WorldWideScience

Sample records for superposed strain time

  1. Superposed epoch analysis of storm time response of the ionosphere-thermosphere (IT) system

    Science.gov (United States)

    Oliveira, D. M.; Zesta, E.; Connor, H.; Su, Y. J.; Sutton, E. K.; Huang, C. Y.; Ober, D. M.; Delay, S. H.; Schuck, P. W.

    2015-12-01

    The thermosphere-ionosphere system response to energy input by Joule heating via Poynting flux and auroral precipitation is strongly intensified during times with high geomagnetic activity or during geomagnetic storms. The most dramatic thermospheric response is the intensification and upwelling of the thermospheric mass density. The neutral mass density is not only a key parameter to understanding the solar wind - IT coupling, but also plays an important role in understanding satellite orbital drag, which in turn impacts satellite position predictions. Results of numerical simulations and satellite observations (CHAMP and GRACE) have shown that the neutral mass density is rapidly intensified (within minutes) after the initial storm shock impact and also after the onset of storm main phase. This almost immediate response is typical of CME-driven storms in which the neutral density is enhanced first in the dayside polar cap and the intensification subsequently spreads out to all magnetic local time regions and lower latitude regions. We perform a superposed epoch analysis using CHAMP and GRACE satellite data as well as DMSP data to study the spatial and temporal distribution of the measured Poynting flux and neutral density response during the main phase of storms of different intensity. We also examine the correlation characteristics between Poynting flux and neutral density response, in space and time during the storm.

  2. Mixed convection in fluid superposed porous layers

    CERN Document Server

    Dixon, John M

    2017-01-01

    This Brief describes and analyzes flow and heat transport over a liquid-saturated porous bed. The porous bed is saturated by a liquid layer and heating takes place from a section of the bottom. The effect on flow patterns of heating from the bottom is shown by calculation, and when the heating is sufficiently strong, the flow is affected through the porous and upper liquid layers. Measurements of the heat transfer rate from the heated section confirm calculations. General heat transfer laws are developed for varying porous bed depths for applications to process industry needs, environmental sciences, and materials processing. Addressing a topic of considerable interest to the research community, the brief features an up-to-date literature review of mixed convection energy transport in fluid superposed porous layers.

  3. Indeterminacy points for superposed Yukawa and Gauss potentials

    Energy Technology Data Exchange (ETDEWEB)

    Choubey, J.; Sharma, L.K. (Government Engineering Coll., Jabalpur (India). Dept. of Applied Physics)

    1981-04-01

    Eigenenergy expansion for the superposition of Yukawa and Gauss potentials for calculating the first indeterminacy points is derived. Behaviour of Regge trajectories for the superposed potential is also studied.

  4. Temporal stability of superposed magnetic fluids in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Zakaria, Kadry; Sirwah, Magdy A; Alkharashi, Sameh [Mathematics Department, Faculty of Science, Tanta University, Tanta (Egypt)

    2008-02-15

    The present work deals with the stability properties of time periodically streaming superposed magnetic fluids through porous media under the influence of an oblique alternating magnetic field. The system is composed of a middle fluid sheet of finite thickness embedded between two other bounded layers. The fluids are assumed to be incompressible and there are no volume charges in the layers of the fluids. Such configurations are of relevance in a variety of astrophysical and space configurations. The solutions of the linearized equations of motion and boundary conditions lead to deriving two more general simultaneous Mathieu equations of damping terms with complex coefficients. The method of multiple time scales is used to obtain approximate solutions and analyze the stability criteria for both the non-resonant and resonant cases and hence transition curves are obtained for such cases. The stability criteria are examined theoretically and numerically from which stability diagrams are obtained. It is found that the fluid sheet thickness plays a destabilizing role in the presence of a constant field and velocity, while the damping role is observed for the resonant cases. Dual roles are observed for the fluid velocity and the porosity in the stability criteria.

  5. The worst moment of superposed surge wave in upstream series double surge tanks of hydropower station

    Science.gov (United States)

    Teng, Y.; Yang, J. D.; Guo, W. C.; Chen, J. P.

    2016-11-01

    It is a consensus to consider the superposed working conditions when calculating the surge wave in surge tank of hydropower station with long diversion tunnel. For the hydropower station with single surge tank, the method of determining the worst superposed moment is mature. However, for the hydropower station with upstream series double surge tanks, research in this field is still blank. Based on an engineering project, this paper investigated the worst moments and the control superposed working conditions about the maximum surge level and the minimum surge level of upstream series double surge tanks using numerical simulation. In addition, the incidence relations between the worst moment of superposed surge wave and the different areal array and distance between the two surge tanks are also carried out. The results showed that: With the decrease of the distance between auxiliary surge tank and upstream reservoir, the maximum values of the highest surge levels in the two surge tanks always reach close to but a little earlier than the bigger one time when the inflowing discharges of the two surge tanks reach the maximum. It is similar to the minimum values of lowest surge levels in the two surge tanks which also reach close to but a little later than the bigger one time when the outflowing discharges of the two surges reach the maximum. Moreover, the closer the area of auxiliary surge tank to the area of main surge tank is, the closer the worst moment to the bigger one time when inflow or outflow of the two surges reach the maximum will become.

  6. Phase retrieval for superposed signals from multiple binary objects

    DEFF Research Database (Denmark)

    Alpers, Andreas; Herman, Gabor T.; Poulsen, Henning Friis

    2010-01-01

    We introduce the binary superposed phase retrieval problem that aims at reconstructing multiple 0/1-valued functions with nonoverlapping bounded supports from moduli of superpositions of several displaced copies of their individual Fourier transforms. We discuss an application in coherent diffrac...... diffraction imaging of crystalline objects, propose two algorithms, and evaluate their performance by means of simulations. © 2010 Optical Society of America...

  7. Job strain and time to pregnancy

    DEFF Research Database (Denmark)

    Hjollund, N H; Jensen, Tina Kold; Bonde, J P

    1998-01-01

    The association between fertility and job strain defined as high job demands and low job control has not previously been studied. A follow-up study was conducted with prospective collection of information on job strain among women, achievement of pregnancy, and potential confounding variables....

  8. Job strain and time to pregnancy

    DEFF Research Database (Denmark)

    Hjollund, N H; Kold Jensen, T; Bonde, Jens Peter;

    1998-01-01

    The association between fertility and job strain defined as high job demands and low job control has not previously been studied. A follow-up study was conducted with prospective collection of information on job strain among women, achievement of pregnancy, and potential confounding variables....

  9. Comparison of Thermal Creep Strain Calculation Results Using Time Hardening and Strain Hardening Rules

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Junehyung; Cheon, Jinsik; Lee, Byoungoon; Lee, Chanbock [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    One of the design criteria for the fuel rod in PGSFR is the thermal creep strain of the cladding, because the cladding is exposed to a high temperature for a long time during reactor operation period. In general, there are two kind of calculation scheme for thermal creep strain: time hardening and strain hardening rules. In this work, thermal creep strain calculation results for HT9 cladding by using time hardening and strain hardening rules are compared by employing KAERI's current metallic fuel performance analysis code, MACSIS. Also, thermal creep strain calculation results by using ANL's metallic fuel performance analysis code, LIFE-METAL which adopts strain hardening rule are compared with those by using MACSIS. Thermal creep strain calculation results for HT9 cladding by using time hardening and strain hardening rules were compared by employing KAERI's current metallic fuel performance analysis code, MACSIS. Also, thermal creep strain calculation results by using ANL's metallic fuel performance analysis code, LIFE-METAL which adopts strain hardening rule were compared with those by using MACSIS. Tertiary creep started earlier in time hardening rule than in strain hardening rule. Also, calculation results by MACSIS with strain hardening and those obtained by using LIFE-METAL were almost identical to each other.

  10. Fiber-guided modes conversion using superposed helical gratings

    Science.gov (United States)

    Ma, Yancheng; Fang, Liang; Wu, Guoan

    2017-03-01

    Optical fibers can support various modal forms, including vector modes, linear polarization (LP) modes, and orbital angular momentum (OAM) modes, etc. The modal correlation among these modes is investigated via Jones matrix, associated with polarization and helical phase corresponding to spin angular momentum (SAM) and OAM of light, respectively. We can generate different modal forms by adopting superposed helical gratings (SHGs) with opposite helix orientations. Detailed analysis and discussion on mode conversion is given as for mode coupling in optical fibers with both low and high contrast index, respectively. Our study may deepen the understanding for various fiber-guided modes and mode conversion among them via fiber gratings.

  11. Mechanism of petroleum migration and accumulation in western China's superposed basins

    Institute of Scientific and Technical Information of China (English)

    Kang Yongshang; Li Peijun; Qi Xuefeng; Wen Yonghong; Li Shuijing

    2012-01-01

    In western China.most petroliferous basins are superposed due to their multi-periodic tectonic evolution,and the mechanisms of petroleum migration and accumulation are so complex that much more sophisticated methodologies are necessary for depiction of these mechanisms and identification of petroleum occurrences.For this purpose,in this article,a new methodology was formulated which includes:(1) vertical identification of petroleum migration and accumulation fluid dynamic systems in the superposed basins;(2) analysis of the effect of large scale regional faults and fault combinations on the fluids exchange between the vertically identified different systems;(3) analysis of petroleum migration and accumulation in each vertically identified system,and establishment of appropriate geological model of petroleum migration and accumulation for each vertically identified system.Using this methodology,the satisfactory results obtained in the Lunnan Uplift of Tarim Basin and Ludong Uplift of Jungar Basin case studies are:(1) existence of different vertical fluid dynamic systems in western China's superposed basins which are very necessary for understanding the mechanism of petroleum migration and accumulation;(2) in deep system,long-distance lateral petroleum migration and accumulation mainly take place along the long time exposed unconformity with weathered,fractured or karst reservoir rocks;(3) regional faults are the main conducts for fluids migration from deep system up to middle and/or upper systems.As to middle and/or upper systems,regional faults play a role of "petroleum source".Small faults within middle and/or upper systems conduct petroleum to carrier beds with less impeding force;(4) petroleum migrated from deep system vertically up to middle and/or upper systems will migrate laterally in carrier beds of these systems and accumulate to form pools near or far from faults.

  12. Restoring paleomagnetic data in complex superposed folding settings: The Boltaña anticline (Southern Pyrenees)

    Science.gov (United States)

    Mochales, T.; Pueyo, E. L.; Casas, A. M.; Barnolas, A.

    2016-03-01

    Complex kinematic scenarios in fold-and-thrust belts often produce superposed and non-coaxial folding. Interpretation of primary linear indicators must be based on a careful restoration to the undeformed stage following the reverse order of the deformation events. Therefore, sequential restoration to the ancient coordinate system is of key importance to obtain reliable kinematic interpretations using paleomagnetic data. In this paper, a new paleomagnetic study in the western flank of the Boltaña anticline (Southern Pyrenees) illustrates a case study of a complex tectonic setting having superposed, non-coaxial folds. The first stage of NW-SE folding linked to the oblique Boltaña anticline took place during Lutetian times. The second stage was linked to the vertical axis rotation and placed the Boltaña anticline in its present-day N-S configuration. Our data support a long-lasting Lutetian to Priabonian period with main rotational activity during the Bartonian-Priabonian; other authors support a VAR coeval with anticlinal growth. The third stage resulted in southwards tilting related to the emplacement of the N120E striking Guarga basement thrust (Oligocene-Early Miocene). Based on this deformational history, a sequential restoration was applied and compared with the classic bedding correction. At the site scale, single bedding correction gives errors ranging between 31° and - 31° in the estimation of vertical axis rotations. At the locality scale, in sites grouped in three folds (from W to E Arbella, Planillo and San Felizes), the bedding corrected data display rotation values in accordance with those found in the Ainsa Basin by other authors. Sequential restoration (based on the afore-mentioned evolution in three-steps) improves both some locality-means and the internal consistency of the data. Therefore, reasonably-constrained sequential restoration becomes essential to reconstruct the actual history of superposed folding areas.

  13. Delay time and Hartman effect in strain engineered graphene

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xi, E-mail: xchen@shu.edu.cn; Deng, Zhi-Yong [Department of Physics, Shanghai University, 200444 Shanghai (China); Ban, Yue, E-mail: yban@shu.edu.cn [Department of Electronic Information Materials, Shanghai University, 200444 Shanghai (China)

    2014-05-07

    Tunneling times, including group delay and dwell time, are studied for massless Dirac electrons transmitting through a one-dimensional barrier in strain-engineered graphene. The Hartman effect, the independence of group delay on barrier length, is induced by the strain effect, and associated with the transmission gap and the evanescent mode. The influence of barrier height/length and strain modulus/direction on the group delay is also discussed, which provides the flexibility to control the group delay with applications in graphene-based devices. The relationship between group delay and dwell time is finally derived to clarify the nature of the Hartman effect.

  14. Time-dependent strains and stresses in a pumpkin balloon

    Science.gov (United States)

    Gerngross, T.; Xu, Y.; Pellegrino, S.

    This paper presents a study of pumpkin-shaped superpressure balloons consisting of gores made from a thin polymeric film attached to high stiffness meridional tendons This type of design is being used for the NASA ULDB balloons The gore film shows considerable time-dependent stress relaxation whereas the behaviour of the tendons is essentially time-independent Upon inflation and pressurization the instantaneous i e linear-elastic strain and stress distributions in the film show significantly higher values in the meridional direction However over time and due to the biaxial visco-elastic stress relaxation of the the gore material the em hoop strains increase and the em meridional stresses decrease whereas the em remaining strain and stress components remain substantially unchanged These results are important for a correct assessment of the structural integrity of a pumpkin balloon in a long-duration mission both in terms of the material performance and the overall stability of the shape of the balloon An experimental investigation of the time dependence of the biaxial strain distribution in the film of a 4 m diameter 48 gore pumpkin balloon is presented The inflated shape of selected gores has been measured using photogrammetry and the time variation in strain components at some particular points of these gores has been measured under constant pressure and temperature The results show good correlation with a numerical study using the ABAQUS finite-element package that includes a widely used model of

  15. Experimentally superposing two pure states with partial prior knowledge

    Science.gov (United States)

    Li, Keren; Long, Guofei; Katiyar, Hemant; Xin, Tao; Feng, Guanru; Lu, Dawei; Laflamme, Raymond

    2017-02-01

    Superposition, arguably the most fundamental property of quantum mechanics, lies at the heart of quantum information science. However, how to create the superposition of any two unknown pure states remains as a daunting challenge. Recently, it was proved that such a quantum protocol does not exist if the two input states are completely unknown, whereas a probabilistic protocol is still available with some prior knowledge about the input states [M. Oszmaniec et al., Phys. Rev. Lett. 116, 110403 (2016), 10.1103/PhysRevLett.116.110403]. The knowledge is that both of the two input states have nonzero overlaps with some given referential state. In this work, we experimentally realize the probabilistic protocol of superposing two pure states in a three-qubit nuclear magnetic resonance system. We demonstrate the feasibility of the protocol by preparing a families of input states, and the average fidelity between the prepared state and expected superposition state is over 99%. Moreover, we experimentally illustrate the limitation of the protocol that it is likely to fail or yields very low fidelity, if the nonzero overlaps are approaching zero. Our experimental implementation can be extended to more complex situations and other quantum systems.

  16. Analysis of the tensile stress-strain behavior of elastomers at constant strain rates. I - Criteria for separability of the time and strain effects

    Science.gov (United States)

    Hong, S. D.; Fedors, R. F.; Schwarzl, F.; Moacanin, J.; Landel, R. F.

    1981-01-01

    A theoretical analysis of the tensile stress-strain relation of elastomers at constant strain rate is presented which shows that the time and the stress effect are separable if the experimental time scale coincides with a segment of the relaxation modulus that can be described by a single power law. It is also shown that time-strain separability is valid if the strain function is linearly proportional to the Cauchy strain, and that when time-strain separability holds, two strain-dependent quantities can be obtained experimentally. In the case where time and strain effect are not separable, superposition can be achieved only by using temperature and strain-dependent shift factors.

  17. Interfacial instabilities in a stratified flow of two superposed fluids

    Science.gov (United States)

    Schaflinger, Uwe

    1994-06-01

    Here we shall present a linear stability analysis of a laminar, stratified flow of two superposed fluids which are a clear liquid and a suspension of solid particles. The investigation is based upon the assumption that the concentration remains constant within the suspension layer. Even for moderate flow-rates the base-state results for a shear induced resuspension flow justify the latter assumption. The numerical solutions display the existence of two different branches that contribute to convective instability: long and short waves which coexist in a certain range of parameters. Also, a range exists where the flow is absolutely unstable. That means a convectively unstable resuspension flow can be only observed for Reynolds numbers larger than a lower, critical Reynolds number but still smaller than a second critical Reynolds number. For flow rates which give rise to a Reynolds number larger than the second critical Reynolds number, the flow is absolutely unstable. In some cases, however, there exists a third bound beyond that the flow is convectively unstable again. Experiments show the same phenomena: for small flow-rates short waves were usually observed but occasionally also the coexistence of short and long waves. These findings are qualitatively in good agreement with the linear stability analysis. Larger flow-rates in the range of the second critical Reynolds number yield strong interfacial waves with wave breaking and detached particles. In this range, the measured flow-parameters, like the resuspension height and the pressure drop are far beyond the theoretical results. Evidently, a further increase of the Reynolds number indicates the transition to a less wavy interface. Finally, the linear stability analysis also predicts interfacial waves in the case of relatively small suspension heights. These results are in accordance with measurements for ripple-type instabilities as they occur under laminar and viscous conditions for a mono-layer of particles.

  18. Fisson-track constrains on superposed folding in the Beishan orogenic belt, southernmost Altaids

    Directory of Open Access Journals (Sweden)

    Zhonghua Tian

    2016-03-01

    Full Text Available The Hongyanjing inter-arc basin, is located at the central part of Beishan Orogenic College (BOC, Gansu Province, northwest China. Thick sequences of Permian sediments were strongly folded, forming extremely spectacular superposed folds. To better understand the thermal history of Hongyanjing inter-arc basin and to potentially constrain the timing of deformation, apatite fission track thermochronology method was applied on two superposed folds in the Hongyanjing Basin. Samples from the basin, yield central AFT ages ranging from ∼206 to 118 Ma. AFT peak ages were largely consistent between samples and can divided into three groups: 245, 204–170 and 112–131 Ma. Subsequent thermal history modeling of the samples from the Hongyanjing Basin can be summarized as follows: (1 thermal reheating by sedimentary burial at ∼ 260 to ∼220 Ma; (2 major cooling from ∼220 to ∼180 Ma; (3 an episode of very slow subsequent cooling from ∼180 to 65 Ma (∼80 °C to present-day outcrop temperatures. Sediments in the Hongyanjing Basin were folded forming F1 fold during the early to late Triassic (∼240–∼220 Ma, by regional stress, and at the time that the adjacent Xingxingxia shear zone started to become active. It is further suggested that the F2 folding occurred at ∼225–219 Ma. The deformation age of F2 should be extended to 180 Ma based on our thermal history modeling for the Hongyanjing Basin, which show a rapid exhumation and cooling at the late Triassic to early Jurassic (∼220–∼180 Ma. In our interpretations, the F1 folding is therefore thought to be related to the final closure of the Paleo-Asian Ocean, while the F2 folding occurred at ∼225–180 Ma associated with a major pulse of orogenesis in the BOC.

  19. Superposed epoch study of ICME sub-structures near Earth and their effects on galactic cosmic rays

    CERN Document Server

    Masías-Meza, J J; Démoulin, P; Rodriguez, L; Janvier, M

    2016-01-01

    Interplanetary coronal mass ejections (ICMEs) are the interplanetary manifestations of solar eruptions. The overtaken solar wind forms a sheath of compressed plasma at the front of ICMEs. Magnetic clouds (MCs) are a subset of ICMEs with specific properties (e.g. the presence of a flux rope). When ICMEs pass near Earth, ground observations indicate that the flux of galactic cosmic rays (GCRs) decreases. The main aims of this paper are to find: common plasma and magnetic properties of different ICME sub-structures, and which ICME properties affect the flux of GCRs near Earth. We use a superposed epoch method applied to a large set of ICMEs observed \\insitu\\ by the spacecraft ACE, between 1998 and 2006. We also apply a superposed epoch analysis on GCRs time series observed with the McMurdo neutron monitors. We find that slow MCs at 1 AU have on average more massive sheaths. We conclude that it is because they are more effectively slowed down by drag during their travel from the Sun. Slow MCs also have a more sym...

  20. The behavior of high-strength unidirectional composites under tension with superposed hydrostatic pressure

    NARCIS (Netherlands)

    Zinoviev, P.A.; Tsvetkov, S.V.; Kulish, G.G.; Berg, van den R.W.; Schepdael, van L.J.M.M.

    2001-01-01

    Three types of high-strength unidirectional composite materials were studied under longitudinal tension with superposed high hydrostatic pressure. Reinforcing fibers were T1000G carbon, S2 glass and Zylon PBO fibers; the Ciba 5052 epoxy resin was used as matrix. The composites were tested under exte

  1. A superposed epoch study of the effects of solar wind stream interface events on the upper mesospheric and lower thermospheric temperature

    Science.gov (United States)

    Ogunjobi, O.; Sivakumar, V.; Sivla, W. T.

