

    Bayless, E.; Lovoy, C. V.; Mcllwain, M. C.; Munafo, P.

    1982-01-01

    Inconel 718, nickel-based alloy used extensively for high-temperature structural service, welded repeatedly without detriment to its strength. According to NASA report, tests show 12 repairs on same weld joint do not adversely affect ultimate tensile strenth, yield strength, fatigue strength, metallurgical grain structures, or ability of weld joint to respond to post weld heat treatments.

  10. Water's Hydrogen Bond Strength

    E-print Network

    Martin Chaplin

    2007-06-10

    Water is necessary both for the evolution of life and its continuance. It possesses particular properties that cannot be found in other materials and that are required for life-giving processes. These properties are brought about by the hydrogen bonded environment particularly evident in liquid water. Each liquid water molecule is involved in about four hydrogen bonds with strengths considerably less than covalent bonds but considerably greater than the natural thermal energy. These hydrogen bonds are roughly tetrahedrally arranged such that when strongly formed the local clustering expands, decreasing the density. Such low density structuring naturally occurs at low and supercooled temperatures and gives rise to many physical and chemical properties that evidence the particular uniqueness of liquid water. If aqueous hydrogen bonds were actually somewhat stronger then water would behave similar to a glass, whereas if they were weaker then water would be a gas and only exist as a liquid at sub-zero temperatures. The overall conclusion of this investigation is that water's hydrogen bond strength is poised centrally within a narrow window of its suitability for life.

  11. The fracture strength and frictional strength of Weber Sandstone

    USGS Publications Warehouse

    Byerlee, J.D.

    1975-01-01

    The fracture strength and frictional strength of Weber Sandstone have been measured as a function of confining pressure and pore pressure. Both the fracture strength and the frictional strength obey the law of effective stress, that is, the strength is determined not by the confining pressure alone but by the difference between the confining pressure and the pore pressure. The fracture strength of the rock varies by as much as 20 per cent depending on the cement between the grains, but the frictional strength is independent of lithology. Over the range 0 2 kb, ??=0??5 + 0??6??n. This relationship also holds for other rocks such as gabbro, dunite, serpentinite, granite and limestone. ?? 1975.

  12. Shear strength of high-strength bolts at elevated temperature

    Microsoft Academic Search

    Kuo-Chen Yang; Re-Jia Hsu; Yan-Jun Chen

    2011-01-01

    Failure of bolted connections has frequently occurred during fire events. Because knowledge of the behavior of high-strength bolts while under fire is insufficient, there is further need to establish the behavior of high-strength bolt while under fire load. In this study, the behavior of high-strength bolts was investigated by a series of tests conducted at elevated temperatures with the parameters

  13. A New Measurement of the E1 Component of the ^12C(,)^16O Reaction

    NASA Astrophysics Data System (ADS)

    Tang, X. D.; Notani, M.; Rehm, K. E.; Ahmad, I.; Greene, J.; Hecht, A. A.; Henderson, D.; Janssens, R. V. F.; Jiang, C. L.; Moore, E. F.; Patel, N.; Pardo, R. C.; Savard, G.; Schiffer, J. P.; Sinha, S.; Paul, M.; Jisonna, L.; Segel, R. E.; Brune, C.; Champagne, A.; Wuosmaa, A.

    2006-10-01

    Durin the past few years we have been involved in a measurement of the E1 component of the ^12C(,)^16O reaction. Using a new approach with a set of high acceptance ionization chambers, we have measured the beta-delayed alpha decay in ^16N. The subthreshold 1^- state, which dominates the S-factor S(E1) at astrophysical energies, produces a small interference peak in the alpha spectrum, whose strength is sensitive to S(E1). The data have been analyzed using extrapolations obtained from R-matrix theory. The results from two independent runs will be presented and compared to previous experiments. The contributions from systematic uncertainties as well as the sensitivity of S(E1) to various R-matrix parameters will be discussed. This work was supported by the US Department of Energy, Nuclear Physics Division, under contract No. W-31-109-ENG-38 and by the NSF Grant No. PHY-02-16783 (Joint Institute for Nuclear Astrophysics).

  14. Strength of Chemical Bonds

    NASA Technical Reports Server (NTRS)

    Christian, Jerry D.

    1973-01-01

    Students are not generally made aware of the extraordinary magnitude of the strengths of chemical bonds in terms of the forces required to pull them apart. Molecular bonds are usually considered in terms of the energies required to break them, and we are not astonished at the values encountered. For example, the Cl2 bond energy, 57.00 kcal/mole, amounts to only 9.46 x 10(sup -20) cal/molecule, a very small amount of energy, indeed, and impossible to measure directly. However, the forces involved in realizing the energy when breaking the bond operate over a very small distance, only 2.94 A, and, thus, f(sub ave) approx. equals De/(r - r(sub e)) must be very large. The forces involved in dissociating the molecule are discussed in the following. In consideration of average forces, the molecule shall be assumed arbitrarily to be dissociated when the atoms are far enough separated so that the potential, relative to that of the infinitely separated atoms, is reduced by 99.5% from the potential of the molecule at the equilibrium bond length (r(sub e)) for Cl2 of 1.988 A this occurs at 4.928 A.

  15. Study of gamma-ray strength functions

    SciTech Connect

    Gardner, D.G.; Gardner, M.A.; Dietrich, F.S.

    1980-08-07

    The use of gamma-ray strength function systematics to calculate neutron capture cross sections and capture gamma-ray spectra is discussed. The ratio of the average capture width, GAMMA/sub ..gamma../-bar, to the average level spacing, D/sub obs/, both at the neutron separation energy, can be derived from such systematics with much less uncertainty than from separate systematics for values of GAMMA/sub ..gamma../-bar and D/sub obs/. In particular, the E1 gamma-ray strength function is defined in terms of the giant dipole resonance (GDR). The GDR line shape is modeled with the usual Lorentzian function and also with a new energy-dependent, Breit-Wigner (EDBW) function. This latter form is further parameterized in terms of two overlapping resonances, even for nuclei where photonuclear measurements do not resolve two peaks. In the mass ranges studied, such modeling is successful for all nuclei away from the N = 50 closed neutron shell. Near the N = 50 shell, a one-peak EDBW appears to be more appropriate. Examples of calculated neutron capture excitation functions and capture gamma-ray spectra using the EDBW form are given for target nuclei in the mass-90 region and also in the Ta-Au mass region. 20 figures.

  16. Do You Have the Strength?

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program and Laboratory, University of Colorado at Boulder

    2012-04-21

    In this activity, students squeeze a tennis ball to demonstrate the strength of the human heart. Working in teams, they think of ways to keep the heart beating if the natural mechanism were to fail. The goal of this activity is to get students to understand the strength and resilience of the heart.

  17. Why do bone strength and \\

    Microsoft Academic Search

    Harold M. Frost

    1999-01-01

    :   Trauma excepted, muscle forces cause the largest loads on bones and the largest bone strains. In children, steadily increasing\\u000a muscle strength increases bone loads and strains above a modeling threshold, which allows modeling to increase bone strength\\u000a and \\

  18. Strength properties of fly ash based controlled low strength materials.

    PubMed

    Türkel, S

    2007-08-25

    Controlled low strength material (CLSM) is a flowable mixture that can be used as a backfill material in place of compacted soils. Flowable fill requires no tamping or compaction to achieve its strength and typically has a load carrying capacity much higher than compacted soils, but it can still be excavated easily. The selection of CLSM type should be based on technical and economical considerations for specific applications. In this study, a mixture of high volume fly ash (FA), crushed limestone powder (filler) and a low percentage of pozzolana cement have been tried in different compositions. The amount of pozzolana cement was kept constant for all mixes as, 5% of fly ash weight. The amount of mixing water was chosen in order to provide optimum pumpability by determining the spreading ratio of CLSM mixtures using flow table method. The shear strength of the material is a measure of the materials ability to support imposed stresses on the material. The shear strength properties of CLSM mixtures have been investigated by a series of laboratory tests. The direct shear test procedure was applied for determining the strength parameters Phi (angle of shearing resistance) and C(h) (cohesion intercept) of the material. The test results indicated that CLSM mixtures have superior shear strength properties compared to compacted soils. Shear strength, cohesion intercept and angle of shearing resistance values of CLSM mixtures exceeded conventional soil materials' similar properties at 7 days. These parameters proved that CLSM mixtures are suitable materials for backfill applications. PMID:17331642

  19. CYP2E1 autoantibodies in liver diseases

    PubMed Central

    Sutti, Salvatore; Rigamonti, Cristina; Vidali, Matteo; Albano, Emanuele

    2014-01-01

    Autoimmune reactions involving cytochrome P4502E1 (CYP2E1) are a feature of idiosyncratic liver injury induced by halogenated hydrocarbons and isoniazid, but are also detectable in about one third of the patients with advanced alcoholic liver disease (ALD) and chronic hepatitis C (CHC). In these latter the presence of anti-CYP2E1 auto-antibodies is an independent predictor of extensive necro-inflammation and fibrosis and worsens the recurrence of hepatitis following liver transplantation, indicating that CYP2E1-directed autoimmunity can contribute to hepatic injury. The molecular characterization of the antigens recognized by anti-CYP2E1 auto-antibodies in ALD and CHC has shown that the targeted conformational epitopes are located in close proximity on the molecular surface. Furthermore, these epitopes can be recognized on CYP2E1 expressed on hepatocyte plasma membranes where they can trigger antibody-mediated cytotoxicity. This does not exclude that T cell-mediated responses against CYP2E1 might also be involved in causing hepatocyte damage. CYP2E1 structural modifications by reactive metabolites and molecular mimicry represent important factors in the breaking of self-tolerance against CYP2E1 in, respectively, ALD and CHC. However, genetic or acquired interferences with the mechanisms controlling the homeostasis of the immune system are also likely to contribute. More studies are needed to better characterize the impact of anti-CYP2E1 autoimmunity in liver diseases particularly in relation to the fact that common metabolic alterations such as obesity and diabetes stimulates hepatic CYP2E1 expression. PMID:25462068

  20. 26 CFR 49.4264(e)-1 - Round trips.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 true Round trips. 49.4264(e)-1 Section 49...Persons § 49.4264(e)-1 Round trips. (a) In general. For purposes of the regulations in this subpart, a round trip shall be considered to consist of two...

  1. 02. Mrz 2012 HIB MINT / Informatik, Campus E1 3

    E-print Network

    Huber, Patrick

    02. März 2012 HIB ­ MINT / Informatik, Campus E1 3 Hörsaal I 14.00 Uhr Computerlinguistik, Prof. Bläser Medieninformatik, Prof. Krüger 17.00 Uhr Wirtschaftsinformatik, Prof. Loos HIB ­ MINT ­ MINT / Ingenieurwissenschaften, Campus E1 3 Hörsaal III 14.00 Uhr Computer- und Kommunikationstechnik

  2. 02. Mrz 2012 HIB MINT / Informatik, Campus E1 3

    E-print Network

    Huber, Patrick

    02. März 2012 HIB ­ MINT / Informatik, Campus E1 3 Hörsaal I 14.00 Uhr Computerlinguistik, Prof. Bläser Medieninformatik, Prof. Krüger 17.00 Uhr Wirtschaftsinformatik, Prof. Dr.-Ing. Maass HIB ­ MINT ­ MINT / Ingenieurwissenschaften, Campus E1 3 Hörsaal III 14.00 Uhr Computer- und Kommunikationstechnik

  3. Lifetime of the yrast I?=5- state and E 1 hindrance in the transitional nucleus Ce13658

    NASA Astrophysics Data System (ADS)

    Alharbi, T.; Regan, P. H.; M?rginean, N.; Podolyák, Zs.; Roberts, O. J.; Bruce, A. M.; Alkhomashi, N.; Britton, R.; Bucurescu, D.; Deleanu, D.; Filipescu, D.; Ghit?, D.; Glodariu, T.; Mihai, C.; Mulholland, K.; Lica, R.; M?rginean, R.; Nakhostin, M.; Negret, A.; Nita, C. R.; Stroe, L.; Sava, T.; Townsley, C.; Zamfir, N. V.

    2015-02-01

    The half-lives of the I?=5- and I?=7- yrast states with Ex=1978 keV and Ex=2307 keV in the N =78 isotone 136Ce, have been measured to be 496(23) ps and 270(24) ps, respectively, using the coincident fast-timing spectroscopy technique following population by a 124Sn(16O ,4 n ) fusion-evaporation reaction at an incident beam energy of 68 MeV. The extracted B (E 1 ;5-?4+) =1.8 (3 ) ×10-6 W.u. value is compared with the systematics of the region and is found to be in line with typical E 1 strengths for single-particle-type decays, rather than showing any evidence for the additional E 1 decay hindrance associated with K -quantum number violation in axially deformed systems observed in lighter Ce isotopes.

  4. Pelvic Muscle Strength After Childbirth

    PubMed Central

    Friedman, Sarah; Blomquist, Joan L.; Nugent, Joann M.; McDermott, Kelly C.; Muñoz, Alvaro; Handa, Victoria L.

    2013-01-01

    OBJECTIVE The objective was to estimate the effect of vaginal childbirth and other obstetric exposures on pelvic muscle strength 6–11 years after delivery and to investigate the relationship between pelvic muscle strength and pelvic floor disorders. METHODS Among 666 parous women, pelvic muscle strength was measured with a perineometer 6–11 years after delivery. Obstetric exposures were classified by review of hospital records. Pelvic floor outcomes, including stress incontinence, overactive bladder, anal incontinence, and prolapse symptoms, were assessed with a validated questionnaire. Pelvic organ support was assessed using the Pelvic Organ Prolapse Quantification system. Kruskal-Wallis tests were used to estimate the univariable associations of obstetric exposures and pelvic floor outcomes with peak muscle strength. Stepwise multivariable linear regression models were used to estimate the association between obstetric exposures and muscle strength. RESULTS In comparison with women who delivered all of their children by cesarean, peak muscle strength and duration of contraction were reduced among women with a history of vaginal delivery (39 compared with 29 cm H2O, P<.001). Pelvic muscle strength was further reduced after history of forceps delivery (17 cm H2O, P<.001). After vaginal delivery, reduced pelvic muscle strength was associated with symptoms of anal incontinence (P=.028) and pelvic organ prolapse on examination (P=.025); these associations were not observed among those who had delivered exclusively by cesarean. CONCLUSION Pelvic muscle strength almost a decade after childbirth is affected by vaginal delivery and by forceps delivery. Although statistically significant, some of the differences observed were small in magnitude. PMID:23090518

  5. Pelvic Muscle Strength After Childbirth.

    PubMed

    Friedman, Sarah; Blomquist, Joan L; Nugent, Joann M; McDermott, Kelly C; Muñoz, Alvaro; Handa, Victoria L

    2012-10-01

    OBJECTIVE:: The objective was to estimate the effect of vaginal childbirth and other obstetric exposures on pelvic muscle strength 6-11 years after delivery and to investigate the relationship between pelvic muscle strength and pelvic floor disorders. METHODS:: Among 666 parous women, pelvic muscle strength was measured with a perineometer 6-11 years after delivery. Obstetric exposures were classified by review of hospital records. Pelvic floor outcomes, including stress incontinence, overactive bladder, anal incontinence, and prolapse symptoms, were assessed with a validated questionnaire. Pelvic organ support was assessed using the Pelvic Organ Prolapse Quantification system. Kruskal-Wallis tests were used to estimate the univariable associations of obstetric exposures and pelvic floor outcomes with peak muscle strength. Stepwise multivariable linear regression models were used to estimate the association between obstetric exposures and muscle strength. RESULTS:: In comparison with women who delivered all of their children by cesarean, peak muscle strength and duration of contraction were reduced among women with a history of vaginal delivery (39 compared with 29 cm H2O, P<.001). Pelvic muscle strength was further reduced after history of forceps delivery (17 cm H2O, P<.001). After vaginal delivery, reduced pelvic muscle strength was associated with symptoms of anal incontinence (P=.028) and pelvic organ prolapse on examination (P=.025); these associations were not observed among those who had delivered exclusively by cesarean. CONCLUSION:: Pelvic muscle strength almost a decade after childbirth is affected by vaginal delivery and by forceps delivery. Although statistically significant, some of the differences observed were small in magnitude. LEVEL OF EVIDENCE:: II. PMID:23044533

  6. P a g e | 1P a g e | 1 THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL

    E-print Network

    Engel, Jonathan

    P a g e | 1P a g e | 1 THE UNIVERSITY OF NORTH CAROLINA AT CHAPEL HILL POLICY ON PROHIBITED OF PROHIBITED HARASSMENT OR DISCRIMINATION #12;P a g e | 2 I. Policy Statement The University of North Carolina community. In accordance with its Policy Statement on Non-Discrimination, The University of North Carolina

  7. ELECTRON EXCITATION COLLISION STRENGTHS FOR SINGLY IONIZED NITROGEN

    SciTech Connect

    Tayal, S. S., E-mail: stayal@cau.edu [Department of Physics, Clark Atlanta University, Atlanta, GA 30314 (United States)

    2011-08-01

    Collision strengths for the astrophysically important lines in N II have been calculated in the close-coupling approximation using the B-spline Breit-Pauli R-matrix method. The multiconfiguration Hartree-Fock method with term-dependent non-orthogonal orbitals is employed for an accurate representation of the target wave functions. The close-coupling expansion includes 58 bound levels of N II. The 58 target levels belong to the terms of the ground 2s {sup 2}2p {sup 2} and singly excited 2s2p {sup 3}, 2s {sup 2}2p3s, 2s {sup 2}2p3p, 2s {sup 2}2p3d, 2s {sup 2}2p4s, 2s {sup 2}2p4p, and 2s2p {sup 2}3s configurations. The effective collision strengths are obtained by averaging the electron collision strengths over a Maxwellian distribution of velocities and these are tabulated for all 1653 fine-structure transitions among the 58 levels at electron temperatures in the range from 500 to 100,000 K. The line strengths, oscillator strengths, and transition probabilities for all E1 transitions are tabulated. The present results are compared with a variety of other close-coupling calculations. There is an overall good agreement with the 23-state calculation by Hudson and Bell in most part, but some significant differences are also noted for some transitions.

  8. Hydrogen degradation of high strength

    Microsoft Academic Search

    J. ?wiek

    Purpose: Purpose of this paper is presentation of hydrogen degradation issue of high strength steels and especially their welded joints. Establishing of applicable mechanisms of hydrogen-enhanced cracking was the aim of performed research. Design\\/methodology\\/approach: High strength quenched and tempered steels grade S690Q were used. Welded joints were prepared with typical technology used in shipyards. Susceptibility to hydrogen degradation in sea

  9. Oscillator strengths and radiative rates for transitions in neutral sulfur

    SciTech Connect

    Deb, N.C. [School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland (United Kingdom); Hibbert, A. [School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, Northern Ireland (United Kingdom)], E-mail: a.hibbert@qub.ac.uk

    2008-07-15

    We present accurate oscillator strengths and radiative rates for 2173 E1 transitions among the 120 levels belonging to 3s{sup 2}3p{sup 4}, 3s3p{sup 5}, and 3s{sup 2}3p{sup 3}({sup 4}S{sup o},{sup 2}D{sup o},{sup 2}P{sup o})nl configurations where nl=4s,5s,6s,4p,5p,6p,3d,4d,4f,5f. A configuration interaction approach is employed through the standard CIV3 program. The 114 LS states included in the present calculation generate 250 fine-structure levels belonging to the above configurations below 100,000 cm{sup -1}. However, results of only 120 fine-structure levels are presented due to the absence of experimental energy values for the remaining levels. Tabulations of oscillator strengths and radiative rates, and their comparison with other calculations, are presented in the first two tables. In a separate table the oscillator strengths and transition probabilities, in length and velocity gauges, are presented for 2173 E1 transitions, and are arranged in ascending order of wavelength.

  10. Nucleotide polymorphisms of the human papillomavirus 16 E1 gene.

    PubMed

    Tsakogiannis, D; Darmis, F; Gortsilas, P; Ruether, I G A; Kyriakopoulou, Z; Dimitriou, T G; Amoutzias, G; Markoulatos, P

    2014-01-01

    The E1 ORF is one of the most conserved regions in the human papillomavirus (HPV) genome. The complete E1 gene of the HPV16 genome was amplified with four overlapping primer sets in 16 high-grade (CIN II, III) and 13 low-grade cervical (CIN I) intraepithelial neoplasias as well as in one cervical cancer case. Sequence analysis of the E6 and E7 genes was also carried out in the same cervical samples in order to confirm the association between nucleotide sequence variations in the HPV16 E1 ORF and HPV16 variant lineages. Analysis of the E1 ORF revealed 27 nucleotide changes, and these changes were correlated with those found in HPV16 Asian American and African type II variants. Of these nucleotide variations, A1668G, G2073A, T2169C, T2189C, A2453T, C2454T, A2587T and G2650A were identified only in high-grade dysplasia cases. A phylogenetic tree of the E1 ORF and nucleotide sequence analysis of the E1, E6 and E7 genes revealed that intratypic nucleotide sequence polymorphisms located in the E1 ORF can be used to identify the major phylogenetic branch to which a HPV16 genome belongs. Moreover, amplification of the E1 ORF revealed a disruption between nucleotides 878 and 1523 in five high- and two low-grade cervical cases, indicating that integration of HPV DNA occurs at an early stage of viral infection. PMID:23881083

  11. Effect of solar wind pressure pulses on the size and strength of the auroral oval

    E-print Network

    Lummerzheim, Dirk

    Effect of solar wind pressure pulses on the size and strength of the auroral oval A. Boudouridis, E. [1] It has recently been found that solar wind dynamic pressure changes can dramatically affect solar wind dynamic pressure increases on the location, size, and intensity of the auroral oval using

  12. Na(+) transport, and the E(1)P-E(2)P conformational transition of the Na(+)/K(+)-ATPase.

    PubMed Central

    Babes, A; Fendler, K

    2000-01-01

    We have used admittance analysis together with the black lipid membrane technique to analyze electrogenic reactions within the Na(+) branch of the reaction cycle of the Na(+)/K(+)-ATPase. ATP release by flash photolysis of caged ATP induced changes in the admittance of the compound membrane system that are associated with partial reactions of the Na(+)/K(+)-ATPase. Frequency spectra and the Na(+) dependence of the capacitive signal are consistent with an electrogenic or electroneutral E(1)P <--> E(2)P conformational transition which is rate limiting for a faster electrogenic Na(+) dissociation reaction. We determine the relaxation rate of the rate-limiting reaction and the equilibrium constants for both reactions at pH 6.2-8.5. The relaxation rate has a maximum value at pH 7.4 (approximately 320 s(-1)), which drops to acidic (approximately 190 s(-1)) and basic (approximately 110 s(-1)) pH. The E(1)P <--> E(2)P equilibrium is approximately at a midpoint position at pH 6.2 (equilibrium constant approximately 0.8) but moves more to the E(1)P side at basic pH 8.5 (equilibrium constant approximately 0.4). The Na(+) affinity at the extracellular binding site decreases from approximately 900 mM at pH 6.2 to approximately 200 mM at pH 8.5. The results suggest that during Na(+) transport the free energy supplied by the hydrolysis of ATP is mainly used for the generation of a low-affinity extracellular Na(+) discharge site. Ionic strength and lyotropic anions both decrease the relaxation rate. However, while ionic strength does not change the position of the conformational equilibrium E(1)P <--> E(2)P, lyotropic anions shift it to E(1)P. PMID:11053130

  13. Observation of large scissors resonance strength in actinides.

    PubMed

    Guttormsen, M; Bernstein, L A; Bürger, A; Görgen, A; Gunsing, F; Hagen, T W; Larsen, A C; Renstrøm, T; Siem, S; Wiedeking, M; Wilson, J N

    2012-10-19

    The orbital M1 scissors resonance has been measured for the first time in the quasicontinuum of actinides. Particle-? coincidences are recorded with deuteron and (3)He-induced reactions on (232)Th. The residual nuclei (231,232,233)Th and (232,233) Pa show an unexpectedly strong integrated strength of B(M1)=11-15?(n)(2) in the E(?)=1.0-3.5 MeV region. The increased ?-decay probability in actinides due to scissors resonance is important for cross-section calculations for future fuel cycles of fast nuclear reactors and may also have an impact on stellar nucleosynthesis. PMID:23215072

  14. Oscillator strengths and lifetimes of Zn I and Ga II

    NASA Astrophysics Data System (ADS)

    Chi, Hsin-Chang; Chou, Hsiang-Shun

    2014-03-01

    We have applied the second-order relativistic many-body perturbation theory to calculate the oscillator strengths for the spin-allowed electric-dipole (E1) transitions in Zn I and Ga II. We have studied 11 transitions among the first 12 levels of Zn I and Ga II. Radiative lifetimes of some levels in Zn I and Ga II are also evaluated. In particular, the present study provides the first relativistic calculation for the transitions (4s4p)\\ ^{3}P_{0,1,2}^{o}\\rightarrow (4p^{2})\\ ^{3}P_{0,1,2} in Zn I whose oscillator strengths are sensitive to the interplay between the relativistic effects and the bound-continuum correlations. The transition amplitudes obtained in different gauges agree within 2%. The present results agree well with experiment.

  15. Nanoscale Strength Measurements and Standards

    E-print Network

    Perkins, Richard A.

    conditions. Methods to fabricate, in- house, silicon (Si) test structures with deep reactive ion etchingNanoscale Strength Measurements and Standards CERAMICS To develop new mechanical test structures methods that enable device producers in the MEMS and NEMS industries to assess, predict, and optimize

  16. Strength of glass (a review)

    Microsoft Academic Search

    B. Sugarman

    1967-01-01

    After defining the termglass, brief consideration is given to the theories of glass structure which have been propounded. That glass, in practice, is very much weaker than its theoretical strength predicts is established, and the prime factor for this is shown to be the surface condition of the glass. Surface defects which are accentuated by heat treatment or other processes

  17. Building Strengths through Adventure Education

    ERIC Educational Resources Information Center

    Loughmiller, Grover C.

    2007-01-01

    Campbell Loughmiller (1906-1993) is widely recognized as a leader in therapeutic work with troubled youngsters in outdoor settings. Rejecting punitive or institutional models of intervention, Loughmiller set out to demonstrate that every young person has strengths, desires to make positive changes, can grow in responsibility, and contribute to…

  18. Strength training for the warfighter.

    PubMed

    Kraemer, William J; Szivak, Tunde K

    2012-07-01

    Optimizing strength training for the warfighter is challenged by past training philosophies that no longer serve the modern warfighter facing the "anaerobic battlefield." Training approaches for integration of strength with other needed physical capabilities have been shown to require a periodization model that has the flexibility for changes and is able to adapt to ever-changing circumstances affecting the quality of workouts. Additionally, sequencing of workouts to limit over-reaching and development of overtraining syndromes that end in loss of duty time and injury are paramount to long-term success. Allowing adequate time for rest and recovery and recognizing the negative influences of extreme exercise programs and excessive endurance training will be vital in moving physical training programs into a more modern perspective as used by elite strength-power anaerobic athletes in sports today. Because the warfighter is an elite athlete, it is time that training approaches that are scientifically based are updated within the military to match the functional demands of modern warfare and are given greater credence and value at the command levels. A needs analysis, development of periodized training modules, and individualization of programs are needed to optimize the strength of the modern warfighter. We now have the knowledge, professional coaches and nonprofit organization certifications with continuing education units, and modern training technology to allow this to happen. Ultimately, it only takes command decisions and implementation to make this possible. PMID:22643142

  19. Joint strength in RCS frames

    E-print Network

    Kirby, Cynthia Dawn

    1998-01-01

    As part of a National Science Foundation (NSF) program ics. on composite and hybrid systems at Texas A&M University, the objective of this thesis is to investigate the joint strength in reinforced column-steel beam (RCS) special moment frames...

  20. The Principles of Strengths-Based Education

    Microsoft Academic Search

    Shane J. Lopez; Michelle C Louis

    2009-01-01

    Doing what we do best leads to high levels of engagement and productivity. Educators who capitalize on their strengths daily help students do what they do best by developing a strengths- based approach to education. The principles of strengths-based education include measurement, individualization, networking, deliberate application, and intentional development. Through a parallel process, educators practice the principles of strengths-based education

  1. Acetaldehyde and parkinsonism: role of CYP450 2E1

    PubMed Central

    Vaglini, Francesca; Viaggi, Cristina; Piro, Valentina; Pardini, Carla; Gerace, Claudio; Scarselli, Marco; Corsini, Giovanni Umberto

    2013-01-01

    The present review update the relationship between acetaldehyde (ACE) and parkinsonism with a specific focus on the role of P450 system and CYP 2E1 isozyme particularly. We have indicated that ACE is able to enhance the parkinsonism induced in mice by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, a neurotoxin able to damage the nigrostriatal dopaminergic pathway. Similarly diethyldithiocarbamate, the main metabolite of disulfiram, a drug widely used to control alcoholism, diallylsulfide (DAS) and phenylisothiocyanate also markedly enhance the toxin-related parkinsonism. All these compounds are substrate/inhibitors of CYP450 2E1 isozyme. The presence of CYP 2E1 has been detected in the dopamine (DA) neurons of rodent Substantia Nigra (SN), but a precise function of the enzyme has not been elucidated yet. By treating CYP 2E1 knockout (KO) mice with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, the SN induced lesion was significantly reduced when compared with the lesion observed in wild-type animals. Several in vivo and in vitro studies led to the conclusion that CYP 2E1 may enhance the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine toxicity in mice by increasing free radical production inside the dopaminergic neurons. ACE is a good substrate for CYP 2E1 enzyme as the other substrate-inhibitors and by this way may facilitate the susceptibility of dopaminergic neurons to toxic events. The literature suggests that ethanol and/or disulfiram may be responsible for toxic parkinsonism in human and it indicates that basal ganglia are the major targets of disulfiram toxicity. A very recent study reports that there are a decreased methylation of the CYP 2E1 gene and increased expression of CYP 2E1 mRNA in Parkinson's disease (PD) patient brains. This study suggests that epigenetic variants of this cytochrome contribute to the susceptibility, thus confirming multiples lines of evidence which indicate a link between environmental toxins and PD. PMID:23801948

  2. 17 CFR 274.127e-1 - Form N-27E-1, notice to periodic payment plan certificate holders of 18-month surrender rights...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... false Form N-27E-1, notice to periodic payment plan certificate holders of 18-month surrender rights with respect to periodic payment plan certificates. 274.127e-1...127e-1 Form N-27E-1, notice to periodic payment plan certificate holders...

  3. Mean-field analysis of ground state and low-lying electric dipole strength in $^{22}$C

    E-print Network

    Tsunenori Inakura; W. Horiuchi; Y. Suzuki; T. Nakatsukasa

    2014-05-30

    Properties of neutron-rich $^{22}$C are studied using the mean-field approach with Skyrme energy density functionals. Its weak binding and large total reaction cross section, which are suggested by recent experiments, are simulated by modifying the central part of Skyrme potential. Calculating $E1$ strength distribution by using the random-phase approximation, we investigate developments of low-lying electric dipole ($E1$) strength and a contribution of core excitations of $^{20}$C. As the neutron Fermi level approaches the zero energy threshold ($\\varepsilon_F >\\sim -1$ MeV), we find that the low-lying $E1$ strength exceeds the energy-weighted cluster sum rule, which indicates an importance of the core excitations with the $1d_{5/2}$ orbit.

  4. E1a induces the expression of epithelial characteristics

    PubMed Central

    1994-01-01

    Cells closely resembling epithelia constitute the first specific cell type in a mammalian embryo. Many other cell types emerge via epithelial- mesenchymal differentiation. The transcription factors and signal transduction pathways involved in this differentiation are being elucidated. I have previously reported (Frisch, 1991) that adenovirus E1a is a tumor suppressor gene in certain human cell lines. In the present report, I demonstrate that E1a expression caused diverse human tumor cells (rhabdomyosarcoma, fibrosarcoma, melanoma, osteosarcoma) and fibroblasts to assume at least two of the following epithelial characteristics: (a) epithelioid morphology; (b) epithelial-type intercellular adhesion proteins localized to newly formed junctional complexes; (c) keratin-containing intermediate filaments; and (d) down- regulation of non-epithelial genes. E1a thus appeared to partially convert diverse human tumor cells into an epithelial phenotype. This provides a new system for molecular analysis of epithelial-mesenchymal interconversions. This effect may also contribute to E1a's tumor suppression activity, possibly through sensitization to anoikis (Frisch, S.M., and H. Francis, 1994. J. Cell Biol. 124:619-626). PMID:7525602

  5. 24. SPILLWAY CHANNEL WALLS REINFORCEMENT DETAILS; MONOLITHS E1 TO ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. SPILLWAY CHANNEL WALLS - REINFORCEMENT DETAILS; MONOLITHS E-1 TO F-4 INCL. & NO. 34. Sheet S-11, June, 1939. File no. SA 342/24(?). - Prado Dam, Spillway, Santa Ana River near junction of State Highways 71 & 91, Corona, Riverside County, CA

  6. Multi-Laboratory Validation of Estrone (E1) ELISA Methods

    EPA Science Inventory

    This project is a round-robin evaluation of commercially available Enzyme-Linked Immunosorbent Assay (ELISA) technology to quantitatively or qualitatively measure the hormone estrone (E1) in combined animal feeding operation (CAFO) receiving streams. ELISA is meant to be a simpl...

  7. EXPRESSION OF ENDOGLUCANASE E1 IN TRANSGENIC DUCKWEED LEMNA MINOR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Transgenic duckweed (Lemna minor) that expresses Acidothermus cellulolyticus E1 endoglucanase was generated using Agrobacterium-mediated transformation. Out of 15 independent transgenic lines, 1 line with the highest CMC-degrading activity was selected for further studies. The 2-week-old transgeni...

  8. Strength gain through eccentric isotonic training without changes in clinical signs or blood markers

    PubMed Central

    2013-01-01

    Background Localized exercises are widely used in rehabilitation processes. The predominant options are exercises with an emphasis on either concentric or eccentric contractions. Eccentric exercises promote greater strength gains compared to classical concentric stimuli, but can cause muscle damage. The aim of present study was to compare strength training composed of 10 sessions with progressive loads between groups with a predominance of concentric versus eccentric contraction through an analysis of isotonic strength, pressure pain threshold, creatine kinase, tumor necrosis factor-alpha and cortisol. Methods One hundred twenty male subjects were divided into four groups: C1 and E1 – single session of maximum strength with emphasis on concentric and eccentric contraction, respectively; C10 and E10 – 10 sessions with progressive loads from 80% to maximum strength with emphasis on concentric and eccentric contraction, respectively. Results Isotonic strength increased by 10% in E10 following the ten training sessions. C1 and E1 exhibited a lower pressure pain threshold 48 hours after the sessions in comparison to C10 and E10, respectively. Creatine kinase was increased in C1 in comparison to baseline, with significant differences (p???0.05) in comparison to E1 at 48 and 96 hours as well as C10 at 48, 72 and 96 hours. No significant differences were found in TNF-? or cortisol among the groups or evaluation times. Conclusion Eccentric contraction training promotes functional adaptation. Moreover, both concentric and eccentric contraction training have a protective effect on the muscle in relation to a single session of maximum strength exercise. Trial registration RBR-75scwh PMID:24261331

  9. Development of strength in cements

    Microsoft Academic Search

    B. Matkovic

    1981-01-01

    The production of doped belite (dicalcium silicate) clinkers as a prospective means for saving energy in Portland cement production is described. This is accomplished by small additions of either barium sulfate (BaSO4), calcium tribasic phosphate (Ca5(PO4)3OH), or vanadium oxide (V2O5) to belite (Ca2SiO4) clinker. In addition to conserving energy, doping the belite with barium sulfate imparts greater strength to the

  10. Electronic correlation strength of Pu

    NASA Astrophysics Data System (ADS)

    Svane, A.; Albers, R. C.; Christensen, N. E.; van Schilfgaarde, M.; Chantis, A. N.; Zhu, Jian-Xin

    2013-01-01

    An electronic quantity, the correlation strength, is defined as a necessary step for understanding the properties and trends in strongly correlated electronic materials. As a test case, this is applied to the different phases of elemental Pu. Within the GW approximation we have surprisingly found a “universal” scaling relationship, where the f-electron bandwidth reduction due to correlation effects is shown to depend only on the local density approximation bandwidth and is otherwise independent of crystal structure and lattice constant.

  11. Physical Strength and Job Performance

    NSDL National Science Digital Library

    Lane, David M.

    Created by David Lane of Rice University, this case study aims to answer the question, "How does one select employees to perform physically demanding jobs?" It examines the relationship between isometric strength tests and job performance for one hundred forty-seven workers. The author has structured the lesson to provide a background, methods and procedures, univariate statistics, scatter plots, correlations, regression and raw data. Some of the main concepts include: correlation, linear regression, multiple regression.

  12. Strength Scaling in Fiber Composites

    NASA Technical Reports Server (NTRS)

    Kellas, Sotiris; Morton, John

    1990-01-01

    A research program was initiated to study and isolate the factors responsible for scale effects in the tensile strength of graphite/epoxy composite laminates. Four layups were chosen with appropriate stacking sequences so as to highlight individual and interacting failure modes. Four scale sizes were selected for investigation including full scale size, 3/4, 2/4, and 1/4, with n = to 4, 3, 2, and 1, respectively. The full scale specimen sizes was 32 piles thick as compared to 24, 16, and 8 piles for the 3/4, 2/4, and 1/4 specimen sizes respectively. Results were obtained in the form of tensile strength, stress-strain curves and damage development. Problems associated with strength degradation with increasing specimen sizes are isolated and discussed. Inconsistencies associated with strain measurements were also identified. Enhanced x ray radiography was employed for damage evaluation, following step loading. It was shown that fiber dominated layups were less sensitive to scaling effects compared to the matrix dominated layups.

  13. The electronic transition moment function of the E 1? u - X 1?{/g +} system of Ag2

    NASA Astrophysics Data System (ADS)

    Anti?-Jovanovi?, A.; Kuzmanovi?, M.; Khakoo, M. A.; Laher, R. R.

    2011-12-01

    Measurement of relative band strengths of 10 absorption bands of the E 1? u - X 1?{/g +} system of diatomic silver, 107,109Ag2, was performed for the first time. Theoretical analysis of the experimental data, based on Rydberg-Klein-Rees potential energy curves, revealed that assumption of the r-centroid approximation is valid for this system. Comparison of the measured and computed band strength ratios for 5 pairs of bands having common lower levels led to the following linear relative electronic transition moment function for the 107,109Ag2 E-X band system: R_e (bar r_{V'V''} ) = 2.36bar r_{V'V''} - 5.64, in arbitrary units, over the 2.65-2.73 Å of internuclear distance.

  14. Strength loss in kraft pulping

    NASA Astrophysics Data System (ADS)

    Iribarne, Jose

    Unbleached kraft pulps from two U.S. mills were 21% and 26% weaker than comparable laboratory pulps from the same chip sources, when assessed as the tear index at a tensile index of 70 kN.m/kg. The phenomena involved were clarified by characterizing the differences between the mill and laboratory pulps in terms of fundamental fiber properties. All of the strength loss could be explained by a reduction in intrinsic fiber strength of 9% to 11%, as estimated from wet zero-span tensile tests and fiber length distributions. Most of the effects of different fiber shape and length were isolated by PFI mill refining and decrilling, respectively. The higher fiber coarseness of mill pulps was a factor in their maximum density and bond strength, but changes in these variables were analogous to those of laboratory pups due to similar swelling. Specific bond strength, determined from a wet pressing experiment, was similar in mill and laboratory pulps. Neither carbohydrate composition nor crystalline structure, assessed through x-ray diffraction analysis, were significant factors in the observed fiber strength differences. The mill pulps were not more heterogeneous than the laboratory pulps, within the resolution of a fractionation experiment. The number of weak points in each pulp was assessed through analysis of the amount of fiber cutting during PFI mill refining and treatments with potassium superoxide or cellulase. The results suggested that the chemistry of kraft pulping preferentially weaken short, slender fibers, while mechanical stresses during the hot discharge of batch digesters mainly affect long, thick fibers. The greater number of weak points in the long-fiber fractions of mill pulps is probably associated with their lower wet zero-span tensile indices. Automated optical detection of major singularities with a prototype instrument suggested that only the weak points induced by mechanical stress could be detected by local variations in birefringence. In contrast, chemically damaged short, slender fibers were not optically active. Strong chemical attack during superoxide treatment appeared to affect all fibers, but the effect of fiber cutting was partially offset by a preferential dissolution of short fibers and fines. A simple model of weak point formation by combinations of mechanical stress and localized chemical attack was sufficient to explain all the experimental results.

  15. Two-photon E1-M1 optical clock

    NASA Astrophysics Data System (ADS)

    Alden, E. A.; Moore, K. R.; Leanhardt, A. E.

    2014-07-01

    An allowed E1-M1 excitation scheme creates optical access to the 1S0?3P0 clock transition in group-II-type atoms. This method does not require the hyperfine mixing or application of an external magnetic field of other optical clock systems. The advantages of this technique include a Doppler-free excitation scheme and increased portability with the use of vapor cells. We will discuss technical mechanisms of a monochromatic excitation scheme for a hot E1-M1 clock and briefly discuss a bichromatic scheme to eliminate light shifts. We determine the optimal experimental parameters for Hg, Yb, Ra, Sr, Ba, Ca, Mg, and Be and calculate that neutral Hg has ideal properties for a hot, portable frequency standard.

  16. A Two-Photon E1-M1 Optical Clock

    E-print Network

    E. A. Alden; K. R. Moore; A. E. Leanhardt

    2014-05-06

    An allowed E1-M1 excitation scheme creates optical access to the ${^1S_0} \\rightarrow {^3P_0}$ clock transition in group II type atoms. This method does not require the hyperfine mixing or application of an external magnetic field of other optical clock systems. The advantages of this technique include a Doppler-free excitation scheme and increased portability with the use of vapor cells. We will discuss technical mechanisms of a monochromatic excitation scheme for a hot E1-M1 clock and briefly discuss a bichromatic scheme to eliminate light shifts. We determine the optimal experimental parameters for Hg, Yb, Ra, Sr, Ba, Ca, Mg, and Be and calculate that neutral Hg has ideal properties for a hot, portable frequency standard.

  17. Possible hemodynamic pathways of intraurethral prostaglandin-E1 (MUSE).

    PubMed

    Bschleipfer, T; Cimniak, H-U; Beckert, R; Hauck, E W; Weidner, W; Sparwasser, C

    2004-08-01

    Intraurethral application of prostaglandin-E1 (MUSE) is a well-tolerated pharmacotherapy for erectile dysfunction. However, the physiological mechanisms of drug transfer into the cavernous bodies are not completely clear. Using spongiosography in 35 patients, our study tried to elucidate existing shunt mechanisms. The X-rays show venous drainage through the deep dorsal vein up to the plexus Santorini. The circumflex veins are also contrasted and the cavernous bodies show opacification in their distal portion only. Structures shunting directly between the corpus spongiosum and the cavernous bodies were not demonstrable. Retrograde filling of the cavernous bodies through the deep dorsal vein and its circumflex braches seems to be the most relevant way of drug transfer after intraurethral application of prostaglandin-E1. Diffusion into the cavernous bodies or a systemic mechanism of action does not seem probable. PMID:14961055

  18. Molecular dynamics simulations of CYP2E1.

    PubMed

    Li, Jue; Wei, Dong-Qing; Wang, Jing-Fang; Yu, Zheng-Tian; Chou, Kuo-Chen

    2012-03-01

    CYP2E1, as a member of the cytochrome P450s (CYPs) super-family, is in charge of six percent drug metabolism involving a diversity of drugs distinct in structures and chemical properties, such as alcohols, monocyclic compounds (e.g., acetaminophen, benzene, p-nitrophenol), bicyclic heterocycles (e.g., coumarin, caffeine) and even fatty acids. The aromatic molecules form a vital species catalyzed by CYP2E1. To investigate the mechanism of metabolizing a diversity of aromatic molecules, five representative aromatic substrates were selected: (1) benzene, the non-polar simple ring; (2) aniline, the monocyclic substrate with smallest substitution on the phenyl ring; (3) acetaminophen, a large monocyclic substrate with highly active reactivity; (4) chlorzoxazone, and (5) theophylline, the bicyclic substrates with low or high catalytic activities. They were docked into X-ray structure of CYP2E1, after which all-atom molecular dynamics simulations of 5 ns were performed on each model. It was found that the active site interact with the aromatic substrates mainly through ?-? stacking, supplied by five hydrophobic phenylalanines in the active site. Our simulations also illustrated the specific movement of different kinds of aromatic substrates in the pocket. Small monocyclic substrates show highly frequent self-rotation and limited translation movement. Substrates with single catalytic position are less movable in the pocket than substrates with multiple products. All these findings are quite useful for understanding the catalytic mechanism of CYP2E1, stimulating novel strategies for conducting further mutagenesis studies for specific drug design. PMID:22385180

  19. Mesenchymal Stem Cell Durotaxis Depends on Substrate Stiffness Gradient Strength

    PubMed Central

    Vincent, Ludovic G.; Choi, Yu Suk; Alonso-Latorre, Baldomero; del Álamo, Juan C.; Engler, Adam J.

    2013-01-01

    Mesenchymal stem cells (MSCs) respond to niche elasticity, which varies between and within tissues. Stiffness gradients result from pathological conditions but also occur through normal variation, e.g. muscle. MSCs undergo directed migration even in response to shallow stiffness gradients before differentiating. More refined gradients of both stiffness range and strength are needed to better understand mechanical regulation of migration in normal and disease pathologies. We describe polyacrylamide stiffness gradient fabrication using three distinct systems that generate stiffness gradients of physiological (1 Pa/µm), pathological (10 Pa/µm), and step (? 100Pa/um) strength spanning physiologically relevant stiffness for most soft tissue, i.e. 1–12 kPa. MSCs migrated to the stiffest region for each gradient. Time-lapse microscopy revealed that migration velocity scaled directly with gradient strength. Directed migration was reduced in the presence of the contractile agonist lysophosphatidic acid (LPA) and cytoskeletal-perturbing drugs nocodazole and cytochalasin; LPA- and nocodazole-treated cells remained spread and protrusive, while cytochalasin-treated cells did not. Untreated and nocodazole-treated cells spread in a similar manner, but nocodazole-treated cells had greatly diminished traction forces. These data suggest that actin is required for migration whereas microtubules are required for directed migration. The data also imply that in vivo, MSCs may have a more significant contribution to repairs in stiffer regions where they may preferentially accumulate. PMID:23390141

  20. Dissecting the roles of E1A and E1B in adenoviral replication and RCAd-enhanced RDAd transduction efficacy on tumor cells.

    PubMed

    Wei, Fang; Wang, Huiping; Chen, Xiafang; Li, Chuanyuan; Huang, Qian

    2014-10-01

    Oncolytic viruses have recently received widespread attention for their potential in innovative cancer therapy. Many telomerase promoter-regulated oncolytic adenoviral vectors retain E1A and E1B. However, the functions of E1A and E1B proteins in the oncolytic role of replication-competent adenovirus (RCAd) and RCAd enhanced transduction of replication defective adenoviruses (RDAd) have not been addressed well. In this study, we constructed viruses expressing E1A alone, E1A plus E1B-19 kDa, and E1A plus E1B-19 kDa/55 kDa. We then tested their roles in oncolysis and replication of RCAd as well as their roles in RCAd enhanced transfection rate and transgene expression of RDAd in various cancer cells in vitro and in xenografted human NCI-H460 tumors in nude mice. We demonstrated that RCAds expressing E1A alone and plus E1B-19 kDa exhibited an obvious ability in replication and oncolytic effects as well as enhanced RDAd replication and transgene expression, with the former showed more effective oncolysis, while the latter exhibited superior viral replication and transgene promotion activity. However, RCAd expressing both E1A and E1B-19 kDa/55 kDa was clearly worst in all these abilities. The effects of E1A and E1B observed through using RCAd were further validated by using plasmids expressing E1A alone, E1A plus E1B-19 kDa, and E1A plus E1B-19 kDa/55 kDa proteins. Our study provided evidence that E1A was essential for inducing replication and oncolytic effects of RCAd as well as RCAd enhanced RDAd transduction, and expression of E1B-19 kDa other than E1B-55 kDa could promote these effects. E1B-55 kDa is not necessary for the oncolytic effects of adenoviruses and somehow inhibits RCAd-mediated RDAd replication and transgene expression. PMID:25019940

  1. Development of strength in cements

    NASA Astrophysics Data System (ADS)

    Matkovic, B.