    2014-11-01

    The response of mesosphere and lower thermosphere (MLT) temperature to energetic particle precipitation over the Earth’s polar regions is not uniform due to complex phenomena within the MLT environment. Nevertheless, the modification of MLT temperatures may require an event-based study to be better observed. This work examines the influence of precipitation, triggered by solar wind stream interfaces (SI) event from 2002 to 2007, on polar MLT temperature. We first test the relationship between the ionospheric absorption measured by the SANAE IV (South African National Antarctic Expedition IV) riometer and the layer of energetic particle precipitation from POES (Polar Orbiting Environmental Satellites). The combined particle measurements from POES 15, 16, 17 and 18 were obtained close in time to the pass of the SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) temperature retrieval. Here, a superposed epoch technique is described and implemented to obtain average temperature profiles during SI-triggered particle precipitation. The superposed epoch average shows no significant temperature decrease below 100 km prior to the onset of SI-triggered precipitation, whereas a clear superposed average temperature decrease is observed at 95 km after the SI impact. A case study of SI event also yields similar observations. Results indicate that cooling effects due to the production of mesospheric odd hydrogen might be major contributors to temperature decrease under compressed solar wind stream.

  2. Natural convection in superposed fluid-porous layers

    CERN Document Server

    Bagchi, Aniruddha

    2013-01-01

    Natural Convection in Composite Fluid-Porous Domains provides a timely overview of the current state of understanding on the phenomenon of convection in composite fluid-porous layers. Natural convection in horizontal fluid-porous layers has received renewed attention because of engineering problems such as post-accident cooling of nuclear reactors, contaminant transport in groundwater, and convection in fibrous insulation systems. Because applications of the problem span many scientific domains, the book serves as a valuable resource for a wide audience.

  3. Lunar Impact Basins: Stratigraphy, Sequence and Ages from Superposed Impact Crater Populations Measured from Lunar Orbiter Laser Altimeter (LOLA) Data

    Science.gov (United States)

    Fassett, C. I.; Head, J. W.; Kadish, S. J.; Mazarico, E.; Neumann, G. A.; Smith, D. E.; Zuber, M. T.

    2012-01-01

    Impact basin formation is a fundamental process in the evolution of the Moon and records the history of impactors in the early solar system. In order to assess the stratigraphy, sequence, and ages of impact basins and the impactor population as a function of time, we have used topography from the Lunar Orbiter Laser Altimeter (LOLA) on the Lunar Reconnaissance Orbiter (LRO) to measure the superposed impact crater size-frequency distributions for 30 lunar basins (D = 300 km). These data generally support the widely used Wilhelms sequence of lunar basins, although we find significantly higher densities of superposed craters on many lunar basins than derived by Wilhelms (50% higher densities). Our data also provide new insight into the timing of the transition between distinct crater populations characteristic of ancient and young lunar terrains. The transition from a lunar impact flux dominated by Population 1 to Population 2 occurred before the mid-Nectarian. This is before the end of the period of rapid cratering, and potentially before the end of the hypothesized Late Heavy Bombardment. LOLA-derived crater densities also suggest that many Pre-Nectarian basins, such as South Pole-Aitken, have been cratered to saturation equilibrium. Finally, both crater counts and stratigraphic observations based on LOLA data are applicable to specific basin stratigraphic problems of interest; for example, using these data, we suggest that Serenitatis is older than Nectaris, and Humboldtianum is younger than Crisium. Sample return missions to specific basins can anchor these measurements to a Pre-Imbrian absolute chronology.

  4. Superposed epoch study of ICME sub-structures near Earth and their effects on Galactic cosmic rays

    Science.gov (United States)

    Masías-Meza, J. J.; Dasso, S.; Démoulin, P.; Rodriguez, L.; Janvier, M.

    2016-08-01

    Context. Interplanetary coronal mass ejections (ICMEs) are the interplanetary manifestations of solar eruptions. The overtaken solar wind forms a sheath of compressed plasma at the front of ICMEs. Magnetic clouds (MCs) are a subset of ICMEs with specific properties (e.g. the presence of a flux rope). When ICMEs pass near Earth, ground observations indicate that the flux of Galactic cosmic rays (GCRs) decreases. Aims: The main aims of this paper are to find common plasma and magnetic properties of different ICME sub-structures and which ICME properties affect the flux of GCRs near Earth. Methods: We used a superposed epoch method applied to a large set of ICMEs observed in situ by the spacecraft ACE, between 1998 and 2006. We also applied a superposed epoch analysis on GCRs time series observed with the McMurdo neutron monitors. Results: We find that slow MCs at 1 AU have on average more massive sheaths. We conclude that this is because they are more effectively slowed down by drag during their travel from the Sun. Slow MCs also have a more symmetric magnetic field and sheaths expanding similarly as their following MC, while in contrast, fast MCs have an asymmetric magnetic profile and a sheath in compression. In all types of MCs, we find that the proton density and the temperature and the magnetic fluctuations can diffuse within the front of the MC due to 3D reconnection. Finally, we derive a quantitative model that describes the decrease in cosmic rays as a function of the amount of magnetic fluctuations and field strength. Conclusions: The obtained typical profiles of sheath, MC and GCR properties corresponding to slow, middle, and fast ICMEs, can be used for forecasting or modelling these events, and to better understand the transport of energetic particles in ICMEs. They are also useful for improving future operative space weather activities.

  5. Painful scoliosis due to superposed giant cell bone tumor and aneurysmal bone cyst in a child.

    Science.gov (United States)

    Togral, Guray; Arikan, Murat; Hasturk, Askin E; Gungor, Safak

    2014-07-01

    Giant cell bone tumors are the most common precursor lesions of aneurysmal bone cysts (ABCs) developing secondarily. In giant cell bone tumors containing an explicit ABC component, the observation of the solid component of the giant cell bone tumor plays a critical role in the separation of the primary ABC. In general, ABC cases together with giant cell tumors in the bone are diagnosed histopathologically. The combination of giant cell bone tumor with superposed ABC and that of painful scoliosis with backache is rarely seen in children. In this case study, we discussed the diagnosis and the treatment of a giant cell tumor and superposed an ABC present in the fifth lumbar spine in a pediatric patient admitted to our clinic with a complaint of acute scoliotic back pain.

  6. Flow non-normality-induced transient growth in superposed Newtonian and non-Newtonian fluid layers

    OpenAIRE

    Ridolfi, Luca; Camporeale, Carlo Vincenzo

    2009-01-01

    In recent years non-normality and transient growths have attracted much interest in fluid mechanics. Here, we investigate these topics with reference to the problem of interfacial instability in superposed Newtonian and non-Newtonian fluid layers. Under the hypothesis of the lubrication theory, we demonstrate the existence of significant transient growths in the parameter space region where the dynamical system is asymptotically stable, and show how they depend on the main physical parameters...

  7. Solar wind conditions leading to efficient radiation belt electron acceleration: A superposed epoch analysis

    OpenAIRE

    Li, W; Thorne, RM; Bortnik, J.; Baker, DN; Reeves, GD; Kanekal, SG; Spence, HE; Green, JC

    2015-01-01

    ©2015. American Geophysical Union. All Rights Reserved. Determining preferential solar wind conditions leading to efficient radiation belt electron acceleration is crucial for predicting radiation belt electron dynamics. Using Van Allen Probes electron observations ( > 1 MeV) from 2012 to 2015, we identify a number of efficient and inefficient acceleration events separately to perform a superposed epoch analysis of the corresponding solar wind parameters and geomagnetic indices. By directly c...

  8. Superpose3D: a local structural comparison program that allows for user-defined structure representations.

    Directory of Open Access Journals (Sweden)

    Pier Federico Gherardini

    Full Text Available Local structural comparison methods can be used to find structural similarities involving functional protein patches such as enzyme active sites and ligand binding sites. The outcome of such analyses is critically dependent on the representation used to describe the structure. Indeed different categories of functional sites may require the comparison program to focus on different characteristics of the protein residues. We have therefore developed superpose3D, a novel structural comparison software that lets users specify, with a powerful and flexible syntax, the structure description most suited to the requirements of their analysis. Input proteins are processed according to the user's directives and the program identifies sets of residues (or groups of atoms that have a similar 3D position in the two structures. The advantages of using such a general purpose program are demonstrated with several examples. These test cases show that no single representation is appropriate for every analysis, hence the usefulness of having a flexible program that can be tailored to different needs. Moreover we also discuss how to interpret the results of a database screening where a known structural motif is searched against a large ensemble of structures. The software is written in C++ and is released under the open source GPL license. Superpose3D does not require any external library, runs on Linux, Mac OSX, Windows and is available at http://cbm.bio.uniroma2.it/superpose3D.

  9. Large-Strain Time-Temperature Equivalence and Adiabatic Heating of Polyethylene

    Energy Technology Data Exchange (ETDEWEB)

    Furmanski, Jevan [Los Alamos National Laboratory; Brown, Eric [Los Alamos National Laboratory; Cady, Carl M. [Los Alamos National Laboratory

    2012-06-06

    Time-temperature equivalence is a well-known phenomenon in time-dependent material response, where rapid events at a moderate temperature are indistinguishable from some occurring at modest rates but elevated temperatures. However, there is as-yet little elucidation of how well this equivalence holds for substantial plastic strains. In this work, we demonstrate time-temperature equivalence over a large range in a previously studied high-density polyethylene formulation (HDPE). At strain-rates exceeding 0.1/s, adiabatic heating confounds the comparison of nominally isothermal material response, apparently violating time-temperature equivalence. Strain-rate jumps can be employed to access the instantaneous true strain rate without heating. Adiabatic heating effects were isolated by comparing a locus of isothermal instantaneous flow stress measurements from strain-rate jumps up to 1/s with the predicted equivalent states at 0.01/s and 0.001/s in compression. Excellent agreement between the isothermal jump condition locus and the quasi-static tests was observed up to 50% strain, yielding one effective isothermal plastic response for each material for a given time-temperature equivalent state. These results imply that time-temperature equivalence can be effectively used to predict the deformation response of polymers during extreme mechanical events (large strain and high strain-rate) from measurements taken at reduced temperatures and nominal strain-rates in the laboratory.

  10. Transfection effect of microbubbles on cells in superposed ultrasound waves and behavior of cavitation bubble.

    Science.gov (United States)

    Kodama, Tetsuya; Tomita, Yukio; Koshiyama, Ken-Ichiro; Blomley, Martin J K

    2006-06-01

    The combination of ultrasound and ultrasound contrast agents (UCAs) is able to induce transient membrane permeability leading to direct delivery of exogenous molecules into cells. Cavitation bubbles are believed to be involved in the membrane permeability; however, the detailed mechanism is still unknown. In the present study, the effects of ultrasound and the UCAs, Optison on transfection in vitro for different medium heights and the related dynamic behaviors of cavitation bubbles were investigated. Cultured CHO-E cells mixed with reporter genes (luciferase or beta-gal plasmid DNA) and UCAs were exposed to 1 MHz ultrasound in 24-well plates. Ultrasound was applied from the bottom of the well and reflected at the free surface of the medium, resulting in the superposition of ultrasound waves within the well. Cells cultured on the bottom of 24-well plates were located near the first node (displacement node) of the incident ultrasound downstream. Transfection activity was a function determined with the height of the medium (wave traveling distance), as well as the concentration of UCAs and the exposure time was also determined with the concentration of UCAs and the exposure duration. Survival fraction was determined by MTT assay, also changes with these values in the reverse pattern compared with luciferase activity. With shallow medium height, high transfection efficacy and high survival fraction were obtained at a low concentration of UCAs. In addition, capillary waves and subsequent atomized particles became significant as the medium height decreased. These phenomena suggested cavitation bubbles were being generated in the medium. To determine the effect of UCAs on bubble generation, we repeated the experiments using crushed heat-treated Optison solution instead of the standard microbubble preparation. The transfection ratio and survival fraction showed no additional benefit when ultrasound was used. These results suggested that cavitation bubbles created by the

  11. Characteristics and mechanisms of strain waves generated in rock by cylindrical explosive charges

    Institute of Scientific and Technical Information of China (English)

    刘科伟; 李萧翰; 李夕兵; 姚志华; 舒宗宪; 袁明华

    2016-01-01

    A superposing principle, by suitably adding the strain waves from a number of concentrated explosive charges to approximate the waves generated by a cylindrical charge based on the strain wave of a point or small spherical explosive charge generated in rock, is used to further study the triggering time of strain gauges installed in radial direction at same distances but different positions surrounding a cylindrical explosive charge in rock. The duration of the first compression phase and peak value of strain wave, and furthermore, their differences are analyzed and some explanations are given. Besides that, the gauge orientation in which the maximum peak value occurs is also discussed. At last, the effect of velocity of detonation (V.O.D.) of a cylindrical explosive charge on the strain waves generated in the surrounding rock is taken as key research and the pattern of peak amplitude of a strain wave varies with the V.O.D. is likely to have been found.

  12. The Statistics of Radio Astronomical Polarimetry: Disjoint, Superposed, and Composite Samples

    Science.gov (United States)

    van Straten, W.; Tiburzi, C.

    2017-02-01

    A statistical framework is presented for the study of the orthogonally polarized modes of radio pulsar emission via the covariances between the Stokes parameters. To accommodate the typically heavy-tailed distributions of single-pulse radio flux density, the fourth-order joint cumulants of the electric field are used to describe the superposition of modes with arbitrary probability distributions. The framework is used to consider the distinction between superposed and disjoint modes, with particular attention to the effects of integration over finite samples. If the interval over which the polarization state is estimated is longer than the timescale for switching between two or more disjoint modes of emission, then the modes are unresolved by the instrument. The resulting composite sample mean exhibits properties that have been attributed to mode superposition, such as depolarization. Because the distinction between disjoint modes and a composite sample of unresolved disjoint modes depends on the temporal resolution of the observing instrumentation, the arguments in favor of superposed modes of pulsar emission are revisited, and observational evidence for disjoint modes is described. In principle, the four-dimensional covariance matrix that describes the distribution of sample mean Stokes parameters can be used to distinguish between disjoint modes, superposed modes, and a composite sample of unresolved disjoint modes. More comprehensive and conclusive interpretation of the covariance matrix requires more detailed consideration of various relevant phenomena, including temporally correlated subpulse modulation (e.g., jitter), statistical dependence between modes (e.g., covariant intensities and partial coherence), and multipath propagation effects (e.g., scintillation and scattering).

  13. Flow non-normality-induced transient growth in superposed Newtonian and non-Newtonian fluid layers.

    Science.gov (United States)

    Camporeale, C; Gatti, F; Ridolfi, L

    2009-09-01

    In recent years non-normality and transient growths have attracted much interest in fluid mechanics. Here, we investigate these topics with reference to the problem of interfacial instability in superposed Newtonian and non-Newtonian fluid layers. Under the hypothesis of the lubrication theory, we demonstrate the existence of significant transient growths in the parameter space region where the dynamical system is asymptotically stable, and show how they depend on the main physical parameters. In particular, the key role of the density ratio is highlighted.

  14. Kelvin-Helmholtz discontinuity in two superposed viscous conducting fluids in a horizontal magnetic field

    Directory of Open Access Journals (Sweden)

    Khan Aiyub

    2008-01-01

    Full Text Available The Kelvin-Helmholtz discontinuity in two superposed viscous conducting fluids has been investigated in the taking account of effects of surface tension, when the whole system is immersed in a uniform horizontal magnetic field. The streaming motion is assumed to be two-dimensional. The stability analysis has been carried out for two highly viscous fluid of uniform densities. The dispersion relation has been derived and solved numerically. It is found that the effect of viscosity, porosity and surface tension have stabilizing influence on the growth rate of the unstable mode, while streaming velocity has a destabilizing influence on the system.

  15. Time-Dependent Regional Myocardial Strains in Patients with Heart Failure with a Preserved Ejection Fraction

    Directory of Open Access Journals (Sweden)

    Shane P. Smith

    2016-01-01

    Full Text Available Objectives. To better understand the etiology of HFpEF in a controlled human population, regional time-varying strains were computed using echocardiography speckle tracking in patients with heart failure with a preserved ejection fraction and normal subjects. Methods. Eleven normal volunteers and ten patients with echo-graded diastolic dysfunction and symptoms of heart failure were imaged with echocardiography and longitudinal, circumferential, and rotational strains were determined using speckle-tracking. Diastolic strain rate was also determined. Patient demographics and echo-derived flows, volumes, and pressures were recorded. Results. Peak longitudinal and circumferential strain was globally reduced in patients (p<0.001, when compared to controls. The patients attained peak longitudinal and circumferential strain at a consistently later point in systole than controls. Rotational strains were not different in most LV regions. Early diastolic strain rate was significantly reduced in the patients (p<0.001. LV mass and wall thickness were significantly increased in the patients; however ejection fraction was preserved and stroke volume was diminished (p<0.001. Conclusions. This study shows that patients with HFpEF have reduced early diastolic strain rate and reduced peak strain that is regionally homogeneous and that they also utilize a longer fraction of systole to achieve peak axial strains.

  16. SUPERPOSE-An excel visual basic program for fracture modeling based on the stress superposition method

    Science.gov (United States)

    Ismail Ozkaya, Sait

    2014-03-01

    An Excel Visual Basic program, SUPERPOSE, is presented to predict the distribution, relative size and strike of tensile and shear fractures on anticlinal structures. The program is based on the concept of stress superposition; addition of curvature-related local tensile stress and regional far-field stress. The method accurately predicts fractures on many Middle East Oil Fields that were formed under a strike slip regime as duplexes, flower structures or inverted structures. The program operates on the Excel platform. The program reads the parameters and structural grid data from an Excel template and writes the results to the same template. The program has two routines to import structural grid data in the Eclipse and Zmap formats. The platform of SUPERPOSE is a single layer structural grid of a given cell size (e.g. 50×50 m). In the final output, a single tensile or two conjugate shear fractures are placed in each cell if fracturing criteria are satisfied; otherwise the cell is left blank. Strike of the representative fracture(s) is calculated and exact, but the length is an index of fracture porosity (fracture density×length×aperture) within that cell.

  17. DYNAMIC STRAIN MAPPING AND REAL-TIME DAMAGE STATE ESTIMATION UNDER BIAXIAL RANDOM FATIGUE LOADING

    Data.gov (United States)

    National Aeronautics and Space Administration — DYNAMIC STRAIN MAPPING AND REAL-TIME DAMAGE STATE ESTIMATION UNDER BIAXIAL RANDOM FATIGUE LOADING SUBHASISH MOHANTY*, ADITI CHATTOPADHYAY, JOHN N. RAJADAS, AND CLYDE...

  18. Specific interplanetary conditions for CIR-, Sheath-, and ICME-induced geomagnetic storms obtained by double superposed epoch analysis

    Directory of Open Access Journals (Sweden)

    Yu. I. Yermolaev

    2010-12-01

    Full Text Available A comparison of specific interplanetary conditions for 798 magnetic storms with Dst <−50 nT during 1976–2000 was made on the basis of the OMNI archive data. We categorized various large-scale types of solar wind as interplanetary drivers of storms: corotating interaction region (CIR, Sheath, interplanetary CME (ICME including both magnetic cloud (MC and Ejecta, separately MC and Ejecta, and "Indeterminate" type. The data processing was carried out by the method of double superposed epoch analysis which uses two reference times (onset of storm and minimum of Dst index and makes a re-scaling of the main phase of the storm in a such way that all storms have equal durations of the main phase in the new time reference frame. This method reproduced some well-known results and allowed us to obtain some new results. Specifically, obtained results demonstrate that (1 in accordance with "output/input" criteria the highest efficiency in generation of magnetic storms is observed for Sheath and the lowest one for MC, and (2 there are significant differences in the properties of MC and Ejecta and in their efficiencies.

  19. Influence of the pressure holding time on strain generation in fuel injection lines

    Energy Technology Data Exchange (ETDEWEB)

    Basara, Adis, E-mail: adis.basara@evonik.com [Process Technology and Engineering, Evonik Degussa GmbH, Rodenbacher Chaussee 4, 63457 Hanau-Wolfgang (Germany); Alt, Nicolas; Schluecker, Eberhard [Institute for Process Technology and Machinery, Friedrich-Alexander University Erlangen-Nuremberg, Cauerstrasse 4, 91058 Erlangen (Germany)

    2011-04-15

    An influence of the pressure holding time on residual strain generation during the autofrettage process was studied experimentally for the first time in the present work. It is the state of the art that fuel injection lines are held at the autofrettage pressure for only a few seconds in an industrial production. In doing so, it is assumed that a desirable residual stress-strain pattern is generated. However, the results of the experimental investigations outlined in this work indicated that completion of the plastic deformation caused by the autofrettage process and generation of the desirable stress-strain pattern require a much longer period. As shown, a third-order polynomial equation best described the interdependence between the time required for the completion of the process, the corresponding autofrettage pressure and the generated strain state. The method presented can be used as a tool for the determination of the optimal autofrettage process parameters in industrial production of fuel injection lines.

  20. Observation and modeling of thermoelastic strain in Southern California Integrated GPS Network daily position time series

    Science.gov (United States)

    Prawirodirdjo, Linette; Ben-Zion, Yehuda; Bock, Yehuda

    2006-02-01

    We suggest that strain in the elastic part of the Earth's crust induced by surface temperature variations is a significant contributor to the seasonal variations observed in the spatially filtered daily position time series of Southern California Integrated GPS Network (SCIGN) stations. We compute the predicted thermoelastic strain from the observed local atmospheric temperature record assuming an elastically decoupled layer over a uniform elastic half-space and compare the seasonal variations in thermoelastic strain to the horizontal GPS position time series. We consider three regions (Palmdale, 29 Palms, and Idyllwild), each with one temperature station and three to six GPS stations. The temperature time series is used to compute thermoelastic strain at each station on the basis of its relative location in the temperature field. For each region we assume a wavelength for the temperature field that is related to the local topography. The depth of the decoupled layer is inferred from the phase delay between the temperature record and the GPS time series. The relative amplitude of strain variation at each GPS station, calculated to be on the order of 0.1 μstrain, is related to the relative location of that station in the temperature field. The goodness of fit between model and data is evaluated from the relative amplitudes of the seasonal signals, as well as the appropriateness of the chosen temperature field wavelength and decoupled layer depth. The analysis shows a good fit between the predicted strains and the GPS time series. This suggests that the model captures the key first-order ingredients that determine the thermoelastic strain in a given area. The results can be used to improve the signal/noise ratio in GPS data.

  1. Development of a Wireless and Near Real-Time 3D Ultrasound Strain Imaging System.

    Science.gov (United States)

    Chen, Zhaohong; Chen, Yongdong; Huang, Qinghua

    2016-04-01

    Ultrasound elastography is an important medical imaging tool for characterization of lesions. In this paper, we present a wireless and near real-time 3D ultrasound strain imaging system. It uses a 3D translating device to control a commercial linear ultrasound transducer to collect pre-compression and post-compression radio-frequency (RF) echo signal frames. The RF frames are wirelessly transferred to a high-performance server via a local area network (LAN). A dynamic programming strain estimation algorithm is implemented with the compute unified device architecture (CUDA) on the graphic processing unit (GPU) in the server to calculate the strain image after receiving a pre-compression RF frame and a post-compression RF frame at the same position. Each strain image is inserted into a strain volume which can be rendered in near real-time. We take full advantage of the translating device to precisely control the probe movement and compression. The GPU-based parallel computing techniques are designed to reduce the computation time. Phantom and in vivo experimental results demonstrate that our system can generate strain volumes with good quality and display an incrementally reconstructed volume image in near real-time.

  2. Real-time monitoring of high-intensity focused ultrasound treatment using axial strain and axial-shear strain elastograms.

    Science.gov (United States)

    Xia, Rongmin; Thittai, Arun K

    2014-03-01

    Axial strain elastograms (ASEs) have been found to help visualize sonographically invisible thermal lesions. However, in most studies involving high-intensity focused ultrasound (HIFU)-induced thermal lesions, elastography imaging was performed separately later, after the lesion was formed. In this article, the feasibility of monitoring, in real time, tissue elasticity variation during HIFU treatment and immediately thereafter is explored using quasi-static elastography. Further, in addition to ASEs, we also explore the use of simultaneously acquired axial-shear strain elastograms (ASSEs) for HIFU lesion visualization. Experiments were performed on commercial porcine liver samples in vitro. The HIFU experiments were conducted at two applied acoustic power settings, 35 and 20 W. The experimental setup allowed us to interrupt the HIFU pulse momentarily several different times during treatment to perform elastographic compression and data acquisition. At the end of the experiments, the samples were cut along the imaging plane and photographed to compare size and location of the formed lesion with those visualized on ASEs and ASSEs. Single-lesion and multiple-lesion experiments were performed to assess the contribution of ASEs and ASSEs to lesion visualization and treatment monitoring tasks. At both power settings, ASEs and ASSEs provided accurate location information during HIFU treatment. At the low-power setting case, ASEs and ASSEs provide accurate lesion size in real-time monitoring. Lesion appearance in ASEs and ASSEs was affected by the cavitation bubbles produced at the high-power setting. The results further indicate that the cavitation bubbles influence lesion appearance more in ASEs than in ASSEs. Both ASEs and ASSEs provided accurate size information after a waiting period that allowed the cavitation bubbles to disappear. The results indicate that ASSEs not only improve lesion visualization and size measurement of a single lesion, but, under certain

  3. Effect of temporal acquisition parameters on image quality of strain time constant elastography.

    Science.gov (United States)

    Nair, Sanjay; Varghese, Joshua; Chaudhry, Anuj; Righetti, Raffaella

    2015-04-01

    Ultrasound methods to image the time constant (TC) of elastographic tissue parameters have been recently developed. Elastographic TC images from creep or stress relaxation tests have been shown to provide information on the viscoelastic and poroelastic behavior of tissues. However, the effect of temporal ultrasonic acquisition parameters and input noise on the image quality of the resultant strain TC elastograms has not been fully investigated yet. Understanding such effects could have important implications for clinical applications of these novel techniques. This work reports a simulation study aimed at investigating the effects of varying windows of observation, acquisition frame rate, and strain signal-to-noise ratio (SNR) on the image quality of elastographic TC estimates. A pilot experimental study was used to corroborate the simulation results in specific testing conditions. The results of this work suggest that the total acquisition time necessary for accurate strain TC estimates has a linear dependence to the underlying strain TC (as estimated from the theoretical strain-vs.-time curve). The results also indicate that it might be possible to make accurate estimates of the elastographic TC (within 10% error) using windows of observation as small as 20% of the underlying TC, provided sufficiently fast acquisition rates (>100 Hz for typical acquisition depths). The limited experimental data reported in this study statistically confirm the simulation trends, proving that the proposed model can be used as upper bound guidance for the correct execution of the experiments.

  4. Evaluation of micro-behavior of strain field in Chinese mainland with the GPS time series

    Institute of Scientific and Technical Information of China (English)

    JING Shao-qun; WANG Jia-wei; WU Yun; ZHOU Shuo-yu; SHI Shun-ying

    2006-01-01

    Based on the time series of GPS station coordinate in the international Earth reference frame (ITRF), we evaluate annual micro-behavior of strain field in Chinese mainland with the triangle method. The results show that the annual micro-behavior of strain field is divided into two parts by the north-south earthquake belt in the research region. The prevailing direction of compressive principal strain field is nearly consistent in the western region. From west to east,the direction varies from NS to NE. It is in accordance with the direction of the modern compressive principal strain field. This suggests that geologic deformation in western region was mainly caused by that India tectonic plate pushes the research region northward and the Siberia plate pushes it southward relatively. It is an inheritance of new tectonic motion. The prevailing direction of the compressive principal strain field does not exist in the eastern region .The annual biggest shear strain is different greatly in every grid-cell. The values varies from 4.13×10-8 to 7.0×10-10. By and large the annual biggest shear strain in the western region is bigger than that in the eastern region. And so is the variation between any two consecutive biggest annual shear strains in the same grid-cell. The annual surface dilatation show that in most grid-cells of the research region the surface dilatation is in compressibility, and the variation between any two consecutive annual surface dilatation in the same grid-cell is small.

  5. A real-time PCR assay for the detection of atypical strains of Chlamydiaceae from pigeons.

    Directory of Open Access Journals (Sweden)

    Aleksandar Zocevic

    Full Text Available Recent evidence of the occurrence of atypical Chlamydiaceae strains in pigeons, different from the established Chlamydiaceae, requires the development of a specific and rapid detection tool to investigate their prevalence and significance. Here is described a new real-time PCR assay that allows specific detection of atypical Chlamydiaceae from pigeons. The assay has been used to assess the dissemination of these strains in field samples collected from Parisian pigeon populations in 2009. The results suggest a limited dissemination compared to the usually higher prevalence of Chlamydia psittaci that is the main species associated with avian chlamydiosis.

  6. Superposed epoch analysis of the ionospheric convection evolution during substorms: onset latitude dependence

    Directory of Open Access Journals (Sweden)

    A. Grocott

    2009-02-01

    Full Text Available Using data from the Super Dual Auroral Radar Network (SuperDARN we investigate the ionospheric convection response to magnetospheric substorms. Substorms were identified using the Far Ultraviolet (FUV instrument on board the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE spacecraft, and were then binned according to the magnetic latitude of their onset. A superposed epoch analysis of the ionospheric convection patterns for each onset-latitude bin was then performed using radar data for the interval 60 min before onset to 90 min after. It is found that lower onset-latitude substorms are associated with generally more enhanced convection than the higher latitude substorms, although they suffer from a significant localised reduction of the flow in the midnight sector during the expansion phase. Higher-latitude substorms are associated with a significant and rapid increase in the nightside convection following substorm onset, with all onset-latitude bins showing an enhancement over onset values by ~60 min into the expansion phase. A rudimentary inspection of the concurrent auroral evolution suggests that the duration of the flow reduction following substorm onset is dependent on the strength and duration of the expansion phase aurora and its associated conductivity enhancement.

  7. On the Flow Behavior in Rotor-Stator System with Superposed Flow

    Directory of Open Access Journals (Sweden)

    Roger Debuchy

    2008-01-01

    Full Text Available The flow between a rotor and a stator at high Reynolds number and small Ekman number is divided into three domains, two boundary layers adjacent to the discs separated by a central core. In the present work, a simple theoretical approach provides analytical solutions for the radial distribution of the core swirl ratio valid for a rotor-stator system with a superposed radial inflow rate. At first, the flow in the rotor boundary layer is assumed to behave as expressed by Owen and Rogers (1989 in the case of a turbulent flow on a rotating single disc. On the stator side, a necessary compensation flow rate must take place according to the conservation of mass. It is found that this compensation flow rate cannot be estimated with a good accuracy using the hypotheses of a stationary disc in a rotating fluid by Owen and Rogers (1989. Thus, two innovative weighting functions are tested, leading to new analytical laws relating the core swirl ratio K to the coefficient of flow rate Cqr introduced by Poncet et al. (2005. The adequacy between the theoretical solutions and numerous results of the literature is clearly improved and the discussion allows a better understanding of the flow behavior.

  8. Dynamics of large-scale solar-wind streams obtained by the double superposed epoch analysis

    CERN Document Server

    Yermolaev, Yu I; Nikolaeva, N S; Yermolaev, M Yu

    2015-01-01

    Using the OMNI data for period 1976-2000 we investigate the temporal profiles of 20 plasma and field parameters in the disturbed large-scale types of solar wind (SW): CIR, ICME (both MC and Ejecta) and Sheath as well as the interplanetary shock (IS). To take into account the different durations of SW types, we use the double superposed epoch analysis (DSEA) method: re-scaling the duration of the interval for all types in such a manner that, respectively, beginning and end for all intervals of selected type coincide. As the analyzed SW types can interact with each other and change parameters as a result of such interaction, we investigate separately 8 sequences of SW types: (1) CIR, (2) IS/CIR, (3) Ejecta, (4) Sheath/Ejecta, (5) IS/Sheath/Ejecta, (6) MC, (7) Sheath/MC, and (8) IS/Sheath/MC. The main conclusion is that the behavior of parameters in Sheath and in CIR are very similar both qualitatively and quantitatively. Both the high-speed stream (HSS) and the fast ICME play a role of pistons which push the pl...

  9. Superposed deformation straddling the continental-oceanic transition in deep-water Angola

    Energy Technology Data Exchange (ETDEWEB)

    Cramez, C. [TotalFina Elf Exploration and Production, Paris La Defense (France); Jackson, M.P.A. [Texas Univ., Austin, TX (United States). Bureau of Economic Geology

    2000-12-01

    The Angolan margin is the type area for raft tectonics. New seismic data reveal the contractional buffer for this thin-skinned extension. A 200-km-long composite section from the Lower Congo Basin and Kwanza Basin illustrates a complex history of superposed deformation caused by: (1) progradation of the margin; and (2) episodic Tertiary epeirogenic uplift. Late Cretaceous tectonics was driven by a gentle slope created by thermal subsidence; extensional rafting took place updip, contractional thrusting and buckling downdip; some distal folds were possibly unroofed to form massive salt walls. Oligocene deformation was triggered by gentle kinking of the Atlantic Hinge Zone as the shelf and coastal plain rose by 2 or 3 km; relative uplift stripped Paleogene cover off the shelf, provided space for Miocene progradation, and steepened the continental slope, triggering more extension and buckling. In the Neogene, a subsalt half graben was inverted or reactivated, creating keystone faults that may have controlled the Congo Canyon; a thrust duplex of seaward-displaced salt jacked up the former abyssal plain, creating a plateau of salt 3-4 km thick on the present lower slope. The Angola Escarpment may be the toe of the Angola thrust nappe, in which a largely Cretaceous roof of gently buckled strata, was transported seawards above the thickened salt by up to {approx}20 km. (author)

  10. Real-time measurement system for in-plane displacement and strain based on vision

    Science.gov (United States)

    Luo, Tao; Jin, Yi; Zhu, Ye; Zhai, Chao

    2013-08-01

    In this paper, combining optical measurement with conventional material testing machine, a real-time in-plane displacement and strain measurement system is built, which is applied to the material testing machine. This system can realize displacement and strain measurement of a large deformation sample moreover it can observe the sample crack on line. The change of displacement field is obtained through the change of center coordinate of each point of a grid lattice in the surface of the testing sample, according to two-dimensional sort coding for the grid in the traditional automated grid method, in this paper, an improved one-dimensional code method is adopted which make calculating speed much faster and the algorithm more adaptable. The measurement of the stability and precision of this system are made using the calibration board whose position precision is about 1.5 micron. The results show that the short-time stability of this system is about 0.5micron. At last, this system is used for strain measurement in a sample tension test, and the result shows that the system can acquire in-plane displacement and strain measurement results accurately and real-time, the velocity of image processing can reach 10 frame per second; or it can observe sample crack on line and storage the test process, the max velocity of observation and storage is 100 frame per second.

  11. Antimicrobial susceptibility testing of 230 Helicobacter pylori strains: importance of medium, inoculum, and incubation time

    DEFF Research Database (Denmark)

    Hartzen, S H; Andersen, L P; Bremmelgaard, A;

    1997-01-01

    No standardized method of susceptibility testing for Helicobacter pylori is currently available, so before a large agar dilution study comprising 230 H. pylori strains belonging to more than 80 genetically different groups was initiated, we performed a relatively small preliminary study....../spot) as the inoculum and 72 h as the incubation time. A modest inoculum effect was noted for amoxicillin and metronidazole. By the methodology derived from our preliminary study, the susceptibilities of 230 H. pylori strains to six antibiotics were subsequently determined. The results were generally in accord...... with those of others, and apart from metronidazole, the MIC of which for approximately 25% of the strains tested was >8 microg/ml, resistance was low in Denmark. The situation might, however, quickly change when and if the number of indications for antibiotic therapy for H. pylori infections increase...

  12. STABILITY IN REAL TIME OF SOME CRYOPRESERVED MICROBIAL STRAINS WITH REFERENCE TO GENETICALLY MODIFIED MICROORGANISMS

    Directory of Open Access Journals (Sweden)

    DANIELA VINTILĂ

    2013-12-01

    Full Text Available The aim of this work is to analyze the viability of microorganisms from Collection of Industrial Microorganisms from Faculty of Animal Science and Biotechnology – Timisoara, during freezing and thawing as part of cryopreservation technique. The stability in real time of 19 strains cryopreserved in 16% glycerol was evaluated during a 6-months period. The strains studied were: Escherichia coli, Lactobacillus acidophilus, Rhizobium meliloti, Saccharomyces cerevisiae, Aspergillus oryzae, Aspergillus niger, Trichoderma viride, Bacillus globigii, Bacillus licheniformis, and 9 strains of Bacillus subtilis. The strains cryopreserved at -20oC and -70oC were activated using the fast thawing protocol. A better cell recovery was achieved with the -70oC protocol reaching an average viability for E. coli of 86,3%, comparing with 78,6% in -20oC protocol. The cell recovery percentages for the other strains were: 92,4% for L. acidophilus, 93,9% for A.niger, 89% for A. oryzae, 86,7% for T. viride, 94,2% for R. meliloti, 82,1% for S. cerevisiae, 89,9% for B. licheniformis. Regarding the viability of genetically modified microorganisms, the values shows a good recovering after freezing and thawing, even after 180 days of cryopreservation. With the -20oC protocol lower viability was observed due probably to the formation of eutectic mixtures and recrystalization processes.

  13. Analysis of time-domain signals of piezoelectric strain sensors on slow spinning planetary gearboxes

    Science.gov (United States)

    Noll, Martin-Christopher; Godfrey, Julian William; Schelenz, Ralf; Jacobs, Georg

    2016-05-01

    Currently, condition monitoring of gearboxes mainly relies on signals of mechanical vibrations (mostly acceleration; fewer velocity and distance) or very high-frequency acoustic emissions as well as oil particle and temperature data. Strains are rarely used, since the common measuring technique employing strain gauges can cause problems in harsh environmental conditions. In the following, time-domain signals of robust piezoelectric strain sensors applied on the surface of the ring gear of a gearbox are analyzed regarding their mechanical basics, measurement chains and inferable information. The gearbox specimen is a main gearbox of a wind energy converter (WEC), which is deployed on a WEC system test rig. It can be shown that the surface strain on fixed ring gears in tangential direction is mainly influenced by the transferred tooth forces between planets and ring gear but also by the stiffnesses and geometries of the ring gear itself and the supporting gearbox structure. A direct comparison of sensor connection in AC- and DC-coupling shows that with the utilized piezoelectric sensors in DC-coupling surface strain signals with very low frequencies down to 0.002 Hz can be obtained. The acquired signals show a very high signal-to-noise-ratio and high repeatability even at very low revolution speeds. Furthermore a direct correlation to the dynamic torque, which is transferred by the gearbox, and to the planetary load sharing is found.

  14. A real-time heat strain risk classifier using heart rate and skin temperature.

    Science.gov (United States)

    Buller, Mark J; Latzka, William A; Yokota, Miyo; Tharion, William J; Moran, Daniel S

    2008-12-01

    Heat injury is a real concern to workers engaged in physically demanding tasks in high heat strain environments. Several real-time physiological monitoring systems exist that can provide indices of heat strain, e.g. physiological strain index (PSI), and provide alerts to medical personnel. However, these systems depend on core temperature measurement using expensive, ingestible thermometer pills. Seeking a better solution, we suggest the use of a model which can identify the probability that individuals are 'at risk' from heat injury using non-invasive measures. The intent is for the system to identify individuals who need monitoring more closely or who should apply heat strain mitigation strategies. We generated a model that can identify 'at risk' (PSI 7.5) workers from measures of heart rate and chest skin temperature. The model was built using data from six previously published exercise studies in which some subjects wore chemical protective equipment. The model has an overall classification error rate of 10% with one false negative error (2.7%), and outperforms an earlier model and a least squares regression model with classification errors of 21% and 14%, respectively. Additionally, the model allows the classification criteria to be adjusted based on the task and acceptable level of risk. We conclude that the model could be a valuable part of a multi-faceted heat strain management system.