    1981-04-01

    The production of doped belite (dicalcium silicate) clinkers as a prospective means for saving energy in Portland cement production is described. This is accomplished by small additions of either barium sulfate (BaSO4), calcium tribasic phosphate (Ca5(PO4)3OH), or vanadium oxide (V2O5) to belite (Ca2SiO4) clinker. In addition to conserving energy, doping the belite with barium sulfate imparts greater strength to the resulting modified belite. Reactants, additives, and factors contributing to the fabrication of Sorel cement are described.

  2. Muscle Strength Helps Baseball Pitchers Avoid Injury

    MedlinePLUS

    ... sharing features on this page, please enable JavaScript. Muscle Strength Helps Baseball Pitchers Avoid Injury Researchers use ... News) -- The strength of a baseball pitcher's arm muscles may play a larger role in elbow injury ...

  3. Bonded joint strength - Static versus fatigue

    NASA Technical Reports Server (NTRS)

    Johnson, W. S.; Mall, S.

    1984-01-01

    Adhesives are commonly characterized only by their static strength even though they are used in structural joints that are subjected to fatigue loads. This paper reviews the relationship between static and fatigue strength for four different specimen types: single-lap-shear, edge-delamination, double cantilever beam, and cracked-lap-shear. It was found that the ratio of static strength to fatigue strength varied from 2.3 to 4.7, depending on the adhesive and specimen configuration.

  4. Strength distribution in commercial silicon carbide materials

    NASA Technical Reports Server (NTRS)

    Dutta, Sunil

    1988-01-01

    Four-point flexural strength testing has been conducted in order to establish the baseline strength and reliability of four different commercial SiC types, in conjunction with reliable Weibull modulus values. Average strength of the samples ranged from 380 to 482 MPa at room temperature and 307 to 470 MPa at 1370 C. The strength scatter reflects the effect of flaw variability, which must be minimized to improve reliability in sintered SiC.

  5. Asymmetry of Muscle Strength in Elite Athletes

    ERIC Educational Resources Information Center

    Drid, Patrik; Drapsin, Miodrag; Trivic, Tatjana; Lukac, Damir; Obadov, Slavko; Milosevic, Zoran

    2009-01-01

    "Study aim": To determine muscle strength variables in elite judoists and wrestlers since thigh muscle strength and bilaterally balanced flexor-to-extensor ratio minimise injury risk and are desirable for achieving sport successes. "Material and methods": Judoists, wrestlers and untrained subjects, 10 each, were subjected to isokinetic strength

  6. Frontiers in Strength-Based Treatment

    ERIC Educational Resources Information Center

    Laursen, Erik K.

    2003-01-01

    "Reclaiming Children and Youth's" guest editor introduces this special issue on promising practices employing strength-based approaches to education and treatment. If we are serious about the commitment to "leave no child behind," then we must be able to cultivate strengths in all children and families. This article surveys the strengths

  7. Fracture strength of polysilicon at stress concentrations

    Microsoft Academic Search

    Jörg Bagdahn; O. Jadaan

    2003-01-01

    Mechanical design of MEMS requires the ability to predict the strength of load-carrying components with stress concentrations. The majority of these microdevices are made of brittle materials such as polysilicon, which exhibit higher fracture strengths when smaller volumes or areas are involved. A review of the literature shows that the fracture strength of polysilicon increases as tensile specimens get smaller.

  8. Breeding Transformed Cotton Expressing Enhanced Fiber Strength

    Microsoft Academic Search

    O. Lloyd May; Thomas J. Wofford

    2001-01-01

    New cotton (Gossypium hirsutum L.) seeds that can produce fiber with enhanced strength would increase efficiency of the rotor form of open end yarn manufacture. We report results of 3-yr of breeding transgenic ‘Deltapine 50’ (DP 50) germplasm expressing enhanced fiber strength. The objective was to identify germplasm that could consistently express and transmit enhanced fiber strength to their progeny.

  9. Bonding Strength of Sheet Molding Compounds

    Microsoft Academic Search

    D. Feldman; S. V. Hoa; E. Coriaty

    1984-01-01

    One of the important problems in the application of sheet molding compounds (SMC) in automobiles is how to join different structures together. In a previ- ous paper [1] a comparison between (adhesive) bonding strength and (metal) bolting strength was studied. It was found that bolting gave better joining strength than bonding. However, bolting creates stress concentration in the SMC and

  10. Strength of anchor bolts in masonry

    Microsoft Academic Search

    A. R. Whitlock; R. H. Brown

    1983-01-01

    The strength properties of bent bar bolts in masonry were evaluated. The variables studied include bolt size, loading direction, embedment substrate, and bolt location. It is found that bolt strength increases with bolt size up to the point where failure is controlled by masonry strength. The loading direction, substrate, and location of bolts are shown to be significant factors in

  11. Internal and Interface Shear Strength of

    E-print Network

    Zornberg, Jorge G.

    1 Internal and Interface Shear Strength of Geosynthetic Clay Liners (GCLs): Additional Data by John., Zornberg, Jorge G., and Swan, Jr., Robert H. Internal and Interface Shear Strength of Geosynthetic Clay space requirements. However, the internal and interface shear strength of GCLs is known

  12. Strengths and Satisfaction across the Adult Lifespan

    ERIC Educational Resources Information Center

    Isaacowitz, Derek M.; Vaillant, George E.; Seligman, Martin E. P.

    2003-01-01

    Positive psychology has recently developed a classification of human strengths (Peterson & Seligman, in press). We aimed to evaluate these strengths by investigating the strengths and life satisfaction in three adult samples recruited from the community (young adult, middle-aged, and older adult), as well as in the surviving men of the Grant study…

  13. Improving the toughness of ultrahigh strength steel

    SciTech Connect

    Soto, Koji

    2002-08-15

    The ideal structural steel combines high strength with high fracture toughness. This dissertation discusses the toughening mechanism of the Fe/Co/Ni/Cr/Mo/C steel, AerMet 100, which has the highest toughness/strength combination among all commercial ultrahigh strength steels. The possibility of improving the toughness of this steel was examined by considering several relevant factors.

  14. The strength of Miranda's lithosphere

    NASA Technical Reports Server (NTRS)

    Pappalardo, Robert; Greeley, Ronald

    1991-01-01

    In attempting to understand the endogenic processes which have shaped the surface of an icy satellite, it is desirable to quantify the failure strength of the satellite's lithosphere. In a crust that is fractured on a large scale, frictional sliding along pre-existing fractures occurs in response to lower differential stresses than required to initiate fracture of pristine rock, thus governing failure of a brittle lithosphere. Failure is predicted along favorably oriented fracture planes; if fractures of all orientations are assumed to be present in the crust (as is expected of a heavily cratered lithosphere), frictional failure relations are directly applicable. The Coulomb criterion predicts that the shear stress (sigma sub t) and normal stress (sigma sub n) components on a fracture plane at failure are related as sigma sub t = mu-sigma sub n + S sub o, where S sub o is the cohesion and mu is the coefficient of friction. At moderate to high pressures, the frictional sliding strength of most materials is found to be sigma sub t = 0.85 sigma sub n.

  15. Strength evaluation of socket joints

    NASA Technical Reports Server (NTRS)

    Rash, Larry C.

    1994-01-01

    This report documents the development of a set of equations that can be used to provide a relatively simple solution for identifying the strength of socket joints and for most cases avoid the need of more lengthy analyses. The analytical approach was verified by comparison of the contact load distributions to results obtained from a finite element analysis. The contacting surfaces for the specific joint in this analysis are in the shape of frustrums of a cone and are representative of the tapered surfaces in the socket-type joints used to join segments of model support systems for wind tunnels. The results are in the form of equations that can be used to determine the contact loads and stresses in the joint from the given geometry and externally applied loads. Equations were determined to define the bending moments and stresses along the length of the joints based on strength and materials principles. The results have also been programmed for a personal computer and a copy of the program is included.

  16. Effect of Tensile Strength by Variations in Peel Strength in Laminated Film for Liquid Package

    NASA Astrophysics Data System (ADS)

    Machida, Yukihiko; Shimamoto, Akira; Aoki, Hiroyuki; Futase, Katsunori

    Good tensile strength of a laminated film for packaging is an indispensable property in preventing leakage. It is known that the peel strength between laminated film layers is closely related to the tensile strength of the film. In this study, we have measured the tensile strength for various peel strengths of two kinds of three layered laminated film; Nylon + Aluminum + Polyethylene and Nylon + Polyester + Polyethylene. These films have two peel layers, so we escalated one peel strength and fix another one. Then we found that the peel strength between the sealant and the boundaries strongly influences the tensile strength. About Nylon + Polyester + Polyethylene film, we researched applied amount of adhesive and observed cross section of specimen at measurement of peel strength. Then we found that there is difference in specimen condition at measurement of peel strength, and examined about relationship of peel strength and stiffness of specimen.

  17. Nondestructive Determination of Bond Strength

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Although many nondestructive techniques have been applied to detect disbonds in adhesive joints, no absolutely reliable nondestructive method has been developed to detect poor adhesion and evaluate the strength of bonded joints prior to the present work which used nonlinear ultrasonic methods to investigate adhesive bond cure conditions. Previously, a variety of linear and nonlinear ultrasonic methods with water coupling had been used to study aluminum-adhesive-aluminum laminates, prepared under different adhesive curing conditions, for possible bond strength determination. Therefore, in the course of this research effort, a variety of finite-amplitude experimental methods which could possibly differentiate various cure conditions were investigated, including normal and oblique incidence approaches based on nonlinear harmonic generation as well as several non-collinear two-wave interaction approaches. Test samples were mechanically scanned in various ways with respect to the focus of a transmitting transducer operated at several variable excitation frequencies and excitation levels. Even when powerful sample-related resonances were exploited by means of a frequency scanning approach, it was very difficult to isolate the nonlinear characteristics of adhesive bonds. However, a multi-frequency multi-power approach was quite successful and reliable. Ultrasonic tone burst signals at increasing power levels, over a wide frequency range, were transmitted through each bond specimen to determine its excitation dependent nonlinear harmonic resonance behavior. Relative amplitude changes were observed particularly in the higher harmonic spectral data and analyzed using a local displacement and strain analysis in the linear approximation. Two analysis approaches of the excitation-dependent data at specific resonances were found to be quite promising. One of these approaches may represent a very robust algorithm for classifying an adhesive bond as being properly cured or not. Another approach, in addition to differentiation between various cure conditions, may even provide information with respect to the bond strength. Several technical papers were published during the course of this research and a summary is presented in the Ph.D. dissertation of Tobias P. Berndt, a graduate student financially supported by this NASA Grant.

  18. RP-1 delivered to E-1 Test Stand

    NASA Technical Reports Server (NTRS)

    2010-01-01

    NASA John C. Stennis Space Center employee Dustan Ladner (left) assists tanker driver David Velasco in transferring RP-1 fuel to a 20,000-gallon underground tank at the E-1 Test Stand during a March 30 delivery. The rocket propellant will be used for testing Aerojet AJ26 rocket engines beginning this summer. Stennis is testing the engines for Orbital Sciences Corporation, which has partnered with NASA to provide eight supply missions to the International Space Station through 2015. The partnership is part of NASA's Commercial Orbital Transportation Services initiative to work closer with companies to provide commercial space transport once the space shuttle is retired later this year.

  19. Octupole deformation in sup 221 Fr; E1 transition rates

    SciTech Connect

    Liang, C.F.; Peghaire, A. (Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, Bat. 104-91406 Campus Orsay (FR)); Sheline, R.K. (Florida State Univ., Tallahassee, FL (USA))

    1990-07-10

    Experimental data following the alpha decay of{sup 225}Ac are interpreted in terms of a spectroscopy in {sup 221}Fr consistent with octupole deformation. However, the measured E1 transition probabilities suggest that the low lying bands in {sup 221}Fr are considerably more mixed than in nuclei with slightly higher mass number. It is suggested that this mixing of states in {sup 221}Fr is indicative of the partial collapse of Nilsson-like orbitals into more degenerate shell model orbitals.

  20. A large scale virtual screen of DprE1.

    PubMed

    Wilsey, Claire; Gurka, Jessica; Toth, David; Franco, Jimmy

    2013-12-01

    Tuberculosis continues to plague the world with the World Health Organization estimating that about one third of the world's population is infected. Due to the emergence of MDR and XDR strains of TB, the need for novel therapeutics has become increasing urgent. Herein we report the results of a virtual screen of 4.1 million compounds against a promising drug target, DrpE1. The virtual compounds were obtained from the Zinc docking site and screened using the molecular docking program, AutoDock Vina. The computational hits have led to the identification of several promising lead compounds. PMID:24055764

  1. On Being a Strength Coach: Child Welfare and the Strengths Model

    Microsoft Academic Search

    Dorinda N. Noble; Kathleen Perkins

    2000-01-01

    Strength coaches help athletes assess their strengths and build on them. Likewise, social workers dealing with children and famihes in the child welfare system, rather than looking for pathology, can learn to help clients discover and develop their strengths, even while dealing with a child welfare bureaucracy. This article gives examples of the strength coach approach. Athletic teams know the

  2. Cobalt: for strength and color

    USGS Publications Warehouse

    Boland, Maeve A.; Kropschot, S.J.

    2011-01-01

    Cobalt is a shiny, gray, brittle metal that is best known for creating an intense blue color in glass and paints. It is frequently used in the manufacture of rechargeable batteries and to create alloys that maintain their strength at high temperatures. It is also one of the essential trace elements (or "micronutrients") that humans and many other living creatures require for good health. Cobalt is an important component in many aerospace, defense, and medical applications and is a key element in many clean energy technologies. The name cobalt comes from the German word kobold, meaning goblin. It was given this name by medieval miners who believed that troublesome goblins replaced the valuable metals in their ore with a substance that emitted poisonous fumes when smelted. The Swedish chemist Georg Brandt isolated metallic cobalt-the first new metal to be discovered since ancient times-in about 1735 and identified some of its valuable properties.

  3. Conditioned reinforcement and response strength.

    PubMed

    Shahan, Timothy A

    2010-03-01

    Stimuli associated with primary reinforcers appear themselves to acquire the capacity to strengthen behavior. This paper reviews research on the strengthening effects of conditioned reinforcers within the context of contemporary quantitative choice theories and behavioral momentum theory. Based partially on the finding that variations in parameters of conditioned reinforcement appear not to affect response strength as measured by resistance to change, long-standing assertions that conditioned reinforcers do not strengthen behavior in a reinforcement-like fashion are considered. A signposts or means-to-an-end account is explored and appears to provide a plausible alternative interpretation of the effects of stimuli associated with primary reinforcers. Related suggestions that primary reinforcers also might not have their effects via a strengthening process are explored and found to be worthy of serious consideration. PMID:20885815

  4. Transition dipole strength of eumelanin

    NASA Astrophysics Data System (ADS)

    Riesz, J. J.; Gilmore, J. B.; McKenzie, Ross H.; Powell, B. J.; Pederson, M. R.; Meredith, P.

    2007-08-01

    We report the transition dipole strength of eumelanin (the principal human photoprotective pigment) in the ultraviolet and visible. We have used both theoretical (density functional) and experimental methods to show that eumelanin is not an unusually strong absorber amongst organic chromophores. This is somewhat surprising given its role as a photoprotectant, and suggests that the dark coloring in vivo (and in vitro) of the eumelanin pigment is a concentration effect. Furthermore, by observing the polymerization of a principle precursor (5,6-dihydroxyindole-2-carboxylic acid) into the full pigment, we observe that eumelanin exhibits a small amount (˜20%) of hyperchromism (i.e., the reaction process enhances the light absorption ability of the resultant macromolecule relative to its monomeric precursor). These results have significant implications for our understanding of the photophysics of these important functional biomolecules. In particular, they appear to be consistent with the recently proposed chemical disorder secondary structure model of eumelanins.

  5. Strength of Welded Aircraft Joints

    NASA Technical Reports Server (NTRS)

    Brueggeman, W C

    1937-01-01

    This investigation is a continuation of work started in 1928 and described in NACA-TR-348 which shows that the insertion of gusset plates was the most satisfactory way of strengthening a joint. Additional tests of the present series show that joints of this type could be improved by cutting out the portion of the plate between the intersecting tubes. T and lattice joints in thin-walled tubing 1 1/2 by 0.020 inch have somewhat lower strengths than joints in tubing of greater wall thickness because of failure by local buckling. In welding the thin-walled tubing, the recently developed "carburizing flux" process was found to be the only method capable of producing joints free from cracks. The "magnetic powder" inspection was used to detect cracks in the joints and flaws in the tubing.

  6. Extra ?-ray strength for 116,117Sn arising from pygmy dipole resonance

    NASA Astrophysics Data System (ADS)

    Kamata, M.; Utsunomiya, H.; Akimune, H.; Yamagata, T.; Itoh, O.; Iwamoto, C.; Kondo, T.; Toyokawa, H.; Lui, Y.-W.; Goriely, S.

    2010-06-01

    Photoneutron cross sections were measured for 117Sn and 116Sn near neutron thresholds with quasi-monochromatic laser Compton scattering ?-rays. The measured cross sections for 117Sn and 116Sn are strongly enhanced from the threshold behavior expected for L = 1 neutron emissions after E1 photoexcitation. This suggests the presence of extra ?-ray strength in the low-energy tail of the giant dipole resonance. The present cross sections were analyzed together with radiative neutron capture cross sections for 116Sn within the framework of the statistical model calculation. It is shown that the extra ?-ray strength can be interpreted as pygmy E1 resonance which was previously reported in the nuclear resonance fluorescence experiment for 116Sn and 124Sn.

  7. Influence of shear bond strength on compressive strength and stress–strain characteristics of masonry

    Microsoft Academic Search

    B. V. Venkatarama Reddy; Ch. V. Uday Vyas

    2008-01-01

    The paper is focused on shear bond strength–masonry compressive strength relationships and the influence of bond strength\\u000a on stress–strain characteristics of masonry using soil–cement blocks and cement–lime mortar. Methods of enhancing shear bond\\u000a strength of masonry couplets without altering the strength and modulus of masonry unit and the mortar are discussed in detail.\\u000a Application of surface coatings and manipulation of

  8. Reduction of benzene metabolism and toxicity in mice that lack CYP2E1 expression

    Microsoft Academic Search

    John L. Valentine; Susanna S.-T. Lee; Mark J. Seaton; Bahman Asgharian; Georgia Farris; J. Christopher Corton; Frank J. Gonzalez; Michele A. Medinsky

    1996-01-01

    Transgenic CYP2E1 knockout mice (cyp2e1-\\/-) were used toinvestigate the involvement of CYP2E1 in the in vivo metabolism of benzene and in the development of benzene-induced toxicity. After benzene exposure, absence of CYP2E1 protein was confirmed by Western blot analysis of mouse liver samples. For the metabolism studies, male cyp2e1-\\/- and wild-type control mice were exposed to 200 ppm benzene, along

  9. [Rat embryo fibroblasts transformed by complementation with oncogenes E1A+E1B-19 and E1A+cHa-ras differ in the ability to realize the G1/S block in serum free media].

    PubMed

    Brichkina, A I; Tararova, N D; Aksenov, N D; Pospelov, V A; Pospelova, T V

    2001-01-01

    The capability of REF cells transformed by EA + E1B-19 kDa and EA + cHa-ras oncogenes to realize the G1/S cell cycle arrest upon serum starvation was studied. The amount of cyclin-kinase inhibitor protein p27/Kip was shown to increase in both normal and transformed cells. However, the p27/Kip-bound cyclin-kinase complexes of transformed cells were found to be active, implying the functional inactivation of p27/Kip inhibitor. Nevertheless, in contrast to E1A + cHa-ras transformants, E1A + E1B-19 kDa transformants undergo the G1 cell cycle arrest. The G1 cell cycle block correlates with the decrease in cyclinE-Cdk2 activity. Since cyclinE-Cdk2 complexes need Thr-160 phosphorylation of Cdk2 by CAK-kinase for full activity, we have analysed the Cdk-7 associated activity upon serum starvation using gst-Cdk2 as a substrate. Serum starvation did not affect CAK activity either in E1A + cHa-ras or in E1A + E1B-19 kDa transformants. Thus, selective suppression of cyclineE-Cdk2 activity in E1A + E1B-19 kDa transformants upon serum starvation does not arise from the action of cyclin-kinase inhibitors, or from change in CAK activity. PMID:11840777

  10. Transition strengths in 79Rb

    NASA Astrophysics Data System (ADS)

    Holcomb, J. W.; Döring, J.; Glasmacher, T.; Johns, G. D.; Johnson, T. D.; Riley, M. A.; Womble, P. C.; Tabor, S. L.

    1993-09-01

    High angular momentum states in 79Rb were populated via the 63Cu(19F,2pn)79Rb and 65Cu(18O,4n)79Rb reactions. The 65 MeV 19F and 65 MeV 18O beams were provided by the Florida State University FN Tandem accelerator. Prompt ?-? coincidences were measured for both reactions. Two additional ? cascades have been assigned to 79Rb, including a new high-excitation structure dominated by dipole transitions. Firm spin assignments were made for the first time for a number of states by means of directional correlation ratios and an angular distribution measurement using the 63Cu(19F,2pn) reaction. The Doppler-shift attenuation method was used to determine lifetimes for states and their respective side-feeding times in both the yrast positive-parity and yrast negative-parity states. Transition quadrupole moments were deduced from the transition strengths and compared with those predicted by Woods-Saxon cranking calculations. The energy spacings and mixing ratios were compared with particle-rotor calculations.

  11. Strength and Power Predictors of Sports Speed

    Microsoft Academic Search

    John B. Cronin; Keir T. Hansen

    2005-01-01

    Cronin, J.B., and K.T. Hansen. Strength and power predictors of sports speed. J. Strength Cond. Res. 19(2):349-357. 2005.— For many sporting activities, initial speed rather than maximal speed would be considered of greater importance to successful performance. The purpose of this study was to iden- tify the relationship between strength and power and measures of first-step quickness (5-m time), acceleration

  12. Strength and sharp contact fracture of silicon

    Microsoft Academic Search

    R. F. Cook

    2006-01-01

    The fracture strength of Si is considered in the context of yield and reliability of microelectronic and microelectromechanical\\u000a (MEMS) devices. An overview of Si fracture, including the strength of Si wafers, dice and MEMS elements, highlights the importance\\u000a of understanding sharp contact flaws, with their attendant residual stress fields, lateral cracks and strength-limiting half-penny\\u000a cracks in advanced Si device manufacturing.

  13. High-Strength Glass for Solar Applications

    NASA Technical Reports Server (NTRS)

    Bouquet, F. L.

    1987-01-01

    Technology for strengthening thin sections reviewed. Report reviews technology of high-strength glass for such solar applications as heat collectors, reflectors, and photovoltaic arrays. Discusses most feasible methods - heat strengthening and chemical strengthening of increasing strength of glass for solar-energy use. Also estimates cost and availability of high-strength glass and considers physical characteristics, amenability to back-silvering, and effects of atmospheric contamination.

  14. The strength of long glass optical fibers

    Microsoft Academic Search

    V. A. Bogatyrev; M. M. Bubnov; N. N. Vechkanov; A. N. Gur'ianov; S. L. Semenov

    1987-01-01

    A technique for the fabrication of high-strength optical fibers has been developed on the basis of systematic fracture-stress tests on fibers prepared by chemical vapor deposition. A strength level of 5.5 GPa has been achieved for meter fiber segments while a strength level of 1.4 GPa has been achieved for fibers of kilometer length. It is shown that a 25-year

  15. Shear strength of reinforced geosynthetic clay liner

    Microsoft Academic Search

    Robert B. Gilbert; Federico Fernandez; David W. Horsfield

    1996-01-01

    Direct shear tests are conducted to evaluate the internal strength of a reinforced geosynthetic clay liner (GCL) at normal stresses between 3.45 and 69.0 kPa. The polypropylene reinforcement increases the peak internal strength compared to that reported in the literature for unreinforced GCLs; however, the reinforced GCL exhibits a postpeak reduction in strength with displacement due to failure of the

  16. The Flexural Strength of Aramid Fiber Composites

    Microsoft Academic Search

    Carl Zweben

    1978-01-01

    An analysis is presented for the strength in three-point flexural loading of a rectangular unidirectional composite beam reinforced with Keviar®1 49 aramid fibers. The material behavior is assumed to be linearly elastic in tension and elastic-perfectly plastic in compression. The statistical effects of volume and stress distribution on tensile strength are included in the model. The predicted strength agrees reasonably

  17. Strength of porcelain fused to titanium beams

    Microsoft Academic Search

    Shane N. White; Ly Ho; Angelo A. Caputo; Edward Goo

    1996-01-01

    The purposes of this study were to measure strengths of layered porcelain fused to titanium beams, determine failure modes, and investigate the porcelain-titanium interface. A three-point flexural test and formulas derived especially for this purpose were used. The strength of layered porcelain-ceramic beams was limited by the cohesive tensile or compressive strengths of the porcelain, not by the porcelaintitanium interfacial

  18. Shear Strength Criteria for Unsaturated Soils

    Microsoft Academic Search

    Daichao Sheng; Annan Zhou; Delwyn G. Fredlund

    2011-01-01

    Shear strength is one of the fundamental properties of unsaturated soils. It has been found to change with matric suction.\\u000a Various shear strength equations have been proposed for predicting the shear strength versus suction relationship for unsaturated\\u000a soils. Some of these equations are based on regression analysis of experimental data, while some are embodied in more complex\\u000a stress–strain constitutive models.

  19. Correlated Strength in Nuclear Spectral Function

    E-print Network

    D. Rohe; C. S. Armstrong; R. Asaturyan; O. K. Baker; S. Bueltmann; C. Carasco; D. Day; R. Ent; H. C. Fenker; K. Garrow; A. Gasparian; P. Gueye; M. Hauger; A. Honegger; J. Jourdan; C. E. Keppel; G. Kubon; R. Lindgren; A. Lung; D. J. Mack; J. H. Mitchell; H. Mkrtchyan; D. Mocelj; K. Normand; T. Petitjean; O. Rondon; E. Segbefia; I. Sick; S. Stepanyan; L. Tang; F. Tiefenbacher; W. F. Vulcan; G. Warren; S. A. Wood; L. Yuan; M. Zeier; H. Zhu; B. Zihlmann

    2004-09-22

    We have carried out an (e,e'p) experiment at high momentum transfer and in parallel kinematics to measure the strength of the nuclear spectral function S(k,E) at high nucleon momenta k and large removal energies E. This strength is related to the presence of short-range and tensor correlations, and was known hitherto only indirectly and with considerable uncertainty from the lack of strength in the independent-particle region. This experiment confirms by direct measurement the correlated strength predicted by theory.

  20. Strength Training in Children and Adolescents

    PubMed Central

    Dahab, Katherine Stabenow; McCambridge, Teri Metcalf

    2009-01-01

    Context: Strength training in children, in combination with plyometric and/or agility training, has become an increasingly popular tactic for athletes to gain a competitive edge during the off-season. The present review clarifies some common myths associated with strength training in children, and it outlines the most current recommendations. Evidence Acquisition: Relevant studies on strength training in children and adolescents were reviewed (search results included studies indexed in PubMed and MEDLINE from 1980 through 2008). Also reviewed were recommendations from consensus guidelines and position statements applicable to strength training in youth. Results: Children can improve strength by 30% to 50% after just 8 to 12 weeks of a well-designed strength training program. Youth need to continue to train at least 2 times per week to maintain strength. The case reports of injuries related to strength training, including epiphyseal plate fractures and lower back injuries, are primarily attributed to the misuse of equipment, inappropriate weight, improper technique, or lack of qualified adult supervision. Conclusion: Youth—athletes and nonathletes alike—can successfully and safely improve their strength and overall health by participating in a well-supervised program. Trained fitness professionals play an essential role in ensuring proper technique, form, progression of exercises, and safety in this age group. PMID:23015875

  1. Accelerated Strength Testing of Thermoplastic Composites

    NASA Technical Reports Server (NTRS)

    Reeder, J. R.; Allen, D. H.; Bradley, W. L.

    1998-01-01

    Constant ramp strength tests on unidirectional thermoplastic composite specimens oriented in the 90 deg. direction were conducted at constant temperatures ranging from 149 C to 232 C. Ramp rates spanning 5 orders of magnitude were tested so that failures occurred in the range from 0.5 sec. to 24 hrs. (0.5 to 100,000 MPa/sec). Below 204 C, time-temperature superposition held allowing strength at longer times to be estimated from strength tests at shorter times but higher temperatures. The data indicated that a 50% drop in strength might be expected for this material when the test time is increased by 9 orders of magnitude. The shift factors derived from compliance data applied well to the strength results. To explain the link between compliance and strength, a viscoelastic fracture model was investigated. The model, which used compliance as input, was found to fit the strength data only if the critical fracture energy was allowed to vary with temperature reduced stress rate. This variation in the critical parameter severely limits its use in developing a robust time-dependent strength model. The significance of this research is therefore seen as providing both the indication that a more versatile acceleration method for strength can be developed and the evidence that such a method is needed.

  2. Pitch strength of normal and dysphonic voices

    PubMed Central

    Shrivastav, Rahul; Eddins, David A.; Anand, Supraja

    2012-01-01

    Two sounds with the same pitch may vary from each other based on saliency of their pitch sensation. This perceptual attribute is called “pitch strength.” The study of voice pitch strength may be important in quantifying of normal and pathological qualities. The present study investigated how pitch strength varies across normal and dysphonic voices. A set of voices (vowel /a/) selected from the Kay Elemetrics Disordered Voice Database served as the stimuli. These stimuli demonstrated a wide range of voice quality. Ten listeners judged the pitch strength of these stimuli in an anchored magnitude estimation task. On a given trial, listeners heard three different stimuli. The first stimulus represented very low pitch strength (wide-band noise), the second stimulus consisted of the target voice and the third stimulus represented very high pitch strength (pure tone). Listeners estimated pitch strength of the target voice by positioning a continuous slider labeled with values between 0 and 1, reflecting the two anchor stimuli. Results revealed that listeners can judge pitch strength reliably in dysphonic voices. Moderate to high correlations with perceptual judgments of voice quality suggest that pitch strength may contribute to voice quality judgments. PMID:22423721

  3. Strain rate, temperature, and humidity on strength and moduli of a graphite/epoxy composite

    NASA Technical Reports Server (NTRS)

    Lifshitz, J. M.

    1981-01-01

    Results of an experimental study of the influence of strain rate, temperature and humidity on the mechanical behavior of a graphite/epoxy fiber composite are presented. Three principal strengths (longitudinal, transverse and shear) and four basic moduli (E1, E2, G12 and U12) of a unidirectional graphite/epoxy composite were followed as a function of strain rate, temperature and humidity. Each test was performed at a constant tensile strain rate in an environmental chamber providing simultaneous temperature and humidity control. Prior to testing, specimens were given a moisture preconditioning treatment at 60 C. Values for the matrix dominated moduli and strength were significantly influenced by both environmental and rate parameters, whereas the fiber dominated moduli were not. However, the longitudinal strength was significantly influenced by temperature and moisture content. A qualitative explanation for these observations is presented.

  4. Lung models: strengths and limitations.

    PubMed

    Martonen, T B; Musante, C J; Segal, R A; Schroeter, J D; Hwang, D; Dolovich, M A; Burton, R; Spencer, R M; Fleming, J S

    2000-06-01

    The most widely used particle dosimetry models are those proposed by the National Council on Radiation Protection, International Commission for Radiological Protection, and the Netherlands National Institute of Public Health and the Environment (the RIVM model). Those models have inherent problems that may be regarded as serious drawbacks: for example, they are not physiologically realistic. They ignore the presence and commensurate effects of naturally occurring structural elements of lungs (eg, cartilaginous rings, carinal ridges), which have been demonstrated to affect the motion of inhaled air. Most importantly, the surface structures have been shown to influence the trajectories of inhaled particles transported by air streams. Thus, the model presented herein by Martonen et al may be perhaps the most appropriate for human lung dosimetry. In its present form, the model's major "strengths" are that it could be used for diverse purposes in medical research and practice, including: to target the delivery of drugs for diseases of the respiratory tract (eg, cystic fibrosis, asthma, bronchogenic carcinoma); to selectively deposit drugs for systemic distribution (eg, insulin); to design clinical studies; to interpret scintigraphy data from human subject exposures; to determine laboratory conditions for animal testing (ie, extrapolation modeling); and to aid in aerosolized drug delivery to children (pediatric medicine). Based on our research, we have found very good agreement between the predictions of our model and the experimental data of Heyder et al, and therefore advocate its use in the clinical arena. In closing, we would note that for the simulations reported herein the data entered into our computer program were the actual conditions of the Heyder et al experiments. However, the deposition model is more versatile and can simulate many aerosol therapy scenarios. For example, the core model has many computer subroutines that can be enlisted to simulate the effects of aerosol polydispersity, aerosol hygroscopicity, patient ventilation, patient lung morphology, patient age, and patient airway disease. PMID:10894463

  5. The Role of Polyunsaturated ?-3 Fatty Acid Eicosapentaenoic Acid–Derived Resolvin E1 (RvE1) in Bone Preservation

    PubMed Central

    Gyurko, Robert; Van Dyke, Thomas E.

    2014-01-01

    Resolvin E1 (RvE1) is a recently discovered lipid-derived mediator that is endogenously synthesized from the polyunsaturated fatty acid eicosapentaenoic acid. RvE1 is locally generated in response to inflammation where it enhances the resolution phase of inflammation by diminishing neutrophil chemotaxis and by enhancing nonphlogistic macrophage-directed clearance of apoptotic neutrophils. RvE1 was also found to be effective in preventing and restoring bone loss in the inflammatory bone disease periodontitis. This review examines experimental evidence on RvE1's actions in bone. Current data indicate that in addition to anti-inflammatory actions, RvE1 also directly acts on bone cells and promotes bone preservation. PMID:24941160

  6. DNA damage and cytotoxicity in pancreatic ?-cells expressing human CYP2E1

    Microsoft Academic Search

    Diane J Lees Murdock; Yvonne A Barnett; Christopher R Barnett

    2004-01-01

    Epidemiological studies have identified nitrosamines as a risk factor for Type I (insulin dependent) diabetes mellitus. These compounds require bioactivation by cytochrome P450 2E1 (CYP2E1) for exertion of their toxic effects. Two mammalian insulin secreting pancreatic ?-cell lines BRIN BD11h2E1 and INS-1h2E1, which express human full length CYP2E1 cDNA, were used to elucidate the role of CYP2E1-mediated nitrosamine bioactivation in

  7. Transfection with the E1A and E1B19kDa Oncogenes Does Not Prevent Rat Embryo Fibroblasts from Cell-Cycle Arrest after ?-Irradiation

    Microsoft Academic Search

    D. V. Bulavin; N. D. Tararova; A. I. Brichkina; N. D. Aksenov; V. A. Pospelov; T. V. Pospelova

    2002-01-01

    Introduction of the E1A early region of the human adenovirus type 5 impairs the ability of mammalian cells to stop in the cell cycle at G1\\/S after damage. Two-parameter fluorescence cell sorting with iododeoxyuridine revealed the radiation-induced G1\\/S arrest in rat embryo fibroblasts transformed with the complementing E1A and E1B-19kDa oncogenes. This was due to selective inhibition of CyclE\\/Cdk2-associated kinase

  8. Static Material Strength Determined Using a DAC

    SciTech Connect

    Cynn, H; Evans, W; Klepeis, J P; Lipp, M; Liermann, P; Yang, W

    2009-06-04

    By measuring sample thickness and pressure gradient using x-ray absorption and x-ray diffraction, respectively, the accurate static yield strengths of Ta and Fe were determined at high pressure. This improved method has several advantages over other similar methods to quantitatively determine static material strength.

  9. 14 CFR 23.627 - Fatigue strength.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Fatigue strength. 23.627 Section 23.627...Design and Construction § 23.627 Fatigue strength. The structure must be...concentration where variable stresses above the fatigue limit are likely to occur in normal...

  10. 14 CFR 23.627 - Fatigue strength.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...2014-01-01 2014-01-01 false Fatigue strength. 23.627 Section 23.627...Design and Construction § 23.627 Fatigue strength. The structure must be...concentration where variable stresses above the fatigue limit are likely to occur in normal...

  11. 14 CFR 23.627 - Fatigue strength.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 2013-01-01 false Fatigue strength. 23.627 Section 23.627...Design and Construction § 23.627 Fatigue strength. The structure must be...concentration where variable stresses above the fatigue limit are likely to occur in normal...

  12. 14 CFR 23.627 - Fatigue strength.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 2012-01-01 false Fatigue strength. 23.627 Section 23.627...Design and Construction § 23.627 Fatigue strength. The structure must be...concentration where variable stresses above the fatigue limit are likely to occur in normal...

  13. 14 CFR 23.627 - Fatigue strength.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Fatigue strength. 23.627 Section 23.627...Design and Construction § 23.627 Fatigue strength. The structure must be...concentration where variable stresses above the fatigue limit are likely to occur in normal...

  14. Strength Development and Motor-Sports Improvement.

    ERIC Educational Resources Information Center

    Clarke, H. Harrison, Ed.

    1974-01-01

    This document examines the effects of strength-development programs on the improvement of motor skills and sports competencies. Part one defines various terms used throughout the development studies. Part two discusses the mixed results of experiments involving speed of movement as the motor item indicative of strength development. Part three…

  15. Strengths: African-American Children and Families.

    ERIC Educational Resources Information Center

    Hilliard, Asa G., III

    It is generally true that when people are deprived of their own cultural forms and are coerced into adopting the cultural forms of others, disorder, stress, and even disability will occur. Conversely, the basic strength of any people results from their experience of historical and cultural continuity. The strengths of African-American children and…

  16. Strength enhancement process for prealloyed powder superalloys

    NASA Technical Reports Server (NTRS)

    Waters, W. J.; Freche, J. C.

    1977-01-01

    A technique involving superplastic processing and high pressure autoclaving was applied to a nickel base prealloyed powder alloy. Tensile strengths as high as 2865 MN/sq m at 480 C were obtained with as-superplastically deformed material. Appropriate treatments yielding materials with high temperature tensile and stress rupture strengths were also devised.

  17. Local mode oscillator strengths in benzene

    Microsoft Academic Search

    Mitchell S. Burberry; A. C. Albrecht

    1979-01-01

    Experimentally, benzene C-H and C-D stretching modes are seen to behave as one dimensional oscillators with respect to both eigenenergies and oscillator strengths. Simple local mode models based on either Morse or quartic power series potential wavefunctions predict the correct behavior for the oscillator strength from the infrared to the visible red special region. However, it appears unlikely that the

  18. Local mode oscillator strengths in benzene

    Microsoft Academic Search

    Mitchell S. Burberry; A. C. Albrecht

    1979-01-01

    Experimentally, benzene C–H and C–D stretching modes are seen to behave as one dimensional oscillators with respect to both eigenenergies and oscillator strengths. Simple local mode models based on either Morse or quartic power series potential wavefunctions predict the correct behavior for the oscillator strength from the infrared to the visible red special region. However, it appears unlikely that the

  19. Giant monopole strength in Ni-58

    E-print Network

    Lui, YW; Clark, HL; Youngblood, David H.

    2000-01-01

    The strength distribution of the giant monopole resonance in Ni-58 has been measured from E-x = 10 to 35 MeV using small-angle scattering of 240-MeV alpha particles. E0 strength corresponding to 74(-12)(+22)% of the E0 EWSR was found between E...

  20. The Strengths Revolution: A Positive Psychology Perspective

    ERIC Educational Resources Information Center

    Peterson, Christopher

    2013-01-01

    Christopher Peterson received the Circle of Courage Award and made the following address in a symposium on "The Strength-Based Revolution" at Wayne State University in Detroit, Michigan (Peterson & Brendtro, 2008). Dr. Peterson shared personal reflections on the strengths movement, which is transforming youth development. His presentation shows…

  1. The genetic architecture of maize stalk strength

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stalk strength is an important trait in maize (Zea mays L.). Strong stalks reduce lodging and maximize harvestable yield. Studies show rind penetrometer resistance (RPR), or the force required to pierce a stalk rind with a spike, is a valid approximation of strength. We measured RPR across 4,892 rec...

  2. Determination of tensile strength of paraffin waxes

    Microsoft Academic Search

    O. G. Asadchii; B. Z. Votlokhin; N. F. Bogdanov; V. P. Gladyshev

    1979-01-01

    The tensile strength of paraffin wax is considered to be one of the important property indices that are used to characterize the service properties of this material. Methods used to determine the tensile strength of waxes are based on the use of Perkins and Tinius-Olsen testers [1]. Essentially, these methods consist of determinations of the force required to break a

  3. The mechanics of composite strength evolution

    Microsoft Academic Search

    Ken Reifsnider; Scott Case; Jeremy Duthoit

    2000-01-01

    The present paper investigates the concept of evolution of strength in fibrous composite systems. In particular, the conceptual foundations of the ‘critical-element method,’ developed by the authors, are defined and systematically combined to construct a philosophy for the prediction of remaining strength and life of composite materials in the presence of combined mechanical, thermal, and environmental applied conditions that may

  4. Surfactant effects on soil aggregate tensile strength

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known regarding a soil aggregate's tensile strength response to surfactants that may be applied to alleviate soil water repellency. Two laboratory investigations were performed to determine surfactant effects on the tensile strength of 1) Ap horizons of nine wettable, agricultural soils co...

  5. Bond Strength of Grade 100 Reinforcing Steel

    E-print Network

    Miller, Shelby

    2007-12-14

    The bond strength of Grade 100 ASTM A 1035 reinforcing steel manufactured by MMFX Technologies Corp. is evaluated with respect to bond strength equations found in ACI 318-05 and ACI 408R-03. Test specimens are fullscale beam-splice specimens tested...

  6. Tools for Building on Youth Strengths

    ERIC Educational Resources Information Center

    Cox, Kathy

    2008-01-01

    While rhetoric about strength-based approaches abounds, this perspective has not penetrated the front lines of practice. Many programs serving troubled youngsters are still mired in a deficit and deviance orientation. This article provides practical strategies for assessing the strengths of children and developing interventions to tap their assets…

  7. Relationship of z-tensile strength with in-plane strength properties of paper

    Microsoft Academic Search

    S P Singh

    Several methods are available for the measurement of strength of paper in the thickness direction. However, the values obtained from these methods are highly correlated with each other and also with the in-plane strength measurements. The relationship between z-direction tensile strength and in-plane tensile index of handsheets made at varying extents of pulp beating, types of strength aids and doses

  8. Extreme strength observed in limpet teeth

    PubMed Central

    Barber, Asa H.; Lu, Dun; Pugno, Nicola M.

    2015-01-01

    The teeth of limpets exploit distinctive composite nanostructures consisting of high volume fractions of reinforcing goethite nanofibres within a softer protein phase to provide mechanical integrity when rasping over rock surfaces during feeding. The tensile strength of discrete volumes of limpet tooth material measured using in situ atomic force microscopy was found to range from 3.0 to 6.5 GPa and was independent of sample size. These observations highlight an absolute material tensile strength that is the highest recorded for a biological material, outperforming the high strength of spider silk currently considered to be the strongest natural material, and approaching values comparable to those of the strongest man-made fibres. This considerable tensile strength of limpet teeth is attributed to a high mineral volume fraction of reinforcing goethite nanofibres with diameters below a defect-controlled critical size, suggesting that natural design in limpet teeth is optimized towards theoretical strength limits. PMID:25694539

  9. Electron impact collision strengths in Ne VII

    SciTech Connect

    Di, L.; Shi, J.R.; Zhao, G., E-mail: gzhao@bao.ac.cn

    2012-07-15

    The lines of Ne VII have been observed in many astronomical objects, and some transitions from high energy levels were observed both in Seyfert galaxies and stellar coronae. Thus, the atomic data for these transitions are important for modeling. Using the code FAC we calculated the collision strengths based on the distorted-wave method with large configuration interactions included. The Maxwellian averaged effective collision strengths covering the typical temperature range of astronomical and laboratory hot plasmas are presented. We extend the calculation of the energy levels to n=4 and 5. The energy levels, wavelengths, spontaneous transition rates, weighted oscillator strengths, and effective collision strengths were reported. Compared with the results from experiment or previous theoretical calculations a general agreement is found. It is found that the resonance effects are important in calculating the effective collision strengths.

  10. Extreme strength observed in limpet teeth.

    PubMed

    Barber, Asa H; Lu, Dun; Pugno, Nicola M

    2015-04-01

    The teeth of limpets exploit distinctive composite nanostructures consisting of high volume fractions of reinforcing goethite nanofibres within a softer protein phase to provide mechanical integrity when rasping over rock surfaces during feeding. The tensile strength of discrete volumes of limpet tooth material measured using in situ atomic force microscopy was found to range from 3.0 to 6.5 GPa and was independent of sample size. These observations highlight an absolute material tensile strength that is the highest recorded for a biological material, outperforming the high strength of spider silk currently considered to be the strongest natural material, and approaching values comparable to those of the strongest man-made fibres. This considerable tensile strength of limpet teeth is attributed to a high mineral volume fraction of reinforcing goethite nanofibres with diameters below a defect-controlled critical size, suggesting that natural design in limpet teeth is optimized towards theoretical strength limits. PMID:25694539

  11. Development of K-Basin High-Strength Homogeneous Sludge Simulants and Correlations Between Unconfined Compressive Strength and Shear Strength

    SciTech Connect

    Onishi, Yasuo; Baer, Ellen BK; Chun, Jaehun; Yokuda, Satoru T.; Schmidt, Andrew J.; Sande, Susan; Buchmiller, William C.

    2011-02-20

    K-Basin sludge will be stored in the Sludge Transport and Storage Containers (STSCs) at an interim storage location on Central Plateau before being treated and packaged for disposal. During the storage period, sludge in the STSCs may consolidate/agglomerate, potentially resulting in high-shear-strength material. The Sludge Treatment Project (STP) plans to use water jets to retrieve K-Basin sludge after the interim storage. STP has identified shear strength to be a key parameter that should be bounded to verify the operability and performance of sludge retrieval systems. Determining the range of sludge shear strength is important to gain high confidence that a water-jet retrieval system can mobilize stored K-Basin sludge from the STSCs. The shear strength measurements will provide a basis for bounding sludge properties for mobilization and erosion. Thus, it is also important to develop potential simulants to investigate these phenomena. Long-term sludge storage tests conducted by Pacific Northwest National Laboratory (PNNL) show that high-uranium-content K-Basin sludge can self-cement and form a strong sludge with a bulk shear strength of up to 65 kPa. Some of this sludge has 'paste' and 'chunks' with shear strengths of approximately 3-5 kPa and 380-770 kPa, respectively. High-uranium-content sludge samples subjected to hydrothermal testing (e.g., 185 C, 10 hours) have been observed to form agglomerates with a shear strength up to 170 kPa. These high values were estimated by measured unconfined compressive strength (UCS) obtained with a pocket penetrometer. Due to its ease of use, it is anticipated that a pocket penetrometer will be used to acquire additional shear strength data from archived K-Basin sludge samples stored at the PNNL Radiochemical Processing Laboratory (RPL) hot cells. It is uncertain whether the pocket penetrometer provides accurate shear strength measurements of the material. To assess the bounding material strength and potential for erosion, it is important to compare the measured shear strength to penetrometer measurements and to develop a correlation (or correlations) between UCS measured by a pocket penetrometer and direct shear strength measurements for various homogeneous and heterogeneous simulants. This study developed 11 homogeneous simulants, whose shear strengths vary from 4 to 170 kPa. With these simulants, we developed correlations between UCS measured by a Geotest E-280 pocket penetrometer and shear strength values measured by a Geonor H-60 hand-held vane tester and a more sophisticated bench-top unit, the Haake M5 rheometer. This was achieved with side-by-side measurements of the shear strength and UCS of the homogeneous simulants. The homogeneous simulants developed under this study consist of kaolin clay, plaster of Paris, and amorphous alumina CP-5 with water. The simulants also include modeling clay. The shear strength of most of these simulants is sensitive to various factors, including the simulant size, the intensity of mixing, and the curing time, even with given concentrations of simulant components. Table S.1 summarizes these 11 simulants and their shear strengths.