  15. Tectonic evolution of the Dabashan orocline, central China: Insights from the superposed folds in the eastern Dabashan foreland

    Directory of Open Access Journals (Sweden)

    Wei Shi

    2013-11-01

    Full Text Available The Dabashan orocline is situated in the northwestern margin of the central Yangtze block, central China. Previous studies have defined the orthogonal superposed folds growing in its central-western segment thereby confirming its two-stage tectonic evolution history. Geological mapping has revealed that more types of superposed folds have developed in the eastern segment of the orocline, which probably provides more clues for probing the structure and tectonic history of the Dabashan orocline. In this paper, based on geological mapping, structural measurements and analyses of deformation, we have identified three groups of folds with different trends (e.g. NW-, NE- and nearly E-trending folds and three types of structural patterns of superposed folds in the eastern Dabashan foreland (e.g. syn-axial, oblique, and conjunctional superposed folds. In combination with geochronological data, we propose that the syn-axial superposed folds are due to two stages of ∼N–S shortening in the west and north of the Shennongjia massif, and that oblique superposed folds have been resulted from the superposition of the NW- and NE-trending folds onto the early ∼E–W folds in the east of the Shennongjia massif in the late Jurassic to early Cretaceous. The conjunctional folds are composed of the NW- and NE-trending folds, corresponding to the regional-scale dual-orocline in the eastern Sichuan as a result of the southwestward expansion of the Dabashan foreland during late Jurassic to early Cretaceous, coeval with the northwestward propagation of the Xuefengshan foreland. Integration of the structure and geochronology of the belt shows that the Dabashan orocline is a combined deformation belt primarily experiencing a two-stage tectonic evolution history in Mesozoic, initiation of the Dabashan orocline as a foreland basin along the front of the Qinling orogen in late Triassic to early Jurassic due to collisional orogeny, and the final formation of the Dabashan

  16. Strain ratio measurement of femoral cartilage by real-time elastosonography: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Ipek, Ali; Unal, Ozlem; Kartal, Merve Gulbiz; Arslan, Halil [Yildirim Beyazit University, Department of Radiology, Faculty of Medicine, Ataturk Training and Research Hospital, Ankara (Turkey); Isik, Cetin; Bozkurt, Murat [Yildirim Beyazit University, Department of Orthopedics, Faculty of Medicine, Ataturk Training and Research Hospital, Ankara (Turkey)

    2015-04-01

    The purpose of this study was to evaluate strain ratio measurement of femoral cartilage using real-time elastosonography. Twenty-five patients with femoral cartilage pathology on MRI (study group) were prospectively compared with 25 subjects with normal findings on MRI (control group) using real-time elastosonography. Strain ratio measurements of pathologic and normal cartilage were performed and compared, both within the study group and between the two groups. Elastosonography colour-scale coding showed a colour change from blue to red in pathologic cartilage and only blue colour-coding in normal cartilage. In the study group, the median strain ratio was higher in pathologic cartilage areas compared to normal areas (median, 1.49 [interquartile range, 0.80-2.53] vs. median, 0.01 [interquartile range, 0.01-0.01], p < 0.001, respectively). The median strain ratio of the control group was 0.01 (interquartile range, 0.01-0.01), and there was no significant difference compared to normal areas of the study group. There was, however, a significant difference between the control group cartilage and pathologic cartilage of the study group (p < 0.001). Elastosonography may be an effective, easily accessible, and relatively simple tool to demonstrate pathologic cartilage and to differentiate it from normal cartilage in the absence of advanced imaging facility such as MRI. (orig.)

  17. Spatial profiles of interelectrode electron density in direct current superposed dual-frequency capacitively coupled plasmas

    Science.gov (United States)

    Ohya, Yoshinobu; Ishikawa, Kenji; Komuro, Tatsuya; Yamaguchi, Tsuyoshi; Takeda, Keigo; Kondo, Hiroki; Sekine, Makoto; Hori, Masaru

    2017-04-01

    We present experimentally determined spatial profiles of the interelectrode electron density (n e) in dual-frequency capacitively coupled plasmas in which the negative direct current (dc) bias voltage (V dc) is superposed; in the experiment, 13 MHz (P low) was applied to the lower electrode and 60 MHz (P high) to the upper electrode. The bulk n e increased substantially with increases in the external power, P high, P low, and with increases in V dc. When P low was insufficient, the bulk n e decreased as the V dc bias increased. The bulk n e increased due to its dependence on V dc, especially for |V dc|  >  500 V. This may correspond to the sheath voltages (V s) of the lower electrode. The n e values in front of the upper electrode were coupled with the V dc: the V dc dependence first decreased and then increased. The dc currents (I dc) of the upper electrode were collected when a large P low was applied. The value of I dc at the threshold value of V dc  ≈  V s (e.g.  ‑500 V) increased with an increase in n e. When |V dc| exceeded the threshold, the spatial n e profile and the I dc dependence were changed relative to the electrical characteristics of the dc superposition; this led to a change in the location of the maximum n e, the width of the area of n e depletion in front of the electrodes, and a transition in the electron heating modes.

  18. The time of palatal fusion in mice: a factor of strain susceptibility to teratogens.

    Science.gov (United States)

    Syska, Edward; Schmidt, Reiner; Schubert, Johannes

    2004-02-01

    Induction of facial clefts in an animal model is often performed in experimental teratology. The susceptibility to teratogens of different strains of mice is genetically determined and seems to depend on the time of palatal fusion during embryogenesis. In order to elucidate the mode of action of preventive measures, we determined the exact time of palatal fusion in different strains of mice used for experiments in our laboratory. Fusion of the secondary palate is finished in the Halle: NMRI-mice at day 15, 0 h of gestation, in Halle: DBA and in A/WySnJ mice at day 15, 6 h and in the Halle: Jena AB-mice at day 15, 12 h. This sequence is at variance with spontaneous cleft rates and susceptibility to teratogens.

  19. Brillouin optical time domain reflectometry for fast detection of dynamic strain incorporating double-edge technique

    Science.gov (United States)

    Shangguan, Mingjia; Wang, Chong; Xia, Haiyun; Shentu, Guoliang; Dou, Xiankang; Zhang, Qiang; Pan, Jian-wei

    2017-09-01

    For the first time, to the best of our knowledge, a direct detection Brillouin optical time-domain reflectometry (BOTDR) is demonstrated for fast distributed dynamic strain sensing incorporating double-edge technique, time-division multiplexing technique and upconversion technique. In order to guarantee the robust stability of the system, the double-edge technique is implemented by using a convert single-channel FPI and a fiber-coupled upconversion single-photon detector, incorporating a time-division multiplexing method. The upconversion single-photon detector is adopted to upconvert the backscattering photons from 1548.1 nm to 863 nm, which is subsequently detected by a Silicon avalanche photodiode (Si-APD). In the experiment, dynamic strain disturbance up to 1.9 mε over 1.5 km of a polarization maintaining fiber is detected at a sampling rate of 30 Hz. An accuracy of ± 30 με and spatial resolution of 0.6 m are realized.

  20. Uniqueness of the interior plane strain time-harmonic viscoelastic inverse problem

    Science.gov (United States)

    Zhang, Yixiao; Barbone, Paul E.; Harari, Isaac; Oberai, Assad A.

    2016-07-01

    Elasticity imaging has emerged as a promising medical imaging technique with applications in the detection, diagnosis and treatment monitoring of several types of disease. In elasticity imaging measured displacement fields are used to generate images of elastic parameters of tissue by solving an inverse problem. When the tissue excitation, and the resulting tissue motion is time-harmonic, elasticity imaging can be extended to image the viscoelastic properties of the tissue. This leads to an inverse problem for the complex-valued shear modulus at a given frequency. In this manuscript we have considered the uniqueness of this inverse problem for an incompressible, isotropic linear viscoelastic solid in a state of plane strain. For a single measured displacement field we conclude that the solution is infinite dimensional, and the data required to render it unique is determined by the measured strain field. In contrast, for two independent displacement fields such that the principal directions of the resulting strain fields are different, the space of possible solutions is eight dimensional, and given additional data, like the value of the shear modulus at four locations, or over a calibration region, we may determine the shear modulus everywhere. We have also considered simple analytical examples that verify these results and offer additional insights. The results derived in this paper may be used as guidelines by the practitioners of elasticity imaging in designing more robust and accurate imaging protocols.

  1. Brillouin optical time domain reflectometry for fast detection of dynamic strain incorporating double-edge technique

    CERN Document Server

    Shangguan, Mingjia; Xia, Haiyun; Qiu, Jiawei; Shentu, Guoliang; Dou, Xiankang; Zhang, Qiang; Pan, Jian-wei

    2016-01-01

    For the first time, a direct detection BOTDR is demonstrated for distributed dynamic strain sensing incorporating double-edge technique, time-division multiplexing technique and upconversion technique. The double edges are realized by using the transmission curve and reflection curve of an all-fiber Fabry-Perot interferometer (FPI). Benefiting from the low loss of the fiber at, the time-division multiplexing technique is performed to realize the double-edge technique by using only a single-channel FPI and only one piece of a detector. In order to detect the weak spontaneous Brillouin backscattering signal efficiently, a fiber-coupled upconversion detector is adopted to upconvert the backscattering signal at 1548.1 nm to 863 nm, which is detected by a Si-APD finally. In the experiment, dynamic strain disturbance up to 1.9m{\\epsilon} over 1.5 km of polarization maintaining fiber is detected at a sampling rate of 30 Hz. An accuracy of 30{\\mu}{\\epsilon} and spatial resolution of 0.6 m is realized.

  2. Quantified Facial Soft-tissue Strain in Animation Measured by Real-time Dynamic 3-Dimensional Imaging

    Directory of Open Access Journals (Sweden)

    Vivian M. Hsu, MD

    2014-09-01

    Conclusions: This pilot study illustrates that the face can be objectively and quantitatively evaluated using dynamic major strain analysis. The technology of 3-dimensional optical imaging can be used to advance our understanding of facial soft-tissue dynamics and the effects of animation on facial strain over time.

  3. Second trimester ultrasound: reference values for two-dimensional speckle tracking-derived longitudinal strain, strain rate and time to peak deformation of the fetal heart

    NARCIS (Netherlands)

    Kapusta, L.; Mainzer, G.; Weiner, Z.; Deutsch, L.; Khoury, A.; Haddad, S.; Lorber, A.

    2012-01-01

    BACKGROUND: Data on myocardial deformation during the internationally widely used second-trimester screening are scarce and confusing. Reference values of time to peak strain are missing. The aims of this study were to assess reference values derived from two-dimensional speckle-tracking echocardiog

  4. Second trimester ultrasound: reference values for two-dimensional speckle tracking-derived longitudinal strain, strain rate and time to peak deformation of the fetal heart

    NARCIS (Netherlands)

    Kapusta, L.; Mainzer, G.; Weiner, Z.; Deutsch, L.; Khoury, A.; Haddad, S.; Lorber, A.

    2012-01-01

    BACKGROUND: Data on myocardial deformation during the internationally widely used second-trimester screening are scarce and confusing. Reference values of time to peak strain are missing. The aims of this study were to assess reference values derived from two-dimensional speckle-tracking

  5. Large-strain time-temperature equivalence in high density polyethylene for prediction of extreme deformation and damage

    Directory of Open Access Journals (Sweden)

    Gray G.T.

    2012-08-01

    Full Text Available Time-temperature equivalence is a widely recognized property of many time-dependent material systems, where there is a clear predictive link relating the deformation response at a nominal temperature and a high strain-rate to an equivalent response at a depressed temperature and nominal strain-rate. It has been found that high-density polyethylene (HDPE obeys a linear empirical formulation relating test temperature and strain-rate. This observation was extended to continuous stress-strain curves, such that material response measured in a load frame at large strains and low strain-rates (at depressed temperatures could be translated into a temperature-dependent response at high strain-rates and validated against Taylor impact results. Time-temperature equivalence was used in conjuction with jump-rate compression tests to investigate isothermal response at high strain-rate while exluding adiabatic heating. The validated constitutive response was then applied to the analysis of Dynamic-Tensile-Extrusion of HDPE, a tensile analog to Taylor impact developed at LANL. The Dyn-Ten-Ext test results and FEA found that HDPE deformed smoothly after exiting the die, and after substantial drawing appeared to undergo a pressure-dependent shear damage mechanism at intermediate velocities, while it fragmented at high velocities. Dynamic-Tensile-Extrusion, properly coupled with a validated constitutive model, can successfully probe extreme tensile deformation and damage of polymers.

  6. The Family Time Squeeze: Perceived Family Time Adequacy Buffers Work Strain in Certified Nursing Assistants With Multiple Caregiving Roles.

    Science.gov (United States)

    DePasquale, Nicole; Mogle, Jacqueline; Zarit, Steven H; Okechukwu, Cassandra; Kossek, Ellen Ernst; Almeida, David M

    2017-01-10

    This study examined how certified nursing assistants (CNAs) with unpaid family caregiving roles for children ("double-duty-child caregivers"), older adults ("double-duty-elder caregivers"), and both children and older adults ("triple-duty caregivers") differed from their nonfamily caregiving counterparts ("workplace-only caregivers") on four work strain indicators (emotional exhaustion, job satisfaction, turnover intentions, and work climate for family sacrifices). The moderating effects of perceived family time adequacy were also evaluated. Regression analyses were conducted on survey data from 972 CNAs working in U.S.-based nursing homes. Compared with workplace-only caregivers, double-and-triple-duty caregivers reported more emotional exhaustion and pressure to make family sacrifices for the sake of work. Triple-duty caregivers also reported less job satisfaction. Perceived family time adequacy buffered double-duty-child and triple-duty caregivers' emotional exhaustion and turnover intentions, as well as reversed triple-duty caregivers' negative perceptions of the work climate. Perceived family time adequacy constitutes a salient psychological resource for double-duty-child and triple-duty caregivers' family time squeezes. Amid an unprecedented demand for long-term care and severe direct-care workforce shortages, future research on workplace factors that increase double-and-triple-duty caregiving CNAs' perceived family time adequacy is warranted to inform long-term care organizations' development of targeted recruitment, retention, and engagement strategies. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Transient deformation from daily GPS displacement time series: postseismic deformation, ETS and evolving strain rates

    Science.gov (United States)

    Bock, Y.; Fang, P.; Moore, A. W.; Kedar, S.; Liu, Z.; Owen, S. E.; Glasscoe, M. T.

    2016-12-01

    underlying physical mechanisms. (3) We present evolving strain dilatation and shear rates based on the SESES velocities for regional subnetworks as a metric for assigning earthquake probabilities and detection of possible time-dependent deformation related to underlying physical processes.

  8. Corresponding Relation Between the Space-time Evolution of Seismic Apparent Strain and the Region of Strong Earthquakes in Yunnan

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    On the basis of our predecessors' research, we study the distribution and the space-time evolution characteristics of the seismic apparent strain field in Yunnan since the 1970's using the seismic data of Yunnan and its surrounding areas. The result shows that there is arather strong corresponding relationship between the anomaly region of seismic apparent strain and strong earthquakes. In the nine earthquakes studied, anomaly areas of seismic apparent strain had appeared before eight earthquakes, including five occurring in the anomaly region and three on the edge. Finally, the investigative result is demonstrated primarily.

  9. Job strain as a risk factor for leisure-time physical inactivity

    DEFF Research Database (Denmark)

    Fransson, Eleonor I; Heikkilä, Katriina; Nyberg, Solja T

    2012-01-01

    Unfavorable work characteristics, such as low job control and too high or too low job demands, have been suggested to increase the likelihood of physical inactivity during leisure time, but this has not been verified in large-scale studies. The authors combined individual-level data from 14...... European cohort studies (baseline years from 1985-1988 to 2006-2008) to examine the association between unfavorable work characteristics and leisure-time physical inactivity in a total of 170,162 employees (50% women; mean age, 43.5 years). Of these employees, 56,735 were reexamined after 2-9 years....... In cross-sectional analyses, the odds for physical inactivity were 26% higher (odds ratio = 1.26, 95% confidence interval: 1.15, 1.38) for employees with high-strain jobs (low control/high demands) and 21% higher (odds ratio = 1.21, 95% confidence interval: 1.11, 1.31) for those with passive jobs (low...

  10. Two-photon polymerization of microstructures by a non-diffraction multifoci pattern generated from a superposed Bessel beam.

    Science.gov (United States)

    Yang, Liang; Qian, Dongdong; Xin, Chen; Hu, Zhijiang; Ji, Shengyun; Wu, Dong; Hu, Yanlei; Li, Jiawen; Huang, Wenhao; Chu, Jiaru

    2017-02-15

    In this Letter, superposed Bessel beams (SBBs) are realized by alternatively imprinting holograms of opposite-order Bessel beams along the radial direction on a spatial light modulator. The propagation invariance and non-rotation properties of SBBs are theoretically predicted and experimentally demonstrated. The focusing property of SBBs with a high numerical aperture (NA) objective is investigated with the Debye vectorial diffraction theory. Near the focal plane, a circularly distributed multiple foci pattern is achieved. The multiple foci generated from SBBs are adopted in a two-photon fabrication system, and micropattern fabrication by a single exposure is demonstrated. Facile fabrication of three-dimensional microstructures with SBBs is realized by dynamically controlling the number of focal spots, and the diameter and rotation of the focal pattern.

  11. Enhanced method with superposed signal-based visible light communication system using multiple-input signal-output beamforming

    Science.gov (United States)

    Qiao, Liang; Liang, Shangyu; Lu, Xingyu; Zhou, Yingjun; Jiang, Yi; Chi, Nan

    2017-08-01

    As a promising candidate technology for the next generation communication systems, visible light communication (VLC), combined with high modulation and coding schemes, can be used to achieve throughput much higher than the traditional RF wireless ones. We propose adopting multiple light-emitting diodes (LEDs) on the transmit side to form a multiple-input signal-output (MISO) VLC system. Through the maximum ratio transmit beamforming, the signals from the multiple LEDs can be added coherently at the receiver side, and, therefore, the signal-to-noise ratio of the system can be improved slightly. Meanwhile, a method of channel estimation with superposed signal is employed for better channel estimation. Extensive lab experiments demonstrate that a two-LED MISO-VLC system can achieve a data rate of 1.0 Gbit/s over a free-space link of 1.2 m.

  12. Stability Of Superposed Fluids Through Magnetic Field With Suspended Particles Of Different Permeability Saturated Through Porous Layer

    Directory of Open Access Journals (Sweden)

    Singh M.

    2015-12-01

    Full Text Available The instability of plane interface between two superposed Rivlin-Ericksen elastico-viscous fluids saturated through a porous medium has been studied to include the suspended (dust particles effect. Following the linearized stability theory and normal mode analysis the dispersion relation is obtained. For stationary convection, the Rivlin-Ericksen elastico-viscous fluid behaves like Newtonian fluids. It found that for a potentially stable arrangement the Rivlin-Ericksen elastico-viscous fluid of different permeabilities in the presence of suspended particles in a porous medium is stable, whereas in a potentially unstable case instability of the system occurs. In the presence of a magnetic field for a potentially stable arrangement the system is always stable and for the potentially unstable arrangement, the magnetic field succeeds in stabilizing certain wave-number band which was unstable in the absence of the magnetic field.

  13. [Changes of resistant phenotype and CRISPR/Cas system of four Shigella strains passaged for 90 times without antibiotics].

    Science.gov (United States)

    Zhang, B; Hong, L J; Duan, G C; Liang, W J; Yang, H Y; Xi, Y L

    2017-02-10

    Objective: To explore the stability of resistant phenotypes and changes of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) gene system on four Shigella strains in the absence of antibiotics. Methods: Four clinical isolated Shigella strains that resistant to different antibiotics were consecutive passaged for 90 times without antibiotics. Agar dilution method was used to determine the minimum inhibitory concentration of Shigella strains. After sequence analysis with PCR, CRISPR Finder and Clustal X 2.1 were applied to identify the changes of CRISPR loci in the Shigella strains. Results: After the consecutive transfer of 90 generations, sensitivity to certain antibiotics of four Shigella strains with different drug resistant spectrums increased. Mel-sf1998024/zz resistance to ampicillin, cephalexin, cefotaxime, chloramphenicol decreased, mel-s2014026/sx resistance to norfloxacin, trimethoprim decreased, mel-sf2004004/sx drug resistance to ampicillin, cefuroxime, cefotaxime, chloramphenicol, trimethoprim decreased and mel-sf2013004/bj resistance to chloramphenicol decreased. The spacer of which matched gene codes Cas and its upstream repeat in 3'end of CRISPR3 got lost in mel-sf1998024/zz and mel-sf2013004/bj. Conclusions:Shigella strains could reduce or lose their resistance to some antibiotics after consecutive transfers, without the interference of antibiotics. CRISPR3 locus had dynamic spacers in Shigella strains while CRISPR3 locus and cas genes might have been co-evolved.

  14. Multilocus sequence typing of Mycoplasma hyorhinis strains identified by a real-time TaqMan PCR assay.

    Science.gov (United States)

    Tocqueville, Véronique; Ferré, Séverine; Nguyen, Ngoc Hong Phuc; Kempf, Isabelle; Marois-Créhan, Corinne

    2014-05-01

    A real-time TaqMan PCR assay based on the gene encoding the protein p37 was developed to detect Mycoplasma hyorhinis. Its specificity was validated with 29 epidemiologically unrelated M. hyorhinis strains (28 field strains and one reference strain) and other mycoplasma species or with other microorganisms commonly found in pigs. The estimated detection limit of this qPCR assay was 125 microorganism equivalents/μl. The same 29 epidemiologically unrelated M. hyorhinis strains and four previously fully sequenced strains were typed by two portable typing methods, the sequencing of the p37 gene and a multilocus sequence typing (MLST) scheme. The first method revealed 18 distinct nucleotide sequences and insufficient discriminatory power (0.934). The MLST scheme was developed with the sequenced genomes of the M. hyorhinis strains HUB-1, GDL-1, MCLD, and SK76 and based on the genes dnaA, rpoB, gyrB, gltX, adk, and gmk. In total, 2,304 bp of sequence was analyzed for each strain. MLST was capable of subdividing the 33 strains into 29 distinct sequence types. The discriminatory power of the method was >0.95, which is the threshold value for interpreting typing results with confidence (D=0.989). Population analysis showed that recombination in M. hyorhinis occurs and that strains are diverse but with a certain clonality (one unique clonal complex was identified). The new qPCR assay and the robust MLST scheme are available for the acquisition of new knowledge on M. hyorhinis epidemiology. A web-accessible database has been set up for the M. hyorhinis MLST scheme at http://pubmlst.org/mhyorhinis/.