  12. Effects of intravenous lipoprostaglandin E1 on neurogenic intermittent claudication.

    PubMed

    Murakami, M; Takahashi, K; Sekikawa, T; Yasuhara, K; Yamagata, M; Moriya, H

    1997-12-01

    Circulation disturbances in the cauda equina and nerve roots have been implicated in the genesis of neurogenic intermittent claudication (NIC) in patients with lumbar spinal stenosis (LSS). We report the clinical results of lipoprostaglandin E1 (lipo-PGE1) treatments in patients with NIC. Lipo-PGE1 was administered intravenously for 10 consecutive days to 40 patients, 31 of whom showed a response to the treatment. Of the clinical symptoms examined, walking ability and leg numbness were significantly improved with an average effective period of 2.5 months. However, patients with radicular pain and severely affected patients did not respond well. Nerve root circulation in eight patients who subsequently underwent surgery was measured with a laser Doppler flowmeter. We observed increased blood flow in seven of these eight patients, after the intraoperative administration of lipo-PGE1. Lipo-PGE1 produced symptomatic improvement for a limited period in the treatment of NIC associated with LSS. The drug appeared to exert its effects through an increase in the circulation of blood in the nerve roots and the cauda equina. PMID:9438815

  13. The character strengths of class clowns.

    PubMed

    Ruch, Willibald; Platt, Tracey; Hofmann, Jennifer

    2014-01-01

    Class clowns traditionally were studied as a type concept and identified via sociometric procedures. In the present study a variable-centered approach was favored and class clown behaviors were studied in the context of character strengths, orientations to happiness and satisfaction with life. A sample of 672 Swiss children and adolescents filled in an 18 item self-report instrument depicting class clown behaviors. A hierarchical model of class clown behaviors was developed distinguishing a general factor and the four positively correlated dimensions of "identified as a class clown," "comic talent," "disruptive rule-breaker," and "subversive joker." Analysis of the general factor showed that class clowns were primarily male, and tended to be seen as class clowns by the teacher. Analyses of the 24 character strengths of the VIA-Youth (Park and Peterson, 2006) showed that class clowns were high in humor and leadership, and low in strengths like prudence, self-regulation, modesty, honesty, fairness, perseverance, and love of learning. An inspection of signature strengths revealed that 75% of class clowns had humor as a signature strength. Furthermore, class clown behaviors were generally shown by students indulging in a life of pleasure, but low life of engagement. The four dimensions yielded different character strengths profiles. While all dimensions of class clowns behaviors were low in temperance strengths, the factors "identified as the class clown" and "comic talent" were correlated with leadership strengths and the two negative factors ("disruptive rule-breaker," "subversive joker") were low in other directed strengths. The disruptive rule breaking class clown was additionally low in intellectual strengths. While humor predicted life satisfaction, class clowning tended to go along with diminished satisfaction with life. It is concluded that different types of class clowns need to be kept apart and need different attention by teachers. PMID:25324796

  14. The character strengths of class clowns

    PubMed Central

    Ruch, Willibald; Platt, Tracey; Hofmann, Jennifer

    2014-01-01

    Class clowns traditionally were studied as a type concept and identified via sociometric procedures. In the present study a variable-centered approach was favored and class clown behaviors were studied in the context of character strengths, orientations to happiness and satisfaction with life. A sample of 672 Swiss children and adolescents filled in an 18 item self-report instrument depicting class clown behaviors. A hierarchical model of class clown behaviors was developed distinguishing a general factor and the four positively correlated dimensions of “identified as a class clown,” “comic talent,” “disruptive rule-breaker,” and “subversive joker.” Analysis of the general factor showed that class clowns were primarily male, and tended to be seen as class clowns by the teacher. Analyses of the 24 character strengths of the VIA-Youth (Park and Peterson, 2006) showed that class clowns were high in humor and leadership, and low in strengths like prudence, self-regulation, modesty, honesty, fairness, perseverance, and love of learning. An inspection of signature strengths revealed that 75% of class clowns had humor as a signature strength. Furthermore, class clown behaviors were generally shown by students indulging in a life of pleasure, but low life of engagement. The four dimensions yielded different character strengths profiles. While all dimensions of class clowns behaviors were low in temperance strengths, the factors “identified as the class clown” and “comic talent” were correlated with leadership strengths and the two negative factors (“disruptive rule-breaker,” “subversive joker”) were low in other directed strengths. The disruptive rule breaking class clown was additionally low in intellectual strengths. While humor predicted life satisfaction, class clowning tended to go along with diminished satisfaction with life. It is concluded that different types of class clowns need to be kept apart and need different attention by teachers. PMID:25324796

  15. Influence of Muscle Strength on Bone Strength during Childhood and Adolescence

    Microsoft Academic Search

    E. Schönau; E. Werhahn; U. Schiedermaier; E. Mokow; H. Schiessl; K. Scheidhauer; D. Michalk

    1996-01-01

    In connection with the prevention of osteoporosis, paediatrics is challenged with ensuring the optimal formation of the skeletal system with maximal bone strength during childhood and youth. Biomechanical use represents the most important stimulus for activating the skeletal system. The measurement of muscle strength (grip strength) in 97 females aged 3-62 years and 71 males aged 3-61 years showed an

  16. Enhanced TRAIL sensitivity by E1A expression in human cancer and normal cell lines: inhibition by adenovirus E1B19K and E3 proteins.

    PubMed

    Hu, Baoli; Zhu, Huabin; Qiu, Songbo; Su, Yue; Ling, Weifang; Xiao, Wei; Qi, Yipeng

    2004-12-24

    TNF-related apoptosis-inducing ligand (TRAIL) is a member of the TNF superfamily of cytokines that induces apoptosis in a variety of cancer cells, but not in normal cells. However, more and more tumor cells remain resistant to TRAIL, which limited its application for cancer therapy. Expression of the adenovirus serotype 5 (Ad5) E1A sensitizes tumor cells to apoptosis by TNF-alpha, Fas-ligand, and TRAIL. Here we asked whether E1A overcomes this resistance and enhances TRAIL-induced apoptosis in the tumor cells. Our results revealed that the tumor cell lines, HeLa and HepG2, with infection by Ad-E1A, were highly sensitive to TRAIL-induced apoptosis. Importantly, we found that in normal primary human lung fibroblast cells (HLF) TRAIL is capable of inducing apoptosis in combination with E1A as efficiently as in some tumor cell lines. The adenovirus type 5 encoding proteins, E1B19K and E3 gene products, have been shown to inhibit E1A and TRAIL-induced apoptosis of HLF cells by using the recombinant adenovirus AdDeltaE1B55K, with mutation of E1B55K, containing E1B19K and complete E3 region. Further results demonstrated that the expression of DR5 and TRAIL was down-regulated in the AdDeltaE1B55K co-infected HLF cells. These findings suggest that TRAIL may play an important role in limiting virus infections and the ability of adenovirus to inhibit killing may prolong acute and persistent infections. The results from this study have also suggested the possibility that the combination of E1A with TRAIL could be used in the treatment of human malignancy, or in the selection of the optimal adenovirus mutant as effective delivering vector for cancer therapy. PMID:15555548

  17. Adenovirus E1A proteins are closely associated with chromatin in productively infected and transformed cells

    Microsoft Academic Search

    Maurice Green; Ninder K. Panesar; Paul M. Loewenstein

    2008-01-01

    The adenovirus E1A 243R oncoprotein encodes a potent transcription-repression function within the N-terminal 80 amino acids. Our proposed model of E1A repression predicts that E1A interacts with important cellular proteins on chromatin. Consistent with this idea, we report here that E1A proteins from in vivo formaldehyde cross-linked 293 cells are closely associated with chromatin even after several stringent purification steps

  18. Geometry and gravity influences on strength capability

    NASA Technical Reports Server (NTRS)

    Poliner, Jeffrey; Wilmington, Robert P.; Klute, Glenn K.

    1994-01-01

    Strength, defined as the capability of an individual to produce an external force, is one of the most important determining characteristics of human performance. Knowledge of strength capabilities of a group of individuals can be applied to designing equipment and workplaces, planning procedures and tasks, and training individuals. In the manned space program, with the high risk and cost associated with spaceflight, information pertaining to human performance is important to ensuring mission success and safety. Knowledge of individual's strength capabilities in weightlessness is of interest within many areas of NASA, including workplace design, tool development, and mission planning. The weightless environment of space places the human body in a completely different context. Astronauts perform a variety of manual tasks while in orbit. Their ability to perform these tasks is partly determined by their strength capability as demanded by that particular task. Thus, an important step in task planning, development, and evaluation is to determine the ability of the humans performing it. This can be accomplished by utilizing quantitative techniques to develop a database of human strength capabilities in weightlessness. Furthermore, if strength characteristics are known, equipment and tools can be built to optimize the operators' performance. This study examined strength in performing a simple task, specifically, using a tool to apply a torque to a fixture.

  19. Identification of a Nuclear Export Signal Sequence for Bovine Papillomavirus E1 Protein

    PubMed Central

    Rosas-Acosta, Germán; Wilson, Van G.

    2008-01-01

    Recent studies have demonstrated nuclear export by papillomavirus E1 proteins, but the requisite export sequence(s) for bovine papillomavirus (BPV) E1 were not defined. In this report we identify three functional nuclear export sequences (NES) present in BPV E1, with NES2 being the strongest in reporter assays. Nuclear localization of BPV1 E1 was modulated by over or under expression of the Crm1, the major cellular exportin, and export was strongly reduced by the Crm1 inhibitor, Leptomycin B, indicating that E1 export occurs primarily through a Crm1-dependent process. Consistent with the in vivo functional results, E1 bound Crm1 in an in vitro pulldown assays. In addition, sumoylated E1 bound Crm1 more effectively than unmodified E1, suggesting that E1 export may be regulated by SUMO modification. Lastly, an E1 NES2 mutant accumulated in the nucleus to a greater extent than wildtype E1, yet was defective for viral origin replication, implying that nucleocytoplasmic shuttling may be required to maintain E1 in a replication competent state. PMID:18201744

  20. Novel mechanism of JNK pathway activation by adenoviral E1A

    PubMed Central

    Morrison, Helen; Pospelova, Tatiana V.; Pospelov, Valery A.; Herrlich, Peter

    2014-01-01

    The adenoviral oncoprotein E1A influences cellular regulation by interacting with a number of cellular proteins. In collaboration with complementary oncogenes, E1A fully transforms primary cells. As part of this action, E1A inhibits transcription of c-Jun:Fos target genes while promoting that of c-Jun:ATF2-dependent genes including jun. Both c-Jun and ATF2 are hyperphosphorylated in response to E1A. In the current study, E1A was fused with the ligand binding domain of the estrogen receptor (E1A-ER) to monitor the immediate effect of E1A activation. With this approach we now show that E1A activates c-Jun N-terminal kinase (JNK), the upstream kinases MKK4 and MKK7, as well as the small GTPase Rac1. Activation of the JNK pathway requires the N-terminal domain of E1A, and, importantly, is independent of transcription. In addition, it requires the presence of ERM proteins. Downregulation of signaling components upstream of JNK inhibits E1A-dependent JNK/c-Jun activation. Taking these findings together, we show that E1A activates the JNK/c-Jun signaling pathway upstream of Rac1 in a transcription-independent manner, demonstrating a novel mechanism of E1A action. PMID:24742962

  1. Novel mechanism of JNK pathway activation by adenoviral E1A.

    PubMed

    Romanov, Vasily S; Brichkina, Anna I; Morrison, Helen; Pospelova, Tatiana V; Pospelov, Valery A; Herrlich, Peter

    2014-04-30

    The adenoviral oncoprotein E1A influences cellular regulation by interacting with a number of cellular proteins. In collaboration with complementary oncogenes, E1A fully transforms primary cells. As part of this action, E1A inhibits transcription of c-Jun:Fos target genes while promoting that of c-Jun:ATF2-dependent genes including jun. Both c-Jun and ATF2 are hyperphosphorylated in response to E1A. In the current study, E1A was fused with the ligand binding domain of the estrogen receptor (E1A-ER) to monitor the immediate effect of E1A activation. With this approach we now show that E1A activates c-Jun N-terminal kinase (JNK), the upstream kinases MKK4 and MKK7, as well as the small GTPase Rac1. Activation of the JNK pathway requires the N-terminal domain of E1A, and, importantly, is independent of transcription. In addition, it requires the presence of ERM proteins. Downregulation of signaling components upstream of JNK inhibits E1A-dependent JNK/c-Jun activation. Taking these findings together, we show that E1A activates the JNK/c-Jun signaling pathway upstream of Rac1 in a transcription-independent manner, demonstrating a novel mechanism of E1A action. PMID:24742962

  2. [Analysis of transient G1/S arrest in E1A+E1B-19kDa transformed cells after ionizing radiation].

    PubMed

    Brichkina, A I; Aksenov, N D; Pospelov, V A; Pospelova, T V

    2003-01-01

    Expression of human adenovirus type 5 E1A oncogene in normal rodent cells leads to disruption of the G1/S cell cycle arrest realization in response to DNA damage. It has been shown here that rat embryo fibroblasts transformed by E1Aad5 oncogene in complementation with E1B-19 kDa gene realize the irradiation-induced transient G1/S arrest, which depends on selective suppression of CyclinE-Cdk2 activity despite functional inactivation of p21Waf1 inhibitor. Inhibitor p21Waf1 is not revealed in complexes with cyclins E and A in E1A + E1B-19 kDa transformants, however, it is not due to p21Waf1 interaction with E1A oncoproteins, because the E1A-p21Waf1 complex formation in E1A + cHa-ras transformants does not prevent the high level of CycIE, A-p21Waf1 association. In the case of p21Waf1 inactivation, the main way of cyclin-kinase activity regulation in E1A + E1B-19 kDa cells may be Cdk2 phosphorylation. However, irradiation of E1A + E1B-19 kDa transformed cells induces no changes in CAK (Cdk7-associated) kinase activity and in the protein level of Cdc25A phosphatase, which are responsible for activating Thr160 phosphoralation and Tyr15 dephosphorylation on Cdk2. Using phospho-Tyr15-Cdk2 specific antibodies, no increase of phosphorylation at Tyr15 position on immunoprecipitated Cdk2 was detected after irradiation. It seems likely that in the case of inactivated inhibitor p21Waf1 the transient G1/S block after irradiation in E1A + E1B-19 kDa transformants depends on suppression of Cycl-E-Cdk2 activity caused by inhibition of Thr160 Cdk2 phosphorylation, but his occurs with the involvement of other kinases rather than CAK. PMID:15027353

  3. Effects of eccentric strength training on different maximal strength and speed-strength parameters of the lower extremity.

    PubMed

    Wirth, Klaus; Keiner, Michael; Szilvas, Elena; Hartmann, Hagen; Sander, Andre

    2014-05-14

    The aim of this investigation was to analyze the effects of an eccentric strength training protocol using supramaximal loads (> 1RM; 1RM = one-repetition maximum) on different maximal and explosive strength parameters of the lower extremity. The eccentric maximal strength (EX max), maximal isometric strength (MVC = "maximal voluntary contraction"), one-repetition maximum (1RM), explosive strength (RFD = "rate of force development"), countermovement jump (CMJ) and squat jump (SJ) height were tested before and after a training period of 6 weeks. The training group was composed of 15 individuals with low-weight training experience and a control group of 13 subjects, also with a low-weight training experience. The lower extremities were trained three days per week using a 45-degree leg press. Each training session comprised 5 sets of 3 repetitions with a 6-min rest between each set. The training weights were adjusted continuously during each training session as well as between training sessions. In each case, a load was chosen that could be lowered unilaterally in a controlled manner by the subjects. For the concentric part of the exercise, two investigators lifted the weight to the starting position. After 6 weeks, strength training with supramaximal loads showed a significant increase in Ex max (28.2%, p <0.001) and 1RM (31.1%, p <0.001). The increases observed in the control group were not significant. Changes in MVC, RFD and vertical jump heights were not significant in both groups. The results of this study suggest that in untrained subjects, unilateral eccentric strength training in the leg press generates equal and significant improvements in unilateral eccentric and bilateral eccentric-concentric maximal strength, with a non-significant transfer to vertical jump performances and unilateral isometric force production. PMID:24832973

  4. Obi-Wan Adobe: Engineering for Strength

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program,

    Students conduct an experiment to determine how varying the composition of a construction material affects its strength. They make several adobe bricks with differing percentages of sand, soil, fibrous material and water. They test the bricks for strength by dropping them onto a concrete surface from progressively greater heights. Students graph the experiment results and use what they learn to design their own special mix that maximizes the bricks' strength. During the course of the experiment, students learn about variables (independent, dependent, control) and the steps of the engineering design process.

  5. Method and apparatus for determining tensile strength

    DOEpatents

    Ratigan, J.L.

    1982-05-28

    A method and apparatus is described for determining the statistical distribution of apparent tensile strength of rock, the size effect with respect to tensile strength, as well as apparent deformation modulus of both intact and fractured or jointed rock. The method is carried out by inserting a plug of deformable material, such as rubber, in an opening of a specimen to be tested. The deformable material is loaded by an upper and lower platen until the specimen ruptures, whereafter the tensile strength is calculated based on the parameters of the test specimen and apparatus.

  6. Modeling strength data for CREW CHIEF

    NASA Technical Reports Server (NTRS)

    Mcdaniel, Joe W.

    1990-01-01

    The Air Force has developed CREW CHIEF, a computer-aided design (CAD) tool for simulating and evaluating aircraft maintenance to determine if the required activities are feasible. CREW CHIEF gives the designer the ability to simulate maintenance activities with respect to reach, accessibility, strength, hand tool operation, and materials handling. While developing the CREW CHIEF, extensive research was performed to describe workers strength capabilities for using hand tools and manual handling of objects. More than 100,000 strength measures were collected and modeled for CREW CHIEF. These measures involved both male and female subjects in the 12 maintenance postures included in CREW CHIEF. The data collection and modeling effort are described.

  7. Method and apparatus for determining tensile strength

    DOEpatents

    Ratigan, Joe L. (Rapid City, SD)

    1984-01-01

    A method and apparatus for determining the statistical distribution of apparent tensile strength of rock, the size effect with respect to tensile strength, as well as apparent deformation modulus of both intact and fractured or jointed rock. The method is carried out by inserting a plug of deformable material, such as rubber, in an opening of a specimen to be tested. The deformable material is loaded by an upper and lower platen until the specimen ruptures, whereafter the tensile strength is calculated based on the parameters of the test specimen and apparatus.

  8. in2p3-00145687,version1-11May2007 Search for low lying dipole strength in the neutron rich nucleus 26

    E-print Network

    Boyer, Edmond

    in2p3-00145687,version1-11May2007 1 Search for low lying dipole strength in the neutron rich 171-8501, Japan c RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama.MeV in order to search for low-lying E1 strength above the neutron emission threshold. Data were also taken

  9. Identification of 2-Piperidone as a Biomarker of CYP2E1 Activity Through Metabolomic Phenotyping

    PubMed Central

    Cheng, Jie; Chen, Chi; Gonzalez, Frank J.

    2013-01-01

    Cytochrome P450 2E1 (CYP2E1) is a key enzyme in the metabolic activation of many low molecular weight toxicants and also an important contributor to oxidative stress. A noninvasive method to monitor CYP2E1 activity in vivo would be of great value for studying the role of CYP2E1 in chemical-induced toxicities and stress-related diseases. In this study, a mass spectrometry–based metabolomic approach was used to identify a metabolite biomarker of CYP2E1 through comparing the urine metabolomes of wild-type (WT), Cyp2e1-null, and CYP2E1-humanized mice. Metabolomic analysis with multivariate models of urine metabolites revealed a clear separation of Cyp2e1-null mice from WT and CYP2E1-humanized mice in the multivariate models of urine metabolomes. Subsequently, 2-piperidone was identified as a urinary metabolite that inversely correlated to the CYP2E1 activity in the three mouse lines. Backcrossing of WT and Cyp2e1-null mice, together with targeted analysis of 2-piperidone in mouse serum, confirmed the genotype dependency of 2-piperidone. The accumulation of 2-piperidone in the Cyp2e1-null mice was mainly caused by the changes in the biosynthesis and degradation of 2-piperidone because compared with the WT mice, the conversion of cadaverine to 2-piperidone was higher, whereas the metabolism of 2-piperidone to 6-hydroxy-2-piperidone was lower in the Cyp2e1-null mice. Overall, untargeted metabolomic analysis identified a correlation between 2-piperidone concentrations in urine and the expression and activity of CYP2E1, thus providing a noninvasive metabolite biomarker that can be potentially used in to monitor CYP2E1 activity. PMID:23811823

  10. Harmonic two-phonon {gamma}-vibrational state in neutron-rich {sup 106}Mo

    SciTech Connect

    Guessous, A.; Schulz, N.; Phillips, W.R.; Ahmad, I.; Bentaleb, M.; Durell, J.L.; Jones, M.A.; Leddy, M.; Lubkiewicz, E.; Morss, L.R.; Piepenbring, R.; Smith, A.G.; Urban, W.; Varley, B.J. [Centre de Recherches Nucleaires, IN2P3-CNRS/Universite Louis Pasteur, 67037 Strasbourg (France)] [Centre de Recherches Nucleaires, IN2P3-CNRS/Universite Louis Pasteur, 67037 Strasbourg (France); [Department of Physics, University of Manchester, M13 9PL (United Kingdom); [Argonne National Laboratory, Argonne, Illinois 60439 (United States); [Institut des Sciences Nucleaires, IN2P3-CNRS/UJF, 38026 Grenoble (France)

    1995-09-18

    The neutron-rich {sup 106}Mo nucleus has been studied by prompt {gamma}-ray spectroscopy following the spontaneous fission of {sup 248}Cm. The characteristics of the rotational band built on a state at 1435 keV identifies the band head as the best candidate for a harmonic double-phonon {ital K}{sup {pi}}=4{sup +} {gamma}-vibrational state observed so far.

  11. High strength oxidation resistant alpha titanium alloy

    SciTech Connect

    Gigliotti, F.X. Jr.; Rowe, R.G.; Wasielewski, G.E.

    1990-03-06

    This patent describes alpha titanium alloys containing aluminum, hafnium and/or tantalum has been found to have improved creep and tensile strengths as well as oxidtion resistance at temperature up to about 700{degrees}C without embrittlement.

  12. Nutritional Supplements for Strength Power Athletes

    NASA Astrophysics Data System (ADS)

    Wilborn, Colin

    Over the last decade research involving nutritional supplementation and sport performance has increased substantially. Strength and power athletes have specific needs to optimize their performance. Nutritional supplementation cannot be viewed as a replacement for a balanced diet but as an important addition to it. However, diet and supplementation are not mutually exclusive, nor does one depend on the other. Strength and power athletes have four general areas of supplementation needs. First, strength athletes need supplements that have a direct effect on performance. The second group of supplements includes those that promote recovery. The third group comprises the supplements that enhance immune function. The last group of supplements includes those that provide energy or have a direct effect on the workout. This chapter reviews the key supplements needed to optimize the performance and training of the strength athlete.

  13. Development of High Specific Strength Envelope Materials

    NASA Astrophysics Data System (ADS)

    Komatsu, Keiji; Sano, Masa-Aki; Kakuta, Yoshiaki

    Progress in materials technology has produced a much more durable synthetic fabric envelope for the non-rigid airship. Flexible materials are required to form airship envelopes, ballonets, load curtains, gas bags and covering rigid structures. Polybenzoxazole fiber (Zylon) and polyalirate fiber (Vectran) show high specific tensile strength, so that we developed membrane using these high specific tensile strength fibers as a load carrier. The main material developed is a Zylon or Vectran load carrier sealed internally with a polyurethane bonded inner gas retention film (EVOH). The external surface provides weather protecting with, for instance, a titanium oxide integrated polyurethane or Tedlar film. The mechanical test results show that tensile strength 1,000 N/cm is attained with weight less than 230g/m2. In addition to the mechanical properties, temperature dependence of the joint strength and solar absorptivity and emissivity of the surface are measured.?

  14. Strength Training Guidelines for Cardiac Patients.

    ERIC Educational Resources Information Center

    Sparling, Phillip B.; Cantwell, John D.

    1989-01-01

    Provides practical guidelines for a strength training program for cardiac patients which may be modified to fit a particular program. The recommendations include criteria for admission, procedures for orientation and instruction, and techniques for supervision. (SM)

  15. Assessing Soil Strength From Geophysical Surveys

    E-print Network

    Khan, Rehan

    2014-04-24

    A study is presented to develop framework for correlating sand strength (friction angle) to geophysical measurements, primarily shear wave and body wave velocities. Triaxial tests accompanied by wave velocity measurements was performed to generate a...

  16. Multiscale strength homogenization : application to shale nanoindentation

    E-print Network

    Gathier, Benjamin

    2008-01-01

    Shales are one of the most encountered materials in sedimentary basins. Because of their highly heterogeneous nature, their strength prediction for oil and gas exploitation engineering has long time been an enigma. In this ...

  17. Range resolution of unequal strength targets

    E-print Network

    Carlson, Blair D.

    This paper examines the problem of resolving targets whose amplitudes may differ. A common metric used for resolution that assumes targets of equal strength is modified for the subject scenario. An expression for range ...

  18. Fatigue Strength of Airplane and Engine Materials

    NASA Technical Reports Server (NTRS)

    Matthaes, Kurt

    1934-01-01

    This report was undertaken to give a brief summary of the laws governing the fatigue stresses and of the most important strength coefficients necessary for the correct dimensioning of the structural members.

  19. Crew Strength Training - Duration: 2:56.

    NASA Video Gallery

    Train to develop your upper and lower body strength in your muscles and bones by performing body-weight squats and push-ups.The Train Like an Astronaut project uses the excitement of exploration to...

  20. 14 CFR 35.24 - Strength.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: PROPELLERS Design and Construction § 35.24 Strength. The maximum stresses developed in the propeller may not exceed values acceptable to the Administrator...

  1. Improvement of fatigue strength of structural steel

    SciTech Connect

    Iwata, M.; Huang, Y.; Samudro [Hiroshima Univ., Higashi-Hiroshima (Japan)

    1994-12-31

    Because fatigue failures occur often at stress concentration sites in steel structures loaded dynamically, the improvement of fatigue strength in these structures becomes an important problem. Therefore, some counter-measures to decrease the stress concentration, for example, reforming shape of structure members, smoothing weld toes, etc. are taken in design or manufacturing process. In this report, the effects of thermomechanical treatments: quench aging, strain aging and work hardening are studied to improve the fatigue strength of structural steel. The result shows that the fatigue strength of rapid-cooled and cold-rolled steel increases remarkably as the cumulative effects of the strain aging and work hardening. An aging treatment at 100 C or 70 C for 2 hours after heating, rapid-cooling, and cold rolling process improves the fatigue strength of steel, due to quench aging in which supersaturated carbon atoms precipitate as fine carbide particles along dislocations, and/or due to accelerate strain aging during fatigue test.

  2. Strengths of serpentinite gouges at elevated temperatures

    USGS Publications Warehouse

    Moore, D.E.; Lockner, D.A.; Ma, S.; Summers, R.; Byerlee, J.D.

    1997-01-01

    Serpentinite has been proposed as a cause of both low strength and aseismic creep of fault zones. To test these hypotheses, we have measured the strength of chrysotile-, lizardite-, and antigorite-rich serpentinite gouges under hydrothermal conditions, with emphasis on chrysotile, which has thus far received little attention. At 25??C, the coefficient of friction, ??, of chrysotile gouge is roughly 0.2, whereas the lizardite- and antigorite-rich gouges are at least twice as strong. The very low room temperature strength of chrysotile is a consequence of its unusually high adsorbed water content. When the adsorbed water is removed, chrysotile is as strong as pure antigorite gouge at room temperature. Heating to ???200??C causes the frictional strengths of all three gouges to increase. Limited data suggest that different polytypes of a given serpentine mineral have similar strengths; thus deformation-induced changes in polytype should not affect fault strength. At 25??C, the chrysotile gouge has a transition from velocity strengthening at low velocities to velocity weakening at high velocities, consistent with previous studies. At temperatures up to ???200??C, however, chrysotile strength is essentially independent of velocity at low velocities. Overall, chrysotile has a restricted range of velocity-strengthening behavior that migrates to higher velocities with increasing temperature. Less information on velocity dependence is available for the lizardite and antigorite gouges, but their behavior is consistent with that outlined for chrysotile. The marked changes in velocity dependence and strength of chrysotile with heating underscore the hazards of using room temperature data to predict fault behavior at depth. The velocity behavior at elevated temperatures does not rule out serpentinite as a cause of aseismic slip, but in the presence of a hydrostatic fluid pressure gradient, all varieties of serpentine are too strong to explain the apparent weakness of faults such as the San Andreas.

  3. Seal strength models for medical device trays

    E-print Network

    Mays, Patricia Faye

    2009-05-15

    OF PHILOSOPHY May 2008 Major Subject: Industrial Engineering SEAL STRENGTH MODELS FOR MEDICAL DEVICE TRAYS A Dissertation by PATRICIA MAYS Submitted to the Office of Graduate Studies of Texas A&M University in partial... Major Subject: Industrial Engineering iii ABSTRACT Seal Strength Models for Medical Device Trays. (May 2008) Patricia Mays, B.S., University of Arkansas at Fayetteville; M.S., University of Arkansas at Fayetteville Chair of Advisory Committee...

  4. REVIEWS OF TOPICAL PROBLEMS: Strength of nanostructures

    NASA Astrophysics Data System (ADS)

    Andrievski, Rostislav A.; Glezer, Aleksandr M.

    2009-04-01

    A state-of-the-art review is presented of research into the strength, the ductility, the superplasticity, and other mechanical properties of metal, alloy, intermetallic, semiconductor, and high-melting-point compound-based nanomaterials. Various theoretical approaches are described. Size effects, interfaces, and other structural factors are examined from the standpoint of their influence on the strength and plasticity of nanostructured materials. Some problems yet to be solved are pointed out.

  5. IMPACT STRENGTH OF GLASS AND GLASS CERAMIC

    SciTech Connect

    Bless, S.; Tolman, J. [Institute for Advanced Technology, University of Texas at Austin, Austin, TX 78759 (United States)

    2009-12-28

    Strength of glass and glass ceramic was measured with a bar impact technique. High-speed movies show regions of tensile and compressive failure. The borosilicate glass had a compressive strength of at least 2.2 GPa, and the glass ceramic at least 4 GPa. However, the BSG was much stronger in tension than GC. In ballistic tests, the BSG was the superior armor.

  6. Nutritional Supplements for Strength Power Athletes

    Microsoft Academic Search

    Colin Wilborn

    2008-01-01

    \\u000a Over the last decade research involving nutritional supplementation and sport performance has increased substantially. Strength\\u000a and power athletes have specific needs to optimize their performance. Nutritional supplementation cannot be viewed as a replacement\\u000a for a balanced diet but as an important addition to it. However, diet and supplementation are not mutually exclusive, nor\\u000a does one depend on the other. Strength

  7. High-Hot-Strength Ceramic Fibers

    NASA Technical Reports Server (NTRS)

    Sayir, Ali; Matson, Lawrence E.

    1994-01-01

    Continuous fibers consisting of laminae of alumina and yttrium aluminum garnet offer exceptionally high strength, resistance to creep, and chemical stability at high temperatures. These fibers exceed tensile strength of sapphire fibers. Leading candidates for reinforcement of intermetallic-matrix composites in exhaust nozzles of developmental high-speed civil transport aircraft engines. Other applications are in aerospace, automotive, chemical-process, and power-generation industries.

  8. Residual Strength of Clays at High Suctions

    Microsoft Academic Search

    Jean Vaunat; Vladimir Merchán; Enrique Romero; Jubert Pineda

    This paper presents a study on the residual shear strength of a plastic clay (Boom clay) under high suction. The device, an\\u000a adaptation of Bromhead ring shear apparatus to allow for suction control during shearing, is first described and the experimental\\u000a procedure detailed. Then, results of shear strength measured under a suction equal to 70 MPa, several vertical stresses and

  9. Compressive strength and microplasticity in polycrystalline alumina

    Microsoft Academic Search

    James Lankford

    1977-01-01

    The compressive strength of polycrystalline alumina at 23° C is found to be strain-rate sensitive, but insensitive to environment. Scanning electron microscopy of specimens loaded to near failure indicates the origin of the strength-strain-rate dependence to be localized plasticity in the form of twinning and, possibly, slip. The interaction of these deformation bands with grain boundaries causes the initiation of

  10. Elastic stability and the limit of strength

    SciTech Connect

    Morris Jr., J.W.; Krenn, C.R.; Roundy, D.; Cohen, Marvin L.

    2002-07-01

    The upper limit of strength (the ''theoretical strength'') has been an active subject of research and speculation for the better part of a century. The subject has recently become important, for two reasons. First, given recent advances in ab initio techniques and computing machines, the limits of strength can be calculated with considerable accuracy, making this one of the very few problems in mechanical behavior that can actually be solved. Second, given recent advances in materials engineering, the limits of strength are being approached in some systems, such as hardened or defect-free films, and their relevance is becoming recognized in others. The present paper discusses some interesting results from recent research on the limits of strength, with an intermixture of speculations based on those results. Topics include the inherent nature of {l_brace}100{r_brace} cleavage and ''pencil slip'' in bcc metals, the inherent ductility of fcc metals, the anomalous properties of Al, and the possibility of measuring ideal strength with nanoindentation.

  11. DNA-binding domain of bovine papillomavirus type 1 E1 helicase: structural and functional aspects.

    PubMed Central

    Thorner, L K; Lim, D A; Botchan, M R

    1993-01-01

    The E1 protein of bovine papillomavirus type 1 is a multifunctional enzyme required for papillomaviral DNA replication. It assists in the initiation of replication both as a site-specific DNA-binding protein and as a DNA helicase. Previous work has indicated that at limiting E1 concentrations, the E2 protein is required for efficient E1 binding to the replication origin. In this study, we have defined the domain of the E1 protein required for site-specific DNA binding. Experiments with a series of truncated proteins have shown that the first amino-terminal 299 amino acids contain the DNA-binding domain; however, the coterminal M protein, which is homologous to E1 for the first 129 amino acids, does not bind origin DNA. A series of small internal deletions and substitution mutations in the DNA-binding domain of E1 show that specific basic residues in this region of the protein, which are conserved in all E1 proteins of the papillomavirus family, likely play a direct role in binding DNA and that a flanking conserved hydrophobic subdomain is also important for DNA binding. A region of E1 that interacts with E2 for cooperative DNA binding is also retained in carboxy-terminal truncated proteins, and we show that the ability of full-length E1 to complex with E2 is sensitive to cold. The E1 substitution mutant proteins were expressed from mammalian expression vectors to ascertain whether site-specific DNA binding by E1 is required for transient DNA replication in the cell. These E1 proteins display a range of mutant phenotypes, consistent with the suggestion that site-specific binding by E1 is important. Interestingly, one E1 mutant which is defective for origin binding but can be rescued for such activity by E2 supports significant replication in the cell. Images PMID:8396665

  12. Lifetime of the K{sup pi} = 8{sup -} isomer in the neutron-rich nucleus, {sup 174}Er and N = 106 E1 systematics.

    SciTech Connect

    Dracoulis, G. D.; Lane, G. J.; Kondev, F. G.; Watanabe, H.; Seweryniak, D.; Zhu, S.; Carpenter, M. P.; Chiara, C. J.; Janssens, R. V. F.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A.; Stefanescu, I.; Australian National Univ.; RIKEN; Univ. of Maryland

    2009-06-01

    Chopped-beam techniques and {gamma}-ray spectroscopy with Gammasphere have been used to measure the lifetime of the 1112-keV 8{sup -} isomeric state in {sup 174}Er. The value obtained of {tau} = 5.8(4) s corresponds to a reduced hindrance of f{sub {nu}} = 98 for the 163-keV E1 transition to the 8{sup +} state of the ground-state band, in good agreement with the systematics of the corresponding E1 strengths in the N = 106 isotones. The K-mixing in the 8{sup -} states is calculated in the context of the particle-rotor model and used to extract the underlying reduced hindrances.

  13. Lifetime of the K{sup {pi}}=8{sup -} isomer in the neutron-rich nucleus {sup 174}Er, and N=106 E1 systematics

    SciTech Connect

    Dracoulis, G. D.; Lane, G. J. [Department of Nuclear Physics, R. S. Phys. S. E, Australian National University, Canberra ACT 0200 (Australia); Kondev, F. G.; Chiara, C. J. [Nuclear Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Watanabe, H. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Seweryniak, D.; Zhu, S.; Carpenter, M. P.; Janssens, R. V. F.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Stefanescu, I. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742 (United States)

    2009-06-15

    Chopped-beam techniques and {gamma}-ray spectroscopy with Gammasphere have been used to measure the lifetime of the 1112-keV 8{sup -} isomeric state in {sup 174}Er. The value obtained of {tau}=5.8(4) s corresponds to a reduced hindrance of f{sub {nu}}=98 for the 163-keV E1 transition to the 8{sup +} state of the ground-state band, in good agreement with the systematics of the corresponding E1 strengths in the N=106 isotones. The K-mixing in the 8{sup -} states is calculated in the context of the particle-rotor model and used to extract the underlying reduced hindrances.

  14. Notched Strength Allowables and Inplane Shear Strength of AS4/VRM-34 Textile Laminates

    NASA Technical Reports Server (NTRS)

    Grenoble, Ray W.; Johnston, William M.

    2013-01-01

    Notched and unnotched strength allowables were developed for a textile composite to provide input data to analytical structural models based on the Pultruded Rod Stiffened Efficient Unitized Structure (PRSEUS) concept. Filled-hole tensile strength, filled-hole compressive strength, and inplane shear strength along stitch lines have been measured. The material system evaluated in this study is based on warp-knitted preforms of AS4 carbon fibers and VRM-34 epoxy resin, which have been processed via resin infusion and oven curing. All specimens were tested in as-fabricated (dry) condition. Filled-hole strengths were evaluated with and without through-thickness stitching. The effects of scaling on filled-hole tensile strength were evaluated by testing specimens in two widths, but with identical width / hole-diameter ratios. Inplane shear specimens were stitched in two configurations, and two specimen thicknesses were tested for each stitch configuration.

  15. Correlation between microstructure and yield strength of a high-strength cold rolled enameling steel

    NASA Astrophysics Data System (ADS)

    Jiang, M.; Zheng, F. J.; Huang, X. F.; Dai, T.; Krakauer, B. W.; Zhu, M. F.

    2012-07-01

    To develop strategies for modifying the enameling steel chemical composition and processing to minimize yield strength reduction during the enamel-fire anneal (EFA), the reasons for yield strength reduction of a high strength cold rolled enameling steel were studied by combining experiments and thermodynamic calculations. The yield strength reductions were evaluated from the primary strengthening mechanism using existing empirical relationships that relate microstructural parameters to yield strength. The results show that yield strength reductions resulted primarily from an increase in grain size and a decrease in dislocation density. The EFA appeared to have a negligible effect on the solubilities of Mn, Si, and P, and the solubilities are nearly equal to the bulk concentrations. On the other hand, the elements C and N are nearly completely tied up as precipitates in the form of cementite and AlN. Thus, they have a negligible contribution to solid solution strengthening.

  16. The effect of mineral bond strength and adsorbed water on fault gouge frictional strength

    USGS Publications Warehouse

    Morrow, C.A.; Moore, D.E.; Lockner, D.A.

    2000-01-01

    Recent studies suggest that the tendency of many fault gouge minerals to take on adsorbed or interlayer water may strongly influence their frictional strength. To test this hypothesis, triaxial sliding experiments were conducted on 15 different single-mineral gouges with various water-adsorbing affinities. Vacuum dried samples were sheared at 100 MPa, then saturated with water and sheared farther to compare dry and wet strengths. The coefficients of friction, ?, for the dry sheet-structure minerals (0.2-0.8), were related to mineral bond strength, and dropped 20-60% with the addition of water. For non-adsorbing minerals (? = 0.6-0.8), the strength remained unchanged after saturation. These results confirm that the ability of minerals to adsorb various amounts of water is related to their relative frictional strengths, and may explain the anomalously low strength of certain natural fault gouges.

  17. The tumor suppression activity of E1A in HER-2/neu-overexpressing breast cancer.

    PubMed

    Chang, J Y; Xia, W; Shao, R; Sorgi, F; Hortobagyi, G N; Huang, L; Hung, M C

    1997-02-01

    The HER-2/neu proto-oncogene is frequently amplified or overexpressed in human breast and ovarian cancers, and is significantly correlated with shorter survival. We have previously reported that the adenovirus type 5 early region 1A (E1A) gene product can repress HER-2/neu overexpression by repressing HER-2/neu promoter activity, and suppress the tumorigenic potential of HER-2/neu-overexpressing ovarian cancer cells. To examine E1A tumor suppressor function in breast cancer, we transduced E1A in vitro by adenovirus into both HER-2/neu-overexpressing and low expressing human breast cancer cell lines. In HER-2/neu-overexpressing cells, E1A greatly inhibited tumor cell growth in vitro. However, in HER-2/neu low expressing cancer cell lines, E1A had no significant effect on cell growth in culture medium. To test the therapeutic efficacy of E1A, we used both adenovirus-mediated and cationic liposome-mediated E1A gene delivery systems in an orthotopic breast cancer animal model. An advanced breast cancer model was established by inoculation of HER-2/neu-overexpressing human breast cancer cells in mammary fat pad and treated by local injections of either replication-deficient adenovirus expressing E1A, Ad.E1A(+) or a liposome-E1A DNA complex. As controls, mice bearing tumors were also treated with Ad.E1A(-) which is virtually the same adenovirus as Ad.E1A(+) except that E1A is deleted, a liposome-E1A frame-shift mutant DNA complex, or just PBS. In mice bearing a HER-2/neu-overexpressing breast cancer cell line, E1A delivered either by adenovirus or liposome significantly inhibited tumor growth and prolonged mouse survival compared with the controls. In fact, 60-80% of E1A-treated mice lived longer than 2 years versus only 0-20% of control mice (P<0.05). Western blot analysis showed that E1A protein was expressed in tumor tissue and immunohistochemical analysis showed that HER-2/neu p185 protein expression was suppressed. Taken together, our results indicated that both adenovirus and cationic liposome delivery systems were effective in transfering E1A gene for tumor suppression in a HER-2/neu-overexpressing breast cancer model. PMID:9053854

  18. Is grip strength a predictor for total muscle strength in healthy children, adolescents, and young adults?

    Microsoft Academic Search

    Anne E. Wind; Tim Takken; Paul J. M. Helders; Raoul H. H. Engelbert

    2010-01-01

    The primary purpose of this study was to examine whether grip strength is related to total muscle strength in children, adolescents,\\u000a and young adults. The second purpose was to provide reference charts for grip strength, which could be used in the clinical\\u000a and research setting. This cross-sectional study was performed at primary and secondary schools and the University of Applied

  19. Effect of OrientationEffect of Orientation on Pinon Pin--bearing Strength for Boltedbearing Strength for Bolted

    E-print Network

    Mottram, Toby

    for Boltedbearing Strength for Bolted Connections in Pultruded JointsConnections in Pultruded Joints Behrouz Zafari. BearingBearing StrengthStrength andand Bolted ConnectionsBolted Connections 2 · Strength variation of bolt is pin-bearing strength for the orientation of material to the resultant connection force. Can

  20. Shear Strength Behavior of Human Trabecular Bone

    PubMed Central

    Sanyal, Arnav; Gupta, Atul; Bayraktar, Harun H.; Kwon, Ronald Y.; Keaveny, Tony M.

    2012-01-01

    The shear strength of human trabecular bone may influence overall bone strength under fall loading conditions and failure at bone-implant interfaces. Here, we sought to compare shear and compressive yield strengths of human trabecular bone and elucidate the underlying failure mechanisms. We analyzed 54 specimens (5-mm cubes), all aligned with the main trabecular orientation and spanning four anatomic sites, 44 different cadavers, and a wide range of bone volume fraction (0.06–0.38). Micro-CT-based non-linear finite element analysis was used to assess the compressive and shear strengths and the spatial distribution of yielded tissue; the tissue-level constitutive model allowed for kinematic non-linearity and yielding with strength asymmetry. We found that the computed values of both the shear and compressive strengths depended on bone volume fraction via power law relations having an exponent of 1.7 (R2=0.95 shear; R2=0.97 compression). The ratio of shear to compressive strengths (mean ± SD, 0.44 ± 0.16) did not depend on bone volume fraction (p=0.24) but did depend on microarchitecture, most notably the intra-trabecular standard deviation in trabecular spacing (R2=0.23, p<0.005). For shear, the main tissue-level failure mode was tensile yield of the obliquely oriented trabeculae. By contrast, for compression, specimens having low bone volume fraction failed primarily by large-deformation-related tensile yield of horizontal trabeculae and those having high bone volume failed primarily by compressive yield of vertical trabeculae. We conclude that human trabecular bone is generally much weaker in shear than compression at the apparent level, reflecting different failure mechanisms at the tissue level. PMID:22884967

  1. Steady-state and transient Zener parameters in viscoplasticity: Drag strength versus yield strength

    NASA Technical Reports Server (NTRS)

    Freed, A. D.; Walker, K. P.

    1990-01-01

    A hypothesis is put forth which enables the viscoplastician to formulate a theory of viscoplasticity that reduces, in closed form, to the classical theory of creep. This hypothesis is applied to a variety of drag and yield strength models. Because of two theoretical restrictions that are a consequence of this hypothesis, three different yield strength models and one drag strength model are shown to be theoretically admissible. One of these yield strength models is selected as being the most appropriate representation for isotropic hardening.

  2. MATERIALS CHARACTERISATION Material properties such as strength, toughness or hardness

    E-print Network

    . Strength, toughness or hardness, which are determined by the chemical composition and thermal treatmentMATERIALS CHARACTERISATION Material properties such as strength, toughness or hardness are usually (shear and longitudinal). However, strength or hardnesscannotbedetermineddirectlyfromthoseparameters

  3. High-Strength Bolt Corrosion Fatigue Life Model and Application

    PubMed Central

    Hui-li, Wang; Si-feng, Qin

    2014-01-01

    The corrosion fatigue performance of high-strength bolt was studied. Based on the fracture mechanics theory and the Gerberich-Chen formula, the high-strength bolt corrosion fracture crack model and the fatigue life model were established. The high-strength bolt crack depth and the fatigue life under corrosion environment were quantitatively analyzed. The factors affecting high-strength bolt corrosion fatigue life were discussed. The result showed that the high-strength bolt corrosion fracture biggest crack depth reduces along with the material yield strength and the applied stress increases. The material yield strength was the major factor. And the high-strength bolt corrosion fatigue life reduced along with the increase of material strength, the applied stress or stress amplitude. The stress amplitude influenced the most, and the material yield strength influenced the least. Low bolt strength and a low stress amplitude level could extend high-strength bolt corrosion fatigue life. PMID:25152916

  4. High-strength bolt corrosion fatigue life model and application.

    PubMed

    Hui-li, Wang; Si-feng, Qin

    2014-01-01

    The corrosion fatigue performance of high-strength bolt was studied. Based on the fracture mechanics theory and the Gerberich-Chen formula, the high-strength bolt corrosion fracture crack model and the fatigue life model were established. The high-strength bolt crack depth and the fatigue life under corrosion environment were quantitatively analyzed. The factors affecting high-strength bolt corrosion fatigue life were discussed. The result showed that the high-strength bolt corrosion fracture biggest crack depth reduces along with the material yield strength and the applied stress increases. The material yield strength was the major factor. And the high-strength bolt corrosion fatigue life reduced along with the increase of material strength, the applied stress or stress amplitude. The stress amplitude influenced the most, and the material yield strength influenced the least. Low bolt strength and a low stress amplitude level could extend high-strength bolt corrosion fatigue life. PMID:25152916

  5. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Boilers and Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength of rivets per square inch of...square inch Iron Rivets in Single Shear 38,000 Iron Rivets in...

  6. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Boilers and Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength of rivets per square inch of...square inch Iron Rivets in Single Shear 38,000 Iron Rivets in...

  7. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Boilers and Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength of rivets per square inch of...square inch Iron Rivets in Single Shear 38,000 Iron Rivets in...

  8. 49 CFR 230.27 - Maximum shearing strength of rivets.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Boilers and Appurtenances Strength of Materials § 230.27 Maximum shearing strength of rivets. The maximum shearing strength of rivets per square inch of...square inch Iron Rivets in Single Shear 38,000 Iron Rivets in...

  9. [E1A oncogene effect on the ability of p21(Waf1) to regulate G1/S arrest in E1A-expressing transformants following irradiation].

    PubMed

    Romanov, V S; Brichkina, A I; Pospelov, V A; Pospelova, T V

    2005-01-01

    P21(Waf1) cyclin-dependent kinase inhibitor blocks cell cycle transition from G1 phase into DNA replication after DNA damage. The main targets of p21(Waf1) are Cyc 1E--Cdk2 and Cyc 1A--Cdk2 complexes, PCNA (proliferating cell nuclear antigen), a subunit of DNA polymerase delta, and E2F-1 transcription factor. The universal mechanism of cell cycle arrest in normal cells is determined as p21(Waf1) interaction with positive regulators of G1 phase. As a rule, DNA integrity control mechanisms are destroyed in the process of oncogenic transformation, which results in proliferation of genetically defective cells. The purpose of our study was to investigate molecular mechanisms of cell cycle regulation in transformants that are able (E1A + E1B-19kDa) or unable (E1A(+) + cHa-ras) to be arrested at G1/S checkpoint. We have shown that p21(Waf1) is able to form complexes with cyclins and Cdks, PCNA and E2F-1 transcryption factor, although it interacts with E1A oncoproducts in both transformants. The presence of E1A bound p21(Waf1) in cyclin-kinase complexes seems to be the cause of activating phosphorilation of Cdk2 at Thr-160 in cyclin A/E--Cdk2 complexes in both control and X-ray irradiated cells. Thus, the absence of G1/S arrest following irradiation in E1A + cHa-ras transformants and its presence in E1A(+) + E1B-19kDa transformants is not connected with differences in interaction of p21(waf1) with the main regulators of G1-to-S transition, but is realized through other not yet identified ways. PMID:16706194

  10. Critical role of cytochrome P450 2E1 (CYP2E1) in the development of high fat-induced nonalcoholic steatohepatitis

    PubMed Central

    Abdelmegeed, Mohamed A.; Banerjee, Atrayee; Yoo, Seong-Ho; Jang, Sehwan; Gonzalez, Frank J.; Song, Byoung-Joon

    2012-01-01

    Background & Aims Ethanol-inducible cytochrome P450 2E1 (CYP2E1) activity contributes to oxidative stress. However, CYP2E1 may have an important role in the pathogenesis of high-fat mediated nonalcoholic steatohepatitis (NASH). Thus, the role of CYP2E1 in high-fat mediated NASH development was evaluated. Methods Male wild-type (WT) and Cyp2e1-null mice were fed a low-fat diet (LFD, 10% energy-derived) or high-fat diet (HFD, 60% energy-derived) for 10 weeks. Liver histology and tissue homogenates were examined for various parameters of oxidative stress and inflammation. Results Liver histology showed that only WT mice fed a HFD developed NASH despite increased steatosis in both WT and Cyp2e1-null mice fed HFD. Markers of oxidative stress such as elevated CYP2E1 activity and protein amounts, lipid peroxidation, protein carbonylation, nitration, and glycation with increased phospho-JNK were all markedly elevated only in the livers of HFD-fed WT mice. Furthermore, while the levels of inflammation markers osteopontin and F4/80 were higher in HFD-fed WT mice, TNF? and MCP-1 contents were lower compared to the corresponding LFD-fed WT. Finally, only HFD-fed WT mice exhibited increased insulin resistance and impaired glucose tolerance. Conclusions These data suggest that CYP2E1 is critically important in NASH development by promoting oxidative/nitrosative stress, protein modifications, inflammation and insulin resistance. PMID:22668639

  11. (Finite) statistical size effects on compressive strength.

    PubMed

    Weiss, Jérôme; Girard, Lucas; Gimbert, Florent; Amitrano, David; Vandembroucq, Damien

    2014-04-29

    The larger structures are, the lower their mechanical strength. Already discussed by Leonardo da Vinci and Edmé Mariotte several centuries ago, size effects on strength remain of crucial importance in modern engineering for the elaboration of safety regulations in structural design or the extrapolation of laboratory results to geophysical field scales. Under tensile loading, statistical size effects are traditionally modeled with a weakest-link approach. One of its prominent results is a prediction of vanishing strength at large scales that can be quantified in the framework of extreme value statistics. Despite a frequent use outside its range of validity, this approach remains the dominant tool in the field of statistical size effects. Here we focus on compressive failure, which concerns a wide range of geophysical and geotechnical situations. We show on historical and recent experimental data that weakest-link predictions are not obeyed. In particular, the mechanical strength saturates at a nonzero value toward large scales. Accounting explicitly for the elastic interactions between defects during the damage process, we build a formal analogy of compressive failure with the depinning transition of an elastic manifold. This critical transition interpretation naturally entails finite-size scaling laws for the mean strength and its associated variability. Theoretical predictions are in remarkable agreement with measurements reported for various materials such as rocks, ice, coal, or concrete. This formalism, which can also be extended to the flowing instability of granular media under multiaxial compression, has important practical consequences for future design rules. PMID:24733930

  12. Tensile & shear strength of porous dust agglomerates

    E-print Network

    Alexander Seizinger; Roland Speith; Wilhelm Kley

    2013-08-23

    Context.Within the sequential accretion scenario of planet formation, planets are build up through a sequence sticking collisions. The outcome of collisions between porous dust aggregates is very important for the growth from very small dust particles to planetesimals. In this work we determine the necessary material properties of dust aggregates as a function the porosity. Aims: Continuum models such as SPH that are capable of simulating collisions of macroscopic dust aggregates require a set of material parameters. Some of them such as the tensile and shear strength are ?difficult to obtain from laboratory experiments. The aim of this work is to determine these parameters from ab-initio molecular dynamics simulations. Methods: We simulate the behavior of porous dust aggregates using a detailed micro-physical model of the interaction of spherical grains that includes adhesion forces, rolling, twisting, and sliding. Using different methods of preparing the samples we study the strength behavior of our samples with varying porosity and coordination number of the material. Results: For the tensile strength, we can reproduce data from laboratory experiments very well. For the shear strength, there are no experimental data available. The results from our simulations differ significantly from previous theoretical models, which indicates that the latter might not be sufficient to describe porous dust aggregates. Conclusions: We have provided functional behavior of tensile and shear strength of porous dust aggregates as a function of the porosity that can be directly applied in continuum simulations of these objects in planet formation scenarios.

  13. Humidity effects on wire insulation breakdown strength.

    SciTech Connect

    Appelhans, Leah

    2013-08-01

    Methods for the testing of the dielectric breakdown strength of insulation on metal wires under variable humidity conditions were developed. Two methods, an ASTM method and the twisted pair method, were compared to determine if the twisted pair method could be used for determination of breakdown strength under variable humidity conditions. It was concluded that, although there were small differences in outcomes between the two testing methods, the non-standard method (twisted pair) would be appropriate to use for further testing of the effects of humidity on breakdown performance. The dielectric breakdown strength of 34G copper wire insulated with double layer Poly-Thermaleze/Polyamide-imide insulation was measured using the twisted pair method under a variety of relative humidity (RH) conditions and exposure times. Humidity at 50% RH and below was not found to affect the dielectric breakdown strength. At 80% RH the dielectric breakdown strength was significantly diminished. No effect for exposure time up to 140 hours was observed at 50 or 80%RH.

  14. Fatigue strength of socket welded pipe joint

    SciTech Connect

    Higuchi, Makoto [Ishikawajima-Harima Heavy Industries, Yokohama (Japan). Research Inst.; Hayashi, Makoto [Hitachi Ltd. (Japan). Mechanical Research Inst.; Yamauchi, Takayoshi [Mitsubishi Heavy Industries Ltd., Takasago (Japan). Takasago Research Inst.; Iida, Kunihiro [Shibaura Inst. of Technology, Tokyo (Japan). Dept. of Mechanical Engineering; Sato, Masanobu [Japan Power Engineering and Inspection Corp., Tokyo (Japan). Welding Engineering Dept.

    1995-12-01

    Fully reversed four point bending fatigue tests were carried out on small diameter socket welded joints made of carbon steels. Experimental parameters were pipe diameter, thicknesses of pipe and socket wall, throat depth and shape of fillet welds, slip-on and diametral gaps in the socket welding, lack of penetration at the root of fillet welds, and peening of fillet welds. In most cases a fatigue crack started from the root of the fillet, but in the case of higher stress amplitude, it tended to start from the toe of fillet. The standard socket welded joint for a pipe with a 50 mm nominal diameter showed a relatively low fatigue strength of 46 MPa in stress amplitude at the 10{sup 7} cycles failure life. This value corresponds to about 1/5 of that for the smoothed base metal specimens in axial fatigue. The fatigue strength decreased with increasing pipe diameter, and increased with increasing thickness of the pipe and socket wall. The effects of throat depth and shape of fillet welds on fatigue strength were not significant. Contrary to expectation, the fatigue strength of a socket welded joint without slip-on gap is Higher than that of the joint with a normal gap. A lack of penetration at the root deleteriously reduced fatigue strength, showing 14 MPa in stress amplitude at the 10{sup 7} cycles failure life for the 50 mm diameter socket joint.

  15. (Finite) statistical size effects on compressive strength

    PubMed Central

    Weiss, Jérôme; Girard, Lucas; Gimbert, Florent; Amitrano, David; Vandembroucq, Damien

    2014-01-01

    The larger structures are, the lower their mechanical strength. Already discussed by Leonardo da Vinci and Edmé Mariotte several centuries ago, size effects on strength remain of crucial importance in modern engineering for the elaboration of safety regulations in structural design or the extrapolation of laboratory results to geophysical field scales. Under tensile loading, statistical size effects are traditionally modeled with a weakest-link approach. One of its prominent results is a prediction of vanishing strength at large scales that can be quantified in the framework of extreme value statistics. Despite a frequent use outside its range of validity, this approach remains the dominant tool in the field of statistical size effects. Here we focus on compressive failure, which concerns a wide range of geophysical and geotechnical situations. We show on historical and recent experimental data that weakest-link predictions are not obeyed. In particular, the mechanical strength saturates at a nonzero value toward large scales. Accounting explicitly for the elastic interactions between defects during the damage process, we build a formal analogy of compressive failure with the depinning transition of an elastic manifold. This critical transition interpretation naturally entails finite-size scaling laws for the mean strength and its associated variability. Theoretical predictions are in remarkable agreement with measurements reported for various materials such as rocks, ice, coal, or concrete. This formalism, which can also be extended to the flowing instability of granular media under multiaxial compression, has important practical consequences for future design rules. PMID:24733930

  16. Genotype and allele frequencies of polymorphic CYP2E1 in the Turkish population

    Microsoft Academic Search

    Gulen Ulusoy; Emel Arinç; Orhan Adali

    2007-01-01

    Cytochrome P4502E1 (CYP2E1) gene shows genetic polymorphisms that vary markedly in frequency among different ethnic and racial groups. We studied the\\u000a genotype distributions and allele frequencies of three CYP2E1 polymorphisms: CYP2E1*5B (RsaI\\/PstI RFLP, C-1053T\\/G-1293C SNP, rs2031920 \\/rs3813867), CYP2E1*6 (DraI RFLP, T7632A SNP, rs6413432), and CYP2E1*7B (DdeI RFLP, G-71T SNP, rs6413420) by PCR\\/RFLP technique in a sample of 206 healthy subjects

  17. Mechanism-Based Inactivation of Human CYP2E1 by Diethyldithocarbamate

    PubMed Central

    Pratt-Hyatt, Matthew; Lin, Hsia-lien

    2010-01-01

    Although the ability of disulfiram to inactivate CYP2E1 has been known for more than 20 years, the mechanism has not yet been elucidated. A metabolite of disulfiram, diethyldithocarbamate (DDC), is converted by CYP2E1 to a reactive intermediate that subsequently inactivates the protein, leading to mechanism-based inactivation. Mass spectral analysis of the inactivated human 2E1 protein demonstrates that the inactivation is due to the formation of an adduct of the reactive metabolite of DDC with the apoprotein. These data, along with mass spectral analysis of a reactive intermediate trapped with GSH, indicate the involvement of a reactive intermediate with a molecular mass of 116 Da. Our results suggest that this binding involves formation of a disulfide bond with one of the eight cysteines in CYP2E1. The inactivation of wild-type CYP2E1 as well as two of its polymorphic mutants, CYP2E1*2 and CYP2E1*4, was also investigated. For wild-type CYP2E1, the KI was 12.2 ?M and the kinact was 0.02 min?1. The KI values for the two polymorphic mutants were 227.6 and 12.4 ?M for CYP2E1.2 and CYP2E1.4, and the kinact values were 0.0061 and 0.0187 min?1, respectively. These data indicate that DDC is a much less efficient inactivator of CYP2E1.2 than it is of either the wild-type or the CYP2E1.4 variant. PMID:20826547

  18. Distinct and redundant functions of cyclin E1 and cyclin E2 in development and cancer

    Microsoft Academic Search

    C ELIZABETH Caldon; Elizabeth A Musgrove

    2010-01-01

    The highly conserved E-type cyclins are core components of the cell cycle machinery, facilitating the transition into S phase through activation of the cyclin dependent kinases, and assembly of pre-replication complexes on DNA. Cyclin E1 and cyclin E2 are assumed to be functionally redundant, as cyclin E1-\\/- E2-\\/- mice are embryonic lethal while cyclin E1-\\/- and E2-\\/- single knockout mice

  19. To Intubate or Not to Intubate? Transporting Infants on Prostaglandin E1

    Microsoft Academic Search

    Garth D. Meckler; Calvin Lowe

    2010-01-01

    OBJECTIVES.The purpose of this work was to describe the pretransport and transport management of infants receiving prostaglandin E1 infusion for congenital heart disease and to compare transport complications among unintubated and electively intubated infants. METHODS.We conducted a retrospective chart review of 202 infants receiving prosta- glandin E1 during transport to our facility from 2000 to 2005. Prostaglandin E1 adverse effects

  20. CHARACTERIZATION OF TENSILE STRENGTH OF GLOVEBOX GLOVES

    SciTech Connect

    Korinko, P.; Chapman, G.

    2012-02-29

    A task was undertaken to compare various properties of different glovebox gloves, having various compositions, for use in gloveboxes at the Savannah River Site (SRS). One aspect of this project was to determine the tensile strength (TS) of the gloves. Longitudinal tensile samples were cut from 15 different gloves and tensile tested. The stress, load, and elongation at failure were determined. All of the gloves that are approved for glovebox use and listed in the glovebox procurement specification met the tensile and elongation requirements. The Viton{reg_sign} compound gloves are not listed in the specification, but exhibited lower tensile strengths than permissible based on the Butyl rubber requirements. Piercan Polyurethane gloves were the thinnest samples and exhibited the highest tensile strength of the materials tested.

  1. U-groove aluminum weld strength improvement

    NASA Technical Reports Server (NTRS)

    Verderaime, V.; Vaughan, R.

    1995-01-01

    Though butt-welds are among the most preferred joining methods in aerostructures, their strength dependence on inelastic mechanics is generally the least understood. This study investigated experimental strain distributions across a thick aluminum U-grooved weld and identified two weld process considerations for improving the multipass weld strength. The extreme thermal expansion and contraction gradient of the fusion heat input across the groove tab thickness produces severe peaking which induces bending under uniaxial loading. The filler strain-hardening deceased with increasing filler pass sequence, producing the weakest welds on the last pass side. Current welding schedules unknowingly compound these effects which reduce the weld strength. A de-peaking index model was developed to select filler pass thicknesses, pass numbers, and sequences to improve de-peaking in the welding process. Intent is to combine the strongest weld pass side with the peaking induced bending tension to provide a more uniform stress and stronger weld under axial tensile loading.

  2. U-Groove aluminum weld strength improvement

    NASA Technical Reports Server (NTRS)

    Verderaime, V.; Vaughan, R.

    1996-01-01

    Though butt-welds are among the most preferred joining methods in aerostructures, their strength dependence on inelastic mechanics is generally the least understood. This study investigated experimental strain distributions across a thick aluminum U-grooved weld and identified two weld process considerations for improving the multipass weld strength. The extreme thermal expansion and contraction gradient of the fusion heat input across the groove tab thickness produces severe peaking, which induces bending under uniaxial loading. The filler strain-hardening decreased with increasing filler pass sequence, producing the weakest welds on the last pass side. Current welding schedules unknowingly compound these effects which reduce the weld strength. A depeaking index model was developed to select filler pass thicknesses, pass numbers, and sequences to improve depeaking in the welding process. The intent is to combine the strongest weld pass side with the peaking induced bending tension to provide a more uniform stress and stronger weld under axial tensile loading.

  3. Strength and conditioning practices in rowing.

    PubMed

    Gee, Thomas I; Olsen, Peter D; Berger, Nicolas J; Golby, Jim; Thompson, Kevin G

    2011-03-01

    There is limited published research on the practices of strength and conditioning (S &C) coaches in Great Britain. Information about training program design would be useful in developing models of good practice and ecologically valid intervention studies. The aim of this research was to quantify the training practices of coaches responsible for the S&C of rowing athletes. A questionnaire was developed that consisted of 6 sections: (a) personal details, (b) physical testing, (c) strength and power development, (d) flexibility development, (e) unique aspects of the program, and (f) any further relevant comments regarding the athletes prescribed training program. Twenty-two rowing and 10 S&C coaches with an average of 10.5 ± 7.2 years' experience agreed to complete the questionnaire. Approximately, 34% coached rowers of Olympic standard, 34% coached national standard, 3% coached regional standard, 19% coached club standard, and 10% coached university standard rowers. All coaches agreed that strength training enhanced rowing performance and the majority (74%) indicated that athletes' strength trained 2-3 times a week. Almost all coaches (94%) reported their rowers performed strength training, with 81% using Olympic lifting, and 91% employing a periodized training model. The clean (63%) and squat (27%) were rated the most important prescribed exercises. Approximately 50% of coaches used plyometrics such as depth jumps, box drills, and standing jumps. Ninety-four percent indicated they conducted physical testing on their rowers, typically assessing cardiovascular endurance (80%), muscular power (70%), muscular strength (70%), and anaerobic capacity (57%). This research represents the only published survey to date on the S&C practices in rowing within Great Britain. PMID:21311351

  4. Shear strength properties of wet granular materials

    NASA Astrophysics Data System (ADS)

    Richefeu, Vincent; El Youssoufi, Moulay Saïd; Radjaï, Farhang

    2006-05-01

    We investigate shear strength properties of wet granular materials in the pendular state (i.e., the state where the liquid phase is discontinuous) as a function of water content. Sand and glass beads were wetted and tested in a direct shear cell and under various confining pressures. In parallel, we carried out three-dimensional molecular dynamics simulations by using an explicit equation expressing capillary force as a function of interparticle distance, water bridge volume, and surface tension. We show that, due to the peculiar features of capillary interactions, the major influence of water content over the shear strength stems from the distribution of liquid bonds. This property results in shear strength saturation as a function of water content. We arrive at the same conclusion by a microscopic analysis of the shear strength. We propose a model that accounts for the capillary force, the granular texture, and particle size polydispersity. We find fairly good agreement of the theoretical estimate of the shear strength with both experimental data and simulations. From numerical data, we analyze the connectivity and anisotropy of different classes of liquid bonds according to the sign and level of the normal force as well as the bond direction. We find that weak compressive bonds are almost isotropically distributed whereas strong compressive and tensile bonds have a pronounced anisotropy. The probability distribution function of normal forces is exponentially decreasing for strong compressive bonds, a decreasing power-law function over nearly one decade for weak compressive bonds, and an increasing linear function in the range of tensile bonds. These features suggest that different bond classes do not play the same role with respect to the shear strength.

  5. Interrelationship between muscle strength, motor units, & aging

    PubMed Central

    Kaya, Ryan D.; Nakazawa, Masato; Hoffman, Richard L.; Clark, Brian C.

    2013-01-01

    The interrelationship between muscle strength, motor unit (MU) number, and age is poorly understood, and in this study we sought to determine whether age-related differences in muscle strength are moderated by estimates of functioning MU number and size. Eighteen older adults (OA; 67±1.20 yrs) and 24 young adults (YA; 22±0.74 yrs) participated in this study. Maximum voluntary pinch grip strength of the nondominant hand was determined and estimates of MU number were obtained from the abductor pollicis brevis muscle using the noninvasive motor unit number index (MUNIX) technique. The MUNIX technique was also utilized to derive a motor unit size index (MUSIX). An analysis of covariance (Age Group X MUNIX or MUSIX) was used to test heterogeneity of regression slopes, with body mass and gender serving as covariates. We observed that the slope of pinch grip strength on the estimated number of MUs between YA and OA differed, indicated by an Age Group X MUNIX interaction (p=0.04). Specifically, after controlling for the effect of body mass and gender, the slope in OA was significantly positive (0.14±0.06 N/MUs, p=0.03), whereas no such relationship was found in YA (?0.08±0.09 N/MUs, p=0.35). A significant Age Group X MUSIX interaction was also observed for strength (p<0.01). In contrast to MUNIX, the slope in younger adults was significantly positive (0.48±0.11 N/?V, p<0.01), whereas no such relationship was found in older adults (?0.30±0.22 N/?V, p=0.18). These findings indicate that there is an interrelationship between muscle strength, MU numbers, and aging, which suggests that a portion of muscle weakness in seniors may be attributable to the loss of functioning motor units. PMID:23832080

  6. Making High-Tensile-Strength Amalgam Components

    NASA Technical Reports Server (NTRS)

    Grugel, Richard

    2008-01-01

    Structural components made of amalgams can be made to have tensile strengths much greater than previously known to be possible. Amalgams, perhaps best known for their use in dental fillings, have several useful attributes, including room-temperature fabrication, corrosion resistance, dimensional stability, and high compressive strength. However, the range of applications of amalgams has been limited by their very small tensile strengths. Now, it has been discovered that the tensile strength of an amalgam depends critically on the sizes and shapes of the particles from which it is made and, consequently, the tensile strength can be greatly increased through suitable choice of the particles. Heretofore, the powder particles used to make amalgams have been, variously, in the form of micron-sized spheroids or flakes. The tensile reinforcement contributed by the spheroids and flakes is minimal because fracture paths simply go around these particles. However, if spheroids or flakes are replaced by strands having greater lengths, then tensile reinforcement can be increased significantly. The feasibility of this concept was shown in an experiment in which electrical copper wires, serving as demonstration substitutes for copper powder particles, were triturated with gallium by use of a mortar and pestle and the resulting amalgam was compressed into a mold. The tensile strength of the amalgam specimen was then measured and found to be greater than 10(exp 4) psi (greater than about 69 MPa). Much remains to be done to optimize the properties of amalgams for various applications through suitable choice of starting constituents and modification of the trituration and molding processes. The choice of wire size and composition are expected to be especially important. Perusal of phase diagrams of metal mixtures could give insight that would enable choices of solid and liquid metal constituents. Finally, whereas heretofore, only binary alloys have been considered for amalgams, ternary additions to liquid or solid components should be considered as means to impart desired properties to amalgams.

  7. Gamma-ray strength function and pygmy resonance in rare earth nuclei

    E-print Network

    A. Voinov; M. Guttormsen; E. Melby; J. Rekstad; A. Schiller; S. Siem

    2000-09-26

    The gamma-ray strength function for gamma energies in the 1-7 MeV region has been measured for 161,162-Dy and 171,172-Yb using the (3-He,alpha gamma) reaction. Various models are tested against the observed gamma-ray strength functions. The best description is based on the Kadmenskii, Markushev and Furman E1 model with constant temperature and the Lorentzian M1 model. A gamma-ray bump observed at E_gamma=3 MeV is interpreted as the so-called pygmy resonance, which has also been observed previously in (n,gamma) experiments. The parameters for this resonance have been determined and compared to the available systematics.

  8. Expression and characterization of a soluble rubella virus E1 envelope protein.

    PubMed

    Seto, N O; Gillam, S

    1994-10-01

    Individual specific antigenic rubella virus (RV) structural proteins are required for accurate serological diagnosis of acute and congenital rubella infections as well as rubella immune status. The RV envelope glycoprotein E1 is the major target antigen and plays an important role in viral-specific immune responses. The native virion is difficult to produce in large quantities and the protein subunits are also difficult to isolate without loss of antigenicity. The production of a soluble RV E1 (designated E1 delta Tm) using the baculovirus-insect cell expression system is described. In contrast to wild-type RV E1, the genetically engineered E1 delta Tm protein lacks a transmembrane anchor. It behaved as a secretory protein and was secreted abundantly from insect cells. Pulse-chase studies were used to examine the synthesis, glycosylation, and secretion of E1 delta Tm by the insect cells. The secreted E1 delta Tm protein was purified from serum-free medium by one-step immunochromatography. The purified E1 delta Tm protein retained full antigenicity and may be a convenient source of E1 protein for use in diagnostic assay and rubella vaccine development. PMID:7852960

  9. Methodology to assay CYP2E1 mixed function oxidase catalytic activity and its induction

    PubMed Central

    Cederbaum, Arthur I.

    2014-01-01

    The cytochrome P450 mixed function oxidase enzymes are the major catalysts involved in drug metabolism. There are many forms of P450. CYP2E1 metabolizes many toxicologically important compounds including ethanol and is active in generating reactive oxygen species. Since several of the contributions in the common theme series “Role of CYP2E1 and Oxidative/Nitrosative Stress in the Hepatotoxic Actions of Alcohol” discuss CYP2E1, this methodology review describes assays on how CYP2E1 catalytic activity and its induction by ethanol and other inducers can be measured using substrate probes such as the oxidation of para-nitrophenol to para-nitrocatechol and the oxidation of ethanol to acetaldehyde. Approaches to validate that a particular reaction e.g. oxidation of a drug or toxin is catalyzed by CYP2E1 or that induction of that reaction is due to induction of CYP2E1 are important and specific examples using inhibitors of CYP2E1, anti-CYP2E1 IgG or CYP2E1 knockout and knockin mice will be discussed. PMID:25454746

  10. Anaerobic Power and Physical Function in Strength-Trained and Non-Strength-Trained Older Adults

    Microsoft Academic Search

    Jill M. Slade; Tanya A. Miszko; Jennifer H. Laity; Subodoh K. Agrawal; M. Elaine Cress

    2002-01-01

    Background. Challenging daily tasks, such as transferring heavy items or rising from the floor, may be dependent on the ability to generate short bursts of energy anaerobically. The purposes of this study were to determine if strength- trained (ST) older adults have higher anaerobic power output compared with non-strength-trained (NST) older adults and to determine the relationship between anaerobic power

  11. Neural network analysis of strength and ductility of welding alloys for high strength low

    E-print Network

    Cambridge, University of

    Neural network analysis of strength and ductility of welding alloys for high strength low alloy in meeting such demands, a neural network was trained and tested on a set of data obtained on weld metals on unseen data. The neural network technique used is due to MacKay, with a Bayesian framework, and hence

  12. Burst Strength of Tubing and Casing Based on Twin Shear Unified Strength Theory

    PubMed Central

    Lin, Yuanhua; Deng, Kuanhai; Sun, Yongxing; Zeng, Dezhi; Liu, Wanying; Kong, Xiangwei; Singh, Ambrish

    2014-01-01

    The internal pressure strength of tubing and casing often cannot satisfy the design requirements in high pressure, high temperature and high H2S gas wells. Also, the practical safety coefficient of some wells is lower than the design standard according to the current API 5C3 standard, which brings some perplexity to the design. The ISO 10400: 2007 provides the model which can calculate the burst strength of tubing and casing better than API 5C3 standard, but the calculation accuracy is not desirable because about 50 percent predictive values are remarkably higher than real burst values. So, for the sake of improving strength design of tubing and casing, this paper deduces the plastic limit pressure of tubing and casing under internal pressure by applying the twin shear unified strength theory. According to the research of the influence rule of yield-to-tensile strength ratio and mechanical properties on the burst strength of tubing and casing, the more precise calculation model of tubing-casing's burst strength has been established with material hardening and intermediate principal stress. Numerical and experimental comparisons show that the new burst strength model is much closer to the real burst values than that of other models. The research results provide an important reference to optimize the tubing and casing design of deep and ultra-deep wells. PMID:25397886

  13. Flexural strength and interlaminar shear strength of stitched GRP laminates following repeated impacts

    Microsoft Academic Search

    A. P. Mouritz; J. Gallagher; A. A. Goodwin

    1997-01-01

    The flexural strength and interlaminar shear strength of stitched and non-stitched glass-reinforced plastic (GRP) laminates were studied under conditions of increasing impact energy and increasing number of repeated impacts. The GRP was stitched through the thickness with Kevlar thread in two orientations with a low or high stitch density. The Mode I interlaminar fracture toughness, GIc, increased with stitch density

  14. The Effects of Strength Training Set Configurations for Improving Muscular Strength in Collegiate Baseball Players

    Microsoft Academic Search

    Sara DeWeerdt; Kate Glomski; Katie Sawyer; Brandon Siakel

    2011-01-01

    This study compared the effect of three different strength training set configurations on 1-RM bench press, leg press, and leg curl strength. Fifteen Division III collegiate baseball players were randomly assigned to 1 of 3 weight training protocols: single-set to failure (SSF), 3 sets not to failure (NF), and 3 clustered sets not to failure (CNF). All subjects performed the

  15. Effect of hydrogen on the yield strength and ultimate strength of iron differing in dispersity

    Microsoft Academic Search

    F. Po Yanchishin; N. Ya. Yaremchenko; M. M. Shved

    1975-01-01

    It was of interest to determine the effect of hydrogen on the yield strength and ultimate strength of Armco iron differing in dispersity in uniaxial tension. The tests were made on flat samples 3 mm wide, 12 mm long, and 0.8 mm thick, with different grain sizes. The grain sizes were varied by means of recrystallization annealing in vacuum at

  16. Electrical Strength of Multilayer Vacuum Insulators

    SciTech Connect

    Harris, J R; Kendig, M; Poole, B; Sanders, D M; Caporaso, G J

    2008-07-01

    The electrical strength of vacuum insulators is a key constraint in the design of particle accelerators and pulsed power systems. Vacuum insulating structures assembled from alternating layers of metal and dielectric can result in improved performance compared to conventional insulators, but previous attempts to optimize their design have yielded seemingly inconsistent results. Here, we present two models for the electrical strength of these structures, one assuming failure by vacuum arcing between adjacent metal layers and the other assuming failure by vacuum surface flashover. These models predict scaling laws which are in agreement with the experimental data currently available.

  17. Unexpected shear strength change in magnetorheological fluids

    NASA Astrophysics Data System (ADS)

    Tian, Yu; Chen, KaiKai; Shan, Lei; Zhang, Xiangjun; Meng, Yonggang

    2014-09-01

    Smart materials of magnetorheological (MR) fluids could be turned from a liquid state into a solid state, which solidification extent or shear strength often increases monotonically with the applied magnetic field. In this study, the shear stress of a dilute MR fluid decreased with increasing applied magnetic field at a constant shear rate. The dynamic shear stress was significantly higher than the stable counterpart at medium magnetic fields. They are ascribed to the slow particle structure transformation. A higher shear rate and particle volume fraction could reduce the transient time and the shear strength difference.

  18. Gaseous hydrogen embrittlement of high strength steels

    NASA Technical Reports Server (NTRS)

    Gangloff, R. P.; Wei, R. P.

    1977-01-01

    The effects of temperature, hydrogen pressure, stress intensity, and yield strength on the kinetics of gaseous hydrogen assisted crack propagation in 18Ni maraging steels were investigated experimentally. It was found that crack growth rate as a function of stress intensity was characterized by an apparent threshold for crack growth, a stage where the growth rate increased sharply, and a stage where the growth rate was unchanged over a significant range of stress intensity. Cracking proceeded on load application with little or no detectable incubation period. Gaseous hydrogen embrittlement susceptibility increased with increasing yield strength.

  19. The undrained strength – liquidity index relationship

    E-print Network

    Vardanega, P. J.; Haigh, S. K.

    2014-04-14

    to be the preferred mathematical function. Keywords: fall cone tests; clay strength; soil classification; Atterberg limits; statistical analysis; liquidity index; logarithmic liquidity index Page 2 of 40 Ca n. G eo te ch . J . D ow nl oa de d fro m w w w... ge c om po sit io n. It m ay d iff er fr om th e fin al o ffi ci al v er sio n of re co rd . 3 The undrained strength – liquidity index relationship P. J. Vardanega and S. K. Haigh 1. INTRODUCTION Atterberg (1911a, 1911b...

  20. Dynamic tensile strength of lunar rock types

    NASA Technical Reports Server (NTRS)

    Cohn, S. N.; Ahrens, T. J.

    1981-01-01

    The dynamic tensile strength of four rocks are determined. A flat plate impact experiment is employed to generate approximately one-microsecond-duration tensile stress pulses in rock samples by superposing rarefaction waves to induce fracture. It is noted that the effect of chemical weathering and other factors has not been explicitly studied. The given tensile strengths are based on a series of experiments on each rock where determination of incipient spallation is made by terminal microscopic examination. The data are generally consistent with previous determinations, at least one of which was for a significantly chemically altered but physically coherent rock.

  1. The principal components of response strength.

    PubMed Central

    Killeen, P R; Hall, S S

    2001-01-01

    As Skinner (1938) described it, response strength is the "state of the reflex with respect to all its static properties" (p. 15), which include response rate, latency, probability, and persistence. The relations of those measures to one another was analyzed by probabilistically reinforcing, satiating, and extinguishing pigeons' key pecking in a trials paradigm. Reinforcement was scheduled according to variable-interval, variable-ratio, and fixed-interval contingencies. Principal components analysis permitted description in terms of a single latent variable, strength, and this was validated with confirmatory factor analyses. Overall response rate was an excellent predictor of this state variable. PMID:11394483

  2. Effect of space flight on bone strength

    NASA Technical Reports Server (NTRS)

    Spengler, D. M.; Morey, E. R.; Carter, D. R.; Turner, R. T.; Baylink, D. J.

    1982-01-01

    To test the possibility that spaceflight has a deleterious effect on bone mechanical properties, femur breaking strength by torsional loading in rats that had been flown for 19 days aboard Cosmos 936 was determined. The results showed that femurs from flight rats were less stiff than the flight controls, and failed under torsion at a lower torque and energy of absorption. The defect was corrected following space flight and could be prevented during space flight by centrifuging the rats at 1 x g. Altered bone geometry due to inhibition of bone formation at the periosteal surface provides the most likely explanation for the decrease in bone strength during spaceflight.

  3. Method for producing high dielectric strength microvalves

    DOEpatents

    Kirby, Brian J. (San Francisco, CA); Reichmuth, David S. (Oakland, CA); Shepodd, Timothy J. (Livermore, CA)

    2006-04-04

    A microvalve having a cast-in-place and lithographically shaped mobile, polymer monolith for fluid flow control in microfluidic devices and method of manufacture. The microvalve contains a porous fluorinated polymer monolithic element whose pores are filled with an electrically insulating, high dielectric strength fluid, typically a perfluorinated liquid. This combination provides a microvalve that combines high dielectric strength with extremely low electrical conductivity. These microvalves have been shown to have resistivities of at least 100 G.OMEGA. and are compatible with solvents such as water at a pH between 2.7 and 9.0, 1-1 propanol, acetonitrile, and acetone.

  4. Nuclear Deformation and Neutron Excess as Competing Effects for Dipole Strength in the Pygmy Region

    NASA Astrophysics Data System (ADS)

    Massarczyk, R.; Schwengner, R.; Dönau, F.; Frauendorf, S.; Anders, M.; Bemmerer, D.; Beyer, R.; Bhatia, C.; Birgersson, E.; Butterling, M.; Elekes, Z.; Ferrari, A.; Gooden, M. E.; Hannaske, R.; Junghans, A. R.; Kempe, M.; Kelley, J. H.; Kögler, T.; Matic, A.; Menzel, M. L.; Müller, S.; Reinhardt, T. P.; Röder, M.; Rusev, G.; Schilling, K. D.; Schmidt, K.; Schramm, G.; Tonchev, A. P.; Tornow, W.; Wagner, A.

    2014-02-01

    The electromagnetic dipole strength below the neutron-separation energy has been studied for the xenon isotopes with mass numbers A =124, 128, 132, and 134 in nuclear resonance fluorescence experiments using the ?ELBE bremsstrahlung facility at Helmholtz-Zentrum Dresden-Rossendorf and the HI?S facility at Triangle Universities Nuclear Laboratory Durham. The systematic study gained new information about the influence of the neutron excess as well as of nuclear deformation on the strength in the region of the pygmy dipole resonance. The results are compared with those obtained for the chain of molybdenum isotopes and with predictions of a random-phase approximation in a deformed basis. It turned out that the effect of nuclear deformation plays a minor role compared with the one caused by neutron excess. A global parametrization of the strength in terms of neutron and proton numbers allowed us to derive a formula capable of predicting the summed E1 strengths in the pygmy region for a wide mass range of nuclides.

  5. Nuclear deformation and neutron excess as competing effects for dipole strength in the pygmy region.

    PubMed

    Massarczyk, R; Schwengner, R; Dönau, F; Frauendorf, S; Anders, M; Bemmerer, D; Beyer, R; Bhatia, C; Birgersson, E; Butterling, M; Elekes, Z; Ferrari, A; Gooden, M E; Hannaske, R; Junghans, A R; Kempe, M; Kelley, J H; Kögler, T; Matic, A; Menzel, M L; Müller, S; Reinhardt, T P; Röder, M; Rusev, G; Schilling, K D; Schmidt, K; Schramm, G; Tonchev, A P; Tornow, W; Wagner, A

    2014-02-21

    The electromagnetic dipole strength below the neutron-separation energy has been studied for the xenon isotopes with mass numbers A=124, 128, 132, and 134 in nuclear resonance fluorescence experiments using the ?ELBE bremsstrahlung facility at Helmholtz-Zentrum Dresden-Rossendorf and the HI?S facility at Triangle Universities Nuclear Laboratory Durham. The systematic study gained new information about the influence of the neutron excess as well as of nuclear deformation on the strength in the region of the pygmy dipole resonance. The results are compared with those obtained for the chain of molybdenum isotopes and with predictions of a random-phase approximation in a deformed basis. It turned out that the effect of nuclear deformation plays a minor role compared with the one caused by neutron excess. A global parametrization of the strength in terms of neutron and proton numbers allowed us to derive a formula capable of predicting the summed E1 strengths in the pygmy region for a wide mass range of nuclides. PMID:24579591

  6. Sex steroid hormones regulate constitutive expression of Cyp2e1 in female mouse liver

    PubMed Central

    Cheng, Jie; Gonzalez, Frank J.

    2013-01-01

    CYP2E1 is of paramount toxicological significance because it metabolically activates a large number of low-molecular-weight toxicants and carcinogens. In this context, factors that interfere with Cyp2e1 regulation may critically affect xenobiotic toxicity and carcinogenicity. The aim of this study was to investigate the role of female steroid hormones in the regulation of CYP2E1, as estrogens and progesterone are the bases of contraceptives and hormonal replacement therapy in menopausal women. Interestingly, a fluctuation in the hepatic expression pattern of Cyp2e1 was revealed in the different phases of the estrous cycle of female mice, with higher Cyp2e1 expression at estrus (E) and lower at methestrus (ME), highly correlated with that in plasma gonadal hormone levels. Depletion of sex steroids by ovariectomy repressed Cyp2e1 expression to levels similar to those detected in males and cyclic females at ME. Hormonal supplementation brought Cyp2e1 expression back to levels detected at E. The role of progesterone appeared to be more prominent than that of 17?-estradiol. Progesterone-induced Cyp2e1 upregulation could be attributed to inactivation of the insulin/PI3K/Akt/FOXO1 signaling pathway. Tamoxifen, an anti-estrogen, repressed Cyp2e1 expression potentially via activation of the PI3K/Akt/FOXO1 and GH/STAT5b-linked pathways. The sex steroid hormone-related changes in hepatic Cyp2e1 expression were highly correlated with those observed in Hnf-1?, ?-catenin, and Srebp-1c. In conclusion, female steroid hormones are clearly involved in the regulation of CYP2E1, thus affecting the metabolism of a plethora of toxicants and carcinogenic agents, conditions that may trigger several pathologies or exacerbate the outcomes of various pathophysiological states. PMID:23548611

  7. Prevalence of HPV16 E1-1374^63nt variants in Greek women.

    PubMed

    Tsakogiannis, D; Kyriakopoulou, Z; Darmis, F; Ruether, I G A; Dimitriou, T G; Orfanoudakis, G; Panotopoulou, E; Markoulatos, P

    2014-05-01

    Recent studies have focused on sequence variation of the HPV16 E1 gene. The present study investigates the prevalence of E1-1374^63nt duplication in the Greek population, and the sequence variation at the 5' end of the E1 and E6 genes from samples that harbored this genetic alteration. Fifty HPV16 positive cervical samples, derived from Greek patients were investigated. The 5' end of the E1 gene was amplified through PCR and the variant amplicons were cloned, sequenced, and bioinformatically analyzed for selective pressure. The E1-1374^63nt duplication was identified in 24% of the examined samples, with the same prevalence in both high and low-grade cervical malignancies. The E1-1374^63nt duplication was linked to the European variant lineage (x² ?=?5.076, P?E1-1374^63nt duplication induces functional constraints on the 5' end of E1 gene, and it is proposed that this duplication might not affect negatively the function or structure of the E1 protein. The E1-1374^63nt duplication is prevalent in the Greek population, whereas the A1053C variation might constitute a significant marker for the characterization of the E1-1374^63nt variant in the Greek population, thus providing significant information about viral pathogenicity. PMID:24519452

  8. Strength and durability of lightweight concrete

    Microsoft Academic Search

    M. N Haque; H Al-Khaiat; O Kayali

    2004-01-01

    Two lightweight aggregate concretes, SLWC35 and SLWC50, of 35 and 50 MPa 28 day cube compressive strength were cast. The concrete specimens made with lightweight coarse aggregates and a dune sand were continuously cured in water for one or 7 days and then exposed to predominantly hot and humid seaside ambient conditions containing air-borne salts. After 7 days of initial

  9. Silicon nitride having a high tensile strength

    DOEpatents

    Pujari, Vimal K. (Northboro, MA); Tracey, Dennis M. (Medfield, MA); Foley, Michael R. (Oxford, MA); Paille, Norman I. (Oxford, MA); Pelletier, Paul J. (Millbury, MA); Sales, Lenny C. (Grafton, MA); Willkens, Craig A. (Sterling, MA); Yeckley, Russell L. (Oakham, MA)

    1996-01-01

    A silicon nitride ceramic comprising: a) inclusions no greater than 25 microns in length, b) agglomerates no greater than 20 microns in diameter, and c) a surface finish of less than about 8 microinches, said ceramic having a four-point flexural strength of at least about 900 MPa.

  10. Wood Structure and Adhesive Bond Strength

    Microsoft Academic Search

    Charles R. Frihart

    Much of the literature on the bonding of wood and other lignocellulosic materials has concentrated on traditional adhesion theories. This has led to misconceptions because wood is a porous material on both the macroscopic and microscopic levels. A better understanding of wood bonding can be developed by investigating the theories of adhesion and bond strength, taking into consideration the unusual

  11. Strength characteristics of Mg–Li alloys

    Microsoft Academic Search

    D. Regenera; V. Tkachenko

    2009-01-01

    We study the mechanical properties of Mg–Li alloys obtained by high-pressure die casting in a cold pressing chamber. A procedure\\u000a of evaluation of the principal strength characteristics obtained under the conditions of high plastic strains is presented.\\u000a The fracture toughness of materials under quasistatic and dynamic concentrated loads is investigated.

  12. PREDICTING TIE STRENGTH WITH SOCIAL MEDIA

    E-print Network

    Karahalios, Karrie G.

    PREDICTING TIE STRENGTH WITH SOCIAL MEDIA Eric Gilbert & Karrie Karahalios University of Illinois TSOWT firms with right mix of ties get better deals strong ties can affect mental health #12;TIE, STRUCTURAL, EMOTIONAL SUPPORT and SOCIAL DISTANCE. As manifested in social media, can these dimensions

  13. Gamow-Teller strength of Mg-26

    E-print Network

    Xu, HM; Gagliardi, Carl A.; Ajupova, G. K.; Kokenge, B.; Lui, YW.

    1996-01-01

    We have measured cross sections for (d,He-2)-induced reactions on Mg-26 at an energy of E(d)=125.2 MeV. The measured Gamow-Teller strength is significantly smaller than that inferred from (p,n) reactions. We demonstrate that beta(+) Gamow...

  14. The strength and dilatancy of sands

    Microsoft Academic Search

    M. D. Bolton

    1986-01-01

    Extensive data of the strength and dilatancy of 17 sands in axisymmetric or plane strain at different densities and confining pressures are collated. The critical state angle of shearing resistance of soil which is shearing at con- stant volume is principally a function of mineralogy and can readily be determined experimentally within a margin of about l\\

  15. Strengths for Coping with Family Conflict

    ERIC Educational Resources Information Center

    Chambers, Jamie C.

    2005-01-01

    Maltreatment in the family occurs through a variety of forms of abuse and neglect. These risks are particularly prevalent in families with parents who abuse substances. The author describes connections between parental addiction and coping behaviors used by the children in these high-risk families. Strength-based strategies enable these youth to…

  16. Silicon nitride having a high tensile strength

    DOEpatents

    Pujari, V.K.; Tracey, D.M.; Foley, M.R.; Paille, N.I.; Pelletier, P.J.; Sales, L.C.; Willkens, C.A.; Yeckley, R.L.

    1996-11-05

    A silicon nitride ceramic is disclosed comprising: (a) inclusions no greater than 25 microns in length, (b) agglomerates no greater than 20 microns in diameter, and (c) a surface finish of less than about 8 microinches, said ceramic having a four-point flexural strength of at least about 900 MPa. 4 figs.

  17. Considerations on strength of intact sedimentary rocks

    Microsoft Academic Search

    G Tsiambaos; N Sabatakakis

    2004-01-01

    This study presents the results of laboratory testing of sedimentary rocks under point loading as well as in uniaxial and triaxial compression. From the statistical analysis of the data, different conversion factors relating uniaxial compressive and point loading strength were determined for soft to strong rocks. Additionally, the material constant mi, an input parameter for the Hoek and Brown failure

  18. Giant monopole resonance strength in Si-28

    E-print Network

    Youngblood, David H.; Clark, HL; Lui, YW.