  15. Structural conservation of prion strain specificities in recombinant prion protein fibrils in real-time quaking-induced conversion.

    Science.gov (United States)

    Sano, Kazunori; Atarashi, Ryuichiro; Nishida, Noriyuki

    2015-01-01

    A major unsolved issue of prion biology is the existence of multiple strains with distinct phenotypes and this strain phenomenon is postulated to be associated with the conformational diversity of the abnormal prion protein (PrP(Sc)). Real-time quaking-induced conversion (RT-QUIC) assay that uses Escherichia coli-derived recombinant prion protein (rPrP) for the sensitive detection of PrP(Sc) results in the formation of rPrP-fibrils seeded with various strains. We demonstrated that there are differences in the secondary structures, especially in the β-sheets, and conformational stability between 2 rPrP-fibrils seeded with either Chandler or 22L strains in the first round of RT-QUIC. In particular, the differences in conformational properties of these 2 rPrP-fibrils were common to those of the original PrP(Sc). However, the strain specificities of rPrP-fibrils seen in the first round were lost in subsequent rounds. Instead, our findings suggest that nonspecific fibrils became the major species, probable owing to their selective growth advantage in the RT-QUIC. This study shows that at least some strain-specific conformational properties of the original PrP(Sc) can be transmitted to rPrP-fibrils in vitro, but further conservation appears to require unknown cofactors or environmental conditions or both.

  16. On the lag time between internal strain and basement involved thrust induced exhumation: The case of the Colombian Eastern Cordillera

    Science.gov (United States)

    Mora, Andrès; Blanco, Vladimir; Naranjo, Julian; Sanchez, Nelson; Ketcham, Richard A.; Rubiano, Jorge; Stockli, Daniel F.; Quintero, Isaid; Nemčok, Michal; Horton, Brian K.; Davila, Hamblet

    2013-07-01

    Thrust sheets accumulate internal strain before they start moving along discrete fault planes. However, there are no previous studies evaluating the time difference between initiation of strain and fault displacement. In this paper we use observations from the Eastern Cordillera of Colombia to evaluate this interval. We utilize multiple thermochronometers and paleothermometers to refine the timing of deformation. Based on these new data we build time-temperature path estimates that together with geometric outcrop-based structural analysis and fluid inclusions allow us to assign relative timing to features associated with strain, such as cleavage, veins and certain types of fractures, and compare that with the timing of thrusting. We find that cleavage was only formed close to maximum paleotemperatures, almost coeval with the onset of thrust-induced denudation by the Late Oligocene. The corresponding structural level of fold-related veins suggest that they were formed later but still when the country rocks were at temperatures higher than 160 °C, mostly during the Early Miocene and still coexisted with the latest stages of cleavage formation. Our data show that the main period of strain hardening was short (probably a few million years) and occurred before first-order basement thrusting was dominant, but was associated with second-order folding.

  17. The strain effect on the Dirac electrons tunneling through the time-periodic scalar and vector barriers

    Science.gov (United States)

    Yan, Weixian

    2017-01-01

    The tunneling of the massless and massive Dirac particle through the strained barriers driven by the time-periodic scalar potentials and the static vector potentials is investigated, where the interrelationships among the strain, the incidence angle, the dynamic scalar potential, the magnetic field and the transmission of the Dirac particle have been discussed. In either massless or massive case, the intersection angle between the obliquely incident Dirac particle and strain determines the extent of deviation of the tunneling profiles from the strainless case. The time-periodic scalar potentials can enhance the capability of the Dirac particle to surmount the energy gap induced by the mass, reflecting quantum nature of the photon-assisted tunneling. When the magnetic field is switched on, the transmission overall presents a remarkably different profile, and decreases with the increase of the magnetic fields due to the conservation of the transverse momentum, which reduces the number of the side-band channels for tunneling.

  18. Rapid detection of Panton-Valentine leukocidin from clinical isolates of Staphylococcus aureus strains by real-time PCR

    NARCIS (Netherlands)

    Deurenberg, Ruud H; Vink, Cornelis; Driessen, Christel; Bes, Michèle; London, Nancy; Etienne, Jerome; Stobberingh, Ellen E

    2004-01-01

    To allow rapid identification of Panton-Valentine leukocidin (PVL)-producing Staphylococcus aureus strains, a real-time PCR assay for detection of PVL was developed. This assay is convenient, since it can be applied directly on bacterial suspensions and does not require previous DNA purification.

  19. Solar-wind turbulence and shear: a superposed-epoch analysis of corotating interaction regions at 1 AU

    Energy Technology Data Exchange (ETDEWEB)

    Borovsky, Joseph E [Los Alamos National Laboratory; Denton, Michael H [LANCASTER UNIV.

    2009-01-01

    A superposed-epoch analysis of ACE and OMNI2 measurements is performed on 27 corotating interaction regions (CIRs) in 2003-2008, with the zero epoch taken to be the stream interface as determined by the maximum of the plasma vorticity. The structure of CIRs is investigated. When the flow measurements are rotated into the local-Parker-spiral coordinate system the shear is seen to be abrupt and intense, with vorticities on the order of 10{sup -5}-10{sup -4} sec{sup -1}. Converging flows perpendicular to the stream interface are seen in the local-Parker-spiral coordinate system and about half of the CIRs show a layer of divergent rebound flow away from the stream interface. Arguments indicate that any spreading of turbulence away from the region where it is produced is limited to about 10{sup 6} km, which is very small compared with the thickness of a CrR. Analysis of the turbulence across the CrRs is performed. When possible, the effects of discontinuities are removed from the data. Fluctuation amplitudes, the Alfvenicity, and the level of Alfvenic correlations all vary smoothly across the CrR. The Alfven ratio exhibits a decrease at the shear zone of the stream interface. Fourier analysis of 4.5-hr subintervals of ACE data is performed and the results are superposed averaged as an ensemble of realizations. The spectral slopes of the velocity, magnetic-field, and total-energy fluctuations vary smoothly across the CIR. The total-energy spectral slope is {approx} 3/2 in the slow and fast wind and in the CrRs. Analysis of the Elsasser inward-outward fluctuations shows a smooth transition across the CrR from an inward-outward balance in the slow wind to an outward dominance in the fast wind. A number of signatures of turbulence driving at the shear zone are sought (entropy change, turbulence amplitude, Alfvenicity, Alfven ratio, spectral slopes, in-out nature): none show evidence of driving of turbulence by shear.

  20. Solar-wind turbulence and shear: a superposed-epoch analysis of corotating interaction regions at 1 AU

    Energy Technology Data Exchange (ETDEWEB)

    Borovsky, Joseph E [Los Alamos National Laboratory; Denton, Michael H [LANCASTER UNIV.

    2009-01-01

    A superposed-epoch analysis of ACE and OMNI2 measurements is performed on 27 corotating interaction regions (CIRs) in 2003-2008, with the zero epoch taken to be the stream interface as determined by the maximum of the plasma vorticity. The structure of CIRs is investigated. When the flow measurements are rotated into the local-Parker-spiral coordinate system the shear is seen to be abrupt and intense, with vorticities on the order of 10{sup -5}-10{sup -4} sec{sup -1}. Converging flows perpendicular to the stream interface are seen in the local-Parker-spiral coordinate system and about half of the CIRs show a layer of divergent rebound flow away from the stream interface. Arguments indicate that any spreading of turbulence away from the region where it is produced is limited to about 10{sup 6} km, which is very small compared with the thickness of a CrR. Analysis of the turbulence across the CrRs is performed. When possible, the effects of discontinuities are removed from the data. Fluctuation amplitudes, the Alfvenicity, and the level of Alfvenic correlations all vary smoothly across the CrR. The Alfven ratio exhibits a decrease at the shear zone of the stream interface. Fourier analysis of 4.5-hr subintervals of ACE data is performed and the results are superposed averaged as an ensemble of realizations. The spectral slopes of the velocity, magnetic-field, and total-energy fluctuations vary smoothly across the CIR. The total-energy spectral slope is {approx} 3/2 in the slow and fast wind and in the CrRs. Analysis of the Elsasser inward-outward fluctuations shows a smooth transition across the CrR from an inward-outward balance in the slow wind to an outward dominance in the fast wind. A number of signatures of turbulence driving at the shear zone are sought (entropy change, turbulence amplitude, Alfvenicity, Alfven ratio, spectral slopes, in-out nature): none show evidence of driving of turbulence by shear.

  1. Quantification of Pseudomonas fluorescens strains F113, CHA0 and Pf153 in the rhizosphere of maize by strain-specific real-time PCR unaffected by the variability of DNA extraction efficiency.

    Science.gov (United States)

    Von Felten, Andreas; Défago, Geneviève; Maurhofer, Monika

    2010-05-01

    Pseudomonas fluorescens strains F113 and CHA0 are well-known plant growth-promoting rhizobacteria (PGPR) often used as model strains in biocontrol experiments. To monitor their persistence in large scale field experiments, culture-independent methods are needed. In this study, a strain-specific real-time PCR quantification tool was developed based on sequence-characterized amplified regions (SCAR) for P. fluorescens strains F113, CHA0 and Pf153. Differences in DNA extraction efficiencies from rhizosphere samples were circumvented using plasmid APA9 as internal standard to normalize C(T) values after real-time amplification. The detection limits of the real-time PCR assays for all three strains were approximately 10 cells for genomic DNA and 10(4)cells/g rhizosphere for maize samples grown in different natural soils. Population sizes of the three strains in the rhizosphere of maize measured by the new real-time PCR approaches were similar to those measured by most probable number (MPN)-PCR. A persistence study of the three strains indicated that the strains persisted differently over a period of 5weeks. In conclusion the newly developed real-time PCR approach is a fast and resource efficient method for monitoring individual biocontrol strains in natural soil, which makes it an apt quantification tool for future large-scale field experiments.

  2. Resimulation of noise: a precision estimator for least square error curve-fitting tested for axial strain time constant imaging.

    Science.gov (United States)

    Nair, S P; Righetti, R

    2015-05-07

    Recent elastography techniques focus on imaging information on properties of materials which can be modeled as viscoelastic or poroelastic. These techniques often require the fitting of temporal strain data, acquired from either a creep or stress-relaxation experiment to a mathematical model using least square error (LSE) parameter estimation. It is known that the strain versus time relationships for tissues undergoing creep compression have a non-linear relationship. In non-linear cases, devising a measure of estimate reliability can be challenging. In this article, we have developed and tested a method to provide non linear LSE parameter estimate reliability: which we called Resimulation of Noise (RoN). RoN provides a measure of reliability by estimating the spread of parameter estimates from a single experiment realization. We have tested RoN specifically for the case of axial strain time constant parameter estimation in poroelastic media. Our tests show that the RoN estimated precision has a linear relationship to the actual precision of the LSE estimator. We have also compared results from the RoN derived measure of reliability against a commonly used reliability measure: the correlation coefficient (CorrCoeff). Our results show that CorrCoeff is a poor measure of estimate reliability for non-linear LSE parameter estimation. While the RoN is specifically tested only for axial strain time constant imaging, a general algorithm is provided for use in all LSE parameter estimation.

  3. A multivariate time-warping based classifier for gesture recognition with wearable strain sensors.

    Science.gov (United States)

    Giorgino, Toni; Tormene, Paolo; Quaglini, Silvana

    2007-01-01

    Conductive elastomer elements can be industrially embedded into garments to form unobtrusive strain sensing stripes. The present article outlines the structure of a strain-sensor based gesture detection algorithm. Current sensing prototypes include several dozens of sensors; their redundancy with respect to the limb's degrees of freedom, and other artifacts implied by this measurement technique, call for the development of novel robust multivariate pattern-matching techniques. The algorithm's construction is explained, and its performances are evaluated in the context of motor rehabilitation exercises for both two-class and multi-class tasks.

  4. Quantified Facial Soft-tissue Strain in Animation Measured by Real-time Dynamic 3-Dimensional Imaging

    Science.gov (United States)

    Hsu, Vivian M.; Wes, Ari M.; Tahiri, Youssef; Cornman-Homonoff, Joshua

    2014-01-01

    Background: The aim of this study is to evaluate and quantify dynamic soft-tissue strain in the human face using real-time 3-dimensional imaging technology. Methods: Thirteen subjects (8 women, 5 men) between the ages of 18 and 70 were imaged using a dual-camera system and 3-dimensional optical analysis (ARAMIS, Trilion Quality Systems, Pa.). Each subject was imaged at rest and with the following facial expressions: (1) smile, (2) laughter, (3) surprise, (4) anger, (5) grimace, and (6) pursed lips. The facial strains defining stretch and compression were computed for each subject and compared. Results: The areas of greatest strain were localized to the midface and lower face for all expressions. Subjects over the age of 40 had a statistically significant increase in stretch in the perioral region while lip pursing compared with subjects under the age of 40 (58.4% vs 33.8%, P = 0.015). When specific components of lip pursing were analyzed, there was a significantly greater degree of stretch in the nasolabial fold region in subjects over 40 compared with those under 40 (61.6% vs 32.9%, P = 0.007). Furthermore, we observed a greater degree of asymmetry of strain in the nasolabial fold region in the older age group (18.4% vs 5.4%, P = 0.03). Conclusions: This pilot study illustrates that the face can be objectively and quantitatively evaluated using dynamic major strain analysis. The technology of 3-dimensional optical imaging can be used to advance our understanding of facial soft-tissue dynamics and the effects of animation on facial strain over time. PMID:25426394

  5. Quantified Facial Soft-tissue Strain in Animation Measured by Real-time Dynamic 3-Dimensional Imaging.

    Science.gov (United States)

    Hsu, Vivian M; Wes, Ari M; Tahiri, Youssef; Cornman-Homonoff, Joshua; Percec, Ivona

    2014-09-01

    The aim of this study is to evaluate and quantify dynamic soft-tissue strain in the human face using real-time 3-dimensional imaging technology. Thirteen subjects (8 women, 5 men) between the ages of 18 and 70 were imaged using a dual-camera system and 3-dimensional optical analysis (ARAMIS, Trilion Quality Systems, Pa.). Each subject was imaged at rest and with the following facial expressions: (1) smile, (2) laughter, (3) surprise, (4) anger, (5) grimace, and (6) pursed lips. The facial strains defining stretch and compression were computed for each subject and compared. The areas of greatest strain were localized to the midface and lower face for all expressions. Subjects over the age of 40 had a statistically significant increase in stretch in the perioral region while lip pursing compared with subjects under the age of 40 (58.4% vs 33.8%, P = 0.015). When specific components of lip pursing were analyzed, there was a significantly greater degree of stretch in the nasolabial fold region in subjects over 40 compared with those under 40 (61.6% vs 32.9%, P = 0.007). Furthermore, we observed a greater degree of asymmetry of strain in the nasolabial fold region in the older age group (18.4% vs 5.4%, P = 0.03). This pilot study illustrates that the face can be objectively and quantitatively evaluated using dynamic major strain analysis. The technology of 3-dimensional optical imaging can be used to advance our understanding of facial soft-tissue dynamics and the effects of animation on facial strain over time.

  6. Inoculation experimental animals with Paracoccidioides brasiliensis strains: an attempt to reestablish the dimorphic process and variation in pathogenicity as a function of time of preservation under mineral oil.

    Science.gov (United States)

    Mendes da Silva, A M; Borba, C M; de Oliveira, P C

    1996-01-01

    In an attempt to reestablish the dimorphic process in strains of Paracoccidioides brasiliensis in the transition phase (Y reversible M) and to reisolate them, five strains in the transitional phase due to the long time of preservation under mineral oil and two strains in the yeast-like phase were inoculated into male albino rats. The animals were then studied for the presence of paracoccidioidomycotic granulomata. Of the seven strains inoculated, five caused granulomatous nodules in several organs of the animals and only two of these five strains, which had been preserved for the shortest period of time (9 years) were reisolated in culture. Two strains were unable to provoke infection, with no lesions detected in any organ. It is assumed that the long period of time during which the strains were left under oil favored the alteration of celt wall contents, leading to differences in pathogenicity.

  7. Experimental study on time-dependent stress and strain of in-plane shear(ModeⅡ) fracture process of rock

    Institute of Scientific and Technical Information of China (English)

    王志; 饶秋华; 谢海峰

    2008-01-01

    Shear-box test with strain measurement was used to study time-dependent stress and strain of in-plane shear(Mode Ⅱ) fracture process of rock and to reveal the mechanism of Mode Ⅱ fracture.Numerical results show that the maximum shear stress τmax at the crack tip is much larger than the maximum tensile stress σ1 and the ratio of τmax/σ1 is about 5,which favors Mode Ⅱ fracture of rock.Test results indicate that the strain-time curve comprises three stages:the linear deformation stage,the micro-cracking stage and the macroscopic crack propagation.The strain in the direction of the original notch plane is negative,due to restraining effect of compressive loading applied to the original notch plane.Both σ1 and τmax are increased as the load increases,but the slope of τmax is larger than that of σ1 and the value of τmax is always larger than that of σ1.Therefore,τmax reaches its limited value at peak load before σ1 and results in Mode Ⅱ fracture of rock.Shear-box(i.e.compression-shear) test becomes a potential standard method for achieving the true Mode Ⅱ fracture and determining Mode Ⅱ fracture toughness of rock.

  8. ULYSSES observations of energetic particle acceleration and the superposed CME and CIR events of November 1992

    Directory of Open Access Journals (Sweden)

    T. L. Lim

    Full Text Available During November 1992, a series of forward and reverse shocks passed the ULYSSES spacecraft. Spectral and anisotropy measurements are reported for protons and alpha particles between 0.28 and 6 MeV observed by the Energetic Particle Composition Experiment, data recorded by the Magnetometer Experiment and the high-energy (2.7–300 MeV proton data from the Kiel Electron Telescope. An analysis of energetic particle, plasma and magnetometer data from ULYSSES has allowed a unique study of the corresponding arrival of fare particles, particles within a corotating interaction region and particles transported with a coronal mass ejection. We present an analysis of these data in terms of possible diffusive shock acceleration but conclude that this is likely to be incompatible with the short transit time of the particles. Shock drift acceleration of particles with energies 0.3 MeV/nucleon or solar acceleration followed by particle trapping behind the shock front are alternative possibilities.

  9. A Two-Layer Model for Superposed Electrified Maxwell Fluids in Presence of Heat Transfer

    Institute of Scientific and Technical Information of China (English)

    Kadry Zakaria; Magdy A. Sirwah; Sameh A. Alkharashi

    2011-01-01

    Based on a modified-Darcy-Maxwell model, two-dimensional, incompressible and heat transfer flow of two bounded layers, through electrified Maxwell fluids in porous media is performed. The driving force for the instability under an electric field, is an electrostatic force exerted on the free charges accumulated at the dividing interface. Normal mode analysis is considered to study the linear stability of the disturbances layers. The solutions of the linearized equations of motion with the boundary conditions lead to an implicit dispersion relation between the growth rate and wave number. These equations are parameterized by Weber number, Reynolds number, Marangoni number, dimensionless conductivities, and dimensionless electric potentials. The case of long waves interfacial stability has been studied. The stability criteria are performed theoretically in which stability diagrams are obtained. In the limiting cases, some previously published results can be considered as particular cases of our results. It is found that the Reynolds number plays a destabilizing role in the stability criteria, while the damping influence is observed for the increasing of Marangoni number and Maxwell relaxation time.

  10. A Two-Layer Model for Superposed Electrified Maxwell Fluids in Presence of Heat Transfer

    Science.gov (United States)

    Kadry, Zakaria; Magdy, A. Sirwah; Sameh, A. Alkharashi

    2011-06-01

    Based on a modified-Darcy—Maxwell model, two-dimensional, incompressible and heat transfer flow of two bounded layers, through electrified Maxwell fluids in porous media is performed. The driving force for the instability under an electric field, is an electrostatic force exerted on the free charges accumulated at the dividing interface. Normal mode analysis is considered to study the linear stability of the disturbances layers. The solutions of the linearized equations of motion with the boundary conditions lead to an implicit dispersion relation between the growth rate and wave number. These equations are parameterized by Weber number, Reynolds number, Marangoni number, dimensionless conductivities, and dimensionless electric potentials. The case of long waves interfacial stability has been studied. The stability criteria are performed theoretically in which stability diagrams are obtained. In the limiting cases, some previously published results can be considered as particular cases of our results. It is found that the Reynolds number plays a destabilizing role in the stability criteria, while the damping influence is observed for the increasing of Marangoni number and Maxwell relaxation time.

  11. Long-time behavior of a class of thermoelastic plates with nonlinear strain

    Science.gov (United States)

    Fatori, L. H.; Jorge Silva, M. A.; Ma, T. F.; Yang, Zhijian

    2015-11-01

    In recent years a class of vibrating plates with nonlinear strain of p-Laplacian type was studied by several authors. The present paper contains a first thermoelastic model of that class of problems including both Fourier and non-Fourier heat laws. Our main result establishes the existence of global and exponential attractors for the strongly damped problem through a stabilizability inequality. In addition, for the weakly damped problem, we establish the exponential stability of its Galerkin semiflows.

  12. Time Domain Strain/Stress Reconstruction Based on Empirical Mode Decomposition: Numerical Study and Experimental Validation.

    Science.gov (United States)

    He, Jingjing; Zhou, Yibin; Guan, Xuefei; Zhang, Wei; Zhang, Weifang; Liu, Yongming

    2016-08-16

    Structural health monitoring has been studied by a number of researchers as well as various industries to keep up with the increasing demand for preventive maintenance routines. This work presents a novel method for reconstruct prompt, informed strain/stress responses at the hot spots of the structures based on strain measurements at remote locations. The structural responses measured from usage monitoring system at available locations are decomposed into modal responses using empirical mode decomposition. Transformation equations based on finite element modeling are derived to extrapolate the modal responses from the measured locations to critical locations where direct sensor measurements are not available. Then, two numerical examples (a two-span beam and a 19956-degree of freedom simplified airfoil) are used to demonstrate the overall reconstruction method. Finally, the present work investigates the effectiveness and accuracy of the method through a set of experiments conducted on an aluminium alloy cantilever beam commonly used in air vehicle and spacecraft. The experiments collect the vibration strain signals of the beam via optical fiber sensors. Reconstruction results are compared with theoretical solutions and a detailed error analysis is also provided.

  13. Time Domain Strain/Stress Reconstruction Based on Empirical Mode Decomposition: Numerical Study and Experimental Validation

    Directory of Open Access Journals (Sweden)

    Jingjing He

    2016-08-01

    Full Text Available Structural health monitoring has been studied by a number of researchers as well as various industries to keep up with the increasing demand for preventive maintenance routines. This work presents a novel method for reconstruct prompt, informed strain/stress responses at the hot spots of the structures based on strain measurements at remote locations. The structural responses measured from usage monitoring system at available locations are decomposed into modal responses using empirical mode decomposition. Transformation equations based on finite element modeling are derived to extrapolate the modal responses from the measured locations to critical locations where direct sensor measurements are not available. Then, two numerical examples (a two-span beam and a 19956-degree of freedom simplified airfoil are used to demonstrate the overall reconstruction method. Finally, the present work investigates the effectiveness and accuracy of the method through a set of experiments conducted on an aluminium alloy cantilever beam commonly used in air vehicle and spacecraft. The experiments collect the vibration strain signals of the beam via optical fiber sensors. Reconstruction results are compared with theoretical solutions and a detailed error analysis is also provided.

  14. Time-Series and Frequency-Spectrum Correlation Analysis of Bridge Performance Based on a Real-Time Strain Monitoring System

    Directory of Open Access Journals (Sweden)

    Mosbeh R. Kaloop

    2016-05-01

    Full Text Available Monitoring bridges’ performance is a vital task to ensure their safety and to plan their maintenance operations. Therefore, it is very important to monitor bridges’ behavior and to analyze their measured data. In this study, the time-series and frequency-spectrum correlation analyses are used to study the performance of Fu-Sui Bridge under harsh environmental and traffic loads. It investigates the bridge performance based on a real-time strain monitoring system, and the ambient environmental and traffic loads are studied and discussed. Furthermore, a simplified method based on signal processing is developed and used to estimate the traffic volumes. The results of this study reveal that the traffic loads influence on static strain is obviously lower than that of air temperature and temperature changes of the bridge cross-section; the non-linearity behavior of the bridge during summer time is more than winter time; and the stability of the whole bridge during winter time is more than during summer time. The time-series and vibration analyses also show that the bridge performance in terms of its rigidity and stability is higher during winter time.

  15. Distributed fiber strain and vibration sensor based on Brillouin optical time-domain reflectometry and polarization optical time-domain reflectometry.

    Science.gov (United States)

    Wang, Feng; Zhang, Xuping; Wang, Xiangchuan; Chen, Haisheng

    2013-07-15

    A distributed fiber strain and vibration sensor which effectively combines Brillouin optical time-domain reflectometry and polarization optical time-domain reflectometry is proposed. Two reference beams with orthogonal polarization states are, respectively, used to perform the measurement. By using the signal obtained from either reference beam, the vibration of fiber can be measured from the polarization effect. After combining the signals obtained by both reference beams, the strain can be measured from the Brillouin effect. In the experiment, 10 m spatial resolution, 0.6 kHz frequency measurement range, 2.5 Hz frequency resolution, and 0.2 MHz uncertainty of Brillouin frequency measurement are realized for a 4 km sensing distance.

  16. Large-strain optical fiber sensing and real-time FEM updating of steel structures under the high temperature effect

    Science.gov (United States)

    Huang, Ying; Fang, Xia; Bevans, Wesley James; Zhou, Zhi; Xiao, Hai; Chen, Genda

    2013-01-01

    Steel buildings are subjected to fire hazards during or immediately after a major earthquake. Under combined gravity and thermal loads, they have non-uniformly distributed stiffness and strength, and thus collapse progressively with large deformation. In this study, large-strain optical fiber sensors for high temperature applications and a temperature-dependent finite element model updating method are proposed for accurate prediction of structural behavior in real time. The optical fiber sensors can measure strains up to 10% at approximately 700 °C. Their measurements are in good agreement with those from strain gauges up to 0.5%. In comparison with the experimental results, the proposed model updating method can reduce the predicted strain errors from over 75% to below 20% at 800 °C. The minimum number of sensors in a fire zone that can properly characterize the vertical temperature distribution of heated air due to the gravity effect should be included in the proposed model updating scheme to achieve a predetermined simulation accuracy.

  17. Real time PCR detection of rabbit haemorrhagic disease virus in rabbits infected with different European strains of RHDV.

    Science.gov (United States)

    Niedźwiedzka-Rystwej, P; Hukowska-Szematowicz, B; Działo, J; Tokarz-Deptuła, B; Deptuła, W

    2013-01-01

    The paper concerns the use of a novel, very effective diagnostic method, a real-time PCR for diagnosis of a viral agent causing viral haemorrhagic disease in rabbits - RHDV. Until now, the method was widely used for detecting many different viruses, both DNA, and RNA, but as far as RHDV is concerned, there are not many records of such use. This study aimed at the detection of 17 different strains from different European regions, differing in biological features and mortality. The study confirmed that real-time PCR is an applicable and effective method for diagnosis of RHDV, irrespective of the stains' features.

  18. Subsidence and current strain patterns on Tenerife Island (Canary Archipelago, Spain) derived from continuous GNSS time series (2008-2015)

    Science.gov (United States)

    Sánchez-Alzola, A.; Martí, J.; García-Yeguas, A.; Gil, A. J.

    2016-11-01

    In this paper we present the current crustal deformation model of Tenerife Island derived from daily CGPS time series processing (2008-2015). Our results include the position time series, a global velocity estimation and the current crustal deformation on the island in terms of strain tensors. We detect a measurable subsidence of 1.5-2 mm/yr. in the proximities of the Cañadas-Teide-Pico Viejo (CTPV) complex. These values are higher in the central part of the complex and could be explained by a lateral spreading of the elastic lithosphere combined with the effect of the drastic descent of the water table in the island experienced during recent decades. The results show that the Anaga massif is stable in both its horizontal and vertical components. The strain tensor analysis shows a 70 nstrain/yr. E-W compression in the central complex, perpendicular to the 2004 sismo-volcanic area, and 50 nstrain/yr. SW-NE extension towards the Northeast ridge. The residual velocity and strain patterns coincide with a decline in volcanic activity since the 2004 unrest.

  19. Effect of temperature on aging and time-temperature superposition in nonergodic laponite suspensions

    Science.gov (United States)

    Awasthi, Varun; Joshi, Yogesh M.

    We have studied the effect of temperature on aging dynamics of laponite suspensions by carrying out the rheological oscillatory and creep experiments. We observed that at higher temperatures the mechanism responsible for aging became faster thereby shifting the evolution of elastic modulus to lower ages. Significantly, in the creep experiments, all the aging time and the temperature dependent strain data superposed to form a master curve. Possibility of such superposition suggests that the rheological behavior depends on the temperature and the aging time only through the relaxation processes and both the variables do not affect the distribution but only the average value of relaxation times. In addition, this procedure allows us to predict long time rheological behavior by carrying out short time tests at high temperatures and small ages.

  20. Evaluation of the dynamic behavior of a Pelton runner based on strain gauge measurements

    Science.gov (United States)

    Mack, Reiner; Probst, Christian

    2016-11-01

    A reliable mechanical design of Pelton runners is very important in the layout of new installations and modernizations. Especially in horizontal machines, where the housing is not embedded into concrete, a rupture of a runner bucket can have severe consequences. Even if a crack in the runner is detected on time, the outage time that follows the malfunction of the runner is shortening the return of investment. It is a fact that stresses caused by the runner rotation and the jet forces are superposed by high frequent dynamic stresses. In case of resonance it even can be the dominating effect that is limiting the lifetime of a runner. Therefore a clear understanding of the dynamic mechanisms is essential for a safe runner design. This paper describes the evaluation of the dynamic behavior of a Pelton runner installed in a model turbine based on strain gauge measurements. Equipped with strain gauges at the root area of the buckets, the time responses of the strains under the influence of various operational parameters were measured. As a result basic theories for the jet bucket excitation were verified and the influence of the water mass was detected by evaluating the frequency shift in case of resonance. Furthermore, the influence of the individual bucket masses onto the dynamic behaviour for different mode shapes got measured.

  1. Time dependence of mesoscopic strain distribution for triaxial woven carbon-fiber-reinforced polymer under creep loading measured by digital image correlation

    Science.gov (United States)

    Koyanagi, Jun; Nagayama, Hideo; Yoneyama, Satoru; Aoki, Takahira

    2016-06-01

    This paper presents the time dependence of the mesoscopic strain of a triaxial woven carbon-fiber-reinforced polymer under creep loading measured using digital image correlation (DIC). Two types of DIC techniques were employed for the measurement: conventional subset DIC and mesh DIC. Static tensile and creep tests were carried out, and the time dependence of the mesoscopic strain distribution was investigated by applying these techniques. The ultimate failure of this material is dominated by inter-bundle decohesion caused by relative rigid rotation and relating shear stress. Therefore, these were focused on in the present study. During the creep tests, the fiber directional strain, shear strain, and rotation were monitored using the DIC, and the mechanism for the increase in the specimen's macro-strain over time was investigated based on the results obtained by the DIC measurement.

  2. Differentiation of Lactobacillus brevis strains using Matrix-Assisted-Laser-Desorption-Ionization-Time-of-Flight Mass Spectrometry with respect to their beer spoilage potential.

    Science.gov (United States)

    Kern, Carola C; Vogel, Rudi F; Behr, Jürgen

    2014-06-01

    Lactobacillus (L.) brevis is one of the most frequently encountered bacteria in beer-spoilage incidents. As the species Lactobacillus brevis comprises strains showing varying ability to grow in beer, ranging from growth in low hopped wheat to highly hopped pilsner beer, differentiation and classification of L. brevis with regard to their beer-spoiling ability is of vital interest for the brewing industry. Matrix-Assisted-Laser-Desorption-Ionization-Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) has been shown as a powerful tool for species and sub-species differentiation of bacterial isolates and is increasingly used for strain-level differentiation. Seventeen L. brevis strains, representative of different spoilage types, were characterized according to their tolerance to iso-alpha-acids and their growth in wheat-, lager- and pilsner beer. MALDI-TOF MS spectra were acquired to perform strain-level identification, cluster analysis and biomarker detection. Strain-level identification was achieved in 90% out of 204 spectra. Misidentification occurred nearly exclusively among strains belonging to the same spoilage type. Though spectra of strongly beer-spoiling strains showed remarkable similarity, no decisive single markers were detected to be present in all strains of one group. However, MALDI-TOF MS spectra can be reliably assigned to the corresponding strain and thus allow to track single strains and connect them to their physiological properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Genetic Influences on Survival Time After Severe Hemorrhage in Inbred Rat Strains

    Science.gov (United States)

    2011-04-12

    were conducted 24 h postsurgery to minimize confounding influences of isoflurane and buprenorphine on survival time. The half - life for isoflurane (30...detail previously (25). At the end of surgery, rats were injected with buprenorphine (25 g/kg body wt sc) and with 10 ml of 0.9% saline (sc)/400 g body...min, Ref. 22) and buprenorphine (2.1–3 h, Ref. 33) would suggest a clearance from the blood compatible with our assumption. However, one cannot

  4. Real-time In-Flight Strain and Deflection Monitoring with Fiber Optic Sensors

    Science.gov (United States)

    Richards, Lance; Parker, Allen R.; Ko, William L.; Piazza, Anthony

    2008-01-01

    This viewgraph presentation reviews Dryden's efforts to develop in-flight monitoring based on Fiber Optics. One of the motivating factors for this development was the breakup of the Helios aircraft. On Ikhana the use of fiber optics for wing shape sensing is being developed. They are being used to flight validate fiber optic sensor measurements and real-time wing shape sensing predictions on NASA's Ikhana vehicle; validate fiber optic mathematical models and design tools; Assess technical viability and, if applicable, develop methodology and approach to incorporate wing shape measurements within the vehicle flight control system, and develop and flight validate advanced approaches to perform active wing shape control.

  5. One time intranasal vaccination with a modified vaccinia Tiantan strain MVTT(ZCI) protects animals against pathogenic viral challenge.

    Science.gov (United States)

    Yu, Wenbo; Fang, Qing; Zhu, Weijun; Wang, Haibo; Tien, Po; Zhang, Linqi; Chen, Zhiwei

    2010-02-25

    To combat variola virus in bioterrorist attacks, it is desirable to develop a noninvasive vaccine. Based on the vaccinia Tiantan (VTT) strain, which was historically used to eradicate the smallpox in China, we generated a modified VTT (MVTT(ZCI)) by removing the hemagglutinin gene and an 11,944bp genomic region from HindIII fragment C2L to F3L. MVTT(ZCI) was characterized for its host cell range in vitro and preclinical safety and efficacy profiles in mice. Despite replication-competency in some cell lines, unlike VTT, MVTT(ZCI) did not cause death after intracranial injection or body weight loss after intranasal inoculation. MVTT(ZCI) did not replicate in mouse brain and was safe in immunodeficient mice. MVTT(ZCI) induced neutralizing antibodies via the intranasal route of immunization. One time intranasal immunization protected animals from the challenge of the pathogenic vaccinia WR strain. This study established proof-of-concept that the attenuated replicating MVTT(ZCI) may serve as a safe noninvasive smallpox vaccine candidate.

  6. Induction time of Fe-SOD synthesis and activity determine different tolerance of two Desmodesmus (green algae) strains to chloridazon: a study with synchronized cultures.

    Science.gov (United States)

    Pokora, Wojciech; Tukaj, Zbigniew

    2013-09-01

    Cells of two Desmodesmus armatus strains (276-4a and 276-4d) grown asynchronously in batch cultures after 24-h treatment revealed different tolerance to chloridazon (photosynthetic herbicide) applied at a concentration of 3.45 mg L(-1). To find time- and cell cycle-dependent biochemical reasons leading to such a difference, a population of young autospores of both strains synchronized by a light/dark (14/10) regime were exposed to chloridazon at the initiation of the light period. Chloridazon reduced the growth and number of divisions of cell strain 276-4d. In consequence, at the end of the dark phase the number of released autospores was reduced by 50% compared with the control. In contrast, the growth and reproductive processes of cell strains 276-4a was unaffected. Moreover, chloridazon treatment speeded up cell development, as a result of which the release of autospores took this process observed in the control cells over. There is a relationship between photosynthetic activity response to chloridazon and time-dependent changes in Fe-SOD content and activity. The energy trapped in the reaction centre (RC) was similar in both strains, but the amount of energy absorbed by RCs was twice as high in strain 276-4d as in 276-4a. In consequence, non-photochemical energy dissipation occurring in the cells of 276-4d strain far exceed the value obtained for 276-4a strain. The control cells of both strains differed significantly in the content of FSD 1 and FSD 2 proteins, whereas the differences in Fe-SOD isoforms activities were slight. The 8-fold increase in SOD content in CHD treated cells of strain 276-4a was associated with the transience of photosynthetic efficiency impairment. In CHD treated cells of strain 276-4d, neither activity of Fe-SOD nor FSDs protein content was instantly affected. Different response of developing cells of two Desmodesmus strains to CHD is influenced by the inherent features of cells; the short time required to induce stress adaptive

  7. Detection of Mycoplasma mycoides subsp. mycoides SC in bronchoalveolar lavage fluids of cows based on a TaqMan real-time PCR discriminating wild type strains from an lppQ− mutant vaccine strain used for DIVA-strategies

    Science.gov (United States)

    Vilei, Edy M.; Frey, Joachim

    2010-01-01

    Contagious bovine pleuropneumonia (CBPP) is the most serious cattle disease in Africa, caused by Mycoplasma mycoides subsp. mycoides small-colony type (SC). CBPP control strategies currently rely on vaccination with a vaccine based on live attenuated strains of the organism. Recently, an lppQ− mutant of the existing vaccine strain T1/44 has been developed (Janis et al., 2008). This T1lppQ− mutant strain is devoid of lipoprotein LppQ, a potential virulence attribute of M. mycoides subsp. mycoides SC. It is designated as a potential live DIVA (Differentiating Infected from Vaccinated Animals) vaccine strain allowing both serological and etiological differentiation. The present paper reports on the validation of a control strategy for CBPP in cattle, whereby a TaqMan real-time PCR based on the lppQ gene has been developed for the direct detection of M. mycoides subsp. mycoides SC in ex vivo bronchoalveolar lavage fluids of cows and for the discrimination of wild type strains from the lppQ− mutant vaccine strain. PMID:20381545

  8. Real-time PCR based analysis of metal resistance genes in metal resistant Pseudomonas aeruginosa strain J007.

    Science.gov (United States)

    Choudhary, Sangeeta; Sar, Pinaki

    2016-07-01

    A uranium (U)-resistant and -accumulating Pseudomonas aeruginosa strain was characterized to assess the response of toxic metals toward its growth and expression of metal resistance determinants. The bacterium showed MIC (minimum inhibitory concentration) values of 6, 3, and 2 mM for Zn, Cu, and Cd, respectively; with resistance phenotype conferred by periplasmic Cu sequestering copA and RND type heavy metal efflux czcA genes. Real-time PCR-based expression analysis revealed significant upregulation of both these genes upon exposure to low concentrations of metals for short duration, whereas the global stress response gene sodA encoding superoxide dismutase enzyme was upregulated only at higher metal concentrations or longer exposure time. It could also be inferred that copA and czcA are involved in providing resistance only at low metal concentrations, whereas involvement of "global stress response" phenomenon (expression of sodA) at higher metal concentration or increased exposure was evident. This study provides significant understanding of the adaptive response of bacteria surviving in metal and radionuclide contaminated environments along with the development of real-time PCR-based quantification method of using metal resistance genes as biomarker for monitoring relevant bacteria in such habitats.

  9. Successive passaging of the scrapie strains, ME7-ha and 139A-ha, generated by the interspecies transmission of mouse-adapted strains into hamsters markedly shortens the incubation times, but maintains their molecular and pathological properties.

    Science.gov (United States)

    Shi, Qi; Xiao, Kang; Zhang, Bao-Yun; Zhang, Xiao-Mei; Chen, Li-Na; Chen, Cao; Gao, Chen; Dong, Xiao-Ping

    2015-04-01

    As a type of zoonotic disease, prion diseases may be transmitted naturally and experimentally among species. In a previous study, we demonstrated that the mouse-adapted scrapie strains, ME7 (ME7-mo) and 139A (139A-mo), can overcome the species barrier and induce experimental scrapie when inoculated into Golden hamsters and generated 2 new hamster-adapted strains, ME7 (ME7-ha) and 139A (139A-ha). In the present study, in order to assess the infectivity and other molecular and neuropathological properties of the newly formed scrapie agents, ME7-ha and 139A-ha were further intracerebrally inoculated into hamsters. Compared with infection with 1st passage strains, the incubation times and clinical courses of infection with 2nd passage strains were markedly shorter, which were quite comparable with those of the mice infected with their parent mouse strains. The glycosylation patterns of brain PrP(Sc) in the animals infected with the 2nd passage of those 2 strains maintained similar features as those in the animals infected with the 1st passage of those strains, with predominantly diglycosylated PrP(Sc). Neuropathological assays revealed comparable spongiform degeneration and microglia proliferation in the brain tissues from the infected mice and hamsters, but markedly more plaque-like deposits of PrP(Sc) and more severe astrogliosis in the brains of the hamster. These data indicate that the strains, ME7-ha 1st and 139A-ha 1st generated by interspecies infection can passage in the new host hamster and stably maintain their molecular and neuropathological characteristics.