    1998-01-01

    The giant resonance region in Si-28 was studied with inelastic scattering of 240 MeV alpha particles at small angles including 0 degrees. The giant resonance peak extended from E-x=12 MeV to 35 MeV and E0 strength corresponding to 54 +/- 6...

  19. Ultra-high-strength boron fibers

    NASA Technical Reports Server (NTRS)

    Behrendt, D. R.; Dicarlo, J. A.; Grimes, H. H.; Smith, R. J.

    1978-01-01

    Boron-on-tungsten fibers with tensile strength and strain-to-failure values increased by fifty percent over commercial grades are produced by controlled chemical-etching process. Improved fibers have potential applications as lightweight composites in ground vehicles, spacecraft, and rotors for energy storage.

  20. Postactivation Potentiation Biases Maximal Isometric Strength Assessment

    PubMed Central

    Lima, Leonardo Coelho Rabello; Oliveira, Felipe Bruno Dias; Oliveira, Thiago Pires; Assumpção, Claudio de Oliveira; Greco, Camila Coelho; Cardozo, Adalgiso Croscato; Denadai, Benedito Sérgio

    2014-01-01

    Postactivation potentiation (PAP) is known to enhance force production. Maximal isometric strength assessment protocols usually consist of two or more maximal voluntary isometric contractions (MVCs). The objective of this study was to determine if PAP would influence isometric strength assessment. Healthy male volunteers (n = 23) performed two five-second MVCs separated by a 180-seconds interval. Changes in isometric peak torque (IPT), time to achieve it (tPTI), contractile impulse (CI), root mean square of the electromyographic signal during PTI (RMS), and rate of torque development (RTD), in different intervals, were measured. Significant increases in IPT (240.6?±?55.7?N·m versus 248.9?±?55.1?N·m), RTD (746?±?152?N·m·s?1versus 727?±?158?N·m·s?1), and RMS (59.1?±?12.2% RMSMAX??versus 54.8?±?9.4% RMSMAX) were found on the second MVC. tPTI decreased significantly on the second MVC (2373?±?1200?ms versus 2784?±?1226?ms). We conclude that a first MVC leads to PAP that elicits significant enhancements in strength-related variables of a second MVC performed 180 seconds later. If disconsidered, this phenomenon might bias maximal isometric strength assessment, overestimating some of these variables. PMID:25133157

  1. Springback analysis of ultra high strength steel

    NASA Astrophysics Data System (ADS)

    Tenma, Kenji; Kina, Futoshi; Suzuki, Wataru

    2013-12-01

    It is an inevitable trend in the automotive industry to apply more and more high strength steels and even ultra-high strength steels. Even though these materials are more difficult to process the development time of forming tools must be reduced. In order to keep the development time under control, simulation tools are used to verify the forming process in advance. At Aoi Machine Industry a project has been executed to accurately simulate springback of ultra-high strength steels in order to reduce the tool tryout time. In the first phase of the project the simulation settings were optimized based on B-Pillar model A made of Dual Phase 980. In the second phase, it was verified with B-Pillar model B whether these simulation settings were usable as general setting. Results showed that with the right settings it is very well possible to accurately simulate springback of ultra-high strength steels. In the third phase the project the stamping of a B-Pillar of Dual Phase 1180 was studied.

  2. Strength distribution of elementary flax fibres

    Microsoft Academic Search

    J. Andersons; E. Sp?rni?š; R. Joffe; L. Wallström

    2005-01-01

    Flax fibres, along with a number of other natural fibres, are being considered as an environmentally friendly alternative of synthetic fibres in fibre-reinforced polymer composites. A common feature of natural fibres is a much higher variability of mechanical properties. This necessitates study of the flax fibre strength distribution and efficient experimental methods for its determination. Elementary flax fibres of different

  3. A Quantitative Analysis of Countries' Research Strengths

    ERIC Educational Resources Information Center

    Saxena, Anurag; Brazer, S. David; Gupta, B. M.

    2009-01-01

    This study employed a multidimensional analysis to evaluate transnational patterns of scientific research to determine relative research strengths among widely varying nations. Findings from this study may inform national policy with regard to the most efficient use of scarce national research resources, including government and private funding.…

  4. Got LEGO Bricks? Children with Spatial Strengths

    ERIC Educational Resources Information Center

    Mann, Rebecca

    2013-01-01

    Individuals with spatial strengths have preferences for visual ideation, holistic reasoning, and innovation. With the emphasis on verbal skills, American schools rarely provide opportunities for children to excel in these areas. Standardized assessments used to judge achievement do not value reflective thinking and innovation; therefore, students…

  5. Family Strengths and Challenges in the USA

    Microsoft Academic Search

    John DeFrain; Sylvia M. Asay

    2007-01-01

    Families in the United States are faced with many challenges both within the family and in the social environment. To balance this discussion of challenges, an exploration of how the strengths of families and couples—their positive abilities and attitudes toward life and each other—help to create an intimate family environment in which love, satisfaction, happiness, and comfort predominate. The discussion

  6. Anchor bolt behavior and strength during earthquakes

    SciTech Connect

    Klingner, R.E. [Univ. of Texas, Austin, TX (United States); Graves, H.L. [Nuclear Regulatory Commission, Washington, DC (United States)

    1994-10-01

    The Seismic Qualification Utility Group (SQUG), a utility group, has developed a Generic Implementation Plant (GIP) including criteria and walkdown procedures that will be used to resolve the concerns of USI A-46. Following NRC approach of the GIP, each utility will conduct a walkdown of its nuclear facilities using the GIP criteria and procedures. The criteria and procedures specified for anchorage walkdown in the GIP contain specific information relating to bolt strength under dynamic conditions. The GIP including criteria and walkdown procedures has been reviewed and accepted by the NRC. However, very little test data are available regarding the behavior and strength of anchor bolts under dynamic conditions (cyclic loads) to validate the criteria in the GIP. It is usually assumed that behavior and strength of anchor bolts under static loads do not differ much from that of earthquake conditions. The adequacy of this assumption has never been adequately verified. The goal of this contract is to verify, by testing, the adequacy of the assumption used in the U.S. nuclear power plant designs that the behavior and strength of anchor bolts (cast-in-place, expansion and bearing-type undercut) and their supporting concrete under seismic loads do not differ significantly from those for static conditions.

  7. Research on shear strength of galvannealed coatings

    Microsoft Academic Search

    Chun Xu; Z. Q. Lin; S. H. Li; W. G. Zhang

    2007-01-01

    Lap shear test can be generally performed by two kinds of methods. However, the shear strengths measured in both methods (bare and compound sample) may be quite different, which results in some influence on evaluating powdering of galvannealed coating. Samples in uniaxial tensile test are modified to measure their yield stress. The stress–strain curves in tensile test are compared with

  8. Aluminum Yield Strength on Quasi-isentropes

    Microsoft Academic Search

    Jeffrey H. Nguyen; J. Reed Patterson; Daniel Orlikowski; L. Peter Martin; Ryan Krone; Roger Minich; Neil C. Holmes

    2008-01-01

    Advances in the functionally graded density impactors (FGDI) have made it possible to carry out dynamic experiments at previously inaccessible regions of the phase diagram. We employed these advances in recent tailored dynamic experiments to gain insight into the yield strength of aluminum along ``hot'' quasi-isentropes. The impactor was specifically designed to deliver a triangular compression wave into a sample

  9. Material Strength on Quasi-isentropes

    Microsoft Academic Search

    Jeffrey H. Nguyen; J. Reed Patterson; Daniel Orlikowski; L. Peter Martin; Neil C. Holmes

    2007-01-01

    We have recently carried out off-Hugoniot dynamic compression experiments on aluminum to gain insight into its yield strength. The samples were initially shocked to a fixed state on the Hugoniot, then quasi-isentropically compressed and released isentropically. We designed the functionally graded density impactor (FGDI) such that the strain rates on compression and release isentropes are nearly equivalent. Here, we will

  10. ROOM TEMPERATURE STRENGTH DEGRADATION OF OPTICAL FIBERS

    E-print Network

    Matthewson, M. John

    ROOM TEMPERATURE STRENGTH DEGRADATION OF OPTICAL FIBERS C. R. Kurkjian, H. H. Yuce Bell of elevated temperatures and at room temperature. Using these data we show that accelerated testing can be used to predict ambient temperature behavior. An activation energy of '90 kJ.mo11 describes the shift

  11. An improved device to measure cottonseed strength

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During processing, seeds of cotton cultivars with fragile seeds often break and produce seed coat fragments that can cause processing problems at textile mills. A cottonseed shear tester, previously developed to measure cottonseed strength, was modified with enhancements to the drive system to provi...

  12. Educating industrial-strength software engineers

    Microsoft Academic Search

    Jorge L. Díaz-Herrera; Gerald M. Powell

    1998-01-01

    A roadmap is proposed for integrating trends in software technology and product development into a graduate curriculum in software engineering. We contend that the causal relationship between building model solutions and developing products from these solutions, provides a sound basis for industrial strength software engineering. We illustrate the impact of modern software technology on the two fundamental, complementary sets of

  13. Physical Property Measurements: Unconfined Compressive Strength (UCS)

    NSDL National Science Digital Library

    Ozdemir, Levent

    This site, by the Colorado School of Mines, addresses the properties of a measurement technique called unconfined compression strength (UCS). Along with defining the technique, the website shows different experiments, pictures and diagrams associated with UCS. This well organized work will be a valuable asset for any geology or engineering classroom.

  14. Erosional Strength Parameters: An Experimental Investigation

    Microsoft Academic Search

    A. R. Maxwell; A. N. Papanicolaou; K. B. Strom; J. F. Fox

    The present research examined the eects of dierent inorganic and organic proper- ties, viz. sediment age, water content, clay\\/sand content, and microbial content on the erosional strength of sediments. For this purpose, 14 detailed erosional experiments were performed in the laboratory under well-controlled conditions in order to (1) isolate the role of each of the properties and (2) evaluate the

  15. Density and strength characteristics of foamed gypsum

    Microsoft Academic Search

    Adnan Çolak

    2000-01-01

    This paper deals with the effect of substances producing and assisting gas and foam formation on the properties of gypsum density and strength. The gas-based foaming method utilises aluminium sulphate, potassium alum or ammonium bicarbonate for the chemical production of gas bubbles in gypsum paste. The second method obtains foamed gypsum by means of air entrainment in wet gypsum paste.

  16. Innovative Degree Programs Matched to City Strengths

    ERIC Educational Resources Information Center

    Sukhatme, Uday

    2011-01-01

    In recent years, IUPUI has steadily acquired a considerable national reputation as an up-and-coming university. Some of the reasons for this recognition include the RISE Initiative and the large number of innovative degree programs recently started at IUPUI based on campus strengths and the priorities of the city of Indianapolis. Some specific…

  17. Predicting tie strength with social media

    Microsoft Academic Search

    Eric Gilbert; Karrie Karahalios

    2009-01-01

    Social media treats all users the same: trusted friend or total stranger, with little or nothing in between. In reality, rela- tionships fall everywhere along this spectrum, a topic social science has investigated for decades under the theme of tie strength. Our work bridges this gap between theory and practice. In this paper, we present a predictive model that maps

  18. High-strength mineralized collagen artificial bone

    NASA Astrophysics Data System (ADS)

    Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

    2014-03-01

    Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

  19. Shear Reinforcement Requirements for High-Strength Concrete Bridge Girders

    Microsoft Academic Search

    J. A. Ramirez; Gerardo Aguilar

    2005-01-01

    A research program was conducted on the shear strength of high-strength concrete members. The objective was to evaluate the shear behavior and strength of concrete bridge members with compressive strengths in the range of 10 000 to 15 000 psi. The goal was to determine if the current minimum amount of shear reinforcement together with maximum spacing limits in the

  20. Men and Art Therapy: A Connection through Strengths

    ERIC Educational Resources Information Center

    Riddle, Jeremy A.; Michel Riddle, Heather

    2007-01-01

    This inquiry examines the strengths of male art therapists and art therapy students using the Values in Action Inventory of Strengths (VIA-IS) survey that measures character strengths. Among this sample of 21 men, two signature strengths emerged most often and had the highest total scores: "curiosity and interest in the world" and "appreciation of…

  1. Assessing the Strengths of Mental Health Consumers: A Systematic Review

    ERIC Educational Resources Information Center

    Bird, Victoria J.; Le Boutillier, Clair; Leamy, Mary; Larsen, John; Oades, Lindsay G.; Williams, Julie; Slade, Mike

    2012-01-01

    Strengths assessments focus on the individual's talents, abilities, resources, and strengths. No systematic review of strengths assessments for use within mental health populations has been published. The aims of this study were to describe and evaluate strengths assessments for use within mental health services. A systematic review identified 12…

  2. American Indian Youth: Personal, Familial, and Environmental Strengths

    ERIC Educational Resources Information Center

    Stiffman, Arlene Rubin; Brown, Eddie; Freedenthal, Stacey; House, Laura; Ostmann, Emily; Yu, Man Soo

    2007-01-01

    We present data from interviews with 401 youths on the relationship of personal, familial, and environmental strengths to the outcomes of urban and reservation American Indian youths. Urban youths consistently nominated more strengths than tribal youths, except in the area of tribal strengths. Quantitative data show how those strengths relate to…

  3. 78 FR 15597 - Special Conditions: GE Aviation CT7-2E1 Turboshaft Engine Model

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-12

    ...Special Conditions: GE Aviation CT7-2E1 Turboshaft Engine Model AGENCY: Federal Aviation Administration...for the General Electric Aviation (GE) CT7-2E1 engine model. This engine model will have a novel or unusual design...

  4. 40 CFR Figure E-1 to Subpart E of... - Designation Testing Checklist

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Testing Physical (Design) and Performance Characteristics of Reference Methods and Class I and Class II Equivalent Methods for PM2.5 or PM10â2.5 Pt. 53, Subpt. E, Fig. E-1 Figure E-1 to Subpart E of Part 53—Designation Testing...

  5. 40 CFR Figure E-1 to Subpart E of... - Designation Testing Checklist

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Testing Physical (Design) and Performance Characteristics of Reference Methods and Class I and Class II Equivalent Methods for PM2.5 or PM10â2.5 Pt. 53, Subpt. E, Fig. E-1 Figure E-1 to Subpart E of Part 53—Designation Testing...

  6. 40 CFR Figure E-1 to Subpart E of... - Designation Testing Checklist

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Testing Physical (Design) and Performance Characteristics of Reference Methods and Class I and Class II Equivalent Methods for PM2.5 or PM10â2.5 Pt. 53, Subpt. E, Fig. E-1 Figure E-1 to Subpart E of Part 53—Designation Testing...

  7. 11 CFR 101.1 - Candidate designations (2 U.S.C. 432(e)(1)).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 false Candidate designations (2 U.S.C. 432(e)(1)). 101.1 Section...GENERAL CANDIDATE STATUS AND DESIGNATIONS (2 U.S.C. 432(e)) § 101.1 Candidate designations (2 U.S.C. 432(e)(1)). (a)...

  8. 17 CFR 240.14e-1 - Unlawful tender offer practices.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 false Unlawful tender offer practices. 240.14e-1 Section...Regulation 14e § 240.14e-1 Unlawful tender offer practices. As a means reasonably...e) of the Act, no person who makes a tender offer shall: (a) Hold such...

  9. An Efficient Strategy for the Acquisition of Weak Galileo E1 OS Signals

    E-print Network

    Paris-Sud XI, Université de

    An Efficient Strategy for the Acquisition of Weak Galileo E1 OS Signals Myriam Foucras 1, 2 the process which needs the most resources. Moreover, acquiring of weak Galileo E1 OS signals is a real in the development of a GPS/Galileo software receiver. Olivier JULIEN is the head of the Signal Processing

  10. Lunar regolith thermal behavior revealed by Chang'E-1 microwave brightness temperature data

    E-print Network

    Chan, Kwing Lam

    of the lunar diurnal cycle. The information can provide surface boundary conditions for further interpretationLunar regolith thermal behavior revealed by Chang'E-1 microwave brightness temperature data Kwing L brightness temperature data obtained by the Chinese Chang'E-1 lunar orbiter are analyzed with the lunar

  11. 26 CFR 48.6416(e)-1 - Refund to exporter or shipper.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...2010-04-01 2010-04-01 true Refund to exporter or shipper. 48.6416(e)-1 ...Taxes § 48.6416(e)-1 Refund to exporter or shipper. (a) In general...of any article may be refunded to the exporter or shipper of the article pursuant to...

  12. Distinct features of cap binding by eIF4E1b proteins.

    PubMed

    Kubacka, Dorota; Miguel, Ricardo Núñez; Minshall, Nicola; Darzynkiewicz, Edward; Standart, Nancy; Zuberek, Joanna

    2015-01-30

    eIF4E1b, closely related to the canonical translation initiation factor 4E (eIF4E1a), cap-binding protein is highly expressed in mouse, Xenopus and zebrafish oocytes. We have previously characterized eIF4E1b as a component of the CPEB mRNP translation repressor complex along with the eIF4E-binding protein 4E-Transporter, the Xp54/DDX6 RNA helicase and additional RNA-binding proteins. eIF4E1b exhibited only very weak interactions with m(7)GTP-Sepharose and, rather than binding eIF4G, interacted with 4E-T. Here we undertook a detailed examination of both Xenopus and human eIF4E1b interactions with cap analogues using fluorescence titration and homology modeling. The predicted structure of eIF4E1b maintains the ?+? fold characteristic of eIF4E proteins and its cap-binding pocket is similarly arranged by critical amino acids: Trp56, Trp102, Glu103, Trp166, Arg112, Arg157 and Lys162 and residues of the C-terminal loop. However, we demonstrate that eIF4E1b is 3-fold less well able to bind the cap than eIF4E1a, both proteins being highly stimulated by methylation at N(7) of guanine. Moreover, eIF4E1b proteins are distinguishable from eIF4E1a by a set of conserved amino acid substitutions, several of which are located near to cap-binding residues. Indeed, eIF4E1b possesses several distinct features, namely, enhancement of cap binding by a benzyl group at N(7) position of guanine, a reduced response to increasing length of the phosphate chain and increased binding to a cap separated by a linker from Sepharose, suggesting differences in the arrangement of the protein's core. In agreement, mutagenesis of the amino acids differentiating eIF4E1b from eIF4E1a reduces cap binding by eIF4E1a 2-fold, demonstrating their role in modulating cap binding. PMID:25463438

  13. Distinct Features of Cap Binding by eIF4E1b Proteins

    PubMed Central

    Kubacka, Dorota; Miguel, Ricardo Núñez; Minshall, Nicola; Darzynkiewicz, Edward; Standart, Nancy; Zuberek, Joanna

    2015-01-01

    eIF4E1b, closely related to the canonical translation initiation factor 4E (eIF4E1a), cap-binding protein is highly expressed in mouse, Xenopus and zebrafish oocytes. We have previously characterized eIF4E1b as a component of the CPEB mRNP translation repressor complex along with the eIF4E-binding protein 4E-Transporter, the Xp54/DDX6 RNA helicase and additional RNA-binding proteins. eIF4E1b exhibited only very weak interactions with m7GTP-Sepharose and, rather than binding eIF4G, interacted with 4E-T. Here we undertook a detailed examination of both Xenopus and human eIF4E1b interactions with cap analogues using fluorescence titration and homology modeling. The predicted structure of eIF4E1b maintains the ? + ? fold characteristic of eIF4E proteins and its cap-binding pocket is similarly arranged by critical amino acids: Trp56, Trp102, Glu103, Trp166, Arg112, Arg157 and Lys162 and residues of the C-terminal loop. However, we demonstrate that eIF4E1b is 3-fold less well able to bind the cap than eIF4E1a, both proteins being highly stimulated by methylation at N7 of guanine. Moreover, eIF4E1b proteins are distinguishable from eIF4E1a by a set of conserved amino acid substitutions, several of which are located near to cap-binding residues. Indeed, eIF4E1b possesses several distinct features, namely, enhancement of cap binding by a benzyl group at N7 position of guanine, a reduced response to increasing length of the phosphate chain and increased binding to a cap separated by a linker from Sepharose, suggesting differences in the arrangement of the protein's core. In agreement, mutagenesis of the amino acids differentiating eIF4E1b from eIF4E1a reduces cap binding by eIF4E1a 2-fold, demonstrating their role in modulating cap binding. PMID:25463438

  14. Determination of polymyxin E1 in rat plasma by high-performance liquid chromatography.

    PubMed

    Gmur, Dennis J; Bredl, Charles R; Steele, Sharon J; Cai, Shaopei; VanDevanter, Donald R; Nardella, Pasqua A

    2003-06-15

    A precise and accurate HPLC assay for polymyxin E(1) in rat and dog plasma has been validated. Samples and standards are extracted from plasma with a 96-well C(8) extraction disk plate. Sample extracts are derivatized with dansyl chloride, and polymyxin E(1) derivative is quantitated on a C(8) column by HPLC with fluorescence detection. The assay is linear in the range of 0.050-5.00 micro g/ml for polymyxin E(1). The precision and accuracy of polymyxin E(1) plasma assay was well within the recommended limits set in the FDA Guidance for Bioanalytical Method Validation. Polymyxin E(1) stability in rat and dog plasma for 24 h at room temperature and through three freeze-thaw cycles was demonstrated. PMID:12742127

  15. Role of CYP2E1 in thioacetamide-induced mouse hepatotoxicity

    SciTech Connect

    Kang, Jin Seok; Wanibuchi, Hideki; Morimura, Keiichirou; Wongpoomchai, Rawiwan; Chusiri, Yaowares [Department of Pathology, Osaka City University Medical School, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan); Gonzalez, Frank J. [Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Building 37, Room 3106, NCI-Bethesda, Bethesda, MD 20892 (United States); Fukushima, Shoji [Department of Pathology, Osaka City University Medical School, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585 (Japan)], E-mail: s-fukushima@jisha.or.jp

    2008-05-01

    Previous experiments showed that treatment of mice and rats with thioacetamide (TAA) induced liver cell damage, fibrosis and/or cirrhosis, associated with increased oxidative stress and activation of hepatic stellate cells. Some experiments suggest that CYP2E1 may be involved in the metabolic activation of TAA. However, there is no direct evidence on the role of CYP2E1 in TAA-mediated hepatotoxicity. To clarify this, TAA-induced hepatotoxicity was investigated using Cyp2e1-null mice. Male wild-type and Cyp2e1-null mice were treated with TAA (200 mg/kg of body weight, single, i.p.) at 6 weeks of age, and hepatotoxicity examined 24 and 48 h after TAA treatment. Relative liver weights of Cyp2e1-null mice were significantly different at 24 h compared to wild-type mice (p < 0.01). Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in Cyp2e1-null mice were significantly different at both time points compared to wild-type mice (p < 0.01). Histopathological examination showed Cyp2e1-null mice represented no hepatototoxic lesions, in clear contrast to severe centriobular necrosis, inflammation and hemorrhage at both time points in wild-type mice. Marked lipid peroxidation was also only limited to wild-type mice (p < 0.01). Similarly, TNF-{alpha}, IL-6 and glutathione peroxidase mRNA expression in Cyp2e1-null mice did not significantly differ from the control levels, contrasting with the marked alteration in wild-type mice (p < 0.01). Western blot analysis further revealed no increase in iNOS expression in Cyp2e1-null mice. These results reveal that CYP2E1 mediates TAA-induced hepatotoxicity in wild-type mice as a result of increased oxidative stress.

  16. Architecture of the hepatitis C virus E1 glycoprotein transmembrane domain studied by NMR.

    PubMed

    Zazrin, Hadas; Shaked, Hadassa; Chill, Jordan H

    2014-03-01

    Oligomerization of hepatitis C viral envelope proteins E1 and E2 is essential to virus fusion and assembly. Although interactions within the transmembrane (TM) domains of these glycoproteins have proven contributions to the E1/E2 heterodimerization process and consequent infectivity, there is little structural information on this entry mechanism. Here, as a first step towards our long-term goal of understanding the interaction between E1 and E2 TM-domains, we have expressed, purified and characterized E1-TM using structural biomolecular NMR methods. An MBP-fusion expression system yielded sufficient quantities of pure E1-TM, which was solubilized in two membrane-mimicking environments, SDS- and LPPG-micelles, affording samples amenable to NMR studies. Triple resonance assignment experiments and relaxation measurements provided information on the secondary structure and global fold of E1-TM in these environments. In SDS micelles E1-TM adopts a helical conformation, with helical stretches at residues 354-363 and 371-379 separated by a more flexible segment of residues 364-370. In LPPG micelles a helical conformation was observed for residues 354-377 with greater flexibility in the 366-367 dyad, suggesting LPPG provides a more native environment for the peptide. Replacement of key positively charged residue K370 with an alanine did not affect the secondary structure of E1-TM but did change the relative positioning within the micelle of the two helices. These results lay the foundation for structure determination of E1-TM and a molecular understanding of how E1-TM flexibility enhances its interaction with E2-TM during heterodimerization and membrane fusion. PMID:24192053

  17. Hedgehog pathway antagonist 5E1 binds hedgehog at the pseudo-active site.

    PubMed

    Maun, Henry R; Wen, Xiaohui; Lingel, Andreas; de Sauvage, Frederic J; Lazarus, Robert A; Scales, Suzie J; Hymowitz, Sarah G

    2010-08-20

    Proper hedgehog (Hh) signaling is crucial for embryogenesis and tissue regeneration. Dysregulation of this pathway is associated with several types of cancer. The monoclonal antibody 5E1 is a Hh pathway inhibitor that has been extensively used to elucidate vertebrate Hh biology due to its ability to block binding of the three mammalian Hh homologs to the receptor, Patched1 (Ptc1). Here, we engineered a murine:human chimeric 5E1 (ch5E1) with similar Hh-binding properties to the original murine antibody. Using biochemical, biophysical, and x-ray crystallographic studies, we show that, like the regulatory receptors Cdon and Hedgehog-interacting protein (Hhip), ch5E1 binding to Sonic hedgehog (Shh) is enhanced by calcium ions. In the presence of calcium and zinc ions, the ch5E1 binding affinity increases 10-20-fold to tighter than 1 nm primarily because of a decrease in the dissociation rate. The co-crystal structure of Shh bound to the Fab fragment of ch5E1 reveals that 5E1 binds at the pseudo-active site groove of Shh with an epitope that largely overlaps with the binding site of its natural receptor antagonist Hhip. Unlike Hhip, the side chains of 5E1 do not directly coordinate the Zn(2+) cation in the pseudo-active site, despite the modest zinc-dependent increase in 5E1 affinity for Shh. Furthermore, to our knowledge, the ch5E1 Fab-Shh complex represents the first structure of an inhibitor antibody bound to a metalloprotease fold. PMID:20504762

  18. Column strength of magnesium alloy AM-57S

    NASA Technical Reports Server (NTRS)

    Holt, M

    1942-01-01

    Tests were made to determine the column strength of extruded magnesium alloy AM-57S. Column specimens were tested with round ends and with flat ends. It was found that the compressive properties should be used in computations for column strengths rather than the tensile properties because the compressive yield strength was approximately one-half the tensile yield strength. A formula for the column strength of magnesium alloy AM-57S is given.

  19. Comparison of the strength and durability performance of normal- and high-strength pozzolanic concretes at elevated temperatures

    Microsoft Academic Search

    Chi-Sun Poon; Salman Azhar; Mike Anson; Yuk-Lung Wong

    2001-01-01

    The strength and durability performance of normal- and high-strength pozzolanic concretes incorporating silica fume, fly ash, and blast furnace slag was compared at elevated temperatures up to 800°C. The strength properties were determined using an unstressed residual compressive strength test, while durability was investigated by rapid chloride diffusion test, mercury intrusion porosimetry (MIP), and crack pattern observations. It was found

  20. Effect of status epilepticus and antiepileptic drugs on CYP2E1 brain expression.

    PubMed

    Boussadia, B; Ghosh, C; Plaud, C; Pascussi, J M; de Bock, F; Rousset, M C; Janigro, D; Marchi, N

    2014-10-01

    P450 metabolic enzymes are expressed in the human and rodent brain. Recent data support their involvement in the pathophysiology of epilepsy. However, the determinants of metabolic enzyme expression in the epileptic brain are unclear. We tested the hypothesis that status epilepticus (SE) or exposure to phenytoin or phenobarbital affects brain expression of the metabolic enzyme CYP2E1. SE was induced in C57BL/6J mice by systemic kainic acid. Brain CYP2E1 expression was evaluated 18-24h after severe SE by immunohistochemistry. Co-localization with neuronal nuclei (NEUN), glial fibrillary acidic protein (GFAP) and CD31 was determined by confocal microscopy. The effect of phenytoin, carbamazepine and phenobarbital on CYP2E1 expression was evaluated in vivo or by using organotypic hippocampal cultures in vitro. CYP2E1 expression was investigated in brain resections from a cohort of drug-resistant epileptic brain resections and human endothelial cultures (EPI-EC). Immunohistochemistry showed an increase of CYP2E1 expression limited to hippocampal CA2/3 and hilar neurons after severe SE in mice. CYP2E1 expression was also observed at the astrocyte-vascular interface. Analysis of human brain specimens revealed CYP2E1 expression in neurons and vascular endothelial cells (EC). CYP2E1 was expressed in cultured human EC and over-expressed by EPI-EC. When analyzing the effect of drug exposure on CYP2E1 expression we found that, in vivo or in vitro, ethanol increased CYP2E1 levels in the brain and liver. Treatment with phenytoin induced localized CYP2E1 expression in the brain whereas no significant effects were exerted by carbamazepine or phenobarbital. Our data indicate that the effect of acute SE on brain CYP2E1 expression is localized and cell specific. Exposure to selected anti-epileptic drugs could play a role in determining CYP2E1 brain expression. Additional investigation is required to fully reproduce the culprits of P450 enzyme expression as observed in the human epileptic brain. PMID:25280786

  1. Role of CYP2E1 in Ethanol-Induced Oxidant Stress, Fatty Liver and Hepatotoxicity

    PubMed Central

    Cederbaum, Arthur I.

    2011-01-01

    Background/Aims Several pathways contribute to mechanisms by which ethanol induces oxidant stress. While some studies support a role for cytochrome P450 2E1 (CYP2E1), others do not. There is a need to develop oral models of significant ethanol-induced liver injury and to evaluate the possible role of CYP2E1 in ethanol actions in such models. Methods We evaluated chronic ethanol-induced liver injury, steatosis and oxidant stress in wild-type (WT) mice, CYP2E1 knockout (KO) mice and in humanized CYP2E1 knockin (KI) mice, where the human 2E1 was added back to mice deficient in the mouse 2E1. WT mice and CYP2E1 KO and KI mice (both provided by Dr. F. Gonzalez, NCI) were fed a high-fat Lieber-DeCarli liquid diet for 3 weeks; pair-fed controls received dextrose. Results Ethanol produced fatty liver and oxidant stress in WT mice, but liver injury (transaminases, histopathology) was minimal. Ethanol-induced steatosis and oxidant stress were blunted in the KO mice (no liver injury) but restored in the KI mice. Significant liver injury was produced in the ethanol-fed KI mice with elevated transaminases and necrosis. This liver injury in the KI mice was associated with elevated oxidant stress and elevated levels of the human CYP2E1 compared to levels of the mouse 2E1 in WT mice. Activation of JNK was observed in the ethanol-fed KI mice compared to the other groups. Fatty liver in WT and KI mice was associated with lower levels of lipolytic PPAR-?. No such changes were found in the ethanol-fed KO mice. Conclusions These results show that CYP2E1 plays a major role in ethanol-induced fatty liver and oxidant stress. Restoring CYP2E1 in the CYP2E1 KO mice restores ethanol-induced fatty liver and oxidant stress. PMID:21525766

  2. HBx Inhibits CYP2E1 Gene Expression via Downregulating HNF4? in Human Hepatoma Cells

    PubMed Central

    Li, Chongyi; Wang, Xiaodong; Cederbaum, Arthur I.; Gan, Lixia; Xie, Bin

    2014-01-01

    CYP2E1, one of the cytochrome P450 mixed-function oxidases located predominantly in liver, plays a key role in metabolism of xenobiotics including ethanol and procarcinogens. Recently, down-expression of CYP2E1 was found in hepatocellular carcinoma (HCC) with the majority to be chronic hepatitis B virus (HBV) carriers. In this study, we tested a hypothesis that HBx may inhibit CYP2E1 gene expression via hepatocyte nuclear factor 4? (HNF4?). By enforced HBx gene expression in cultured HepG2 cells, we determined the effect of HBx on CYP2E1 mRNA and protein expression. With a bioinformatics analysis, we found a consensus HNF-4? binding sequence located on ?318 to ?294 bp upstream of human CYP2E1 promoter. Using reporter gene assay and site-directed mutagenesis, we have shown that mutation of this site dramatically decreased CYP2E1 promoter activity. By silencing endogenous HNF-4?, we have further validated knockdown of HNF-4? significantly decreased CYP2E1expression. Ectopic overexpression of HBx in HepG2 cells inhibits HNF-4? expression, and HNF-4? levels were inversely correlated with viral proteins both in HBV-infected HepG2215 cells and as well as HBV positive HCC liver tissues. Moreover, the HBx-induced CYP2E1 reduction could be rescued by ectopic supplement of HNF4? protein expression. Furthermore, human hepatoma cells C34, which do not express CYP2E1, shows enhanced cell growth rate compared to E47, which constitutively expresses CYP2E1. In addition, the significantly altered liver proteins in CYP2E1 knockout mice were detected with proteomics analysis. Together, HBx inhibits human CYP2E1 gene expression via downregulating HNF4? which contributes to promotion of human hepatoma cell growth. The elucidation of a HBx-HNF4?-CYP2E1 pathway provides novel insight into the molecular mechanism underlining chronic HBV infection associated hepatocarcinogenesis. PMID:25238230

  3. E1-Mediated Recruitment of a UAF1-USP Deubiquitinase Complex Facilitates Human Papillomavirus DNA Replication

    PubMed Central

    Lehoux, Michaël; Gagnon, David

    2014-01-01

    ABSTRACT The human papillomavirus (HPV) E1 helicase promotes viral DNA replication through its DNA unwinding activity and association with host factors. The E1 proteins from anogenital HPV types interact with the cellular WD repeat-containing factor UAF1 (formerly known as p80). Specific amino acid substitutions in E1 that impair this interaction inhibit maintenance of the viral episome in immortalized keratinocytes and reduce viral DNA replication by up to 70% in transient assays. In this study, we determined by affinity purification of UAF1 that it interacts with three deubiquitinating enzymes in C33A cervical carcinoma cells: USP1, a nuclear protein, and the two cytoplasmic enzymes USP12 and USP46. Coimmunoprecipitation experiments indicated that E1 assembles into a ternary complex with UAF1 and any one of these three USPs. Moreover, expression of E1 leads to a redistribution of USP12 and USP46 from the cytoplasm to the nucleus. Chromatin immunoprecipitation studies further revealed that E1 recruits these threes USPs to the viral origin in association with UAF1. The function of USP1, USP12, and USP46 in viral DNA replication was investigated by overproduction of catalytically inactive versions of these enzymes in transient assays. All three dominant negative USPs reduced HPV31 DNA replication by up to 60%, an effect that was specific, as it was not observed in assays performed with a truncated E1 lacking the UAF1-binding domain or with bovine papillomavirus 1 E1, which does not bind UAF1. These results highlight the importance of the USP1, USP12, and USP46 deubiquitinating enzymes in anogenital HPV DNA replication. IMPORTANCE Human papillomaviruses are small DNA tumor viruses that induce benign and malignant lesions of the skin and mucosa. HPV types that infect the anogenital tract are the etiological agents of cervical cancer, the majority of anal cancers, and a growing proportion of head-and-neck cancers. Replication of the HPV genome requires the viral protein E1, a DNA helicase that also interacts with host factors to promote viral DNA synthesis. We previously reported that the E1 helicase from anogenital HPV types associates with the WD40 repeat-containing protein UAF1. Here, we show that UAF1 bridges the interaction of E1 with three deubiquitinating enzymes, USP1, USP12, and USP46. We further show that these deubiquitinases are recruited by E1/UAF1 to the viral origin of DNA replication and that overexpression of catalytically inactive versions of these enzymes reduces viral DNA replication. These results highlight the need for an E1-associated deubiquitinase activity in anogenital HPV genome replication. PMID:24850727

  4. Oscillator strengths and transition probabilities from the Breit-Pauli R-matrix method: Ne IV

    NASA Astrophysics Data System (ADS)

    Nahar, Sultana N.

    2014-09-01

    The atomic parameters-oscillator strengths, line strengths, radiative decay rates (A), and lifetimes-for fine structure transitions of electric dipole (E1) type for the astrophysically abundant ion Ne IV are presented. The results include 868 fine structure levels with n? 10, l? 9, and 1/2?J? 19/2 of even and odd parities, and the corresponding 83,767 E1 transitions. The calculations were carried out using the relativistic Breit-Pauli R-matrix method in the close coupling approximation. The transitions have been identified spectroscopically using an algorithm based on quantum defect analysis and other criteria. The calculated energies agree with the 103 observed and identified energies to within 3% or better for most of the levels. Some larger differences are also noted. The A-values show good to fair agreement with the very limited number of available transitions in the table compiled by NIST, but show very good agreement with the latest published multi-configuration Hartree-Fock calculations. The present transitions should be useful for diagnostics as well as for precise and complete spectral modeling in the soft X-ray to infra-red regions of astrophysical and laboratory plasmas.

  5. Adenovirus mediated overexpression of CYP2E1 increases sensitivity of HepG2 cells to acetaminophen induced cytotoxicity

    Microsoft Academic Search

    Jingxiang Bai; Arthur I. Cederbaum

    2004-01-01

    To study the biochemical and toxicological properties of cytochrome P450 2E1 (CYP2E1), an adenovirus containing human CYP2E1 cDNA (Ad-CYP2E1) was constructed and was shown to successfully mediate the overexpression of CYP2E1 in HepG2 cells. Acetaminophen (APAP) toxicity to HepG2 cells infected with Ad-CYP2E1 was characterized as a preliminary proof of principle experiment to validate the functionality of the CYP2E1 adenovirus.

  6. Effects of end conditions on compressive strength and static elastic modulus of very high strength concrete

    Microsoft Academic Search

    Mehmet Geso?lu; Erhan Güneyisi; Turan Özturan

    2002-01-01

    The use of bonded and unbonded caps in testing very high strength concrete cylinders has been investigated experimentally. A hundred and ninety-two concrete cylinder specimens of 150-mm diameter and 300-mm height were cast and tested using packing with softboard, neat cement paste, neoprene pad and sulfur mortar. The design strength level of 75–100 MPa was achieved using water-cementitious material ratios

  7. Preventing Strength Loss of Unbleached Kraft Pulp

    SciTech Connect

    Martin Hubbe; Richard Venditti; John Heitmann

    2003-04-16

    Kraft pulp fibers lose inter-fiber bonding ability when they are dried during the manufacture of paper. Adverse environmental consequences of this loss include (a) limitations on the number of times that kraft fibers can be recycled, (b) reduced paper strength, sometimes making it necessary to use heavier paper or paperboard to meet product strength requirements, increasing the usage of raw materials, (c) decreased rates of paper production in cases where the fiber furnish has been over-refined in an attempt to regain inter-fiber bonding ability. The present study is the first of its type to focus on unbleached kraft fibers, which are a main ingredient of linerboard for corrugated containers. About 90 million tons of unbleached kraft fiber are used worldwide every year for this purpose.

  8. Strength of fabric reinforced Blackglas composites

    SciTech Connect

    Lei, C.; Ko, F.K. [Drexel Univ., Philadelphia, PA (United States)

    1996-12-31

    In brittle matrix composites the role of matrix porosity; interface; and matrix/fiber properties degradation due to processing are especially critical for the strength of the composite. In this paper, the Fabric Geometry Model (FGM) is modified to predict the strength of fabric composites. An incremental strain approach in conjunction with strain energy criterion is presented in order to account for the potentially nonlinear behavior of the materials, as seen in the experimental stress-strain curves of Nextel/Blackglas, composites. The failure of the composite is determined by use of a modified maximum strain energy criterion, which is based on the relative magnitudes of the various energy terms in corresponding direction. The effects of porosity, microcracks, fiber and matrix degradation, and fiber/matrix interface are also considered in the modified model.

  9. Rock strength under confined shock conditions

    SciTech Connect

    Scholz, C.H.

    1982-10-01

    This report addresses the laboratory measurements of the static strength of rock needed to simulate the response of rock to an underground explosion. The approach is to identify the variables that affect the strength of rock and to discuss each effect in terms of the underlying processes that cause it. Most of the report is the result of a literature review, although some new analyses and concepts are presented. Attention is directed at three basic rock types: low porosity brittle rock such as granodiorite, high porosity brittle rock such as volcanic tuff, and a rock that may be ductile under the relevant conditions, salt. These three rock types are sufficiently different that somewhat different constitutive laws may have to be used to model their behavior.

  10. On the Ultimate Strength of Condensed Matter

    NASA Astrophysics Data System (ADS)

    Bourne, Neil K.

    2014-07-01

    This and an accompanying paper track a range of thresholds for the response of condensed matter under loading in compression, from the ambient state to the point at which the material bond strength is overcome and it becomes warm dense matter. The threshold considered here is the weak shock limit that differentiates weak- from strong shock dynamic loading. This work examines this threshold and shows a correlation with the theoretical strength of the material. The structure of the shock that evolves has steady and unsteady phases that sweep different regions in a target in differing manners. This is put in context with scale to show it as a transit to a hydrodynamic regime. Limits on the applicability of solid mechanics are discussed in relation to the mechanisms observed.

  11. Strength of footing with punching shear preventers.

    PubMed

    Lee, Sang-Sup; Moon, Jiho; Park, Keum-Sung; Bae, Kyu-Woong

    2014-01-01

    The punching shear failure often governs the strength of the footing-to-column connection. The punching shear failure is an undesirable failure mode, since it results in a brittle failure of the footing. In this study, a new method to increase the strength and ductility of the footing was proposed by inserting the punching shear preventers (PSPs) into the footing. The validation and effectiveness of PSP were verified through a series of experimental studies. The nonlinear finite element analysis was then performed to demonstrate the failure mechanism of the footing with PSPs in depth and to investigate the key parameters that affect the behavior of the footing with PSPs. Finally, the design recommendations for the footing with PSPs were suggested. PMID:25401141

  12. Cryogenic insulation strength and bond tester

    NASA Technical Reports Server (NTRS)

    Schuerer, P. H.; Ehl, J. H.; Prasthofer, W. P. (inventors)

    1985-01-01

    A method and apparatus for testing the tensile strength and bonding strength of sprayed-on foam insulation attached to metal cryogenic fuel tanks is described. A circular cutter is used to cut the insulation down to the surface of the metal tank to form plugs of the insulation for testing in situ on the tank. The apparatus comprises an electromechanical pulling device powered by a belt battery pack. The pulling device comprises a motor driving a mechanical pulling structure comprising a horizontal shaft connected to two bell cracks which are connected to a central member. When the lower end of member is attached to a fitting, which in turn is bonded to a plug, a pulling force is exerted on the plug sufficient to rupture it. The force necessary to rupture the plug or pull it loose is displayed as a digital read-out.

  13. Tensile & shear strength of porous dust agglomerates

    E-print Network

    Seizinger, Alexander; Kley, Wilhelm

    2013-01-01

    Context.Within the sequential accretion scenario of planet formation, planets are build up through a sequence sticking collisions. The outcome of collisions between porous dust aggregates is very important for the growth from very small dust particles to planetesimals. In this work we determine the necessary material properties of dust aggregates as a function the porosity. Aims: Continuum models such as SPH that are capable of simulating collisions of macroscopic dust aggregates require a set of material parameters. Some of them such as the tensile and shear strength are ?difficult to obtain from laboratory experiments. The aim of this work is to determine these parameters from ab-initio molecular dynamics simulations. Methods: We simulate the behavior of porous dust aggregates using a detailed micro-physical model of the interaction of spherical grains that includes adhesion forces, rolling, twisting, and sliding. Using different methods of preparing the samples we study the strength behavior of our samples...

  14. Material Strength on Quasi-isentropes

    NASA Astrophysics Data System (ADS)

    Nguyen, Jeffrey H.; Reed Patterson, J.; Orlikowski, Daniel; Martin, L. Peter; Holmes, Neil C.

    2007-06-01

    We have recently carried out off-Hugoniot dynamic compression experiments on aluminum to gain insight into its yield strength. The samples were initially shocked to a fixed state on the Hugoniot, then quasi-isentropically compressed and released isentropically. We designed the functionally graded density impactor (FGDI) such that the strain rates on compression and release isentropes are nearly equivalent. Here, we will discuss the details of the experiments and error analysis in deriving the yield strength of aluminum on a ``hot'' quasi-isentrope. We will also discuss recent advances in the FGDI technology that made these experiments possible with significantly reduced uncertainties. Methods to characterize these advances will be discussed. Work performed under the auspices of the U.S. DOE at the University of California/Lawrence Livermore National Laboratory under contract W-7405-ENG-48.

  15. Material Strength on Quasi-isentropes

    NASA Astrophysics Data System (ADS)

    Nguyen, Jeffrey; Patterson, Jeremy R.; Orlikowski, Daniel; Martin, Louis P.; Holmes, Neil C.

    2007-03-01

    We have recently performed experiments to study strength properties of aluminum on quasi-isentropes. The aluminum samples were initially shocked to a fixed state on the Hugoniot, then quasi-isentropically compressed and released isentropically. In these experiments, the strain rates on compression and release isentropes are nearly equivalent. We will discuss the details of the experiments and data and error analysis in deriving strength of aluminum. Recent advances in the functionally graded density impactor technology have made it possible for us to carry out these experiments with significantly reduced uncertainties. We will discuss these advances including reproducibility and planarity of the impactors. Methods to characterize these advances will be discussed. [1] Work performed under the auspices of the U.S. DOE at the University of California/Lawrence Livermore National Laboratory under contract W-7405-ENG-48.

  16. Strength of Footing with Punching Shear Preventers

    PubMed Central

    Lee, Sang-Sup; Moon, Jiho; Park, Keum-Sung; Bae, Kyu-Woong

    2014-01-01

    The punching shear failure often governs the strength of the footing-to-column connection. The punching shear failure is an undesirable failure mode, since it results in a brittle failure of the footing. In this study, a new method to increase the strength and ductility of the footing was proposed by inserting the punching shear preventers (PSPs) into the footing. The validation and effectiveness of PSP were verified through a series of experimental studies. The nonlinear finite element analysis was then performed to demonstrate the failure mechanism of the footing with PSPs in depth and to investigate the key parameters that affect the behavior of the footing with PSPs. Finally, the design recommendations for the footing with PSPs were suggested. PMID:25401141

  17. Photophoretic Strength on Chondrules 1: Modeling

    E-print Network

    Loesche, Christoph; Teiser, Jens; Friedrich, Jon M; Bischoff, Addi

    2013-01-01

    Photophoresis is a physical process that transports particles in optical thin parts of protoplanetary disks, especially at the inner edge and at the optically surface. To model the transport and resulting effects in detail, it is necessary to quantify the strength of photophoresis for different particle classes as a fundamental input. Here, we explore photophoresis for a set of chondrules. The composition and surface morphology of these chondrules was measured by X-ray tomography. Based on the three-dimensional models, heat transfer through illuminated chondrules was calculated. The resulting surface temperature map was then used to calculate the photophoretic strength. We found that irregularities in particle shape and variations in composition induce variations in the photophoretic force. These depend on the orientation of a particle with respect to the light source. The variations of the absolute value of the photophoretic force on average over all chondrules is $4.17\\%$. The deviation between the directio...