  10. Usefulness of ultrasonic strain measurement-based mechanical properties imaging technique: toward realization of short time diagnosis/treatment

    Science.gov (United States)

    Sumi, Chikayoshi; Kubota, Mitsuhiro; Wakabayashi, Gou; Tanabe, Minoru

    2003-06-01

    For various soft tissues (e.g., liver, breast, etc.), we are developing the ultrasonic strain measurement-based mechanical properties (shear modulus, visco-shear modulus, etc.) reconstruction/imaging technique. To clarify the limitation of our quantitative reconstruction/imaging technique as a diagnostic tool for differentiating malignancies, together with improving the spatial resolution and the dynamic range we are collecting the clinical reconstruction image data. Furthermore, we are applying our technique as a monitoring technique for the effectiveness of chemical therapy (e.g., anticancer drug, ethanol, etc.), thermal therapy (e.g., micro, and rf electromagnetic wave, HIFU, LASER, etc.), and cryotherapy. As soft tissues are deformed in 3-D space due to externally situated quasi-static and/or low frequency mechanical sources, multidimensional signal processing improves strain measurement accuracy and reduces inhomogeneity-dependent modulus reconstruction artifacts. These have been verified by us through simulations and phantom/animal in vitro experiments. Briefly, here we discuss the limitations of low dimensional signal processing. Moreover, we exhibit the superiority both on differential diagnosis for these human in vivo malignancies and monitoring for these therapies of our quasi-real time imaging (using conventional US equipment) to conventional B-mode imaging. Our technique is available as a clinical visualization technique both for diagnosis and treatment, and monitored mechanical properties data can also be effectively utilized as the measure for controlling the therapy, i.e., the exposure energy, the foci, the exposure interval, etc. In the near future, suitable combination of various simple and low-invasive therapy techniques with our imaging technique will open up a new clinical style allowing diagnosis and the subsequently immediate treatment. This must substantially reduce the total medical expenses.

  11. Real-time reverse transcription polymerase chain reaction method for detection of Canine distemper virus modified live vaccine shedding for differentiation from infection with wild-type strains.

    Science.gov (United States)

    Wilkes, Rebecca P; Sanchez, Elena; Riley, Matthew C; Kennedy, Melissa A

    2014-01-01

    Canine distemper virus (CDV) remains a common cause of infectious disease in dogs, particularly in high-density housing situations such as shelters. Vaccination of all dogs against CDV is recommended at the time of admission to animal shelters and many use a modified live virus (MLV) vaccine. From a diagnostic standpoint for dogs with suspected CDV infection, this is problematic because highly sensitive diagnostic real-time reverse transcription polymerase chain reaction (RT-PCR) tests are able to detect MLV virus in clinical samples. Real-time PCR can be used to quantitate amount of virus shedding and can differentiate vaccine strains from wild-type strains when shedding is high. However, differentiation by quantitation is not possible in vaccinated animals during acute infection, when shedding is low and could be mistaken for low level vaccine virus shedding. While there are gel-based RT-PCR assays for differentiation of vaccine strains from field strains based on sequence differences, the sensitivity of these assays is unable to match that of the real-time RT-PCR assay currently used in the authors' laboratory. Therefore, a real-time RT-PCR assay was developed that detects CDV MLV vaccine strains and distinguishes them from wild-type strains based on nucleotide sequence differences, rather than the amount of viral RNA in the sample. The test is highly sensitive, with detection of as few as 5 virus genomic copies (corresponding to 10(-1) TCID(50)). Sequencing of the DNA real-time products also allows phylogenetic differentiation of the wild-type strains. This test will aid diagnosis during outbreaks of CDV in recently vaccinated animals.

  12. Real time investigation of the effect of thermal expansion coefficient mismatch on film-substrate strain partitioning in Ag/Si systems

    Science.gov (United States)

    Das, Debolina; Banu, Nasrin; Bisi, Bhaskar; Mahato, J. C.; Srihari, V.; Halder, Rumu; Dev, B. N.

    2016-10-01

    We have used X-ray diffraction (XRD) to investigate strain partitioning between an epitaxial layer and the substrate as a function of temperature, where the substrate (Si) and the epilayer material (Ag) have large thermal expansion coefficient (α) mismatch. The Ag/Si(111) system undergoes morphological changes upon heating, and the larger and taller islands are formed exposing more substrate surfaces. Sample heating was carried out under nitrogen flow. At >300 °C, the Si(111) diffraction peak splits into three. One of these components conforms to the thermal expansion of bulk Si. The other two components correspond to a highly nonlinear decrease and increase of Si-d(111) planar spacing. The decreasing component has been associated with strained Si under Ag and the increasing component with strained Si under SiO2, which has been formed partly prior to the XRD experiment and partly during sample heating. The opposite trends of these two Si-d(111) components are because of the larger value of α for Ag (7 times) and smaller for SiO2 (1/5th) compared to Si. The out-of-plane strain partitioning has been such that at room temperature, the Si substrate is unstrained and the strain in Ag is ˜0.3%. At 800 °C, Ag is practically relaxed, while Si under Ag is ˜-0.7% strained. A temperature dependent strain partitioning factor has been introduced to fit the data.

  13. Comparative proteomic profiles of Aspergillus fumigatus and Aspergillus lentulus strains by surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS

    Directory of Open Access Journals (Sweden)

    Pelloux Hervé

    2011-07-01

    Full Text Available Abstract Background Surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS was applied to analyze the protein profiles in both somatic and metabolic extracts of Aspergillus species. The study was carried out on some Aspergillus species within the Fumigati section (Aspergillus fumigatus wild-types and natural abnormally pigmented mutants, and Aspergillus lentulus. The aim was to validate whether mass spectrometry protein profiles can be used as specific signatures to discriminate different Aspergillus species or even mutants within the same species. Results The growth conditions and the SELDI-TOF parameters were determined to generate characteristic protein profiles of somatic and metabolic extracts of Aspergillus fumigatus strains using five different ProteinChips®, eight growth conditions combining two temperatures, two media and two oxygenation conditions. Nine strains were investigated: three wild-types and four natural abnormally pigmented mutant strains of A. fumigatus and two strains of A. lentulus. A total of 242 fungal extracts were prepared. The spectra obtained are protein signatures linked to the physiological states of fungal strains depending on culture conditions. The best resolutions were obtained using the chromatographic surfaces CM10, NP20 and H50 with fractions of fungi grown on modified Sabouraud medium at 37°C in static condition. Under these conditions, the SELDI-TOF analysis allowed A. fumigatus and A. lentulus strains to be grouped into distinct clusters. Conclusions SELDI-TOF analysis distinguishes A. fumigatus from A. lentulus strains and moreover, permits separate clusters of natural abnormally pigmented A. fumigatus strains to be obtained. In addition, this methodology allowed us to point out fungal components specifically produced by a wild-type strain or natural mutants. It offers attractive potential for further studies of the Aspergillus biology or pathogenesis.

  14. Variable immune cell frequencies in peripheral blood of LEW.1AR1-iddm rats over time compared to other congenic LEW strains

    Science.gov (United States)

    Arndt, T; Jörns, A; Hedrich, H-J; Lenzen, S; Wedekind, D

    2014-01-01

    The LEW.1AR1-iddm rat is an animal model of human type 1 diabetes (T1D), which arose through a spontaneous mutation within the major histocompatibility complex (MHC)-congenic background strain LEW.1AR1. The LEW.1AR1-iddm rat is characterized by two phenotypes: diabetes development with a diabetes incidence of 60% and a variable T cell frequency in peripheral blood. In this study the immune cell repertoire of LEW.1AR1-iddm rats was analysed over time from days 30 to 90 of life and compared to the background strain LEW.1AR1 and the LEW rat strain as well as the LEW.1WR1 rat strain. The LEW.1AR1-iddm rats are characterized by a high variability of CD3+, CD4+ and CD8+ T cell frequencies in peripheral blood over time, and the frequency is unique for each animal. The variability within the frequencies resulted in changes of the CD4+ : CD8+ T cell ratio. The other three rat strains studied were characterized by a stable but nevertheless strain-specific T cell frequency resulting in a specific CD4+ : CD8+ T cell ratio. The frequency of natural killer (NK) cells and B cells in LEW.1AR1-iddm rats was increased, with a higher variability compared to the other strains. Only monocytes showed no differences in frequency and variability between all strains studied. These variabilities of immune cell frequencies in the LEW.1AR1-iddm rats might lead to imbalances between autoreactive and regulatory T cells in peripheral blood as a prerequisite for diabetes development. PMID:24628466

  15. Temperature-dependent strain and temperature sensitivities of fused silica single mode fiber sensors with pulse pre-pump Brillouin optical time domain analysis

    Science.gov (United States)

    Bao, Yi; Chen, Genda

    2016-06-01

    This paper reports a distributed temperature and strain sensor based on pulse pre-pump Brillouin optical time domain analysis. An uncoated, telecom-grade fused silica single-mode fiber as a distributed sensor was calibrated for its sensitivity coefficients under various strains and temperatures up to 800 °C. The Brillouin frequency of fiber samples changed nonlinearly with temperature and linearly with strain. The temperature sensitivity decreased from 1.113 to 0.830 MHz /°C in the range of 22-800 °C. The strain sensitivity was reduced from 0.054 to 0.042 MHz /μɛ as the temperature increased from 22 to 700 °C and became unstable at higher temperatures due to creep effect. The strain measurement range was reduced from 19 100 to 6000 μɛ in the temperature range of 22-800 °C due to fused silica’s degradation. The calibrated fiber optic sensor demonstrated adequate accuracy and precision for strain and temperature measurements and stable performance in heating-cooling cycles. It was validated in an application setting.

  16. Complete Genome Sequence of Pelosinus sp. Strain UFO1 Assembled Using Single-Molecule Real-Time DNA Sequencing Technology

    Energy Technology Data Exchange (ETDEWEB)

    Steven D. Brown; Sagar M. Utturkar; Timothy S. Magnuson; Allison E. Ray; Farris L. Poole; W. Andrew Lancaster; Michael P. Thorgersen; Michael W. W. Adams; Dwayne A. Elias

    2014-09-01

    Pelosinus fermentans strain R7 was isolated from Russian kaolin clays as the type strain and it can reduce Fe(III) during fermentative growth (1). Draft genome sequences for P. fermentans R7 and four strains from Hanford, Washington, USA, have been published (2–4). The P. fermentans 16S rRNA sequence dominated the lactate-based enrichment cultures from three geochemically contrasting soils from the Melton Branch Watershed, Oak Ridge, Tennessee, USA (5) and also at another stimulated, uraniumcontaminated field site near Oak Ridge (6). For the current work, strain UFO1 was isolated from pristine sediments at a background field site in Oak Ridge and characterized as facilitating U(VI) reduction and precipitation with phosphate (7).

  17. A Novel Duplex Real-Time Reverse-Transcription PCR Assay for the Detection of Influenza A and the Novel Influenza A(H1N1 Strain

    Directory of Open Access Journals (Sweden)

    Theo P. Sloots

    2009-12-01

    Full Text Available Timely implementation of antiviral treatment and other public health based responses are dependent on accurate and rapid diagnosis of the novel pandemic influenza A(H1N1 strain. In this study we developed a duplex real-time PCR (RT-PCR (dFLU-TM assay for the simultaneous detection of a broad range of influenza A subtypes and specific detection of the novel H1N1 2009 pandemic strain. The assay was compared to the combined results of two previously described monoplex RT-PCR assays using 183 clinical samples and 10 seasonal influenza A isolates. Overall, the results showed that the dFLU-TM RT-PCR method is suitable for detection of influenza A, including the novel H1N1 pandemic strain, in clinical samples.

  18. Strain differences in paroxetine-induced reduction of immobility time in the forced swimming test in mice: role of serotonin.

    Science.gov (United States)

    Guzzetti, Sara; Calcagno, Eleonora; Canetta, Alessandro; Sacchetti, Giuseppina; Fracasso, Claudia; Caccia, Silvio; Cervo, Luigi; Invernizzi, Roberto W

    2008-10-10

    We studied the antidepressant-like effect of paroxetine in strains of mice carrying different isoforms of tryptophan hydroxylase-2 (TPH-2), the enzyme responsible for the synthesis of brain serotonin (5-HT). The effect of paroxetine alone and in combination with pharmacological treatments enhancing or lowering 5-HT synthesis or melatonin was assessed in the forced swimming test in mice carrying allelic variants of TPH-2 (1473C in C57BL/6 and 1473G in DBA/2 and BALB/c). Changes in brain 5-hydroxytryptophan (5-HTP) accumulation and melatonin levels were measured by high-performance liquid chromatography. Paroxetine (2.5 and 5 mg/kg) reduced immobility time in C57BL/6J and C57BL/6N mice but had no such effect in DBA/2J, DBA/2N and BALB/c mice, even at 10 mg/kg. Enhancing 5-HT synthesis with tryptophan reinstated the antidepressant-like effect of paroxetine in DBA/2J, DBA/2N and BALB/c mice whereas inhibition of 5-HT synthesis prevented the effect of paroxetine in C57BL/6N mice. The response to paroxetine was not associated with changes in locomotor activity, brain melatonin or brain levels of the drug measured at the end of the behavioral test. These results support the importance of 5-HT synthesis in the response to SSRIs and suggest that melatonin does not contribute to the ability of tryptophan to rescue the antidepressant-like effect of paroxetine.

  19. Rapid real-time PCR methods to distinguish Salmonella Enteritidis wildtype field isolates from vaccine strains Salmovac SE/Gallivac SE and AviPro SALMONELLA VAC E.

    Science.gov (United States)

    Maurischat, Sven; Szabo, Istvan; Baumann, Beatrice; Malorny, Burkhard

    2015-05-01

    Salmonella enterica serovar Enteritidis is a major non-typhoid Salmonella serovar causing human salmonellosis mainly associated with the consumption of poultry and products thereof. To reduce infections in poultry, S. Enteritidis live vaccine strains AviPro SALMONELLA VAC E and Salmovac SE/Gallivac SE have been licensed and used in several countries worldwide. To definitively diagnose a S. Enteritidis contamination in vaccinated herds a reliable and fast method for the differentiation between vaccine and wildtype field isolates is required. In this study, we developed and validated real-time PCR (qPCR) assays to distinguish those variants genetically. Suitable target sequences were identified by whole genome sequencing (WGS) using the Illumina MiSeq system. SNP regions in kdpA and nhaA proved to be most useful for differentiation of AviPro SALMONELLA VAC E and Salmovac SE/Gallivac SE, respectively, from wildtype strains. For each vaccine strain one TaqMan-qPCR assay and one alternative approach using High Resolution Melting (HRM) analysis was designed. All 30 Salmovac SE and 7 AviPro SALMONELLA VAC E vaccine strain reisolates tested were correctly identified by both approaches (100% inclusivity). Furthermore, all 137 (TaqMan) and 97 (HRM) Salmonella non-vaccine and related Enterobacteriaceae strains tested were excluded (100% exclusivity). The analytical detection limits were determined to be approx. 10(2) genome copies/reaction for the TaqMan and 10(4) genome copies/reaction for the HRM approach. The real-time PCR assays proved to be a reliable and fast alternative to the cultural vaccine strain identification tests helping decision makers in control measurements to take action within a shorter period of time.

  20. One-step multiplex real-time RT-PCR assay for detecting and genotyping wild-type group A rotavirus strains and vaccine strains (Rotarix® and RotaTeq® in stool samples

    Directory of Open Access Journals (Sweden)

    Rashi Gautam

    2016-01-01

    Full Text Available Background. Group A rotavirus (RVA infection is the major cause of acute gastroenteritis (AGE in young children worldwide. Introduction of two live-attenuated rotavirus vaccines, RotaTeq® and Rotarix®, has dramatically reduced RVA associated AGE and mortality in developed as well as in many developing countries. High-throughput methods are needed to genotype rotavirus wild-type strains and to identify vaccine strains in stool samples. Quantitative RT-PCR assays (qRT-PCR offer several advantages including increased sensitivity, higher throughput, and faster turnaround time. Methods. In this study, a one-step multiplex qRT-PCR assay was developed to detect and genotype wild-type strains and vaccine (Rotarix® and RotaTeq® rotavirus strains along with an internal processing control (Xeno or MS2 RNA. Real-time RT-PCR assays were designed for VP7 (G1, G2, G3, G4, G9, G12 and VP4 (P[4], P[6] and P[8] genotypes. The multiplex qRT-PCR assay also included previously published NSP3 qRT-PCR for rotavirus detection and Rotarix® NSP2 and RotaTeq® VP6 qRT-PCRs for detection of Rotarix® and RotaTeq® vaccine strains respectively. The multiplex qRT-PCR assay was validated using 853 sequence confirmed stool samples and 24 lab cultured strains of different rotavirus genotypes. By using thermostable rTth polymerase enzyme, dsRNA denaturation, reverse transcription (RT and amplification (PCR steps were performed in single tube by uninterrupted thermocycling profile to reduce chances of sample cross contamination and for rapid generation of results. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Results. The VP7 qRT-PCRs exhibited 98.8–100% sensitivity, 99.7–100% specificity, 85–95% efficiency and a limit of detection of 4–60 copies per singleplex reaction. The VP7 qRT-PCRs exhibited 81–92% efficiency and limit of detection of 150–600 copies in multiplex reactions. The VP4 q

  1. One-step multiplex real-time RT-PCR assay for detecting and genotyping wild-type group A rotavirus strains and vaccine strains (Rotarix® and RotaTeq®) in stool samples.

    Science.gov (United States)

    Gautam, Rashi; Mijatovic-Rustempasic, Slavica; Esona, Mathew D; Tam, Ka Ian; Quaye, Osbourne; Bowen, Michael D

    2016-01-01

    Background. Group A rotavirus (RVA) infection is the major cause of acute gastroenteritis (AGE) in young children worldwide. Introduction of two live-attenuated rotavirus vaccines, RotaTeq® and Rotarix®, has dramatically reduced RVA associated AGE and mortality in developed as well as in many developing countries. High-throughput methods are needed to genotype rotavirus wild-type strains and to identify vaccine strains in stool samples. Quantitative RT-PCR assays (qRT-PCR) offer several advantages including increased sensitivity, higher throughput, and faster turnaround time. Methods. In this study, a one-step multiplex qRT-PCR assay was developed to detect and genotype wild-type strains and vaccine (Rotarix® and RotaTeq®) rotavirus strains along with an internal processing control (Xeno or MS2 RNA). Real-time RT-PCR assays were designed for VP7 (G1, G2, G3, G4, G9, G12) and VP4 (P[4], P[6] and P[8]) genotypes. The multiplex qRT-PCR assay also included previously published NSP3 qRT-PCR for rotavirus detection and Rotarix® NSP2 and RotaTeq® VP6 qRT-PCRs for detection of Rotarix® and RotaTeq® vaccine strains respectively. The multiplex qRT-PCR assay was validated using 853 sequence confirmed stool samples and 24 lab cultured strains of different rotavirus genotypes. By using thermostable rTth polymerase enzyme, dsRNA denaturation, reverse transcription (RT) and amplification (PCR) steps were performed in single tube by uninterrupted thermocycling profile to reduce chances of sample cross contamination and for rapid generation of results. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Results. The VP7 qRT-PCRs exhibited 98.8-100% sensitivity, 99.7-100% specificity, 85-95% efficiency and a limit of detection of 4-60 copies per singleplex reaction. The VP7 qRT-PCRs exhibited 81-92% efficiency and limit of detection of 150-600 copies in multiplex reactions. The VP4 qRT-PCRs exhibited 98

  2. Non-destructive magneto-strain analysis of YB2Cu3Oy superconducting magnets using neutron diffraction in the time-of-flight mode

    Science.gov (United States)

    Tomita, M.; Muralidhar, M.; Suzuki, K.; Ishihara, A.; Fukumoto, Y.; Osamura, K.; Machiya, S.; Harjo, S.

    2012-09-01

    In general, neutron diffraction allows a non-destructive investigation of bulk samples. In this study, a magneto-strain analysis of the trapped field in YB2Cu3Oy "YBCO" superconducting bulks was carried out at 45 K using neutron diffraction time-of-flight (TOF) method. The TAKUMI TOF neutron diffractometer offers unique advantages, including accommodation of large objectives, control of the experimental set-up using a 4-axial goniometer (XYZθ), and a positional resolution of 0.01 mm allowing an accurate sample positioning. As a result, the lattice strain in the YB2Cu3Oy material could be estimated in both radial and hoop directions by estimating the difference of plane spacing with/without the trapped magnetic field. The results indicate that the samples with a low trapped field values have smaller magnetic strain than those with a high trapped field. Further, the strain in the hoop direction is higher than that in the radial direction. The present results indicate that neutron diffraction measurements are an effective method for evaluating the bulk residual strains in a non-destructive manner.