  18. Tensile strength of the chromaffin granule membrane.

    PubMed

    Hiram, Y; Nir, A; Zinder, O

    1982-07-01

    Catecholamine release from chromaffin granules, suspended in sucrose solutions of various osmotic strengths, was determined at different temperatures between 2 degrees and 44 degrees C. Dynamic measurements showed that steady state is achieved within 15 min of incubation at all temperatures. The effect of temperature on the release was established in terms of the median granular fragility (MGF) defined as the concentration of sucrose solution causing 50% lysis. The MGF was determined as the inflection point of the Gaussian distribution of granular fragility. The MGF was found to decrease with fall in temperature implying a corresponding increase of the tensile strength of the vesicle membrane. Critical resultant forces at lysis were calculated and found to vary from 8.2 dyn/cm at 2 degrees C to 4.2 dyn/cm at 44 degrees C. These compare well with tensions at lysis found earlier for erythrocytes. PMID:7104452

  19. Tensile Strength of the Chromaffin Granule Membrane

    PubMed Central

    Hiram, Yael; Nir, Avinoam; Zinder, Oren

    1982-01-01

    Catecholamine release from chromaffin granules, suspended in sucrose solutions of various osmotic strengths, was determined at different temperatures between 2° and 44°C. Dynamic measurements showed that steady state is achieved within 15 min of incubation at all temperatures. The effect of temperature on the release was established in terms of the median granular fragility (MGF) defined as the concentration of sucrose solution causing 50% lysis. The MGF was determined as the inflection point of the Gaussian distribution of granular fragility. The MGF was found to decrease with fall in temperature implying a corresponding increase of the tensile strength of the vesicle membrane. Critical resultant forces at lysis were calculated and found to vary from 8.2 dyn/cm at 2°C to 4.2 dyn/cm at 44°C. These compare well with tensions at lysis found earlier for erythrocytes. PMID:7104452

  20. The Papillomavirus E1 Helicase Activates a Cellular DNA Damage Response in Viral Replication Foci?

    PubMed Central

    Sakakibara, Nozomi; Mitra, Ruchira; McBride, Alison A.

    2011-01-01

    The papillomavirus E1 and E2 proteins are essential for viral genome replication. E1 is a helicase that unwinds the viral origin and recruits host cellular factors to replicate the viral genome. E2 is a transcriptional regulator that helps recruit the E1 helicase to the origin and also plays a role in genome partitioning. We find that when coexpressed, the E1 and E2 proteins from several papillomavirus types localize to defined nuclear foci and result in growth suppression of the host cells. Growth suppression was due primarily to E1 protein function, and nuclear expression of E1 was accompanied by activation of a DNA damage response, resulting in phosphorylation of ATM, Chk2, and H2AX. Growth suppression and ATM activation required the ATPase and origin-specific binding functions of the E1 protein and resulted in active DNA repair, as evidenced by incorporation of nucleotide analogs and detection of free DNA ends. In the presence of the E2 protein, these activities became localized to nuclear foci. We postulate that these foci represent viral replication factories and that a cellular DNA damage response is activated to facilitate replication of viral DNA. PMID:21734054

  1. Creatine Supplementation in Strength-Power Sports

    Microsoft Academic Search

    Darryn S. Willoughby

    The exogenous ingestion of creatine (Cr) is typically used as a performance enhancing (ergogenic) supplement because it is\\u000a known to improve performance in muscular strength and power activities, enhance short bursts of muscular endurance, and allow\\u000a for greater muscular overload in order to improve training effectiveness. Creatine has become one of the most popular ingested\\u000a nutritional supplements due to its

  2. Bearing strength of the lunar soil

    NASA Technical Reports Server (NTRS)

    Jaffe, L. D.

    1972-01-01

    A discussion is presented on the bearing strength and bearing load-penetration relations in lunar soil. These were measured in air as a function of bulk density. It was found that the relation between bulk density and the logarithm of the bearing capacity is about linear. Shapes of the load vs penetration curves were observed to be similar to those obtained with particulate material of terrestrial origin.

  3. Characteristic strength of quasi-brittle materials

    Microsoft Academic Search

    L. Biolzi

    1998-01-01

    The failure of rock-like, quasi-brittle materials is influenced by the development of an intrinsic process zone in the form of a localized region of microcracking. In particular, the process zone has a fundamental importance for defining the structural or system behavior in terms of the post-peak instability, a qualitative size effect, and the maximum stress or material strength, a quantitative

  4. Oscillator strengths for ionized iron and manganese

    NASA Technical Reports Server (NTRS)

    De Boer, K. S.; Pottasch, S. R.; Morton, D. C.; York, D. G.

    1974-01-01

    The observed strengths of interstellar absorption lines of Fe II and Mn II in the spectra of alpha Vir, beta Cen, pi Sco, and zeta Oph along with laboratory f values of some of these lines between 2343 and 2606 A have been used to determine curves of growth for these ions and the f-values of ten lines of Fe II and three lines of Mn II between 1055 and 1261 A. The Fe and Mn abundances are derived.

  5. Exogrip: assisted hand strength glove - biomed 2011.

    PubMed

    Best, Jade E; Bostick, Nehemiah F; Connelly, John R; Dunn, Michael G; Gelles, Richard A; Norvell, Elizabeth K; Waugaman, William B; Mims, Capt Willie H

    2011-01-01

    A large number of American troops fighting in Afghanistan and Iraq have received wounds in their upper extremities leading to significant nerve damage and loss of strength. These injuries impair their ability to perform day-to-day tasks such as lifting a cup of coffee or opening a door. Although the cause of some injuries in service-people is often unique to their employment, civilian employees in other industries are also plagued with similar physical damage due to other kinds of injuries. Our goal is to develop a device to augment the strength of injured troops and civilian workers so they can perform everyday tasks despite their physical limitations. The ExoGrip is a glove designed to provide this necessary strength augmentation. The ExoGrip consists primarily of pressure sensors, linear actuators, and a microcontroller to provide a force multiplier based on a person?s strength. The goal of the first phase of the project was to conduct research and also produce a working prototype of one finger. This goal was achieved by a group of classmates who started the project a year before. Their research and feasibility analysis ended in the mechanical movement of a single finger when the sensors were activated. The next phase of this project is to design and integrate a working prototype that manipulates all four fingers, while keeping the thumb in a fixed position. This paper describes the integration of new microcontrollers, linear actuators utilizing pulse width modulation technology, and improved pressure sensors needed to manipulate the fingers, as well as laying the foundation for future testing and development of a final product. PMID:21525608

  6. Residual strength of thin panels with cracks

    NASA Astrophysics Data System (ADS)

    Madenci, Erdogan

    1994-12-01

    The previous design philosophies involving safe life, fail-safe and damage tolerance concepts become inadequate for assuring the safety of aging aircraft structures. For example, the failure mechanism for the Aloha Airline accident involved the coalescence of undetected small cracks at the rivet holes causing a section of the fuselage to peel open during flight. Therefore, the fuselage structure should be designed to have sufficient residual strength under worst case crack configurations and in-flight load conditions. Residual strength is interpreted as the maximum load carrying capacity prior to unstable crack growth. Internal pressure and bending moment constitute the two major components of the external loads on the fuselage section during flight. Although the stiffeners in the form of stringers, frames and tear straps sustain part of the external loads, the significant portion of the load is taken up by the skin. In the presence of a large crack in the skin, the crack lips bulge out with considerable yielding; thus, the geometric and material nonlinearities must be included in the analysis for predicting residual strength. Also, these nonlinearities do not permit the decoupling of in-plane and out-of-plane bending deformations. The failure criterion combining the concepts of absorbed specific energy and strain energy density addresses the aforementioned concerns. The critical absorbed specific energy (local toughness) for the material is determined from the global specimen response and deformation geometry based on the uniaxial tensile test data and detailed finite element modeling of the specimen response. The use of the local toughness and stress-strain response at the continuum level eliminates the size effect. With this critical parameter and stress-strain response, the finite element analysis of the component by using STAGS along with the application of this failure criterion provides the stable crack growth calculations for residual strength predictions.

  7. Sex Differences in Tibial Bone Strength

    NASA Technical Reports Server (NTRS)

    Arnaud, Sara B.; Hutchinson, T. M.; Torikoshi, S.; Hutchinson, K. J.; Hargens, Alan R.; Steele, C. R.

    1995-01-01

    We have used an instrument (MRTA or Mechanical Response Tissue Analyzer) that measures bending stiffness (EI) non-Invasively to evaluate the strength of the tibia, a long bone in the weightbearing skeleton highly vulnerable to mineral loss during space flight. In healthy men, we found asymmetry in EI consistent with the bone's support function (L greater than R). In this study, we analyzed EI in women and compared the results to those in men.

  8. Oscillator strengths for singly ionized oxygen

    Microsoft Academic Search

    ?. Ate?; G. Tekeli; G. Çelik; E. Akin; M. Taser

    2009-01-01

    The electric dipole oscillator strengths for multiplet and \\u000a individual lines between some doublet and quartet levels have been \\u000a calculated using the weakest bound electron potential model theory (WBEPMT) \\u000a in singly ionized oxygen. We employed both numerical Coulomb approximation \\u000a (NCA) wave functions and numerical non-relativistic Hartree-Fock (NRHF) wave \\u000a functions for expectation values of radii in determination of parameters. \\u000a The calculated oscillator

  9. Strength of tubular members containing holes

    SciTech Connect

    Hsu, T.M. (Chevron Petroleum Technology Co., La Habra, CA (United States))

    1994-08-01

    A small-scale, compressive-load test program was conducted at Chevron to determine the strength of tubular members with 1 to 3 holes. The parameters evaluated include the hole size, hole shape, hole location, and number of holes. Results from these tests provide a basis for platform ultimate strength calculations that are needed in making decisions on platform repairs. More than 50 specimens were tested in air under displacement control. Test specimen lengths were limited by the test apparatus to 45 in. (1,143 mm). Tubulars used in the test had an outside diameter of 3.5 in. (89 mm), which gave member slenderness ratios of about 40. The tests were needed because of the lack of relevant compression tests on members with holes. Based on test results, there appears to be a limiting value of hole size below which the compression-load capacity of the member is practically not affected by the existence of the hole. For example, a hole that is 10% of the member diameter does not significantly reduce member strength. This means remedial treatment is not necessary for many small holes, when ultimate strength is the controlling consideration. Non-linear finite element shell analyses using both ADINA and FACTS computer programs and a simplified analysis using DENTA-II PC program were performed and results compared with data. The authors found that nonlinear finite element programs provide good predictions of capacities of members with holes, and that a simplified DENTA-II program provides adequate and efficient predictions.

  10. Dynamic Behavior of High Strength Armor Steels

    Microsoft Academic Search

    H. Nahme; E. Lach

    1997-01-01

    The dynamic properties of the armor steels Mars 190, Mars 240 and Mars 300 have been detamkd for strain rates s-' < &\\/dt < lo6 s-' . The planar plate impact technique in combination with a VISAR has been used for high strain rate testing (&\\/dt > lo4 s-' ). The dynamic properties Hugoniot-elastic-limit, spa11 strength, shock velocity-particle verlocity-relation and

  11. Insolation driven variations of Mercury's lithospheric strength

    Microsoft Academic Search

    Jean-Pierre Williams; Javier Ruiz; Margaret A. Rosenburg; Oded Aharonson; Roger J. Phillips

    2011-01-01

    Mercury's coupled 3:2 spin-orbit resonance in conjunction with its relatively high eccentricity of ?0.2 and near-zero obliquity results in both a latitudinal and longitudinal variation in annual average solar insolation and thus equatorial hot and cold regions. This results in an asymmetric temperature distribution in the lithosphere and a long wavelength lateral variation in lithosphere structure and strength that mirrors

  12. Interfacial shear strength of fiber reinforced soil

    Microsoft Academic Search

    Chao-Sheng Tang; Bin Shi; Li-Zheng Zhao

    2010-01-01

    The interfacial mechanical interaction between the reinforcement and soil matrix is a key factor in controlling the engineering properties of reinforced soil. To evaluate the factors affecting the interfacial strength properties of polypropylene fiber (PP-fiber) reinforced soil, single fiber pull-out tests were performed by using a modified special apparatus. It has been found that the designed pull-out test is an

  13. High toughness-high strength iron alloy

    NASA Technical Reports Server (NTRS)

    Stephens, J. R.; Witzke, W. R. (inventors)

    1980-01-01

    An iron alloy is provided which exhibits strength and toughness characteristics at cryogenic temperatures. The alloy consists essentially of about 10 to 16 percent by weight nickel, about 0.1 to 1.0 percent by weight aluminum, and 0 to about 3 percent by weight copper, with the balance being essentially iron. The iron alloy is produced by a process which includes cold rolling at room temperature and subsequent heat treatment.

  14. Mechanisms by which exercise improves bone strength

    Microsoft Academic Search

    Charles H. Turner; Alexander G. Robling

    2005-01-01

    Certain exercises can induce osteogenesis and improve bone strength, yet the biological processes involved in bone mechanotransduction\\u000a are only beginning to be understood. Several pathways are emerging from current research, including calcium signaling associated\\u000a with membrane ion channels, adenosine triphosphate signaling, second messengers such as prostaglandins and nitric oxide, and\\u000a signaling involving mitogen-activated protein kinase. One characteristic of the mechanosensing

  15. Simulation studies for surfaces and materials strength

    NASA Technical Reports Server (NTRS)

    Halicioglu, Timur

    1988-01-01

    During this six month period of the Simulation Studies for Surfaces and Materials Strength program investigations were carried out in two general areas: (1) Energy barriers and structural transitions between isomers of small Al clusters were investigated. In this study an empirical potential function which was parametrized based on accurate first principle results was employed; (2) A comparative study was conducted to investigate the applicability of most commonly employed model potential functions in calculating various bulk, surface and small cluster properties.

  16. High power ultrasonic bond strength evaluation

    Microsoft Academic Search

    1973-01-01

    S>Bond strength of diffusion and adhesive bonds has long remained one of ;\\u000a the unsolved problems facing the materials testing industry. Many techniques are ;\\u000a available for the detection of unbonds but these tend to become inaccurate when ;\\u000a the unbonded surfaces are in intimate contact. Weak bonds in almost all cases ;\\u000a cannot be distinguished from bends which approach

  17. Factors Influencing the Fatigue Strength of Materials

    NASA Technical Reports Server (NTRS)

    Bollenrath, F

    1941-01-01

    A number of factors are considered which influence the static and fatigue strength of materials under practical operating conditions as contrasted with the relations obtaining under conditions of the usual testing procedure. Such factors are interruptions in operation, periodically fluctuating stress limits and mean stresses with periodic succession of several groups and stress states, statistical changes and succession of stress limits and mean stresses, frictional corrosion at junctures, and notch effects.

  18. Shear adhesion strength of aligned electrospun nanofibers.

    PubMed

    Najem, Johnny F; Wong, Shing-Chung; Ji, Guang

    2014-09-01

    Inspiration from nature such as insects' foot hairs motivates scientists to fabricate nanoscale cylindrical solids that allow tens of millions of contact points per unit area with material substrates. In this paper, we present a simple yet robust method for fabricating directionally sensitive shear adhesive laminates. By using aligned electrospun nylon-6, we create dry adhesives, as a succession of our previous work on measuring adhesion energies between two single free-standing electrospun polymer fibers in cross-cylinder geometry, randomly oriented membranes and substrate, and peel forces between aligned fibers and substrate. The synthetic aligned cylindrical solids in this study are electrically insulating and show a maximal Mode II shear adhesion strength of 27 N/cm(2) on a glass slide. This measured value, for the purpose of comparison, is 270% of that reported from gecko feet. The Mode II shear adhesion strength, based on a commonly known "dead-weight" test, is 97-fold greater than the Mode I (normal) adhesion strength of the same. The data indicate a strong shear binding on and easy normal lifting off. Anisotropic adhesion (Mode II/Mode I) is pronounced. The size and surface boundary effects, crystallinity, and bending stiffness of fibers are used to understand these electrospun nanofibers, which vastly differ from otherwise known adhesive technologies. The anisotropic strength distribution is attributed to a decreasing fiber diameter and an optimized laminate thickness, which, in turn, influences the bending stiffness and solid-state "wettability" of points of contact between nanofibers and surface asperities. PMID:25105533

  19. Rock strength reductions during incipient weathering

    NASA Astrophysics Data System (ADS)

    Kelly, P. J.; Anderson, S. P.; Blum, A.

    2012-12-01

    Patrick Kelly, Suzanne Anderson, Alex Blum In rock below the surface, temperature swings are damped, water flow is limited, and biota are few. Yet rock weathers, presumably driven by these environmental parameters. We use rock strength as an indicator of rock weathering in Gordon Gulch in the Boulder Creek Critical Zone Observatory, a watershed at 2500 m underlain by Proterozoic gneiss intruded by the Boulder Creek granodiorite. Fresh rock is found at depths of 8-30 m in this area, and the thickness of the weathered rock zone imaged with shallow seismic refraction is greater on N-facing slopes than S-facing slopes (Befus et al., 2011, Vadose Zone J.). We use the Brazilian splitting test to determine tensile strength of cores collected with a portable drilling rig. Spatial variations in rock strength that we measure in the top 2 m of the weathered rock mantle can be connected to two specific environmental variables: slope aspect and the presence of a soil mantle. We find weaker rock on N-facing slopes and under soil. There is no clear correlation between rock strength and the degree of chemical alteration in these minimally weathered rocks. Denudation rates of 20-30 microns/yr imply residence times of 105-106 years within the weathered rock layers of the critical zone. Given these timescales, rock weathering is more likely to have occurred under glacial climate conditions, when periglacial processes prevailed in this non-glaciated watershed. Incipient weathering of rock appears to be controlled by water and frost cracking in Gordon Gulch. Water is more effectively delivered to the subsurface on N-facing slopes, and is more likely held against rock surfaces under soil than on outcrops. These moisture conditions, and the lower surface temperatures that prevail on N-facing slopes also favor frost cracking as an important weathering process.

  20. Rsf-1, a chromatin remodeling protein, interacts with cyclin E1 and promotes tumor development

    PubMed Central

    Sheu, Jim Jinn-Chyuan; Choi, Jung Hye; Guan, Bin; Tsai, Fuu-Jen; Hua, Chun-Hung; Lai, Ming-Tsung; Wang, Tian-Li; Shih, Ie-Ming

    2015-01-01

    Chromosome 11q13.5 containing RSF1 (HBXAP), a gene involved in chromatin remodeling, is amplified in several human cancers including ovarian carcinoma. Our previous studies demonstrated requirement of Rsf-1 for cell survival in cancer cells, which contributed to tumor progression; however, its role in tumorigenesis has not yet been elucidated. In this study, we co-immunoprecipitated proteins with Rsf-1 followed by nanoelectrospray mass spectrometry and identified cyclin E1, besides SNF2H, as one of the major Rsf-1 interacting proteins. Like RSF1, CCNE1 is frequently amplified in ovarian cancer, and both Rsf-1 and cyclin E1 were found co-upregulated in ovarian cancer tissues. Ectopic expression of Rsf-1 and cyclin E1 in non-tumorigenic TP53mut RK3E cells led to an increase in cellular proliferation and tumor formation by activating cyclin E1-associated kinase (CDK2). Tumorigenesis was not detected if either cyclin E1 or Rsf-1 was expressed, or they were expressed in a TP53wt background. Domain mapping showed that cyclin E1 interacted with the first 441 amino acids of Rsf-1. Ectopic expression of this truncated domain significantly suppressed G1/S-phase transition, cellular proliferation and tumor formation of RK3E-p53R175H/Rsf-1/cyclin E1 cells. The above findings suggest that Rsf-1 interacts and collaborates with cyclin E1 in neoplastic transformation and TP53 mutations are prerequisite for tumor-promoting functions of RSF/cyclin E1 complex. PMID:23378270

  1. Positive regulation of jun/AP-1 by E1A.

    PubMed Central

    de Groot, R; Foulkes, N; Mulder, M; Kruijer, W; Sassone-Corsi, P

    1991-01-01

    Proteins encoded by the adenovirus E1A oncogene are capable of positive and negative transcriptional regulation of both viral and cellular genes. E1A regulatory function is commonly thought to involve modifications of specific cellular factors that interact with responsive promoters. In this report we present evidence that E1A induces the activity of the jun/AP-1 transcription factor in three different cell types: P19, JEG-3, and HeLa. AP-1 binds to 12-O-tetradecanoylphorbol-13-acetate (TPA)-responsive elements (TREs); therefore, E1A might modulate a specific signal transduction pathway normally induced by activation of the protein kinase C. Binding of jun/AP-1 to a TRE is induced in all cell types studied when E1A is expressed. We observe that the expression of endogenous c-jun and jun B genes is induced by E1A, which directly transactivates the promoters of c-fos, c-jun, and jun B. Similar inducibility is obtained by treatment with retinoic acid and differentiation of P19-embryonal carcinoma cells. The E1A 13S product transactivates TRE sequences and cooperates with c-jun in the transcriptional stimulation. The 12S E1A product does not activate a TRE sequence, but cotransfection with c-jun circumvents this lack of stimulation. Coexpression of c-fos and E1A 12S, however, blocks the transactivation by c-jun, suggesting an important role for fos in determining the dominance of the 12S or 13S protein. Images PMID:1824713

  2. ZERODUR: bending strength data for etched surfaces

    NASA Astrophysics Data System (ADS)

    Hartmann, Peter; Leys, Antoine; Carré, Antoine; Kerz, Franca; Westerhoff, Thomas

    2014-07-01

    In a continuous effort since 2007 a considerable amount of new data and information has been gathered on the bending strength of the extremely low thermal expansion glass ceramic ZERODUR®. By fitting a three parameter Weibull distribution to the data it could be shown that for homogenously ground surfaces minimum breakage stresses exist lying much higher than the previously applied design limits. In order to achieve even higher allowable stress values diamond grain ground surfaces have been acid etched, a procedure widely accepted as strength increasing measure. If surfaces are etched taking off layers with thickness which are comparable to the maximum micro crack depth of the preceding grinding process they also show statistical distributions compatible with a three parameter Weibull distribution. SCHOTT has performed additional measurement series with etch solutions with variable composition testing the applicability of this distribution and the possibility to achieve further increase of the minimum breakage stress. For long term loading applications strength change with time and environmental media are important. The parameter needed for prediction calculations which is combining these influences is the stress corrosion constant. Results from the past differ significantly from each other. On the basis of new investigations better information will be provided for choosing the best value for the given application conditions.

  3. Tensile strength of liquid 4He

    NASA Astrophysics Data System (ADS)

    Nissen, J. A.; Bodegom, E.; Brodie, L. C.; Semura, J. S.

    1989-10-01

    Experiments to measure the tensile strength of liquids have often failed to reach the predicted value, presumably due to the onset of heterogeneous nucleation. Since it seemed impossible to completely eliminate all heterogeneous nucleation, we adopted a strategy that minimized its effect. A piezoelectric transducer in the form of a hemispherical shell was used to focus a short burst of ultrasound into a small volume of liquid 4He. The onset of cavitation was detected by the scattering of laser light. The experimental results both above and below the ? transition are in agreement with homogeneous-nucleation theory for a nucleation rate of approximately 1015 critical-size bubbles/s cm3. An apparent lowering of the tensile strength near the extension of the ? line into the metastable liquid is noted and discussed. This experiment extends the range of confirmation of the theoretically predicted tensile strength of liquids to a reduced pressure eight times further into the negative-pressure region than previous studies in any other liquid.

  4. The tensile strength of liquid helium four

    NASA Astrophysics Data System (ADS)

    Nissen, Joel Alan

    1988-08-01

    It is well known that most liquids exhibit a tensile strength which is much smaller in magnitude than the tensile strength predicted by homogeneous nucleation theory. Liquid helium occupies a unique place among liquids for tensile strength measurements because all foreign gases are frozen out at liquid temperatures. Moreover, superfluid He-4 should fill all crevises on solid surfaces, eliminating the chance of heterogeneous nucleation on helium vapor pockets. A piezoelectric transducer in the form of a hemispherical shell was used to focus high intensity ultrasound into a small volume of He-4. The transducer was gated at its resonant frequency of 566 kHz with gate widths of less than 1 msec in order to minimize the effects of transducer heating and acoustic streaming. The onset of nucleation was detected from the absorption of acoustic energy and the scattering of laser light from microscopic bubbles. A theory for light diffraction from the focal zone of a spherical converging sound wave was developed to confirm calculations of the acoustic pressure amplitude at the focus of the transducer, calculations based on the acoustic power radiated into the liquid and nonlinear sound absorption.

  5. Selective activation of microglia facilitates synaptic strength.

    PubMed

    Clark, Anna K; Gruber-Schoffnegger, Doris; Drdla-Schutting, Ruth; Gerhold, Katharina J; Malcangio, Marzia; Sandkühler, Jürgen

    2015-03-18

    Synaptic plasticity is thought to be initiated by neurons only, with the prevailing view assigning glial cells mere specify supportive functions for synaptic transmission and plasticity. We now demonstrate that glial cells can control synaptic strength independent of neuronal activity. Here we show that selective activation of microglia in the rat is sufficient to rapidly facilitate synaptic strength between primary afferent C-fibers and lamina I neurons, the first synaptic relay in the nociceptive pathway. Specifically, the activation of the CX3CR1 receptor by fractalkine induces the release of interleukin-1? from microglia, which modulates NMDA signaling in postsynaptic neurons, leading to the release of an eicosanoid messenger, which ultimately enhances presynaptic neurotransmitter release. In contrast to the conventional view, this form of plasticity does not require enhanced neuronal activity to trigger the events leading to synaptic facilitation. Augmentation of synaptic strength in nociceptive pathways represents a cellular model of pain amplification. The present data thus suggest that, under chronic pain states, CX3CR1-mediated activation of microglia drives the facilitation of excitatory synaptic transmission in the dorsal horn, which contributes to pain hypersensitivity in chronic pain states. PMID:25788673

  6. Bacterial cellulose gels with high mechanical strength.

    PubMed

    Numata, Yukari; Sakata, Tadanori; Furukawa, Hidemitsu; Tajima, Kenji

    2015-02-01

    A composite structure was formed between polyethylene glycol diacrylate (PEGDA) and bacterial cellulose (BC) gels swollen in polyethylene glycol (PEG) as a solvent (BC/PEG gel) to improve the mechanical strength of the gels. The mechanical strength under compression and the rheostatic properties of the gels were evaluated. The compression test results indicated that the mechanical strength of the gels depended on the weight percent of cross-linked PEGDA in the gel, the chain length between the cross-linking points, and the cross-linking density of PEGDA polymers. The PEGDA polymers around the cellulose fibers were resistant to pressure; thus, the BC/PEG-PEGDA gel was stronger than the BC/PEG gel under compression. The results of transmittance measurements and thermomechanical analysis showed that the rheostatic properties of the gels were retained even after composite structure formation. BC/PEG-PEGDA gels, which are expected to be biocompatible, may be useful for clinical applications as a soft material. PMID:25492172

  7. Hydrogen trapping in high-strength steels

    SciTech Connect

    Pound, B.G. [SRI International, Menlo Park, CA (United States). Materials Research Center] [SRI International, Menlo Park, CA (United States). Materials Research Center

    1998-10-09

    Hydrogen trapping in three high-strength steels -- AerMet 100 and AISI 4340 and H11 -- was studied using a potentiostatic pulse technique. Irreversible trapping constants (k) and hydrogen entry fluxes were determined for these alloys in 1 mol/1 acetic acid/1 mol/1 sodium acetate. The order of the k values for the three steels and two 18Ni maraging steels previously studies inversely parallels their threshold stress intensities for stress corrosion cracking (K{sub 1SCC}). Irreversible trapping in AerMet 100 varies with aging temperature and appears to depend on the type of carbide (Fe{sub 3}C or M{sub 2}C) present. For 4340 steel, k can be correlated with K{sub 1SCC} over a range of yield strengths. The change in k is consistent with a change in the principal type of irreversible trap from matrix boundaries to incoherent Fe{sub 3}C. The principal irreversible traps in H11 at high yield strengths are thought to be similar to those in 4340 steel.

  8. Selective Activation of Microglia Facilitates Synaptic Strength

    PubMed Central

    Clark, Anna K.; Gruber-Schoffnegger, Doris; Drdla-Schutting, Ruth; Gerhold, Katharina J.; Malcangio, Marzia

    2015-01-01

    Synaptic plasticity is thought to be initiated by neurons only, with the prevailing view assigning glial cells mere specify supportive functions for synaptic transmission and plasticity. We now demonstrate that glial cells can control synaptic strength independent of neuronal activity. Here we show that selective activation of microglia in the rat is sufficient to rapidly facilitate synaptic strength between primary afferent C-fibers and lamina I neurons, the first synaptic relay in the nociceptive pathway. Specifically, the activation of the CX3CR1 receptor by fractalkine induces the release of interleukin-1? from microglia, which modulates NMDA signaling in postsynaptic neurons, leading to the release of an eicosanoid messenger, which ultimately enhances presynaptic neurotransmitter release. In contrast to the conventional view, this form of plasticity does not require enhanced neuronal activity to trigger the events leading to synaptic facilitation. Augmentation of synaptic strength in nociceptive pathways represents a cellular model of pain amplification. The present data thus suggest that, under chronic pain states, CX3CR1-mediated activation of microglia drives the facilitation of excitatory synaptic transmission in the dorsal horn, which contributes to pain hypersensitivity in chronic pain states. PMID:25788673

  9. U-Groove Aluminum Weld Strength Improvement

    NASA Technical Reports Server (NTRS)

    Verderaime, V.; Vaughan, R.

    1997-01-01

    Though butt-welds are among the most preferred joining methods in aerostructures, their strength dependence on inelastic mechanics is generally the least understood. This study investigated experimental strain distributions across a thick aluminum U-grooved weld and identified two weld process considerations for improving the multipass weld strength. One is the source of peaking in which the extreme thermal expansion and contraction gradient of the fusion heat input across the groove tab thickness produces severe angular distortion that induces bending under uniaxial loading. The other is the filler strain hardening decreasing with increasing filler pass sequences, producing the weakest welds on the last weld pass side. Both phenomena are governed by weld pass sequences. Many industrial welding schedules unknowingly compound these effects, which reduce the weld strength. A depeaking index model was developed to select filler pass thickness, pass numbers, and sequences to improve depeaking in the welding process. The result was to select the number and sequence of weld passes to reverse the peaking angle such as to combine the strongest weld pass side with the peaking induced bending tension component side to provide a more uniform stress and stronger weld under axial tensile loading.

  10. A Role for E1B-AP5 in ATR Signaling Pathways during Adenovirus Infection?

    PubMed Central

    Blackford, Andrew N.; Bruton, Rachel K.; Dirlik, Orkide; Stewart, Grant S.; Taylor, A. Malcolm R.; Dobner, Thomas; Grand, Roger J. A.; Turnell, Andrew S.

    2008-01-01

    E1B-55K-associated protein 5 (E1B-AP5) is a cellular, heterogeneous nuclear ribonucleoprotein that is targeted by adenovirus (Ad) E1B-55K during infection. The function of E1B-AP5 during infection, however, remains largely unknown. Given the role of E1B-55K targets in the DNA damage response, we examined whether E1B-AP5 function was integral to these pathways. Here, we show a novel role for E1B-AP5 as a key regulator of ATR signaling pathways activated during Ad infection. E1B-AP5 is recruited to viral replication centers during infection, where it colocalizes with ATR-interacting protein (ATRIP) and the ATR substrate replication protein A 32 (RPA32). Indeed, E1B-AP5 associates with ATRIP and RPA complex component RPA70 in both uninfected and Ad-infected cells. Additionally, glutathione S-transferase pull-downs show that E1B-AP5 associates with RPA components RPA70 and RPA32 directly in vitro. E1B-AP5 is required for the ATR-dependent phosphorylation of RPA32 during infection and contributes to the Ad-induced phosphorylation of Smc1 and H2AX. In this regard, it is interesting that Ad5 and Ad12 differentially promote the phosphorylation of RPA32, Rad9, and Smc1 during infection such that Ad12 promotes a significant phosphorylation of RPA32 and Rad9, whereas Ad5 only weakly promotes RPA32 phosphorylation and does not induce Rad9 phosphorylation. These data suggest that Ad5 and Ad12 have evolved different strategies to regulate DNA damage signaling pathways during infection in order to promote viral replication. Taken together, our results define a role for E1B-AP5 in ATR signaling pathways activated during infection. This might have broader implications for the regulation of ATR activity during cellular DNA replication or in response to DNA damage. PMID:18480432

  11. P a g e | 1 SFU Marine Vessel Registration, Insurance & Operations Guide

    E-print Network

    P a g e | 1 SFU Marine Vessel Registration, Insurance & Operations Guide Table of Contents Last ...........................................................................................................7 Purchasing marine vessels ................................................................................................................................ 7 How to deregister & dispose of SFU marine vessels.............................................8 6

  12. Information Technology Security Training Requirements Appendix E --Training Cross Reference E-1

    E-print Network

    Information Technology Security Training Requirements APPENDIX E Appendix E -- Training Cross Reference E-1 #12;Information Technology Security Training Requirements Appendix E -- Training Cross Reference E-2 #12;Information Technology Security Training Requirements APPENDIX E -- JOB FUNCTION

  13. Prostaglandins E1 and E2 prevent bronchoconstriction in the guinea-pig.

    PubMed

    Herxheimer, H

    1974-02-01

    Prostaglandin E(1) and E(2) aerosols protected the guinea-pig against bronchoconstriction caused by anaphylactic microshock, 1% histamine, 4% acetylcholine and 1% 5-hydroxytryptamine aerosols. PMID:4425768

  14. Prostaglandins E1 and E2 prevent bronchoconstriction in the guinea-pig

    PubMed Central

    Herxheimer, H.

    1974-01-01

    Prostaglandin E1 and E2 aerosols protected the guinea-pig against bronchoconstriction caused by anaphylactic microshock, 1% histamine, 4% acetylcholine and 1% 5-hydroxytryptamine aerosols. PMID:4425768

  15. University Advising Services P a g e | 1 FOUNDATIONS OF SOCIETY & HUMAN BEHAVIOR

    E-print Network

    Fernandez, Eduardo

    , and Sexuality ___ SYP 2450 ................Global Society (GP) Social Work Department ___ SOW 1005University Advising Services P a g e | 1 FOUNDATIONS OF SOCIETY & HUMAN BEHAVIOR (6 credits..............................Disability and Society Geosciences Department ___ EVR 2017 .............................Environment

  16. 26 CFR 1.1031(e)-1 - Exchange of livestock of different sexes.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...false Exchange of livestock of different sexes. 1.1031(e)-1 Section 1.1031...1 Exchange of livestock of different sexes. Section 1031(e) provides that livestock of different sexes are not property of like kind....

  17. 26 CFR 1.1031(e)-1 - Exchange of livestock of different sexes.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...true Exchange of livestock of different sexes. 1.1031(e)-1 Section 1.1031...1 Exchange of livestock of different sexes. Section 1031(e) provides that livestock of different sexes are not property of like kind....

  18. 26 CFR 1.1031(e)-1 - Exchange of livestock of different sexes.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...false Exchange of livestock of different sexes. 1.1031(e)-1 Section 1.1031...1 Exchange of livestock of different sexes. Section 1031(e) provides that livestock of different sexes are not property of like kind....

  19. 26 CFR 1.1031(e)-1 - Exchange of livestock of different sexes.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...false Exchange of livestock of different sexes. 1.1031(e)-1 Section 1.1031...1 Exchange of livestock of different sexes. Section 1031(e) provides that livestock of different sexes are not property of like kind....

  20. 26 CFR 1.1031(e)-1 - Exchange of livestock of different sexes.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...false Exchange of livestock of different sexes. 1.1031(e)-1 Section 1.1031...1 Exchange of livestock of different sexes. Section 1031(e) provides that livestock of different sexes are not property of like kind....

  1. 26 CFR 1.263(e)-1 - Expenditures in connection with certain railroad rolling stock.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Expenditures in connection with certain railroad rolling stock. 1.263(e)-1...Expenditures in connection with certain railroad rolling stock. (a) Allowance of...with the rehabilitation of a unit of railroad rolling stock (as defined in...

  2. 26 CFR 1.263(e)-1 - Expenditures in connection with certain railroad rolling stock.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Expenditures in connection with certain railroad rolling stock. 1.263(e)-1...Expenditures in connection with certain railroad rolling stock. (a) Allowance of...with the rehabilitation of a unit of railroad rolling stock (as defined in...

  3. 26 CFR 1.263(e)-1 - Expenditures in connection with certain railroad rolling stock.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Expenditures in connection with certain railroad rolling stock. 1.263(e)-1...Expenditures in connection with certain railroad rolling stock. (a) Allowance of...with the rehabilitation of a unit of railroad rolling stock (as defined in...

  4. 26 CFR 1.263(e)-1 - Expenditures in connection with certain railroad rolling stock.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Expenditures in connection with certain railroad rolling stock. 1.263(e)-1...Expenditures in connection with certain railroad rolling stock. (a) Allowance of...with the rehabilitation of a unit of railroad rolling stock (as defined in...

  5. 26 CFR 1.263(e)-1 - Expenditures in connection with certain railroad rolling stock.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Expenditures in connection with certain railroad rolling stock. 1.263(e)-1...Expenditures in connection with certain railroad rolling stock. (a) Allowance of...with the rehabilitation of a unit of railroad rolling stock (as defined in...

  6. 26 CFR 301.6511(e)-1 - Special rules applicable to manufactured sugar.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Special rules applicable to manufactured sugar. 301.6511(e)-1 Section 301...Special rules applicable to manufactured sugar. (a) Use as livestock feed and for...accrues as of the date the manufactured sugar, or article manufactured...

  7. 26 CFR 301.6511(e)-1 - Special rules applicable to manufactured sugar.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Special rules applicable to manufactured sugar. 301.6511(e)-1 Section 301...Special rules applicable to manufactured sugar. (a) Use as livestock feed and for...accrues as of the date the manufactured sugar, or article manufactured...

  8. 26 CFR 301.6511(e)-1 - Special rules applicable to manufactured sugar.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Special rules applicable to manufactured sugar. 301.6511(e)-1 Section 301...Special rules applicable to manufactured sugar. (a) Use as livestock feed and for...accrues as of the date the manufactured sugar, or article manufactured...

  9. 26 CFR 301.6511(e)-1 - Special rules applicable to manufactured sugar.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...Special rules applicable to manufactured sugar. 301.6511(e)-1 Section 301...Special rules applicable to manufactured sugar. (a) Use as livestock feed and for...accrues as of the date the manufactured sugar, or article manufactured...

  10. 26 CFR 301.6511(e)-1 - Special rules applicable to manufactured sugar.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...Special rules applicable to manufactured sugar. 301.6511(e)-1 Section 301...Special rules applicable to manufactured sugar. (a) Use as livestock feed and for...accrues as of the date the manufactured sugar, or article manufactured...

  11. Packaging of ColE1 DNA having a lambda phage cohesive end site

    Microsoft Academic Search

    Kenichi Umene; Kazunori Shimada; Yasuyuki Takagi

    1978-01-01

    The mechanism of ? phage-mediated transduction of hybrid colicin E1 DNAs of various lengths was studied, and factors influencing the formation of these transducing particles were investigated. The results were as follows:

  12. Resolvin E1 Improves Tear Production and Decreases Inflammation in a Dry Eye Mouse Model

    PubMed Central

    Li, Na; He, Jiucheng; Schwartz, Carl Eric; Gjorstrup, Per

    2010-01-01

    Abstract Purpose Dry eye (DE) is a common ocular surface disease, particularly among women and the elderly, with chronic symptoms of eye irritation and, in severe cases, blurred vision. Several studies have shown that there is an inflammatory component in DE, although the pathogenesis is not thoroughly understood. Resolvin E1 (RvE1; RX-10001) is an endogenous mediator derived from the omega-3 polyunsaturated fatty acid eicosapentaenoic acid and is involved in inflammation resolution and tissue protection. Here we investigated the role of RvE1 in a DE mouse model. Methods Thirteen- to 14-week-old female BALB/C mice were exposed to desiccating conditions. One week after DE exposure, animals were treated topically with drug or vehicle 4 times per day for an additional week. Controls were nontreated animals placed in a normal environment. Schirmer's test was performed before treatment initiation and at days 2 and 4 after treatment. Density of corneal epithelial cells was analyzed in vivo using the Rostock Cornea Module of the Heidelberg Retina Tomograph (HRT-II). Corneas were processed using Western blot analysis and immunofluorescence examination. Results Schirmer's test showed a significant decrease in tear production in DE compared with controls. There was no change at 2 and 4 days after treatment with the vehicle, but a significant increase was observed at 2 and 4 days in the RvE1-treated group. The density of the superficial epithelial cells showed a significant decrease after DE compared with controls, which increased after 7 days of RvE1 treatment. Western blot analysis showed that ?-smooth muscle actin and cyclooxygenase-2 (COX-2) expression were strongly upregulated after DE and decreased after 7 days of RvE1 treatment. Immunofluorescence confirmed strong positive staining of ?-smooth muscle actin and COX-2 in stroma and/or in epithelia after DE, which decreased with RvE1 treatment. The percentage of infiltrating CD4+ T cells and CD11b+ cells decreased after RvE1 treatment when compared with DE. Conclusion RvE1 promotes tear production, corneal epithelial integrity, and a decrease in inflammatory inducible COX-2. In the stroma, RvE1 inhibits keratocyte transformation to myofibroblasts and lowers the number of monocytes/macrophages in this DE mouse model. These results suggest that RvE1 and similar resolvin analogs have therapeutic potential in the treatment of DE. PMID:20874497

  13. Cisplatin-induced hepatotoxicity is enhanced by elevated expression of cytochrome P450 2E1.

    PubMed

    Lu, Yongke; Cederbaum, Arthur I

    2006-02-01

    In this study, the possible potentiation of cisplatin-induced hepatotoxicity by cytochrome P450 2E1 (CYP2E1) was examined both in vitro and in vivo. Transfected HepG2 cells expressing CYP2E1 (E47 cells) and not expressing CYP2E1 (C34 cells) were used as an in vitro model, and mice drinking 2% acetone for 7 days to induce CYP2E1 were used as an in vivo model. Exposure of E47 cells to cisplatin caused a much greater loss of cell viability, more striking depletion of reduced glutathione (GSH), and higher reactive oxygen species (ROS) production as compared with C34 cells. The prooxidant L-buthionine-[R,S]-sulfoximine (BSO), which depletes GSH, enhanced cisplatin-induced loss of cell viability, whereas the antioxidant glutathione ethyl ester, or the iron chelator deferoxamine mesylate (DFO) protected against the cisplatin-induced loss of E47 cell viability. Diallyl sulfide (DAS), an inhibitor of CYP2E1, also protected against the cisplatin toxicity in the E47 cells. After being injected with cisplatin (ip, 45 mg/kg), mice drinking 2% acetone with increased CYP2E1 levels exhibited elevated levels of serum ALT and AST, liver caspase-3 activity and positive staining of TUNEL increased, and histopathology indicated the presence of necrotic foci in livers of acetone plus cisplatin-treated mice. Lipid peroxidation and protein oxidation as indicated by carbonyl formation, staining of 3-nitrotyrosine (3-NT) and iron were higher in the cisplatin plus acetone group, compared with cisplatin alone group. Both in vitro and in vivo results indicate that elevated CYP2E1 enhances cisplatin-induced hepatotoxicity, and the mechanism may involve increased production of ROS and oxidative stress. PMID:16251482

  14. Resveratrol Stimulates the Proliferation and Differentiation of Osteoblastic MC3T3-E1 Cells

    Microsoft Academic Search

    Kenichi Mizutani; Katsumi Ikeda; Yasuhiro Kawai; Yukio Yamori

    1998-01-01

    Nutritional and pharmacological factors are needed to prevent bone loss that occurs with increasing age. The chemical compounds that act on bone metabolism as nutrients in food, however, are poorly understood. The effect of resveratrol, a natural phytoestrogen, on the proliferation and differentiation of osteoblastic MC3T3-E1 cells was studied. Resveratrol dose-dependently increased DNA synthesis (10?9?10?7M) of MC3T3-E1 cells. In addition,

  15. Sindbis Virus Conformational Changes Induced by a Neutralizing Anti-E1 Monoclonal Antibody

    Microsoft Academic Search

    Raquel Hernandez; Angel Paredes; Dennis T. Brown

    2008-01-01

    A rare Sindbis virus anti-E1 neutralizing monoclonal antibody, Sin-33, was investigated to determine the mechanism of in vitro neutralization. A cryoelectron microscopic reconstruction of Sindbis virus (SVHR) neutral- ized with FAb from Sin-33 (FAb-33) revealed conformational changes on the surface of the virion at a resolution of 24 Å. FAb-33 was found to bind E1 in less than 1:1 molar

  16. Incompatibility and transforming efficiency of ColE1 and related plasmids

    Microsoft Academic Search

    Gareth Warren; David Sherratt

    1978-01-01

    Replicons derived from the ColE1 plasmid are incompatible with one another, but are compatible with their naturally occurring relatives ColK and CloDF13. The incompatibility results in loss, by segregation, of one or the other ColE1 plasmid. In most cases, the smaller derivatives tend to displace the larger ones, and the rate of displacement depends on the difference in size. One

  17. Impact of resolvin E1 on murine neutrophil phagocytosis in type 2 diabetes.

    PubMed

    Herrera, Bruno S; Hasturk, Hatice; Kantarci, Alpdogan; Freire, Marcelo O; Nguyen, Olivia; Kansal, Shevali; Van Dyke, Thomas E

    2015-02-01

    Diabetic complications involve inflammation-mediated microvascular and macrovascular damage, disruption of lipid metabolism, glycosylation of proteins, and abnormalities of neutrophil-mediated events. Resolution of inflamed tissues to health and homeostasis is an active process mediated by endogenous lipid agonists, including lipoxins and resolvins. This proresolution system appears to be compromised in type 2 diabetes (T2D). The goal of this study was to investigate unresolved inflammation in T2D. Wild-type (WT) and genetically engineered mice, including T2D mice (db/db), transgenic mice overexpressing the human resolvin E1 (RvE1) receptor (ERV1), and a newly bred strain of db/ERV1 mice, were used to determine the impact of RvE1 on the phagocytosis of Porphyromonas gingivalis in T2D. Neutrophils were isolated and incubated with fluorescein isothiocyanate-labeled P. gingivalis, and phagocytosis was measured in a fluorochrome-based assay by flow cytometry. Mitogen-activated protein kinase (MAPK) (p42 and p44) and Akt (Thr308 and Ser473) phosphorylation was analyzed by Western blotting. The mouse dorsal air pouch model was used to evaluate the in vivo impact of RvE1. Results revealed that RvE1 increased the neutrophil phagocytosis of P. gingivalis in WT animals but had no impact in db/db animals. In ERV1-transgenic and ERV1-transgenic diabetic mice, phagocytosis was significantly increased. RvE1 decreased Akt and MAPK phosphorylation in the transgenic animals. In vivo dorsal air pouch studies revealed that RvE1 decreases neutrophil influx into the pouch and increases neutrophil phagocytosis of P. gingivalis in the transgenic animals; cutaneous fat deposition was reduced, as was macrophage infiltration. The results suggest that RvE1 rescues impaired neutrophil phagocytosis in obese T2D mice overexpressing ERV1. PMID:25486994

  18. The E1-E2 center in gallium arsenide is the divacancy.

    PubMed

    Schultz, Peter A

    2015-02-25

    Based on defect energy levels computed from first-principles calculations, it is shown the E1-E2 center in irradiated GaAs cannot be due to an isolated arsenic vacancy. The only simple intrinsic defect with levels compatible with E1 and E2 is the divacancy. The arsenic monovacancy is reassigned to the E3 center in irradiated GaAs. These new assignments are shown to reconcile a number of seemingly contradictory experimental observations. PMID:25634829

  19. Calculation of energy levels, {ital E}1 transition amplitudes, and parity violation in francium

    Microsoft Academic Search

    V. A. Dzuba; V. V. Flambaum; O. P. Sushkov

    1995-01-01

    Many-body perturbation theory in the screened Coulomb interaction was used to calculate energy levels, {ital E}1 trransition amplitudes, and the parity-nonconserving (PNC) {ital E}1 amplitude of the 7{ital s}-8{ital s} transition in francium. The method takes into account the core-polarization effect, the second-order correlations, and the three dominating sequences of higher-order correlation diagrams: screening of the electron-electron interaction, particle-hole interaction,

  20. The E1–E2 center in gallium arsenide is the divacancy

    NASA Astrophysics Data System (ADS)

    Schultz, Peter A.

    2015-02-01

    Based on defect energy levels computed from first-principles calculations, it is shown the E1–E2 center in irradiated GaAs cannot be due to an isolated arsenic vacancy. The only simple intrinsic defect with levels compatible with E1 and E2 is the divacancy. The arsenic monovacancy is reassigned to the E3 center in irradiated GaAs. These new assignments are shown to reconcile a number of seemingly contradictory experimental observations.

  1. Genetic Polymorphism of Human CYP2E1: Characterization of Two Variant Alleles

    Microsoft Academic Search

    YIN HU; MIKAEL OSCARSON; INGER JOHANSSON; MARJA-LIISA DAHL; MARCO TABONE; EMANUELE ALBANO; MAGNUS INGELMAN-SUNDBERG

    SUMMARY Ethanol-inducible CYP2E1 is an enzyme of major toxicological interest because it metabolizes several precarcinogens, drugs, and solvents to reactive metabolites. CYP2E1 has also been implicated in alcohol liver disease because of its contribution to oxidative stress. Previously, polymorphic alleles with mutations in introns and in the 59-flanking regulatory region have been described, and their presence has been related to

  2. Location of non-DNA components of closed circular colicin E1 plasmid DNA

    Microsoft Academic Search

    Yoshinobu Sugino; Jun-Ichi Tomizawa; TSUYOSHI KAKEFUDA

    1975-01-01

    COLICIN E1 plasmid (Col E1) DNA usually exists as closed-circular duplex molecules of molecular weight 4.2×106 (ref. 1). In addition to the form that is assumed to contain only deoxyribonucleotides linked by phosphodiester bonds, two other types of supercoiled closed-circular molecules have been described. One is a DNA-protein complex, called a relaxation complex2. When the protein is denatured or destroyed,

  3. Unexpected structure for the N-terminal domain of hepatitis C virus envelope glycoprotein E1

    PubMed Central

    El Omari, Kamel; Iourin, Oleg; Kadlec, Jan; Sutton, Geoff; Harlos, Karl; Grimes, Jonathan M.; Stuart, David I.

    2014-01-01

    Hepatitis C virus (HCV) infection remains a major health problem worldwide. HCV entry into host cells and membrane fusion are achieved by two envelope glycoproteins, E1 and E2. We report here the 3.5-Å resolution crystal structure of the N-terminal domain of the HCV E1 ectodomain, which reveals a complex network of covalently linked intertwined homodimers that do not harbour the expected truncated class II fusion protein fold. PMID:25224686

  4. Application of a map Bayesian method for CYP2E1 phenotyping

    Microsoft Academic Search

    T. M. Nicholas; M. R. Gastonguay; K. R. Sweeney; T. D. Nolin; R. F. Frye

    2004-01-01

    Purpose: The CYP2E1 probe drug chlorzoxazone (CZ) is extensively metabolized to 6-OHchlorzoxazone (HCZ). The HCZ\\/CZ ratio is used as an index of CYP2E1 activity, but it is not valid in patients with kidney disease. Individual estimates of HCZ formation clearance (CLf) obtained via MAP Bayesian estimation (MBE) could be an alternative to full profile (FP) PK studies. Methods: A population

  5. CYP2E1-dependent elevation of serum cholesterol, triglycerides, and hepatic bile acids by isoniazid

    SciTech Connect

    Cheng, Jie; Krausz, Kristopher W. [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States)] [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Li, Feng; Ma, Xiaochao [Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, 4089 KLSIC, MS 1018, 3901 Rainbow Boulevard, Kansas City, KS 66160 (United States)] [Department of Pharmacology, Toxicology and Therapeutics, The University of Kansas Medical Center, 4089 KLSIC, MS 1018, 3901 Rainbow Boulevard, Kansas City, KS 66160 (United States); Gonzalez, Frank J., E-mail: fjgonz@helix.nih.gov [Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States)

    2013-01-15

    Isoniazid is the first-line medication in the prevention and treatment of tuberculosis. Isoniazid is known to have a biphasic effect on the inhibition–induction of CYP2E1 and is also considered to be involved in isoniazid-induced hepatotoxicity. However, the full extent and mechanism of involvement of CYP2E1 in isoniazid-induced hepatotoxicity remain to be thoroughly investigated. In the current study, isoniazid was administered to wild-type and Cyp2e1-null mice to investigate the potential toxicity of isoniazid in vivo. The results revealed that isoniazid caused no hepatotoxicity in wild-type and Cyp2e1-null mice, but produced elevated serum cholesterol and triglycerides, and hepatic bile acids in wild-type mice, as well as decreased abundance of free fatty acids in wild-type mice and not in Cyp2e1-null mice. Metabolomic analysis demonstrated that production of isoniazid metabolites was elevated in wild-type mice along with a higher abundance of bile acids, bile acid metabolites, carnitine and carnitine derivatives; these were not observed in Cyp2e1-null mice. In addition, the enzymes responsible for bile acid synthesis were decreased and proteins involved in bile acid transport were significantly increased in wild-type mice. Lastly, treatment of targeted isoniazid metabolites to wild-type mice led to similar changes in cholesterol, triglycerides and free fatty acids. These findings suggest that while CYP2E1 is not involved in isoniazid-induced hepatotoxicity, while an isoniazid metabolite might play a role in isoniazid-induced cholestasis through enhancement of bile acid accumulation and mitochondria ?-oxidation. -- Highlights: ? Isoniazid metabolites were elevated only in wild-type mice. ? Isoniazid caused no hepatotoxicity in wild-type and Cyp2e1-null mice. ? Isoniazid elevated serum cholesterol and triglycerides, and hepatic bile acids. ? Bile acid transporters were significantly decreased in isoniazid-treated mice.

  6. Propolis protects CYP 2E1 enzymatic activity and oxidative stress induced by carbon tetrachloride

    Microsoft Academic Search

    Monika Bhadauria; Satendra Kumar Nirala; Sangeeta Shukla

    2007-01-01

    Induction of CYP 2E1 by carbon tetrachloride (CCl4) is one of the central pathways by which CCl4 generates oxidative stress in hepatocytes. Experimental liver injury was induced in rats by CCl4 to determine toxicological actions on CYP 2E1 by microsomal drug metabolizing enzymes. In this report, ethanolic extract\\u000a of propolis at a dose of 200 mg\\/kg (po) was used after 24 h

  7. Cyclin E1 Regulates Kv2.1 Channel Phosphorylation and Localization in Neuronal Ischemia

    PubMed Central

    Shah, Niyathi H.; Schulien, Anthony J.; Clemens, Katerina; Aizenman, Talia D.; Hageman, Thomas M.; Wills, Zachary P.

    2014-01-01

    Kv2.1 is a major delayed rectifying K+ channel normally localized to highly phosphorylated somatodendritic clusters in neurons. Excitatory stimuli induce calcineurin-dependent dephosphorylation and dispersal of Kv2.1 clusters, with a concomitant hyperpolarizing shift in the channel's activation kinetics. We showed previously that sublethal ischemia, which renders neurons transiently resistant to excitotoxic cell death, can also induce Zn2+-dependent changes in Kv2.1 localization and activation kinetics, suggesting that activity-dependent modifications of Kv2.1 may contribute to cellular adaptive responses to injury. Recently, cyclin-dependent kinase 5 (Cdk5) was shown to phosphorylate Kv2.1, with pharmacological Cdk5 inhibition being sufficient to decluster channels. In another study, cyclin E1 was found to restrict neuronal Cdk5 kinase activity. We show here that cyclin E1 regulates Kv2.1 cellular localization via inhibition of Cdk5 activity. Expression of cyclin E1 in human embryonic kidney cells prevents Cdk5-mediated phosphorylation of Kv2.1, and cyclin E1 overexpression in rat cortical neurons triggers dispersal of Kv2.1 channel clusters. Sublethal ischemia in neurons induces calcineurin-dependent upregulation of cyclin E1 protein expression and cyclin E1-dependent Kv2.1 channel declustering. Importantly, overexpression of cyclin E1 in neurons is sufficient to reduce excitotoxic cell death. These results support a novel role for neuronal cyclin E1 in regulating the phosphorylation status and localization of Kv2.1 channels, a likely component of signaling cascades leading to ischemic preconditioning. PMID:24647953

  8. Specialized Transduction of Colicin E1 DNA in Escherichia coli K-12 by Phage Lambda

    Microsoft Academic Search

    Yasuyuki Fukumaki; Kazunori Shimada; Yasuyuki Takagi

    1976-01-01

    Genetic studies were made on E. coli K-12 TM96, which carries recombinant molecules constructed by in vitro combination of colicin E1 DNA and a DNA fragment of E. coli for guanine synthesis derived from transducing phage. The recombinant molecules existed as stable plasmids within the cell and contained genes for colicin E1 immunity and the guaA enzyme (xanthosine 5'-monophosphate aminase)

  9. New Accurate Oscillator Strengths and Electron Excitation Collision Strengths for N1

    NASA Technical Reports Server (NTRS)

    Tayal, S. S.

    2006-01-01

    The nonorthogonal orbitals technique in a multiconfiguration Hartree-Fock approach is used to calculate oscillator strengths and transition probabilities of N(I) lines. The relativistic effects are allowed by means of Breit-Pauli operators. The length and velocity forms of oscillator strengths show good agreement for most transitions. The B-spline R-matrix with pseudostates approach has been used to calculate electron excitation collision strengths and rates. The nonorthogonal orbitals are used for an accurate description of both target wave functions and the R-matrix basis functions. The 24 spectroscopic bound and autoionizing states together with 15 pseudostates are included in the close-coupling expansion. The collision strengths for transitions between fine-structure levels are calculated by transforming the LS-coupled K-matrices to K-matrices in an intermediate coupling scheme. Thermally averaged collision strengths have been determined by integrating collision strength over a Maxwellian distribution of electron energies over a temperature range suitable for the modeling of astrophysical plasmas. The oscillator strengths and thermally averaged collision strengths are presented for transitions between the fine-structure levels of the 2s(sup 2)p(sup 3) (sup 4)S(sup 0), (sup 2)D(sup 0), (sup 2)P(sup 0), 2s2p(sup 4) (sup 4)P, 2s(sup 2)2p(sup 2)3s (sup 4)P, and (sup 2)P terms and from these levels to the levels of the 2s(sup 2)2p(sup 2)3p (sup 2)S(sup 0), (sup 4)D(sup 0), (sup 4)P(sup 0), (sup 4)S(sup 0), (sup 2)D(sup 0), (sup 2)P(sup 0),2s(sup 2)2p(sup 2)3s(sup 2)D, 2s(sup 2)2p(sup 2)4s(sup 4)P, (sup 2)P, 2s(sup 2)2p(sup 2)3d(sup 2)P, (sup 4)F,(sup 2)F,(sup 4)P, (sup 4)D, and (sup 2)D terms. Thermally averaged collision strengths are tabulated over a temperature range from 500 to 50,000 K.

  10. Design Considerations of a Galileo E1 Correlator on the Namuru Platform

    E-print Network

    Nagaraj C Shivaramaiah; Andrew G Dempster

    2009-01-01

    This paper details the design modifications required to receive and process Galileo E1b and E1c signals on the Namuru platform along with the existing GPS L1 C/A correlator. Modifications starting at the lowest level module in hardware up to the acquisition and tracking loop algorithms in the software is explained with the realization techniques. Even though the major differences are in obtaining the local code and sub-carrier, there are several challenges which are encountered in building a complete Galileo correlator. Some of these include the E-P-L shift register clock generation, accumulator bit-width, handling E1b and E1c signals, code delay and Doppler programming during the acquisition etc. In addition, due to the code length, code search step and integration time requirements, search time for each Doppler bin is increased compared to the GPS L1 C/A case, which is reduced by parallel search of the frequency bins using different channels. The tracking is implemented in two stages, first to find the phase of the secondary code and then to look for the data. The E1b and E1c interfaces from the baseband hardware to the NIOS processor are kept independent so that the software has the flexibility in choosing the acquisition and tracking algorithms. Finally, the resource usage and the results of acquisition and tracking from the GIOVE-A satellite are presented.

  11. Specific uptake of radioiodinated fragment E1 by venous thrombi in pigs

    SciTech Connect

    Knight, L.C.; Olexa, S.A.; Malmud, L.S.; Budzynski, A.Z.

    1983-12-01

    Fragment E1, a product of plasmic digestion of cross-linked fibrin, binds specifically in vitro to polymerized fibrin but not to fibrinogen. Purified human Fragment E1 was radiolabeled with /sup 125/I or /sup 131/I by the Iodogen technique. The uptake of radioiodinated Fragment E1 in vitro into forming or preformed clots was demonstrated. Animal biodistribution studies of radioiodinated Fragment E1 showed its rapid removal from the circulation; radioactive catabolites did not reside long in any organ and were excreted in the urine. The uptake in vivo was evaluated in pigs with preexisting venous thrombi of various ages from 1 h up to 5 d at the time of intravenous systemic injection of the tracer. Radioiodinated fibrinogen was also injected into the same animals to compare the uptake of the two tracers. Thrombus-to-blood ratios for Fragment E1 averaged 43:1 (range 10-108) and 29:1 (range 8-107) in thrombi 1-6 h and 1-5 d old, respectively. In contrast, mean thrombus-to-blood ratios for fibrinogen were, in the same time intervals, 26:1 (range 17-41) and 2:1 (range 0.5-3.9), respectively. It is concluded that radioiodinated Fragment E1 is a specific marker of thrombi in vivo: its uptake by fresh thrombi is better than that of labeled fibrinogen and, in contrast to radioiodinated fibrinogen, this fragment is incorporated into old thrombi as well.

  12. Heterogeneous deformation and mechanical strength of materials - Approach to the theoretical strength

    NASA Astrophysics Data System (ADS)

    Fujita, H.; Fujita, N.

    2002-01-01

    Grain size in polycrystalline materials was changed from larger than phi 10 mum to smaller than phi 10 nm, and the effects of both grain size and strain rate on the strength has been investigated from a view point of heterogeneous deformation. Grains of phi10 nm or less in size were obtained by crystallization of amorphous alloys. The experimental results are summarized as follows: (a) Heterogeneous deformation is effectively suppressed when grain size decreases smaller than about phi0.1 mum. As a result, the strength remarkably increases in this grain size range, and takes the maximum value when grains of phi10 nm in size are homogeneously formed, (b) When grain size becomes smaller than phi10 nm, those ultrafine grains are embedded into the amorphous matrix, and the strength decreases with increasing volume fraction of amorphous phase. (c) Heterogeneous deformation is also effectively suppressed by increasing strain rate in general as well as decreasing grain size. The maximum strength obtained experimentally is compared with the theoretical strengths estimated under various conditions.

  13. The Effective Strength of Accreted Planetary Bodies

    NASA Astrophysics Data System (ADS)

    Kadish, J.; Barber, J. R.; Scheeres, D. J.; Washabaugh, P. D.

    2004-11-01

    The terrestrial planets, asteroids, and comets all formed by the accretion of solid planetesimals. The maximum spin of these objects is determined from their stress fields and failure criterion. The typical elasticity analysis cannot be used to determine the stress fields of accreted bodies because it does not account for the manner in which the body was constructed (e.g. Holsapple, Icarus 154). We have analytically determined the explicit stress field of an accreted, triaxial ellipsoid whose spin rate varies during the accretion process using linear, small deformation theory. In the resulting stress field a state of residual stress is present for all time; if the object were stopped spinning and gravity ``turned off", then a non-zero state of stress would still exist in the body. We find that the effective strength of the object (parameterized by its maximum spin) is significantly affected by its growth history. Assuming that an accreted body's spin is constant during its growth and using a no-tension failure criterion, its effective strength can be as much as 21.2% higher than that of a non-accreted body and can be as much as 13.0% higher if the Mohr-Coulomb failure criterion is used with friction properties of sand or gravel. Dones and Tremaine (Icarus 103) showed that an object's spin is not necessarily constant during accretion. Using physical data on asteroids and comets, their model allows us to characterize differences in the growth histories of comets and asteroids. From this we find that asteroids can have an effective strength up to 45% higher than that of comets, after accounting for density differences. This could explain why the spin rates of comets are relatively slow as compared to asteroids.

  14. Design Project Design for an Elementary Strength

    NSDL National Science Digital Library

    Lissenden, Cliff

    Our goal is to enable deeper learning by undergraduate engineering students via experience with an open-ended design project. In addition to knowledge, comprehension, and application, engineering design requires students to analyze and synthesize. Furthermore, students must practice divergent thinking to explore the entire design space, which is an immensely important skill for developing creative and effective solutions. Learning design via a team-based design project promotes cognitive skills, social skills, management skills, and positive personal traits. Design and development of an open ended design project is discussed. The team-based project progresses over approximately ten weeks in an elementary strength of materials course. This provides a significant design experience for engineering students that helps bridge the gap between the first-year engineering design course and the capstone design project that engineering students typically do in their senior year. The project requires student teams to: work together, apply standards, create a conceptual design, select appropriate materials, identify applied loading scenarios, perform the design analysis, check design calculations from another team, create design drawings, estimate the cost, and write a design report. In order to accomplish all this in a course like strength of materials, which is laden with analysis, the project must be well organized and accompanied with web-based tools. This paper discusses design of the design project, course content that is beyond the traditional strength of materials course coverage, and development of web-based tools that make this possible. The web-based tools provide guidance on: the design process with interactive examples, analysis and simulation, materials properties and selection, administering team projects (for instructors), working team projects (for students), as well as environmental, economical, social, and ethical issues.

  15. Spatially heterogeneous strength in thrust fault zones

    NASA Astrophysics Data System (ADS)

    Erickson, S. Gregg; Wiltschko, David V.

    1991-05-01

    Deformation in the hanging wall of the Lewis thrust fault at Marias Pass, northwest Montana, is heterogeneous in space, with regions dominated by either large-scale contraction or extension faults. The distribution of mesoscopic structures within the two regions also differs. The density of fractures is highest in the extensional region, whereas the density of solution seams is highest in the contractional regime. This spatial heterogeneity of structures at the base of the Lewis thrust sheet may result from spatially heterogeneous fault zone strength. In analytical models of an elastic thrust sheet overlying a fault represented by spatial heterogeneity in shear traction or displacement, stress magnitudes and principal directions vary with position within the model thrust sheet. With the application of a Mohr-Coulomb criterion, contraction and extension faults initiate within localized regions at the base of the model thrust sheet. Spatial variations in mean stress at the base of the thrust sheet predicted by the models may explain both the greater density of solution seams in the contractional region than in the extensional region and the greater density of mesoscopic faults and veins in the extensional region than in the contractional region of the Marias Pass exposure. The spatial heterogeneity of pressure solution and cataclasis in response to variable mean stress within a fault zone of heterogeneous strength may facilitate thrust sheet movement relative to movement over a fault zone of uniform strength, because a decrease in mean stress enhances cataclasis and an increase in mean stress maintains a constant shear stress during pressure solution.

  16. Spatially heterogeneous strength in thrust faults zones

    NASA Astrophysics Data System (ADS)

    Gregg Erickson, S.; Wiltschko, David V.

    1991-05-01

    Deformation in the hanging wall of the Lewis thrust at Marias Pass, northwest Montana, is heterogeneous in space, with regions dominanted by either large-scale contraction or extension faults. The distribution of mesoscopic structures within the two regions also differs. The density of fracture is highest in the extensional region, whereas the density of solution seams is highest in the contractional regime. This spatial heterogeneity of strutures at the base the Lewis thrust sheet may result from spatially heterogeneous fault zone strength. In analytical models of an elastic thrust sheet overlying a fault represented by spatial heterogeneity in shear traction or displacement, stress magnitude and principal directions vary with position within the model thrust sheet. With the application of a Mohr-Coulomb criterion, contraction and extension faults initiate within localized regions at the base of the model thrust sheet. Spatial variations in mean stress at the base of the thrust sheet predicted by the models may explain both the greater density of solution seams in the contractional region than in the extensional region and the greater density of mesoscopic faults and veins in the extensional region than in the contractional region of the mesoscopic faults and veins in the extensional region than int he contractional region of the Marias Pass exposure. The spatial heterogeneity of pressure solution and cataclasis in response to variable mean stress within a fault zone of heterogeneous strength may facilitate thrust sheet movement relative to movement over a fault zone of uniform strength, because a decrease in mean stress enhances cataclasis and an increase in mean stress maintains a constant shear stress during pressure solution.

  17. Engineers Edge: Strength and Mechanics of Materials

    NSDL National Science Digital Library

    The mission of Engineers Edge is "to be the preferred online destination for designers, engineers and manufacturing professionals" by offering training, seminars, and online technical information and products. This section of their website on Strength and Mechanics of Materials offers an overview of topics in Materials Science, including sections on stress, strain, Hookes Law, malleability, fatigue and vibration. The short explanations are accompanied by related figures and equations. The section also provides a link to their free Technical / Engineering Publications, which cover a variety of topics including: Machine Design, Electronic Design, and Processing Magazine. This site is also reviewed in the August 13, 2004 _NSDL MET Report_.

  18. Dynamic Strength of Molybdenum Approaching Melt Conditions

    NASA Astrophysics Data System (ADS)

    Kleiser, Geremy; Chhabildas, Lalit; Reinhart, William; Anderson, William

    2011-06-01

    The purpose of this study is to investigate the dynamic strength of molybdenum at high pressures as it approaches melt. Symmetric impact experiments were conducted using a two-stage gas gun and VISAR diagnostic system to examine the molybdenum behavior up to pressures of 3.5 Mbar. The approach required compensating for the wave interaction occurring due to the low impedance LiF window, but provided detailed information regarding the release behavior from the Hugoniot state. This paper describes the strategy, experimental method, and corresponding results which are used to draw conclusions about the dynamic behavior of molybdenum at high pressure.

  19. Electromagnetic Dipole Strength in Transitional Nuclei

    E-print Network

    S. Q. Zhang; I. Bentley; S. Brant; F. Dönau; S. Frauendorf; B. Kämpfer; R. Schwengner; A. Wagner

    2008-08-19

    Electromagnetic dipole absorption cross-sections of transitional nuclei with large-amplitude shape fluctuations are calculated in a microscopic way by introducing the concept of Instantaneous Shape Sampling. The concept bases on the slow shape dynamics as compared to the fast dipole vibrations. The elctromagnetic dipole strength is calculated by means of RPA for the instantaneous shapes, the probability of which is obtained by means of IBA. Very good agreement with the experimental absorption cross sections near the nucleon emission threshold is obtained.

  20. Protective claddings for high strength chromium alloys

    NASA Technical Reports Server (NTRS)

    Collins, J. F.

    1971-01-01

    The application of a Cr-Y-Hf-Th alloy as a protective cladding for a high strength chromium alloy was investigated for its effectiveness in inhibiting nitrogen embrittlement of a core alloy. Cladding was accomplished by a combination of hot gas pressure bonding and roll cladding techniques. Based on bend DBTT, the cladding alloy was effective in inhibiting nitrogen embrittlement of the chromium core alloy for up to 720 ks (200hours) in air at 1422 K (2100 F). A significant increase in the bend DBTT occurred with longer time exposures at 1422 K or short time exposures at 1589 K (2400 F).

  1. Magnetic quadrupole strength in sup12C

    SciTech Connect

    Castel, B.; Johnstone, I.P.; van Hees, A.G.M.

    1985-07-01

    The question of the origin of the missing M2 strength in sup12C is examined. A large scale shell model calculation of 2sup- states and their decay is presented. It indicates that the role of 2p-2h correlations is probably the most important in explaining the M2 quenching and that the two-body spin-orbit force is instrumental in inducing such a quenching. The role of the tensor force as well as of the ..delta..-N excitations remains fairly modest.

  2. Experimentally determined oscillator strengths in Rh II

    NASA Astrophysics Data System (ADS)

    Bäckström, E.; Nilsson, H.; Engström, L.; Hartman, H.; Mannervik, S.

    2013-10-01

    This paper presents new experimentally determined branching fractions and oscillator strengths (log gf) for lines originating from 17 levels belonging to 5 terms of the first excited odd configuration 4d7(4D)5p in Rh II. The intensity calibrated spectra of Rh II have been recorded with a Fourier transform spectrometer between 25000 and 45000 cm-1 (2200-4000 Å). In this region, 49 lines have been identified and measured. By combining the branching fractions obtained from the spectra with previously measured lifetimes, log gf values are reported. The new results are compared with previous theoretical work.

  3. Dynamic strength tests for low elongation lanyards.

    PubMed

    Baszczy?ski, Krzysztof

    2007-01-01

    Lanyards are still important and common components of personal systems protecting against falls from a height. Experience with dynamic strength tests of lanyards indicates that test methods based on EN and ISO standards do not make objective assessment possible. This paper presents the results of theoretical and laboratory investigations of the performance of adjustable lanyards during fall arrest. The obtained results indicate that methods of testing and assessment based on those standards demonstrate considerable shortcomings when applied to low elongation lanyards. The assumptions for improved requirements and test methods of lanyards made of, e.g., steel wire and aramid ropes are also presented. PMID:17362657

  4. Thermophilic anaerobic digestion of high strength wastewaters

    SciTech Connect

    Wiegant, W.M.; Claassen, J.A.; Lettinga, G.

    1985-09-01

    Investigations on the thermophilic anaerobic treatment of high-strength wastewaters (14-65 kg COD/mT) are presented. Vinasse, the wastewater of alcohol distilleries, was used as an example of such wastewaters. Semicontinuously fed digestion experiments at high retention times revealed that the effluent quality of digestion at 55C is comparable with that at 30C at similar loading rates. The amount of methane formed per kilogram of vinasse drops almost linearly with increasing vinasse concentrations. The treatment of vinasse was also investigated using upflow anaerobic sludge blanket (UASB) reactors.

  5. Hydrodynamic compressibility of high-strength ceramics

    SciTech Connect

    Grady, D.E.

    1993-08-01

    In this study we have developed the techniques to investigate the hydrodynamic response of high-strength ceramics by mixing these powders with copper powder, preparing compacts, and performing shock compression tests on these mixtures. Hydrodynamics properties of silicon carbide, titanium diboride, and boron carbide to 30 GPa were examined by this method, and hydrodynamic compression data for these ceramics have been determined. We have concluded, however, that the measurement method is sensitive to sample preparation and uncertainties in shock wave measurements. Application of the experimental technique is difficult and further efforts are needed.

  6. 14 CFR 23.641 - Proof of strength.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Wings § 23.641 Proof of strength. The strength of stressed-skin wings must be proven by load tests or by combined structural...

  7. 14 CFR 23.641 - Proof of strength.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Wings § 23.641 Proof of strength. The strength of stressed-skin wings must be proven by load tests or by combined structural...

  8. 14 CFR 23.641 - Proof of strength.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Wings § 23.641 Proof of strength. The strength of stressed-skin wings must be proven by load tests or by combined structural...

  9. 14 CFR 23.641 - Proof of strength.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Wings § 23.641 Proof of strength. The strength of stressed-skin wings must be proven by load tests or by combined structural...

  10. 14 CFR 23.641 - Proof of strength.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Wings § 23.641 Proof of strength. The strength of stressed-skin wings must be proven by load tests or by combined structural...

  11. The Development and Initial Validation of the Preschool Strengths Inventory

    E-print Network

    Owens, Rhea Lillian

    2011-08-31

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Social Competence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25 Prosocial Behavior... traits, specifically the Big Five personality factors, and interpersonal skills, including social competence and prosocial behavior, were reviewed to identify the strengths preschool children possess. Conceptualizing and Defining Strengths Several models...

  12. Micromechanical Modeling of Strength and Damage of Fiber

    E-print Network

    , fracture mechanics and continuum damage mechanics based models and numerical micromechanical modelsMicromechanical Modeling of Strength and Damage of Fiber Reinforced Composites Leon Mishnaevsky Jr Mishnaevsky Jr., Povl Brøndsted Title: Micromechanical Modeling of Strength and Damage of Fiber Reinforced

  13. Aluminum/steel wire composite plates exhibit high tensile strength

    NASA Technical Reports Server (NTRS)

    1966-01-01

    Composite plate of fine steel wires imbedded in an aluminum alloy matrix results in a lightweight material with high tensile strength. Plates have been prepared having the strength of titanium with only 85 percent of its density.

  14. Role of CYP2E1 in ketone-stimulated insulin release in pancreatic B-cells

    Microsoft Academic Search

    Diane J. Lees Murdock; Jacqueline Clarke; Peter R. Flatt; Yvonne A. Barnett; Christopher R. Barnett

    2004-01-01

    The role of CYP2E1 in ketone-stimulated insulin release was investigated using isolated pancreatic islets of Langerhans and two mammalian insulin secreting pancreatic ?-cell lines engineered to stably express human CYP2E1 (designated BRIN BD11h2E1 and INS-1h2E1). Isolated rat pancreatic islets were shown to express the CYP2E1 isoform which was inducible by pretreatment of animals with acetone. The cDNA encoded CYP2E1 was

  15. Effects of intravenous administration of prostaglandin E 1 and lipo-prostaglandin E 1 on cochlear blood flow in guinea pigs

    Microsoft Academic Search

    Tadashi Nishimura; Kazuhiko Nario; Hiroshi Hosoi

    2002-01-01

    Prostaglandin E1 (PGE1), a vasodilator and an inhibitor of platelet aggregation, has been used for the treatment of idiopathic sudden sensorineural hearing loss, despite the fact that its effectiveness has not been proven. Furthermore, it is rapidly metabolized in the lungs, which makes it difficult to use clinically. In an attempt to prevent this, PGE1 was coated with a 0.2-µg

  16. SIZE DEPENDENCE OF FLEXURAL STRENGTH AND FATIGUE STRENGTH OF PAVEMENT CONCRETE

    NASA Astrophysics Data System (ADS)

    Yoshimoto, Toru; Sato, Ryoichi

    The size effect on flexural fatigue strength of concrete was experime ntally investigated. For this purpose, specimens of two sizes were prepared: 150mm x 150mm x 530mm (span=450mm) and 200mm x 450mm x 1800mm (span=1350mm). The stress levels were set at 70%, 80% and 90% of the compressive strength. Experimental results showed that the number of loading cycles at failure increased with the enlargement of specimens. Based on a fracture mechanics approach, with a stress level of 70%, this dependence of flexural fatigue strength on size was explained by the difference in the stress distributions in the sections of small and large sized specimens. A te nsion softening stress region was formed in the section of the small specimen, whereas elastic stress was produced over the full section in the large specimen.

  17. Diabetes mellitus increases the in vivo activity of cytochrome P450 2E1 in humans

    PubMed Central

    Wang, Zaiqi; Hall, Stephen D; Maya, Juan F; Li, Lang; Asghar, Ali; Gorski, J C

    2003-01-01

    Aim Cytochrome P450 2E1 (CYP2E1) is thought to activate a number of protoxins, and has been implicated in the development of liver disease. Increased hepatic expression of CYP2E1 occurs in rat models of diabetes but it is unclear whether human diabetics display a similar up-regulation. This study was designed to test the hypothesis that human diabetics experience enhanced CYP2E1 expression. Methods The pharmacokinetics of a single dose of chlorzoxazone (500 mg), used as an index of hepatic CYP2E1 activity, was determined in healthy subjects (n = 10), volunteers with Type I (n = 13), and Type II (n = 8) diabetes mellitus. Chlorzoxazone and 6-hydroxychlorzoxazone in serum and urine were analysed by high-performance liquid chromatography. The expression of CYP2E1 mRNA in peripheral blood mononuclear cells was quantified by reverse transcriptase-polymerase chain reaction. Results The mean ± s.d. (90% confidence interval of the difference) chlorzoxazone area under the plasma concentration-time curve was significantly (P ? 0.05) reduced in obese Type II diabetics (15.7 ± 11.3 µg h ml?1; 9, 22) compared with healthy subjects (43.5 ± 16.9 µg h ml?1; 16, 40) and Type I diabetics (32.8 ± 9.2 µg h ml?1; 9, 25). There was a significant two-fold increase in the oral clearance of chlorzoxazone in obese Type II diabetics compared with healthy volunteers and Type I diabetics. The protein binding of chlorzoxazone was not significantly different between the three groups. In contrast, Type 1 diabetics and healthy volunteers demonstrated no difference in the oral clearance of chlorzoxazone. The urinary recovery of 6-hydroxychlorzoxazone as a percentage of the administered dose was not different between healthy, Type I and obese Type II diabetics. The elimination half-life of chlorzoxazone did not differ between the three groups. CYP2E1 mRNA was significantly elevated in Type I and obese Type II diabetics compared with healthy volunteers. The oral clearance of chlorzoxazone, elimination half-life, Tmax, and Cmax were not significantly influenced by weight, body mass index, serum glucose, serum cholesterol, or glycosylated haemoglobin. Conclusions There was a marked increase in hepatic CYP2E1 activity in obese Type II diabetics as assessed by chlorzoxazone disposition. Increased expression of CYP2E1 mRNA in peripheral blood mononuclear cells was found in both types of diabetes mellitus. Adverse hepatic events associated with Type II diabetes may be in part a result of enhanced CYP2E1 expression and activity. PMID:12534643

  18. Cytochrome p450 2E1 polymorphisms and the risk of gastric cardia cancer

    PubMed Central

    Cai, Lin; Zheng, Zong-Li; Zhang, Zuo-Feng

    2005-01-01

    AIM: Genetic polymorphisms of drug-metabolizing enzymes have recently been shown to affect susceptibility to chemical carcinogenesis. Cytochrome P450 2E1 (CYP2E1) enzyme catalyzes the metabolism of many procarcinogens, such as N-nitrosamines and related compounds. The gene coding for this enzyme is polymorphic and thus may play a role in gastric cardia cancer (GCC) etiology. In this hospital-based case-control study, we evaluate the relationship between genetic polymorphisms of CYP2E1 and the risk of GCC. METHODS: The study subjects comprised 159 histologically confirmed GCC cases identified via hospital cancer registry and surgical records at five hospitals in Fuzhou, Fujian Province, China, between April and November 2001. Controls were 192 patients admitted to the same hospitals for nonmalignant conditions. The genotypes of CYP2E1 were detected by a PCR-based RFLP assay. The odds ratios were estimated by logistic regression analyses and were adjusted for potential confounding factors. RESULTS: The distribution of three genotypes of CYP2E1 in GCC cases and controls was significantly different (?2 = 16.04, P<0.01). The frequency of the CYP2E1 (c1/c1) genotype in GCC cases and controls was 60.4% and 40.1%, respectively. The CYP2E1 (c1/c1) genotype was associated with an increased risk for GCC (the adjusted (OR) was 2.37, 95% confidence interval (CI): 1.52-3.70). Subjects who carried the CYP2E1 (c1/c1) genotype and were habitual smokers were at a significantly higher risk of developing GCC (OR = 4.68, 95%CI: 2.19-10.04) compared with those who had the CYP2E1 (c1/c2 or c2/c2) genotype and did not smoke. CONCLUSION: These results suggest that the CYP2E1 genotype may influence individual susceptibility to development of GCC, and that the risk increases significantly in smokers. PMID:15793883

  19. Human cells arrest in S phase in response to adenovirus 12 E1A.

    PubMed

    Grand, R J; Ibrahim, A P; Taylor, A M; Milner, A E; Gregory, C D; Gallimore, P H; Turnell, A S

    1998-05-10

    It has previously been shown that following viral infection, Ad5 E1A induces cell cycle progression of quiescent rodent cells, leading to DNA synthesis and mitosis. Here we have examined the effect of Ad12 E1A on the cell cycle characteristics of human cells. Human tumor (A549, KB, and HeLa) cells were infected with Ad12 d/620, a mutant virus which has a lesion in the E1B gene and essentially expresses only E1A. These infected cells progressed from being largely in G1 into S phase, where they arrested. Even up to 96 h postinfection (p.i.) the cells remained blocked in S phase. DNA synthesis did, however, proceed in Ad12 d/620-infected cells, giving rise to multiple copies of cellular DNA. Similar results were obtained when primary human skin fibroblasts were infected, although the polyploidy was less marked. The expression of cyclins A, B1, and E in the tumor cells increased appreciably in response to E1A. In contrast, there was a dramatic reduction in the levels of cyclin D1 and D3. Increases in cyclin D1 expression could be detected at very late times p.i. In those cell lines expressing low levels of cdc2 and cdk2 an appreciable increase in expression was seen soon after Ad12 E1A could be detected. The elevated levels of cyclins A, B1, and E were associated with increased protein kinase activity directed against histone H1. An increase in cyclin D1-associated kinase activity against Rb1 was also observed at late times. This deregulation of the cell cycle was not solely dependent on E1A inactivation of Rb, since similar effects were seen in Ad12 d/620-infected retinoblastoma (Y-79) cells, implicating p107 and p130 in E1A-mediated changes in cell cycle progression. We propose that the E1A-induced levels of cyclins A, B1, and E by Ad12 E1A in human cells may lead to an uncoupling of S phase from cell cycle progression. PMID:9601504

  20. Strength of optical glass under conditions of axial compression

    Microsoft Academic Search

    G. M. Okhrimenko; Yu. M. Rodichev; V. P. Maslov

    1985-01-01

    Conclusions 1.The strength of optical glass in uniaxial compression is one-third to one-half lower than the strength of high-strength technical glass, e. g., glass 13v, the sample variation coefficient is 50 to 100% larger, and therefore a higher safety factor is required in designing highly stressed components made of the given materials.2.The strength of optical glass under axial compression, and

  1. Internal stress and yield strength of copper films on substrates

    NASA Astrophysics Data System (ADS)

    Zhang, Jian-Min; Zhang, Yan; Xu, Ke-Wei

    2005-05-01

    Internal stress and yield strength of pure copper films on substrates were characterized by x-ray diffraction and thermal-cycle substrate curvature methods. The internal stress was of tension and decreased with increasing working-gas (argon) pressure and increased with increasing film thickness. Tensile yield strength of copper films on steel substrate was reciprocal to the film thickness. Similarly, the compressive yield strength depended strongly on the film thickness: the thinner the film thickness, the larger the compressive yield strength.

  2. Short-span compressive strength and interlaminar shear resistance

    SciTech Connect

    Amini, J.; Robillard, N. [Domtar Inc., Senneville, Quebec (Canada); Bardeau, C.E. [3M Canada Inc., London, Ontario (Canada)

    1995-12-31

    A relatively simple relation between short-span compressive strength and ultimate interlaminar shear strain is derived and shown to fit data for machine-made boards from different sources. Interlaminar shear resistance seems to be the pertinent bond test for edgewise compression strength studies. Experimental results illustrate how (shear) bond strength can be monitored by measuring in-plane modulus and short-span compression strength. Practical aspects of the interlaminar shear resistance test are also discussed.

  3. Climate strength: a new direction for climate research

    Microsoft Academic Search

    Benjamin Schneider; Amy Nicole Salvaggio; Montse Subirats

    2002-01-01

    Climate strength was conceptualized within D. Chan's (1998) discussion of compositional models and the concept of culture strength from the organizational culture literature. Climate strength was opera- tionalized in terms of within-group variability in climate perceptions—the less within-group variability, the stronger the climate. The authors studied climate strength in the context of research linking employee service climate perceptions to customer

  4. Indicators propose and analysis on national logistics competitive strength

    Microsoft Academic Search

    Yong Geng; Weizhong Zhou

    2010-01-01

    In the context of international financial crisis and logistics adjustment and revitalization plan, how to enhance national logistics competitive strength has become an urgent problem to be solved for government macro-management department. To enhance national logistics competitive strength, we need to evaluate and keep abreast of status of it. To evaluate national logistics competitive strength, we must build indicators system

  5. Mapping regolith strength for bauxite mine rehabilitation using instrumented bulldozers

    Microsoft Academic Search

    Faron C. Mengler; Bob Gilkes; Geoff Kew

    2004-01-01

    The high strength of some regolith types can limit the growth of replanted jarrah forest following bauxite mining in southwestern Australia. Ripping mine floors to a depth of 1.5m can successfully alleviate high strength zones and improve root exploration of some substrates; however, this practice is expensive. An understanding of the spatial distribution of regolith strength enables a mining company

  6. Liquefied strength ratio from liquefaction flow failure case histories

    Microsoft Academic Search

    Scott M. Olson; Timothy D. Stark

    2002-01-01

    The shear strength of liquefied soil, su(LIQ), mobilized during a liquefaction flow failure is normalized with re- spect to the vertical effective stress ( ? vo ' ) prior to failure to evaluate the liquefied strength ratio, su(LIQ)\\/? vo ' . Liquefied strength ratios mobilized during 33 cases of liquefaction flow failure are estimated using a procedure developed to directly

  7. Shear Strength Model for Lightly Reinforced Concrete Columns

    Microsoft Academic Search

    Halil Sezen

    2004-01-01

    Parameters affecting the shear strength of reinforced concrete columns having a rectangular cross section and light transverse reinforcement are investigated using data from numerous column tests. A new model is proposed to predict the column shear strength based on theoretical formulations and experimental evidence. The proposed shear strength equation includes contributions from the concrete and transverse reinforcement. Primary parameters in

  8. Strength of Si Wafers with Microcracks: A Theoretical Model (Poster)

    SciTech Connect

    Rupnowski, P.; Sopori, B.

    2008-05-01

    A new analytical expression that takes into account the surface, edge, and bulk properties of a wafer has been proposed to describe the strength of the brittle materials. A new proposed fracture-mechanics numerical simulation successfully predicted the strength of the cast silicon wafers. It has been shown that the predicted wafer strength distribution agrees well with the available experimental results.

  9. Effect of chemical additives on the strength of sandstone

    Microsoft Academic Search

    M. Seto; D. K. Nag; V. S. Vutukuri; K. Katsuyama

    1997-01-01

    Chemical alteration of the strength of sandstone has been investigated to establish the fundamental knowledge for chemically assisted fracturing. If the rock strength can be chemically lowered, this technology would be useful to raise the fracturing efficiency. The purpose of the present study is to evaluate the effect of chemical solutions on the strength. To evaluate experimentally the effect, Brazilian

  10. The Principles of Strength and Fatigue in Optical Fibers

    Microsoft Academic Search

    J. Carr; S. Saikkonen

    1986-01-01

    Tensile strength is defined as the applied stress (tensile load per unit cross-sectional area) recorded at the instant of rupture for a test specimen. Historically, attempts to catalogue and report the intrinsic strength of glass were frustrated by considerable dispersion in the acquired measurement data. In addition to large variability, typical strength values were found to be one, two or

  11. Testing the Shear Strength of Gummy Bear Mountain

    NSDL National Science Digital Library

    Amanda Keen-Zebert

    Students do background reading from the text on physical weathering and the components of shear strength. Students write hypotheses about the shear strength of different sizes and shapes of gummy candy. The students then uses simple experiments to demonstrate and test the shear strength of the candy types.

  12. A General Theory of Strength for Anisotropic Materials

    Microsoft Academic Search

    Stephen W. Tsai; Edward M. Wu

    1971-01-01

    An operationally simple strength criterion for anisotropic materials is developed from a scalar function of two strength tensors. Differing from existing quadratic approximations of failure surfaces, the present theory satisfies the invariant requirements of coordinate transforma tion, treats interaction terms as independent components, takes into account the difference in strengths due to positive and negative stresses, and can be specialized

  13. Liquid nitrogen strengths of coated optical glass fibres

    Microsoft Academic Search

    P. W. France; M. J. Paradine; M. H. Reeve; G. R. Newns

    1980-01-01

    The strengths of plastic-coated glass fibres have been measured at liquid nitrogen temperatures using a bending technique. The method yields data on the strengths of coated optical fibres in the absence of stress corrosion. Pristine strengths corresponding to a breaking strain of 21% have been measured for silica fibre and 12% for sodium borosilicate compound glass fibre, corrected to 50

  14. DRAINED RESIDUAL STRENGTH FOR LANDSLIDES Timothy D. Stark1

    E-print Network

    -2352; PH (217) 333-7516; email: hussain2@illinois.edu ABSTRACT Drained residual shear strength shear tests were performed to investigate the gain in strength, if any, along a preexisting shear shear tests at effective normal stresses of 100 kPa or less. However, the recovered strength observed

  15. Shear strength of granular materials Farhang Radjai and Emilien Azma

    E-print Network

    Paris-Sud XI, Université de

    Shear strength of granular materials Farhang Radjai and Emilien Azéma LMGC, CNRS the role of fabric and force anisotropies with respect to the critical-state shear strength. Then, a model. KEYWORDS: granular media, shear strength, fabric anisotropy, weak and strong forces. Revue, Volume X ­ n

  16. Shear strength properties of wet granular materials Vincent Richefeu,

    E-print Network

    Paris-Sud XI, Université de

    Shear strength properties of wet granular materials Vincent Richefeu, Moulay Sa¨id El Youssoufi shear strength properties of wet granular materials in the pendular state (i.e. the state where of capillary interactions, the major influence of water content over the shear strength stems from

  17. The residual shear strength of some Hellenic clayey soils

    Microsoft Academic Search

    N. Kalteziotis

    1993-01-01

    A programme of residual shear strength testing has been undertaken on a number of Hellenic soil types: Marls, Clays and Flysch. The residual strength was determined using the Bromhead ring shear aparatus. For the applied normal stress range the residual strength envelope was straight and the resultant residual friction angle values are correlated with the index properties, such as Atterberg

  18. COMPARISON OF DIFFERENT PROCEDURES TO PREDICT UNSATURATED SOIL SHEAR STRENGTH

    Microsoft Academic Search

    S. K. Vanapalli; D. G. Fredlund

    Several procedures have been proposed in the recent years to predict the shear strength of an unsaturated soil. The soil- water characteristic curve has been used as a tool either directly or indirectly in the prediction of the shear strength along with the saturated shear strength parameters in these procedures. This paper provides comparisons between the measured and predicted values

  19. Grip strength of college and professional football players

    Microsoft Academic Search

    W. F. STRAUB

    1979-01-01

    Although strength is basic to human performance in sport, the relationship between grip strength and playing performance has not been clearly established. Therefore, it was the purpose of this study to determine the correlation between grip strength and football playing performance at college and professional levels of competition. The subjects of the investigation were 40 members of an NCAA (Division

  20. 47 CFR 73.686 - Field strength measurements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...antenna above ground, above mean sea level, and above...equipment used in the field strength survey, which...above map, showing the field strength at each measuring...Computations of the mean and standard deviation of all measured field strengths, or a...

  1. 47 CFR 73.314 - Field strength measurements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...antenna above ground, above mean sea level, and above...equipment used in the field strength survey, which...above map, showing the field strength at each measuring...Computations of the mean and standard deviation of all measured field strengths, or a...

  2. 47 CFR 73.314 - Field strength measurements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...antenna above ground, above mean sea level, and above...equipment used in the field strength survey, which...above map, showing the field strength at each measuring...Computations of the mean and standard deviation of all measured field strengths, or a...

  3. 47 CFR 73.686 - Field strength measurements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...antenna above ground, above mean sea level, and above...equipment used in the field strength survey, which...above map, showing the field strength at each measuring...Computations of the mean and standard deviation of all measured field strengths, or a...

  4. Drained Shear Strength Parameters for Analysis of Landslides

    E-print Network

    Drained Shear Strength Parameters for Analysis of Landslides Timothy D. stark'; Hangseok choi2;and of drained shear strength parameters for analysis of landslides. In particular, the importance, existence for landslide analyses, empirical relationships for the drained residual and fully softened strengths

  5. Autism Severity and Muscle Strength: A Correlation Analysis

    ERIC Educational Resources Information Center

    Kern, Janet K.; Geier, David A.; Adams, James B.; Troutman, Melissa R.; Davis, Georgia; King, Paul G.; Young, John L.; Geier, Mark R.

    2011-01-01

    The current study examined the relationship between muscle strength, as measured by hand grip strength, and autism severity, as measured by the Childhood Autism Rating Scale (CARS). Thirty-seven (37) children with a diagnosis of autism spectrum disorder (ASD) were evaluated using the CARS and then tested for hand muscle strength using a hand grip…

  6. Test of Insulation Electrical Strength of LARP Technological Quadrupoles (TQ)

    Microsoft Academic Search

    D. Tooke; G. Ambrosio; N. Andreev; R. Bossert

    This is a report about measuring the Insulation Electrical Strength of a TQC and a TQS practice coil. Tests were performed under transverse pressure up to 190 MPa at voltage up to 1000 V. Turn-to-turn insulation strength was measured between cables within the inner layer and within the outer layer. Layer-to-layer insulation strength was measured as well.

  7. Hamstrings strength imbalance in professional football (soccer) players in australia.

    PubMed

    Ardern, Clare L; Pizzari, Tania; Wollin, Martin R; Webster, Kate E

    2015-04-01

    Ardern, CL, Pizzari, T, Wollin, MR, and Webster, KE. Hamstrings strength imbalance in professional football (soccer) players in Australia. J Strength Cond Res 29(4): 997-1002, 2015-The aim of this study was to describe the isokinetic thigh muscle strength profile of professional male football players in Australia. Concentric (60° and 240°·s) and eccentric (30° and 120°·s) hamstrings and quadriceps isokinetic strength was measured with a HUMAC NORM dynamometer. The primary variables were bilateral concentric and eccentric hamstring and quadriceps peak torque ratios, concentric hamstring-quadriceps peak torque ratios, and mixed ratios (eccentric hamstring 30°·s ÷ concentric quadriceps 240°·s). Hamstring strength imbalance was defined as deficits in any 2 of: bilateral concentric hamstring peak torque ratio <0.86, bilateral eccentric hamstring peak torque ratio <0.86, concentric hamstring-quadriceps ratio <0.47, and mixed ratio <0.80. Fifty-five strength tests involving 42 players were conducted. Ten players (24%) were identified as having hamstring strength imbalance. Athletes with strength imbalance had significantly reduced concentric and eccentric bilateral hamstring peak torque ratios at all angular velocities tested; and reduced eccentric quadriceps peak torque (30°·s) in their stance leg, compared with those without strength imbalance. Approximately, 1 in 4 players had preseason hamstring strength imbalance; and all strength deficits were observed in the stance leg. Concentric and eccentric hamstrings strength imbalance may impact in-season football performance and could have implications for the future risk of injury. PMID:25426513

  8. Strength determines coalitional strategies in humans

    PubMed Central

    Benenson, Joyce F.; Markovits, Henry; Emery Thompson, Melissa; Wrangham, Richard W.

    2009-01-01

    Coalitions enhance survival and reproductive success in many social species, yet they generate contradictory impulses. Whereas a coalition increases the probability of successfully obtaining rewards for its members, it typically requires a division of rewards among members, thereby diminishing individual benefits. Non-human primate data indicate that coalition formation is more likely when an individual's probability of success is low when competing alone. No comparable studies exist for humans. Here we show using a computerized competitive game that humans exhibit a systematic, intuitive strategy for coalition formation based on their own and others' levels of perceived strength, a pattern that resembles coalition formation in chimpanzees, Pan troglodytes. Despite equal expected pay-offs for all strategies, subjects were more likely to form coalitions as their own level of perceived strength waned. Those chosen as coalition partners tended to be stronger individuals or arbitrarily designated ‘friends’. Results suggest a heuristic for human coalitionary decisions that rests on the perception of relative power rather than on the assessment of pay-offs. PMID:19364733

  9. Determinants of eggshell strength in endangered raptors.

    PubMed

    Castilla, Aurora M; Herrel, Anthony; Van Dongen, Stefan; Furio, Naoki; Negro, Juan José

    2009-04-01

    We compared eggshell strength in a group of falcon taxa including the peregrine falcon (Falco peregrinus peregrinus), the red shaheen falcon (F. peregrinus babylonicus), the saker falcon (F. cherrug), the gyr falcon (F. rusticolus) and some interspecific and intraspecific hybrids. Our results showed that smaller falcons (<1,000 g) of the peregrine group have eggshells that are significantly softer (x=13.3 N) and thinner (x=0.26 mm) (n=107 eggs) than larger falcons (>1,000 g) of the gyr-saker group (x=20.8 N and 0.39 mm, respectively, n=81 eggs). We found a significant positive correlation between egg hardness and eggshell thickness. Linear mixed models showed that clutches from heavier females consisted of larger and harder eggs with thicker shells and thicker egg membranes. Eggs produced by older females and eggs laid later in the laying sequence were relatively smaller and softer and had relatively thin egg membranes and eggshells. Individual females, irrespective of their age, contributed significantly to the observed variation in egg strength. Egg size and hardness of hybrid eggs were similar to that of the pure species suggesting that hybridization does not affect eggshell hardness or thickness. Our study provides quantitative evidence of several factors, other than levels of contamination, which may affect eggshell thickness and hardness in falcons. PMID:19267399

  10. Abstract Spatial Reasoning as an Autistic Strength

    PubMed Central

    Stevenson, Jennifer L.; Gernsbacher, Morton Ann

    2013-01-01

    Autistic individuals typically excel on spatial tests that measure abstract reasoning, such as the Block Design subtest on intelligence test batteries and the Raven’s Progressive Matrices nonverbal test of intelligence. Such well-replicated findings suggest that abstract spatial processing is a relative and perhaps absolute strength of autistic individuals. However, previous studies have not systematically varied reasoning level – concrete vs. abstract – and test domain – spatial vs. numerical vs. verbal, which the current study did. Autistic participants (N?=?72) and non-autistic participants (N?=?72) completed a battery of 12 tests that varied by reasoning level (concrete vs. abstract) and domain (spatial vs. numerical vs. verbal). Autistic participants outperformed non-autistic participants on abstract spatial tests. Non-autistic participants did not outperform autistic participants on any of the three domains (spatial, numerical, and verbal) or at either of the two reasoning levels (concrete and abstract), suggesting similarity in abilities between autistic and non-autistic individuals, with abstract spatial reasoning as an autistic strength. PMID:23533615

  11. Abstract spatial reasoning as an autistic strength.

    PubMed

    Stevenson, Jennifer L; Gernsbacher, Morton Ann

    2013-01-01

    Autistic individuals typically excel on spatial tests that measure abstract reasoning, such as the Block Design subtest on intelligence test batteries and the Raven's Progressive Matrices nonverbal test of intelligence. Such well-replicated findings suggest that abstract spatial processing is a relative and perhaps absolute strength of autistic individuals. However, previous studies have not systematically varied reasoning level--concrete vs. abstract--and test domain--spatial vs. numerical vs. verbal, which the current study did. Autistic participants (N?=?72) and non-autistic participants (N?=?72) completed a battery of 12 tests that varied by reasoning level (concrete vs. abstract) and domain (spatial vs. numerical vs. verbal). Autistic participants outperformed non-autistic participants on abstract spatial tests. Non-autistic participants did not outperform autistic participants on any of the three domains (spatial, numerical, and verbal) or at either of the two reasoning levels (concrete and abstract), suggesting similarity in abilities between autistic and non-autistic individuals, with abstract spatial reasoning as an autistic strength. PMID:23533615

  12. Magnetic field strength of active region filaments

    NASA Astrophysics Data System (ADS)

    Kuckein, C.; Centeno, R.; Martínez Pillet, V.; Casini, R.; Manso Sainz, R.; Shimizu, T.

    2009-07-01

    Aims: We study the vector magnetic field of a filament observed over a compact active region neutral line. Methods: Spectropolarimetric data acquired with TIP-II (VTT, Tenerife, Spain) of the 10 830 Å spectral region provide full Stokes vectors that were analyzed using three different methods: magnetograph analysis, Milne-Eddington inversions, and PCA-based atomic polarization inversions. Results: The inferred magnetic field strengths in the filament are around 600-700 G by all these three methods. Longitudinal fields are found in the range of 100-200 G whereas the transverse components become dominant, with fields as high as 500-600 G. We find strong transverse fields near the neutral line also at photospheric levels. Conclusions: Our analysis indicates that strong (higher than 500 G, but below kG) transverse magnetic fields are present in active region filaments. This corresponds to the highest field strengths reliably measured in these structures. The profiles of the helium 10 830 Å lines observed in this active region filament are dominated by the Zeeman effect.

  13. Radiofrequency and its effect on suture strength.

    PubMed

    Shah, Anup A; Kang, Parminder; Deutsch, Allen

    2009-12-01

    The use of radiofrequency-based electrocautery for hemostasis and ablation within the subacromial space and glenohumeral joint can cause damage to suture material. Prior studies have focused on the mechanical properties of sutures including their ability to withstand abrasion. The purpose of this study was to determine the effect of electrical energy on the mechanical properties of 5 different brands of #2 suture used for arthroscopic shoulder repair: FiberWire (Arthrex Inc, Naples, Florida); Orthocord (DePuy Mitek, Norwood, Massachusetts); Hi-Fi (formally Herculine; Linvatec Corp, Largo, Florida); MaxBraid (Teleflex Medical, Research Triangle Park, North Carolina); and Ethibond (Ethicon, Inc, Somerville, New Jersey). A matched pair of human deltoid muscle submerged in buffered saline solution (pH 7.4) was used as a test medium. The suture strengths were tested in 3 different scenarios. The 3 groups were as follows: control group without electrical current, coagulation group with direct introduction of electrical current on a coagulate setting for 2 seconds, and a cutting group with direct introduction of electrical current on a cut setting for 2 seconds. Hi-Fi suture seemed to be the least susceptible to damage by direct electrocautery application. Orthocord suffered the greatest loss of strength of all materials tested. This study demonstrates that exposure to electrocautery damages and weakens suture. Great care should be taken when electrocautery is used during arthroscopic repairs to prevent suture failure and preserve repair integrity. PMID:19968222

  14. Dynamic strength of HFIR vessel for fracture

    SciTech Connect

    Chang, Shih-Jung

    1992-06-01

    Dynamic strength of the High Flux Isotope Reactor (HFIR) vessel to resist hypothetical accidents is analyzed by using the method of fracture mechanics. Vessel critical stresses are estimated by applying dynamic pressure pulses of a range of magnitudes and pulse-durations. The pulses versus time functions are assumed to be step functions. The probability of vessel fracture is then calculated by assuming a distribution of possible surface cracks of different crack depths. The probability distribution function for the crack depths is based on the form that is recommended by the Marshall report. The toughness of the vessel steel used in the analysis is based on the projected and embrittled value after 10 effective full power years from 1986. From the study made by Cheverton, Merkle and Nanstad, the weakest point on the vessel for fracture evaluation is known to be located within the region surrounding the tangential beam tube HB3. The increase in the probability of fracture is obtained as an extension of the result from that report for the regular operating condition to include conditions of higher dynamic pressures due to accident loadings. The increase in the probability of vessel fracture is plotted for a range of hoop stresses to indicate the vessel strength against hypothetical accident conditions.

  15. Dynamic strength of HFIR vessel for fracture

    SciTech Connect

    Chang, Shih-Jung.

    1992-01-01

    Dynamic strength of the High Flux Isotope Reactor (HFIR) vessel to resist hypothetical accidents is analyzed by using the method of fracture mechanics. Vessel critical stresses are estimated by applying dynamic pressure pulses of a range of magnitudes and pulse-durations. The pulses versus time functions are assumed to be step functions. The probability of vessel fracture is then calculated by assuming a distribution of possible surface cracks of different crack depths. The probability distribution function for the crack depths is based on the form that is recommended by the Marshall report. The toughness of the vessel steel used in the analysis is based on the projected and embrittled value after 10 effective full power years from 1986. From the study made by Cheverton, Merkle and Nanstad, the weakest point on the vessel for fracture evaluation is known to be located within the region surrounding the tangential beam tube HB3. The increase in the probability of fracture is obtained as an extension of the result from that report for the regular operating condition to include conditions of higher dynamic pressures due to accident loadings. The increase in the probability of vessel fracture is plotted for a range of hoop stresses to indicate the vessel strength against hypothetical accident conditions.

  16. Aluminum Yield Strength on Quasi-isentropes

    NASA Astrophysics Data System (ADS)

    Nguyen, Jeffrey H.; Reed Patterson, J.; Orlikowski, Daniel; Martin, L. Peter; Krone, Ryan; Minich, Roger; Holmes, Neil C.

    2008-03-01

    Advances in the functionally graded density impactors (FGDI) have made it possible to carry out dynamic experiments at previously inaccessible regions of the phase diagram. We employed these advances in recent tailored dynamic experiments to gain insight into the yield strength of aluminum along ``hot'' quasi-isentropes. The impactor was specifically designed to deliver a triangular compression wave into a sample where the strain rates on the compression and release isentropes were nearly identical. The aluminum samples were initially shocked to a fixed state on the Hugoniot, then quasi-isentropically compressed, and finally allowed to release isentropically. Here, we will discuss the details of the experiments and error analysis in deriving the yield strength of aluminum on a ``hot'' quasi-isentrope. We will also discuss recent advances in the FGDI technology that made these experiments possible with significantly reduced uncertainties. Methods to characterize these advances will be discussed. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory in part under Contract W-7405-Eng-48 and in part under Contract DE-AC52-07NA27344.

  17. Neural adaptations to electrical stimulation strength training.

    PubMed

    Hortobágyi, Tibor; Maffiuletti, Nicola A

    2011-10-01

    This review provides evidence for the hypothesis that electrostimulation strength training (EST) increases the force of a maximal voluntary contraction (MVC) through neural adaptations in healthy skeletal muscle. Although electrical stimulation and voluntary effort activate muscle differently, there is substantial evidence to suggest that EST modifies the excitability of specific neural paths and such adaptations contribute to the increases in MVC force. Similar to strength training with voluntary contractions, EST increases MVC force after only a few sessions with some changes in muscle biochemistry but without overt muscle hypertrophy. There is some mixed evidence for spinal neural adaptations in the form of an increase in the amplitude of the interpolated twitch and in the amplitude of the volitional wave, with less evidence for changes in spinal excitability. Cross-sectional and exercise studies also suggest that the barrage of sensory and nociceptive inputs acts at the cortical level and can modify the motor cortical output and interhemispheric paths. The data suggest that neural adaptations mediate initial increases in MVC force after short-term EST. PMID:21643920

  18. Photophoretic Strength on Chondrules. 1. Modeling

    NASA Astrophysics Data System (ADS)

    Loesche, Christoph; Wurm, Gerhard; Teiser, Jens; Friedrich, Jon M.; Bischoff, Addi

    2013-12-01

    Photophoresis is a physical process that transports particles in optically thin parts of protoplanetary disks, especially at the inner edge and at the optical surface. To model the transport and resulting effects in detail, it is necessary to quantify the strength of photophoresis for different particle classes as a fundamental input. Here, we explore photophoresis for a set of chondrules. The composition and surface morphology of these chondrules were measured by X-ray tomography. Based on the three-dimensional models, heat transfer through illuminated chondrules was calculated. The resulting surface temperature map was then used to calculate the photophoretic strength. We found that irregularities in particle shape and variations in composition induce variations in the photophoretic force. These depend on the orientation of a particle with respect to the light source. The variation of the absolute value of the photophoretic force on average over all chondrules is 4.17%. The deviation between the direction of the photophoretic force and illumination is 3.°0 ± 1.°5. The average photophoretic force can be well approximated and calculated analytically assuming a homogeneous sphere with a volume equivalent mean radius and an effective thermal conductivity. We found an analytic expression for the effective thermal conductivity. The expression depends on the two main phases of a chondrule and decreases with the amount of fine-grained devitrified, plagioclase-normative mesostasis up to factor of three. For the chondrule sample studied (Bjurböle chondrite), we found a dependence of the photophoretic force on chondrule size.

  19. Kinetic characterization of CYP2E1 inhibition in vivo and in vitro by the chloroethylenes.

    PubMed

    Lilly, P D; Thornton-Manning, J R; Gargas, M L; Clewell, H J; Andersen, M E

    1998-10-01

    Trans- and cis-1,2-dichloroethylene (DCE) isomers inhibit their own metabolism in vivo by inactivation of the metabolizing enzyme, presumably the cytochrome P450 isoform, CYP2E1. In this study, we examined cytochrome P450 isoform-specific inhibition by three chloroethylenes, cis-DCE, trans-DCE, and trichloroethylene (TCE), and evaluated several kinetic mechanisms of enzyme inhibition with physiological models of inhibition. Trans-DCE was more potent than cis-DCE, and both were much more effective than TCE in inhibiting CYP2E1. The kinetics of in vitro loss of p-nitrophenol hydroxylase (pNP-OH) activity (a marker of CYP2E1) in microsomal incubations and of the in vivo gas uptake results were most consistent with a mechanism in which inhibition of the metabolizing enzyme (CYP2E1) was presumed to be related to interaction of a reactive DCE metabolite with remaining substrate-bound, active CYP2E1. The kinetics of inhibition by TCE, a weak inhibitor in vitro, were very different from that of the dichloroethylenes. With TCE, parent compound concentrations influenced enzyme loss. Trans-DCE was a more potent inhibitor of CYP2E1 than cis-DCE based on both in vivo and in vitro studies. Quantitative differences in the inhibitory properties of the 1,2-DCE isomers may be due to the different stability of epoxides formed from bioactivation by CYP2E1. Epoxide intermediates of DCE metabolism, reacting by water addition, would yield dialdehyde, a potent cross-linking reagent. PMID:9851676

  20. Multifactorial Comparative Proteomic Study of Cytochrome P450 2E1 Function in Chronic Alcohol Administration

    PubMed Central

    Wang, Yuan; Kou, Yan; Wang, Xiaodong; Cederbaum, Arthur; Wang, Rong

    2014-01-01

    With the use of iTRAQ technique, a multifactorial comparative proteomic study can be performed. In this study, to obtain an overview of ethanol, CYP2E1 and gender effects on liver injury and gain more insight into the underlying molecular mechanism, mouse liver proteomes were quantitatively analyzed using iTRAQ under eight conditions including mice of different genders, wild type versus CYP2E1 knockout, and normal versus alcohol diet. A series of statistical and bioinformatic analyses were explored to simplify and clarify multifactorial comparative proteomic data. First, with the Principle Component analysis, six proteins, CYP2E1, FAM25, CA3, BHMT, HIBADH and ECHS1, involved in oxidation reduction, energy and lipid metabolism and amino acid metabolism, were identified as the most differentially expressed gene products across all of the experimental conditions of our chronic alcoholism model. Second, hierarchical clustering analysis showed CYP2E1 knockout played a primary role in the overall differential protein expression compared with ethanol and gender factors. Furthermore, pair-wise multiple comparisons have revealed that the only significant expression difference lied in wild-type and CYP2E1 knockout mice both treated with ethanol. Third, K-mean clustering analysis indicated that the CYP2E1 knockout had the reverse effect on ethanol induced oxidative stress and lipid oxidation. More importantly, IPA analysis of proteomic data inferred that the gene expressions of two upstream regulators, NRF2 and PPAR?, regulated by chronic alcohol feeding and CYP2E1 knockout, are involved in ethanol induced oxidative stress and lipid oxidation. The present study provides an effectively comprehensive data analysis strategy to compare multiple biological factors, contributing to biochemical effects of alcohol on the liver. The mass spectrometry proteomics data have been deposited to the ProteomeXchange with data set identifier of PXD000635. PMID:24658151

  1. Increased Cytochrome P4502E1 Expression and Altered Hydroxyeicosatetraenoic Acid Formation Mediate Diabetic Vascular Dysfunction

    PubMed Central

    Schäfer, Andreas; Galuppo, Paolo; Fraccarollo, Daniela; Vogt, Christian; Widder, Julian D.; Pfrang, Julia; Tas, Piet; Barbosa-Sicard, Eduardo; Ruetten, Hartmut; Ertl, Georg; Fleming, Ingrid; Bauersachs, Johann

    2010-01-01

    OBJECTIVE We investigated the mechanisms underlying vascular endothelial and contractile dysfunction in diabetes as well as the effect of HMR1766, a novel nitric oxide (NO)-independent activator of soluble guanylyl cyclase (sGC). RESEARCH DESIGN AND METHODS Two weeks after induction of diabetes by streptozotocin, Wistar rats received either placebo or HMR1766 (10 mg/kg twice daily) for another 2 weeks; thereafter, vascular function was assessed. RESULTS Endothelial function and contractile responses were significantly impaired, while vascular superoxide formation was increased in the aortae from diabetic versus healthy control rats. Using RNA microarrays, cytochrome P4502E1 (CYP2E1) was identified as the highest upregulated gene in diabetic aorta. CYP2E1 protein was significantly increased (16-fold) by diabetes, leading to a reduction in levels of the potent vasoconstrictor 20-hydroxy-eicosatetraenoic acid (20-HETE). Induction of CYP2E1 expression in healthy rats using isoniazide mimicked the diabetic noncontractile vascular response while preincubation of aortae from STZ-diabetic rats in vitro with 20-HETE rescued contractile function. Chronic treatment with the sGC activator HMR1766 improved NO sensitivity and endothelial function, reduced CYP2E1 expression and superoxide formation, enhanced 20-HETE levels, and reversed the contractile deficit observed in the diabetic rats that received placebo. CONCLUSIONS Upregulation of CYP2E1 is essentially involved in diabetic vascular dysfunction. Chronic treatment with the sGC activator HMR1766 reduced oxidative stress, decreased CYP2E1 levels, and normalized vasomotor function in diabetic rats. PMID:20522591

  2. Mutation in E1, the Ubiquitin Activating Enzyme, Reduces Drosophila Lifespan and Results in Motor Impairment

    PubMed Central

    Liu, Hsiu-Yu; Pfleger, Cathie M.

    2013-01-01

    Neurodegenerative diseases cause tremendous suffering for those afflicted and their families. Many of these diseases involve accumulation of mis-folded or aggregated proteins thought to play a causal role in disease pathology. Ubiquitinated proteins are often found in these protein aggregates, and the aggregates themselves have been shown to inhibit the activity of the proteasome. These and other alterations in the Ubiquitin Pathway observed in neurodegenerative diseases have led to the question of whether impairment of the Ubiquitin Pathway on its own can increase mortality or if ongoing neurodegeneration alters Ubiquitin Pathway function as a side-effect. To address the role of the Ubiquitin Pathway in vivo, we studied loss-of-function mutations in the Drosophila Ubiquitin Activating Enzyme, Uba1 or E1, the most upstream enzyme in the Ubiquitin Pathway. Loss of only one functional copy of E1 caused a significant reduction in adult lifespan. Rare homozygous hypomorphic E1 mutants reached adulthood. These mutants exhibited further reduced lifespan and showed inappropriate Ras activation in the brain. Removing just one functional copy of Ras restored the lifespan of heterozygous E1 mutants to that of wild-type flies and increased the survival of homozygous E1 mutants. E1 homozygous mutants also showed severe motor impairment. Our findings suggest that processes that impair the Ubiquitin Pathway are sufficient to cause early mortality. Reduced lifespan and motor impairment are seen in the human disease X-linked Infantile Spinal Muscular Atrophy, which is associated with mutation in human E1 warranting further analysis of these mutants as a potential animal model for study of this disease. PMID:23382794

  3. Spectral studies of tert-butyl isothiocyanate-inactivated P450 2E1.

    PubMed

    Kent, U M; Roberts-Kirchhoff, E S; Moon, N; Dunham, W R; Hollenberg, P F

    2001-06-19

    Inactivation of cytochrome P450 2E1 by tert-butyl isothiocyanate (tBITC) resulted in a loss in the spectrally detectable P450-reduced CO complex. The heme prosthetic group does not appear to become modified, since little loss of the heme was observed in the absolute spectra or the pyridine hemochrome spectra, or in the amount of heme recovered from HPLC analysis of the tBITC-inactivated samples. Prolonged incubations of the inactivated P450 2E1 with dithionite and CO resulted in a recovery of both the CO complex and the enzymatic activity. Inactivated samples that were first reduced with dithionite for 1 h prior to CO exposure recovered their CO spectrum to the same extent as samples not pretreated with dithionite, suggesting that the major defect was an inability of the inactivated sample to bind CO. Spectral binding studies with 4-methylpyrazole indicated that the inactivated P450 2E1 had an impaired ability to bind the substrate. Enzymatic activity could not be restored with iodosobenzene as the alternate oxidant. EPR analysis indicated that approximately 24% of the tBITC-inactivated P450 2E1 was EPR-silent. Of the remaining tBITC-inactivated P450 2E1, approximately 45% exhibited an unusual low-spin EPR signal that was attributed to the displacement of a water molecule at the sixth position of the heme by a tBITC modification to the apoprotein. ESI-LC-MS analysis of the inactivated P450 2E1 showed an increase in the mass of the apoprotein of 115 Da. In combination, the data suggest that tBITC inactivated P450 2E1 by binding to a critical active site amino acid residue(s). This modified amino acid(s) presumably acts as the sixth ligand to the heme, thereby interfering with oxygen binding and substrate binding. PMID:11401573

  4. Osteogenic gene expression of murine osteoblastic (MC3T3-E1) cells under cyclic tension

    NASA Astrophysics Data System (ADS)

    Kao, C. T.; Chen, C. C.; Cheong, U.-I.; Liu, S. L.; Huang, T. H.

    2014-08-01

    Low-level laser therapy (LLLT) can promote cell proliferation. The remodeling ability of the tension side of orthodontic teeth affects post-orthodontic stability. The purpose of the present study was to investigate the osteogenic effects of LLLT on osteoblast-like cells treated with a simulated tension system that provides a mechanical tension regimen. Murine osteoblastic (MC3T3-E1) cells were cultured in a Flexcell strain unit with programmed loads of 12% elongation at a frequency of 0.5?Hz for 24 and 48?h. The cultured cells were treated with a low-level diode laser using powers of 5?J and 10?J. The proliferation of MC3T3-E1 cells was determined using the Alamar Blue assay. The expression of osteogenic genes (type I collagen (Col-1), osteopontin (OPN), osteocalcin (OC), osteoprotegerin (OPG), receptor activator of nuclear factor kappa B ligand (RANKL), bone morphologic protein (BMP-2), and bone morphologic protein (BMP-4)) in MC3T3-E1 cells was analyzed using reverse transcription polymerase chain reaction (RT-PCR). The data were analyzed using one-way analysis of variance. The proliferation rate of tension-cultured MC3T3-E1 cells under 5?J and 10?J LLLT increased compared with that of the control group (p < 0.05). Prominent mineralization of the MC3T3-E1 cells was visible using a von Kossa stain in the 5?J LLLT group. Osteogenic genes (Col-1, OC, OPG and BMP-2) were significantly expressed in the MC3T3-E1 cells treated with 5?J and 10?J LLLT (p < 0.05). LLLT in tension-cultured MC3T3-E1 cells showed synergistic osteogenic effects, including increases in cell proliferation and Col-1, OPN, OC, OPG and BMP-2 gene expression. LLLT might be beneficial for bone remodeling on the tension side of orthodontics.

  5. CAPACITY OF SHEAR JOINTS BETWEEN HIGH-STRENGTH PRECAST ELEMENTS AND NORMAL-STRENGTH CAST-IN-PLACE DECKS

    Microsoft Academic Search

    K. Zilch; R. Reinecke

    High-strength concrete precast elements with normal-strength cast-in-place decks are considered to be an economic way of construction, combining the advantages of both materials and the construction process. In this paper the shear joint between the high- strength precast element and the normal-strength concrete is investigated. During the experiments, practicality and the effects of surface preparation were evaluated and different roughening

  6. Adenovirus E1B 19-Kilodalton Protein Modulates Innate Immunity through Apoptotic Mimicry

    PubMed Central

    Grigera, Fernando; Ucker, David S.; Cook, James L.

    2014-01-01

    ABSTRACT Cells that undergo apoptosis in response to chemical or physical stimuli repress inflammatory reactions, but cells that undergo nonapoptotic death in response to such stimuli lack this activity. Whether cells dying from viral infection exhibit a cell death-type modulatory effect on inflammatory reactions is unknown. We compared the effects on macrophage inflammatory responses of cells dying an apoptotic or a nonapoptotic death as a result of adenoviral infection. The results were exactly opposite to the predictions from the conventional paradigm. Cells dying by apoptosis induced by infection with an adenovirus type 5 (Ad5) E1B 19-kilodalton (E1B 19K) gene deletion mutant did not repress macrophage NF-?B activation or cytokine responses to proinflammatory stimuli, whereas cells dying a nonapoptotic death from infection with E1B 19K-competent, wild-type Ad5 repressed these macrophage inflammatory responses as well as cells undergoing classical apoptosis in response to chemical injury. The immunorepressive, E1B 19K-related cell death activity depended upon direct contact of the virally infected corpses with responder macrophages. Replacement of the viral E1B 19K gene with the mammalian Bcl-2 gene in cis restored the nonapoptotic, immunorepressive cell death activity of virally infected cells. These results define a novel function of the antiapoptotic, adenoviral E1B 19K protein that may limit local host innate immune inflammation during accumulation of virally infected cells at sites of infection and suggest that E1B 19K-deleted, replicating adenoviral vectors might induce greater inflammatory responses to virally infected cells than E1B 19K-positive vectors, because of the net effect of their loss-of-function mutation. IMPORTANCE We observed that cells dying a nonapoptotic cell death induced by adenovirus infection repressed macrophage proinflammatory responses while cells dying by apoptosis induced by infection with an E1B 19K deletion mutant virus did not repress macrophage proinflammatory responses and enhanced some cytokine responses. Our results define a new function of the antiapoptotic, adenoviral protein E1B 19K, which we have termed “apoptotic mimicry.” Our studies suggest the possibility that the presence or absence of this E1B 19K function could alter the immunological outcome of both natural and therapeutic adenoviral infections. For example, emerging, highly immunopathogenic adenovirus serotypes might induce increased host inflammatory responses as a result of altered E1B 19K function or expression. It is also possible that engineered variations in E1B 19K expression/function could be created during adenovirus vector design that would increase the therapeutic efficacy of replicating adenovirus vectors for vaccines or oncolytic viral targeting of neoplastic cells. PMID:24352454

  7. 2-Carboxyquinoxalines Kill Mycobacterium tuberculosis through Noncovalent Inhibition of DprE1.

    PubMed

    Neres, João; Hartkoorn, Ruben C; Chiarelli, Laurent R; Gadupudi, Ramakrishna; Pasca, Maria Rosalia; Mori, Giorgia; Venturelli, Alberto; Savina, Svetlana; Makarov, Vadim; Kolly, Gaelle S; Molteni, Elisabetta; Binda, Claudia; Dhar, Neeraj; Ferrari, Stefania; Brodin, Priscille; Delorme, Vincent; Landry, Valérie; de Jesus Lopes Ribeiro, Ana Luisa; Farina, Davide; Saxena, Puneet; Pojer, Florence; Carta, Antonio; Luciani, Rosaria; Porta, Alessio; Zanoni, Giuseppe; De Rossi, Edda; Costi, Maria Paola; Riccardi, Giovanna; Cole, Stewart T

    2015-03-20

    Phenotypic screening of a quinoxaline library against replicating Mycobacterium tuberculosis led to the identification of lead compound Ty38c (3-((4-methoxybenzyl)amino)-6-(trifluoromethyl)quinoxaline-2-carboxylic acid). With an MIC99 and MBC of 3.1 ?M, Ty38c is bactericidal and active against intracellular bacteria. To investigate its mechanism of action, we isolated mutants resistant to Ty38c and sequenced their genomes. Mutations were found in rv3405c, coding for the transcriptional repressor of the divergently expressed rv3406 gene. Biochemical studies clearly showed that Rv3406 decarboxylates Ty38c into its inactive keto metabolite. The actual target was then identified by isolating Ty38c-resistant mutants of an M. tuberculosis strain lacking rv3406. Here, mutations were found in dprE1, encoding the decaprenylphosphoryl-d-ribose oxidase DprE1, essential for biogenesis of the mycobacterial cell wall. Genetics, biochemical validation, and X-ray crystallography revealed Ty38c to be a noncovalent, noncompetitive DprE1 inhibitor. Structure-activity relationship studies generated a family of DprE1 inhibitors with a range of IC50's and bactericidal activity. Co-crystal structures of DprE1 in complex with eight different quinoxaline analogs provided a high-resolution interaction map of the active site of this extremely vulnerable target in M. tuberculosis. PMID:25427196

  8. Cooperative effects for CYP2E1 differ between styrene and its metabolites

    PubMed Central

    Hartman, Jessica H.; Boysen, Gunnar; Miller, Grover P.

    2014-01-01

    Cooperative interactions are frequently observed in the metabolism of drugs and pollutants by cytochrome P450s; nevertheless, the molecular determinants for cooperativity remain elusive. Previously, we demonstrated that steady-state styrene metabolism by CYP2E1 exhibits positive cooperativity.We hypothesized that styrene metabolites have lower affinity than styrene toward CYP2E1 and limited ability to induce cooperative effects during metabolism. To test the hypothesis, we determined the potency and mechanism of inhibition for styrene and its metabolites toward oxidation of 4-nitrophenol using CYP2E1 Supersomes® and human liver microsomes.Styrene inhibited the reaction through a mixed cooperative mechanism with high affinity for the catalytic site (67 ?M) and lower affinity for the cooperative site (1100 ?M), while increasing substrate turnover at high concentrations. Styrene oxide and 4-vinylphenol possessed similar affinity for CYP2E1. Styrene oxide behaved cooperatively like styrene, but 4-vinylphenol decreased turnover at high concentrations. Styrene glycol was a very poor competitive inhibitor. Among all compounds, there was a positive correlation with binding and hydrophobicity.Taken together, these findings for CYP2E1 further validate contributions of cooperative mechanisms to metabolic processes, demonstrate the role of molecular structure on those mechanisms and underscore the potential for heterotropic cooperative effects between different compounds. PMID:23327532

  9. Olive cultivar origin is a major cause of polymorphism for Ole e 1 pollen allergen

    PubMed Central

    Hamman-Khalifa, AbdelMounim; Castro, Antonio Jesús; Jiménez-López, José Carlos; Rodríguez-García, María Isabel; Alché, Juan de Dios

    2008-01-01

    Background Pollens from different olive (Olea europaea L.) cultivars have been shown to differ significantly in their content in Ole e 1 and in their overall allergenicity. This allergen is, in addition, characterized by a high degree of polymorphism in its sequence. The purpose of this study is to evaluate the putative presence of divergences in Ole e 1 sequences from different olive cultivars. Results RNA from pollen individually collected from 10 olive cultivars was used to amplify Ole e 1 sequences by RT-PCR, and the sequences were analyzed by using different bioinformatics tools. Numerous nucleotide substitutions were detected throughout the sequences, many of which resulted in amino acid substitutions in the deduced protein sequences. In most cases variability within a single variety was much lower than among varieties. Key amino acid changes in comparison with "canonical" sequences previously described in the literature included: a) the substitution of C19-relevant to the disulphide bond structure of the protein-, b) the presence of an additional N-glycosylation motif, and c) point substitutions affecting regions of Ole e 1 already described like relevant for the immunogenicity/allergenicity of the protein. Conclusion Varietal origin of olive pollen is a major factor determining the diversity of Ole e 1 variants. We consider this information of capital importance for the optimal design of efficient and safe allergen formulations, and useful for the genetic engineering of modified forms of the allergen among other applications. PMID:18218146

  10. Effects of a collagen matrix containing prostaglandin E(1) on wound contraction.

    PubMed

    Ono, I; Zhou, L J; Tateshita, T

    2001-02-01

    In this study, we evaluated the effectiveness of prostaglandin (PG) E(1) in inhibiting wound contraction, both alone and in combination with collagen matrix, using a in vivo full thickness skin defect model. To clarify the mechanisms involved in this inhibition we also used a fibroblast-populated collagen gel contraction in vitro model. We demonstrated that collagen matrix alone significantly inhibited wound contraction PG E(1) alone did not. Interestingly, their combination was much more effective than either collagen matrix or PG E(1) alone, a finding which was also supported by histopathological examination. Wounds treated with collagen matrix, but not control wounds, showed horizontal rearrangement of collagen fibers in the dermal part as well as evidence of active fibroblast proliferation which was not observed in scar regions surrounded by normal dermis. With the fibroblast-populated collagen gel contraction in vitro model, we found that PG E(1) significantly inhibited contraction at a high dose. It was concluded that collagen matrix combined with PG E(1) is effective for preventing contracture producing so called neodermis than collagen matrix alone, which remains one of the most challenging problems in treating full thickness type wounds. PMID:11164707

  11. Expression and Characterization of Acidothermus celluloyticus E1 Endoglucanase in Transgenic Duckweed Lemna minor 8627

    SciTech Connect

    Sun, Y.; Cheng, J. J.; Himmel, M. E.; Skory, C. D.; Adney, W. S.; Thomas, S. R.; Tisserat, B.; Nishimura, Y.; Yamamoto, Y. T.

    2007-01-01

    Endoglucanase E1 from Acidothermus cellulolyticus was expressed cytosolically under control of the cauliflower mosaic virus 35S promoter in transgenic duckweed, Lemna minor 8627 without any obvious observable phenotypic effects on morphology or rate of growth. The recombinant enzyme co-migrated with the purified catalytic domain fraction of the native E1 protein on western blot analysis, revealing that the cellulose-binding domain was cleaved near or in the linker region. The duckweed-expressed enzyme was biologically active and the expression level was up to 0.24% of total soluble protein. The endoglucanase activity with carboxymethylcellulose averaged 0.2 units mg protein{sup -1} extracted from fresh duckweed. The optimal temperature and pH for E1 enzyme activity were about 80 C and pH 5, respectively. While extraction with HEPES (N-[2-hydroxyethyl]piperazine-N{prime}-[2-ethanesulfonic acid]) buffer (pH 8) resulted in the highest recovery of total soluble proteins and E1 enzyme, extraction with citrate buffer (pH 4.8) at 65 C enriched relative amounts of E1 enzyme in the extract. This study demonstrates that duckweed may offer new options for the expression of cellulolytic enzymes in transgenic plants.

  12. Probabilistic simulation of uncertainties in composite uniaxial strengths

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.; Stock, T. A.

    1990-01-01

    Probabilistic composite micromechanics methods are developed that simulate uncertainties in unidirectional fiber composite strengths. These methods are in the form of computational procedures using composite mechanics with Monte Carlo simulation. The variables for which uncertainties are accounted include constituent strengths and their respective scatter. A graphite/epoxy unidirectional composite (ply) is studied to illustrate the procedure and its effectiveness to formally estimate the probable scatter in the composite uniaxial strengths. The results show that ply longitudinal tensile and compressive, transverse compressive and intralaminar shear strengths are not sensitive to single fiber anomalies (breaks, intergacial disbonds, matrix microcracks); however, the ply transverse tensile strength is.

  13. Explosive Strength Imbalances in Professional Basketball Players

    PubMed Central

    Schiltz, Marc; Lehance, Cédric; Maquet, Didier; Bury, Thierry; Crielaard, Jean-Michel; Croisier, Jean-Louis

    2009-01-01

    Context: Despite the high rate of lower limb injuries in basketball players, studies of the dominant-limb effect in elite athletes often neglect injury history. Objective: To determine lower limb explosive-strength asymmetries in professional basketball players compared with junior basketball players and control participants. Design: Cohort study. Setting: Academic medical institution. Patients or Other Participants: 15 professional basketball players, 10 junior basketball players, and 20 healthy men. Main Outcome Measure(s): We performed an isokinetic examination to evaluate the knee extensor (Ext) and flexor (Fl) concentric peak torque at 60°·s?1 and 240°·s?1 and (Fl only) eccentric peak torque at 30°·s?1 and 120°·s?1. Functional evaluation included countermovement jump, countermovement jump with arms, 10-m sprint, single-leg drop jump, and single-leg, 10-second continuous jumping. Variables were compared among groups using analysis of variance or a generalized linear mixed model for bilateral variables. Results: The 2 groups of basketball players demonstrated better isokinetic and functional performances than the control group did. No differences in functional or relative isokinetic variables were noted between professional and junior basketball players. Professional players with a history of knee injury failed to reach normal knee extensor strength at 60°·s?1. Knee Ext (60°·s?1) and Fl (eccentric 120°·s?1) torque values as well as 10-second continuous jumping scores were higher in those professional players without a history of knee injury than those with such a history. Compared with the group without a history of knee injury, the group with a history of knee injury maintained leg asymmetry ratios greater than 10% for almost all isokinetic variables and more than 15% for unilateral functional variables. Conclusions: The relative isokinetic and functional performances of professional basketball players were similar to those of junior players, with no dominant-side effect. A history of knee injury in the professional athlete, however, was reflected in bilateral isokinetic and functional asymmetries and should be considered in future studies of explosive strength. PMID:19180217

  14. A fracture criterion for the notch strength of high strength steels in the presence of hydrogen

    NASA Astrophysics Data System (ADS)

    Ayas, C.; Deshpande, V. S.; Fleck, N. A.

    2014-02-01

    High strength steels can suffer from a loss of ductility when exposed to hydrogen, and this may lead to sudden failure. The hydrogen is either accommodated in the lattice or is trapped at defects, such as dislocations, grain boundaries and carbides. The challenge is to identify the effect of hydrogen located at different sites upon the drop in tensile strength of a high strength steel. For this purpose, literature data on the failure stress of notched and un-notched steel bars are re-analysed; the bars were tested over a wide range of strain rates and hydrogen concentrations. The local stress state at failure has been determined by the finite element (FE) method, and the concentration of both lattice and trapped hydrogen is predicted using Oriani's theory along with the stress-driven diffusion equation. The experimental data are rationalised in terms of a postulated failure locus of peak maximum principal stress versus lattice hydrogen concentration. This failure locus is treated as a unique material property for the given steel and heat treatment condition. We conclude that the presence of lattice hydrogen increases the susceptibility to hydrogen embrittlement whereas trapped hydrogen has only a negligible effect. It is also found that the observed failure strength of hydrogen charged un-notched bars is less than the peak local stress within the notched geometries. Weakest link statistics are used to account for this stressed volume effect.

  15. Dynamics of cytochrome P4502E1 activity in man: induction by ethanol and disappearance during withdrawal phase

    Microsoft Academic Search

    Carl M Oneta; Charles S Lieber; JunJie Li; Sigmund Rüttimann; Beat Schmid; Jürg Lattmann; Alan S Rosman; Helmut K Seitz

    2002-01-01

    Background\\/Aims: Chronic ethanol consumption results in the induction of hepatic cytochrome P4502E1 (CYP2E1) in man, which is believed to play an important role in the pathogenesis of alcoholic liver disease. However, the amount and duration of alcohol intake associated with CYP2E1 induction is not known but limited information is available on the disappearance of CYP2E1 following alcohol withdrawal.Methods: To study

  16. Performance of An Adjustable Strength Permanent Magnet Quadrupole

    SciTech Connect

    Gottschalk, S.C.; DeHart, T.E.; Kangas, K.W.; /STI Optronics, Bellevue; Spencer, C.M.; /SLAC; Volk, J.T.; /Fermilab

    2006-03-01

    An adjustable strength permanent magnet quadrupole suitable for use in Next Linear Collider has been built and tested. The pole length is 42cm, aperture diameter 13mm, peak pole tip strength 1.03Tesla and peak integrated gradient * length (GL) is 68.7 Tesla. This paper describes measurements of strength, magnetic CL and field quality made using an air bearing rotating coil system. The magnetic CL stability during -20% strength adjustment proposed for beam based alignment was < 0.2 microns. Strength hysteresis was negligible. Thermal expansion of quadrupole and measurement parts caused a repeatable and easily compensated change in the vertical magnetic CL. Calibration procedures as well as CL measurements made over a wider tuning range of 100% to 20% in strength useful for a wide range of applications will be described. The impact of eddy currents in the steel poles on the magnetic field during strength adjustments will be reported.

  17. Adhesion Strength of HVOF Sprayed IN718 Coatings

    NASA Astrophysics Data System (ADS)

    Lyphout, Christophe; Nylen, Per; Östergren, Lars Gösta

    2012-01-01

    The adhesion strength of high-velocity oxyfuel thermally sprayed coatings is of prime importance when thick coatings are to be sprayed in repair applications. In this study, relationships between process parameters, particle in-flight characteristics, residual stresses, and adhesion strength were explored. The most important process parameters that influence HVOF sprayed IN718 coating adhesion strength on IN718 substrate material were identified. Residual stress distributions were determined using the modified layer removal method, and adhesion strength was measured using an in-house-developed tensile test. Relationships between process parameters, particle in-flight characteristics, coating microstructure, and adhesion strength were established. Particle temperature, particle velocity, substrate preparation, and deposition temperature were identified as critical parameters to attain high adhesion strength. Controlling these parameters can significantly improve the adhesion strength, thus enabling thick coatings to be sprayed for repair applications.

  18. Self-perceived strengths among people who are homeless.

    PubMed

    Tweed, Roger G; Biswas-Diener, Robert; Lehman, Darrin R

    2012-11-01

    This study examined self-perceived strengths among 116 people who were homeless. Those who had experienced a longer period of current homelessness tended to report fewer personal strengths (r = -0.23). Nonetheless, in spite of their marginalized position in society, the vast majority of participants (114 out of 116) perceived personal strengths. A prior diagnosis with mental illness was not associated with the number of strengths reported, but self-perception of strengths was associated with altruistic orientation. The Values in Action (VIA) taxonomy of character strengths captured many of the responses generated by this population. The most frequently mentioned character categories included social intelligence, kindness, persistence, authenticity and humour. The most frequently mentioned other strengths included personal skills (e.g. music, sports), job skills, intelligence and education. The results have relevance for efforts to build self-perceptions that facilitate escape from homelessness. PMID:23173008

  19. Climate strength: a new direction for climate research.

    PubMed

    Schneider, Benjamin; Salvaggio, Amy Nicole; Subirats, Montse

    2002-04-01

    Climate strength was conceptualized within D. Chan's (1998) discussion of compositional models and the concept of culture strength from the organizational culture literature. Climate strength was operationalized in terms of within-group variability in climate perceptions-the less within-group variability, the stronger the climate. The authors studied climate strength in the context of research linking employee service climate perceptions to customer satisfaction. The hypothesis was tested that climate strength moderates the relationship between employee perceptions of service climate and customer satisfaction experiences. Partial support for the hypothesis was reported in both a concurrent and predictive (3-year) test across 118 branches of a bank. In the predictive study only the interaction of climate and climate strength predicted customer satisfaction. Implications for future research on climate and climate strength are discussed. PMID:12002951

  20. Community needs and strengths assessments as an active learning project.

    PubMed

    Misra, Ranjita; Ballard, Danny

    2003-09-01

    The Community Needs and Strengths Assessment Project (CNSAP) incorporated development of needs and strengths assessment research into an undergraduate Community Health course as an active learning project--one of seven principles for effective practice in undergraduate education. Community needs and strengths assessments prove useful to health educators primarily in planning programs and promoting effective public relations. Assessments also help to identify and diagnose health problems and to evaluate programs. Through the CNSAP students completed a process health educators use to identify gaps between current and required programs and to prioritize assets and resources based on community needs and strengths. The CNSAP focused on mastery of four skills required for completing a needs and strengths assessment: identifying data sources, conducting primary data collection from a target audience, analyzing data and prioritizing identified needs and strengths, and abstracting information concisely. The project, which included substantial community involvement, helped students identify needs and strengths necessary for addressing community health problems and concerns. PMID:14513630