  3. Time-Space Evolution of Seismic Strain Release in the Area Shocked by the August 24-October 30 Central Italy Seismic Sequence

    Science.gov (United States)

    Barani, Simone; Mascandola, Claudia; Serpelloni, Enrico; Ferretti, Gabriele; Massa, Marco; Spallarossa, Daniele

    2017-05-01

    In this study, we analyze the space-time evolution of the seismic strain release in the area shocked by the still ongoing Italian Central Apennines seismic crisis started on August 24, 2016 and culminated with the October 30 main shock of M w 6.5. Specifically, we examine the variation in time and space of the seismic strain release rate with the aim of identifying the presence of peculiar seismicity patterns, such as seismic gaps, according to the seismic cycle theory. To this end, seismic strain rates are checked for consistency with strain rates from GPS measurements to possibly adjust them for missing events due to limited seismic catalog extension or incompleteness at large magnitudes. Our results has revealed that the seismic crisis followed a long-term quiescence of about 310 years, characterized by the absence of M6.5+ earthquakes, and marked by an almost steady release of seismic deformation. Such temporal gap started after the occurrence of two nearby strong events in 1703 (Valnerina and L'Aquila earthquakes with magnitudes of 6.9 and 6.7, respectively) and terminated with the beginning of the current Central Apennines seismic crisis.

  4. [Identification of mycobacteria by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry--using reference strains and clinical isolates of Mycobacterium].

    Science.gov (United States)

    Niitsuma, Katsunao; Saito, Miwako; Koshiba, Shizuko; Kaneko, Michiyo

    2014-05-01

    Matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS) method is being played an important role for the inspection of clinical microorganism as a rapid and the price reduction. Mass spectra obtained by measuring become points of identification whether the peak pattern match any species mass spectral pattern. We currently use MALDI-TOF MS for rapid and accurate diagnosis of inactivated reference and clinical isolates of Mycobacterium because of the improved pretreatment techniques compared with former inspection methods that pose a higher risk of infection to the operator. The identification matching rate of score value (SV) peak pattern spectra was compared with that of conventional methods such as strain diffusion/amplification. Also, cultures were examined after a fixed number of days. Compared with the initial inspection technique, the pretreatment stage of current MALDI-TOF MS inspection techniques can improve the analysis of inactivated acid-fast bacteria that are often used as inspection criteria strains of clinical isolates. Next, we compared the concordance rate for identification between MALDI-TOF MS and conventional methods such as diffusion/amplification by comparison of peak pattern spectra and evaluated SV spectra to identify differences in the culture media after the retention period. In examination of 158 strains of clinical isolated Mycobacterium tuberculosis complex (MTC), the identification coincidence rate in the genus level in a matching pattern was 99.4%, when the species level was included 94.9%. About 37 strains of nontuberculous mycobacteria (NTM), the identification coincidence rate in the genus level was 94.6%. M. bovis BCG (Tokyo strain) in the reference strain was judged by the matching pattern to be MTC, and it suggested that they are M. tuberculosis and affinity species with high DNA homology. Nontuberculous mycobacterial M. gordonae strain JATA 33-01 shared peak pattern spectra, excluding the

  5. The superposed orogenesis of the alpine-mediterranean edifice; Las orogenesis superpuestas del edificio alpino-mediterraneo

    Energy Technology Data Exchange (ETDEWEB)

    Argyriadis, I.

    2016-10-01

    The circum-Mediterranean chains must be considered as the result of two distinct orogenies. The apparent unity of the present structure is of formal order, due to the latest deformations. Since the Hercynian time there have been two periods of paroxysmal deformation; the younger fits the definition of the alpine orogeny; the older occured during the Cretaceous and may correspond to the first great convergent relative drift of the Eurasiatic and African blocks. The Cretaceous or Mesogean orogeny is independent from the Alpine orogeny stricto sensu (Oligo-Miocene) and cannot be considered as its prefiguration. Being independent in time, it is independent in space as well. Even if this Mesogean orogeny can appear locally restricted to the internal parts of the Alpine chains (Central Mediterranean area, Carpathes, Dinarides) this cannot be taken as a rule: towards the west, the Cretaceous deformations cross the axis of the western Alps and extend (new investigations) over Provence to the Betic chains and the Pyrenean area. Towards the east, the deformations of this period cross the Hellenides (new observations) and spread over the external area in a spectacular way, interesting areas which have never been tectonised again (Cyprus, south-eastern Anatolia, northern Syria, Oman). As a whole, this large Cretaceous orogenic zone is part of a wider domain which extends over central Iran towards the Himalayas and eastern Asia, and has its equivalent on the western side of the Atlantic Ocean, in the Caribbean islands, Mexico and the Americas. (Author)

  6. Detection and differentiation of field and vaccine strains of canine distemper virus using reverse transcription followed by nested real time PCR (RT-nqPCR) and RFLP analysis.

    Science.gov (United States)

    Fischer, Cristine Dossin Bastos; Ikuta, Nilo; Canal, Cláudio Wageck; Makiejczuk, Aline; Allgayer, Mariangela da Costa; Cardoso, Cristine Hoffmeister; Lehmann, Fernanda Kieling; Fonseca, André Salvador Kazantzi; Lunge, Vagner Ricardo

    2013-12-01

    Canine distemper virus (CDV) is the cause of a severe and highly contagious disease in dogs. Practical diagnosis of canine distemper based on clinical signs and laboratory tests are required to confirm CDV infection. The present study aimed to develop a molecular assay to detect and differentiate field and vaccine CDV strains. Reverse transcription followed by nested real time polymerase chain reaction (RT-nqPCR) was developed, which exhibited analytical specificity (all the samples from healthy dogs and other canine infectious agents were not incorrectly detected) and sensitivity (all replicates of a vaccine strain were positive up to the 3125-fold dilution - 10(0.7) TCID50). RT-nqPCR was validated for CDV detection on different clinical samples (blood, urine, rectal and conjunctival swabs) of 103 animals suspected to have distemper. A total of 53 animals were found to be positive based on RT-nqPCR in at least one clinical sample. Blood resulted in more positive samples (50 out of 53, 94.3%), followed by urine (44/53, 83.0%), rectal (38/53, 71%) and conjunctival (27/53, 50.9%) swabs. A commercial immunochromatography (IC) assay had detected CDV in only 30 conjunctival samples of these positive dogs. Nucleoprotein (NC) gene sequencing of 25 samples demonstrated that 23 of them were closer to other Brazilian field strains and the remaining two to vaccine strains. A single nucleotide sequences difference, which creates an Msp I restriction enzyme digestion, was used to differentiate between field and vaccine CDV strains by restriction fragment length polymorphism (RFLP) analysis. The complete assay was more sensitive than was IC for the detection of CDV. Blood was the more frequently positive specimen and the addition of a restriction enzyme step allowed the differentiation of vaccine and Brazilian field strains.

  7. Characterization of viral loads, strain and state of equine herpesvirus-1 using real-time PCR in horses following natural exposure at a racetrack in California.

    Science.gov (United States)

    Pusterla, Nicola; Wilson, W David; Mapes, Samantha; Finno, Carrie; Isbell, Diane; Arthur, Rick M; Ferraro, Gregory L

    2009-02-01

    The objective of this study was to determine viral loads, strain (neuropathogenic versus non-neuropathogenic) and state (lytic, non-replicating, latent) of equine herpesvirus-1 (EHV-1) by real-time polymerase chain reaction (PCR) in the blood and nasopharyngeal secretions of adult horses following natural exposure. The index case, a 4-year-old Thoroughbred gelding with confirmed EHV-1 myeloencephalopathy, as well as potentially exposed horses, were sampled over a period of 3 weeks. The study population comprised of 39 adult Thoroughbred horses and 35 adult "pony" and outrider horses of various breeds housed at a racetrack in Northern California. Blood samples and nasopharyngeal secretions (NPS) from all horses were tested on several occasions for EHV-1 DNA viral loads, targeting the glycoprotein B (gB) gene, viral strain, targeting the ORF 30 gene, and transcriptional activity of EHV-1, targeting the gB gene and latency-associated transcripts (LATs). Viral loads and transcriptional activity of the gB gene declined rapidly in the index case following antiviral treatment. The prevalence of EHV-1 infection in NPS determined by PCR slowly decreased over the 22 day study period from 25% to 14%. The initial surveillance showed multiple clusters of exposure, one associated with the index case and two related to horses that had recently returned from a different racetrack. Viral strain differentiation showed that only two horses (the index case and a neighboring horse) were infected with only a neuropathogenic strain, while all other horses were infected with either a non-neuropathogenic strain or were dually infected with both neuropathogenic and non-neuropathogenic strains. In most cases, the virus was present in either a lytic or a non-replicating form, while latent virus was found in blood and NPS much less frequently. The molecular approach used in this study showed promise for assessing the risk of exposing other horses to EHV-1 and for studying viral kinetics in

  8. Comparison of ultrasound B-mode, strain imaging, acoustic radiation force impulse displacement and shear wave velocity imaging using real time clinical breast images

    Science.gov (United States)

    Manickam, Kavitha; Machireddy, Ramasubba Reddy; Raghavan, Bagyam

    2016-04-01

    It has been observed that many pathological process increase the elastic modulus of soft tissue compared to normal. In order to image tissue stiffness using ultrasound, a mechanical compression is applied to tissues of interest and local tissue deformation is measured. Based on the mechanical excitation, ultrasound stiffness imaging methods are classified as compression or strain imaging which is based on external compression and Acoustic Radiation Force Impulse (ARFI) imaging which is based on force generated by focused ultrasound. When ultrasound is focused on tissue, shear wave is generated in lateral direction and shear wave velocity is proportional to stiffness of tissues. The work presented in this paper investigates strain elastography and ARFI imaging in clinical cancer diagnostics using real time patient data. Ultrasound B-mode imaging, strain imaging, ARFI displacement and ARFI shear wave velocity imaging were conducted on 50 patients (31 Benign and 23 malignant categories) using Siemens S2000 machine. True modulus contrast values were calculated from the measured shear wave velocities. For ultrasound B-mode, ARFI displacement imaging and strain imaging, observed image contrast and Contrast to Noise Ratio were calculated for benign and malignant cancers. Observed contrast values were compared based on the true modulus contrast values calculated from shear wave velocity imaging. In addition to that, student unpaired t-test was conducted for all the four techniques and box plots are presented. Results show that, strain imaging is better for malignant cancers whereas ARFI imaging is superior than strain imaging and B-mode for benign lesions representations.

  9. Dynamics of large-scale solar-wind streams obtained by the double superposed epoch analysis. 2. CIR.vs.Sheath and MC.vs.Ejecta comparisons

    CERN Document Server

    Yermolaev, Yu I; Nikolaeva, N S; Yermolaev, M Yu

    2016-01-01

    This work is a continuation of our previous paper [Yermolaevetal2015] which describes the average temporal profiles of interplanetary plasma and field parameters in large-scale solar-wind (SW) streams: CIR, ICME (both MC and Ejecta) and Sheath as well as the interplanetary shock (IS). Like in the previous work we use data of OMNI database, our catalog of large-scale solar-wind phenomena during 1976--2000 [Yermolaevetal2009] and the double superposed epoch analysis (DSEA) method [Yermolaevetal2010]: re-scaling the duration of interval for all types in such a manner that, respectively, beginning and end for all intervals of selected type coincide. We present new detailed results of comparison of two pair phenomena: (1) both types of compression regions (CIR.vs.Sheath) and (2) both types of ICMEs (MC.vs.Ejecta). Obtained data allows us to suggest that the formation of all types of compression regions has the same physical mechanism irrespective of piston (High-Speed Stream (HSS) or ICME) type and differences are...

  10. Superposed epoch analysis and storm statistics from 25 years of the global geomagnetic disturbance index, USGS-Dst

    Science.gov (United States)

    Gannon, J.L.

    2012-01-01

    Statistics on geomagnetic storms with minima below -50 nanoTesla are compiled using a 25-year span of the 1-minute resolution disturbance index, U.S. Geological Survey Dst. A sudden commencement, main phase minimum, and time between the two has a magnitude of 35 nanoTesla, -100 nanoTesla, and 12 hours, respectively, at the 50th percentile level. The cumulative distribution functions for each of these features are presented. Correlation between sudden commencement magnitude and main phase magnitude is shown to be low. Small, medium, and large storm templates at the 33rd, 50th, and 90th percentile are presented and compared to real examples. In addition, the relative occurrence of rates of change in Dst are presented.

  11. X-ray peak broadening analysis of Fe50Ni50 nanocrystalline alloys prepared under different milling times and BPR using size strain plot (SSP) method

    Indian Academy of Sciences (India)

    L Hosseinzadeh; J Baedi; A Khorsand Zak

    2014-08-01

    Fe50Ni50 nanocrystalline alloys were prepared by mechanical alloying method at different milling times of 2, 5, 10, 30, 50 and 70 h and ball powder ratios (BPR) of 10 : 1, 20 : 1 and 30 : 1. The structures of prepared powders were studied by X-ray diffraction (XRD). The broadening of the diffraction peaks were analysed using size strain plot (SSP) method and the lattice strain and crystallite size of the nanocrystals were calculated. In addition, the typical morphological studies were performed by scanning electron and transmission electron microscopies (SEM and TEM). The results showed that the crystallite size of the nanocrystals decreased with the milling time and BPR increases; whereas, the lattice constant () increased. Vibrating sample magnetometer (VSM) study of the powder prepared at 50 h and BPR 30 : 1 showed that the sample exhibits both the superparamagnetic and ferromagnetic properties in nanocrystallite size range.

  12. Analysis of transient deformation and pre-seismic strain anomalies in SW Taiwan by time series of continuous GPS and PS-InSAR

    Science.gov (United States)

    Min-Chien, Tsai

    2017-04-01

    The high precision Global Navigation Satellite System (GNSS) survey technique provides an efficient tool to study active tectonics and geodynamics. The data of more than 400 cGPS stations are processed with the GAMIT/GLOBK 10.6 software. After strictly data control, time series analysis, noise analysis, and common-mode error correction, we can drive a more realistic interseismic ITRF2008 velocity field Taiwan area. This result not only provides high precision GPS data for all of GPS or other users, also can be a basis for the crustal strain rate estimation and analysis of GPS baseline variation. The 2016 Meinong earthquake is the most deadly earthquake occurred in Taiwan after the 1999 Chichi earthquake. This project will focus on characterizing high strain anomalies and transient deformation from time series analysis of cGPS and PS-INSAR to assess the seismic hazards and potential active structures in the SW Taiwan area in terms of the temporal and spatial strain variations.

  13. Three-dimensional structure of the enveloped bacteriophage phi12: an incomplete T = 13 lattice is superposed on an enclosed T = 1 shell.

    Directory of Open Access Journals (Sweden)

    Hui Wei

    Full Text Available BACKGROUND: Bacteriophage phi12 is a member of the Cystoviridae, a unique group of lipid containing membrane enveloped bacteriophages that infect the bacterial plant pathogen Pseudomonas syringae pv. phaseolicola. The genomes of the virus species contain three double-stranded (dsRNA segments, and the virus capsid itself is organized in multiple protein shells. The segmented dsRNA genome, the multi-layered arrangement of the capsid and the overall viral replication scheme make the Cystoviridae similar to the Reoviridae. METHODOLOGY/PRINCIPAL FINDINGS: We present structural studies of cystovirus phi12 obtained using cryo-electron microscopy and image processing techniques. We have collected images of isolated phi12 virions and generated reconstructions of both the entire particles and the polymerase complex (PC. We find that in the nucleocapsid (NC, the phi12 P8 protein is organized on an incomplete T = 13 icosahedral lattice where the symmetry axes of the T = 13 layer and the enclosed T = 1 layer of the PC superpose. This is the same general protein-component organization found in phi6 NC's but the detailed structure of the entire phi12 P8 layer is distinct from that found in the best classified cystovirus species phi6. In the reconstruction of the NC, the P8 layer includes protein density surrounding the hexamers of P4 that sit at the 5-fold vertices of the icosahedral lattice. We believe these novel features correspond to dimers of protein P7. CONCLUSIONS/SIGNIFICANCE: In conclusion, we have determined that the phi12 NC surface is composed of an incomplete T = 13 P8 layer forming a net-like configuration. The significance of this finding in regard to cystovirus assembly is that vacancies in the lattice could have the potential to accommodate additional viral proteins that are required for RNA packaging and synthesis.

  14. Detection of the pediocin gene pedA in strains from human faeces by real-time PCR and characterization of Pediococcus acidilactici UVA1

    Directory of Open Access Journals (Sweden)

    Cereghetti Tania

    2007-09-01

    Full Text Available Abstract Background Bacteriocin-producing lactic acid bacteria are commonly used as natural protective cultures. Among them, strains of the genus Pediococcus are particularly interesting for their ability to produce pediocin, a broad spectrum antimicrobial peptide with a strong antagonistic activity against the food-borne pathogen Listeria monocytogenes. Furthermore, there is increasing interest in isolating new bacteriocin-producing strains of human intestinal origin that could be developed for probiotic effects and inhibition of pathogenic bacteria in the gut. In this work, we typed a new strain, co-isolated from baby faeces together with a Bifidobacterium thermophilum strain, and characterized its proteinaceous compound with strong antilisterial activity. Results The newly isolated strain UVA1 was identified as a Pediococcus acidilactici by carbohydrate fermentation profile, growth at 50°C and 16S rDNA sequencing. The partially purified bacteriocin was heat resistant up to 100°C, active over a wide range of pH (2 to 9 and susceptible to proteolytic enzymes. The molecular weight, estimated by SDS-PAGE, was similar to that of pediocin AcH/PA-1 (4.5 kDa. P. acidilactici UVA1 harboured a 9.5-kb plasmid that could be cured easily, which resulted in the loss of the antimicrobial activity. Southern hybridization using the DIG-labelled pedA-probe established that the bacteriocin gene was plasmid-borne as for all pediocin described so far. Nucleotide sequence of the whole operon (3.5 kb showed almost 100 % similarity to the pediocin AcH/PA-1 operon. The mRNA transcript for pedA could be detected in P. acidilactici UVA1 but not in the cured derivative, confirming the expression of the pedA-gene in UVA1. Using a new real-time PCR assay, eleven out of seventeen human faecal samples tested were found to contain pedA-DNA. Conclusion We identified and characterised the first pediocin produced by a human intestinal Pediococcus acidilactici isolate and

  15. Comparison of two real-time RT-PCR assays for differentiation of C-strain vaccinated from classical swine fever infected pigs and wild boars.

    Science.gov (United States)

    Widén, F; Everett, H; Blome, S; Fernandez Pinero, J; Uttenthal, A; Cortey, M; von Rosen, T; Tignon, M; Liu, L

    2014-10-01

    Classical swine fever is one of the most important infectious diseases for the pig industry worldwide due to its economic impact. Vaccination is an effective means to control disease, however within the EU its regular use is banned owing to the inability to differentiate infected and vaccinated animals, the so called DIVA principle. This inability complicates monitoring of disease and stops international trade thereby limiting use of the vaccine in many regions. The C-strain vaccine is safe to use and gives good protection. It is licensed for emergency vaccination in the EU in event of an outbreak. Two genetic assays that can distinguish between wild type virus and C-strain vaccines have recently been developed. Here the results from a comparison of these two real-time RT-PCR assays in an interlaboratory exercise are presented. Both assays showed similar performance.

  16. Transient spirals as superposed instabilities

    CERN Document Server

    Sellwood, J A

    2014-01-01

    We present evidence that recurrent spiral activity, long manifested in simulations of disk galaxies, results from the super-position of a few transient spiral modes. Each mode lasts between five and ten rotations at its corotation radius where its amplitude is greatest. The scattering of stars as each wave decays takes place over narrow ranges of angular momentum, causing abrupt changes to the impedance of the disk to subsequent traveling waves. Partial reflections of waves at these newly created features, allows new standing-wave instabilities to appear that saturate and decay in their turn, scattering particles at new locations, creating a recurring cycle. The spiral activity causes the general level of random motion to rise, gradually decreasing the ability of the disk to support further activity unless the disk contains a dissipative gas component from which stars form on near-circular orbits. We also show that this interpretation is consistent with the behavior reported in other recent simulations with l...

  17. Transient spirals as superposed instabilities

    Energy Technology Data Exchange (ETDEWEB)

    Sellwood, J. A. [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Carlberg, R. G., E-mail: sellwood@physics.rutgers.edu, E-mail: carlberg@astro.utoronto.ca [Department of Astronomy and Astrophysics, University of Toronto, Toronto, ON M5S 3H4 (Canada)

    2014-04-20

    We present evidence that recurrent spiral activity, long manifested in simulations of disk galaxies, results from the superposition of a few transient spiral modes. Each mode lasts between 5 and 10 rotations at its corotation radius where its amplitude is greatest. The scattering of stars as each wave decays takes place over narrow ranges of angular momentum, causing abrupt changes to the impedance of the disk to subsequent traveling waves. Partial reflections of waves at these newly created features allows new standing-wave instabilities to appear that saturate and decay in their turn, scattering particles at new locations, creating a recurring cycle. The spiral activity causes the general level of random motion to rise, gradually decreasing the ability of the disk to support further activity unless the disk contains a dissipative gas component from which stars form on near-circular orbits. We also show that this interpretation is consistent with the behavior reported in other recent simulations with low-mass disks.

  18. Development of a hydrolysis probe-based real-time assay for the detection of tropical strains of Fusarium oxysporum f. sp. cubense race 4

    Science.gov (United States)

    Cerf-Wendling, Isabelle; Hostachy, Bruno; Viljoen, Altus; Ioos, Renaud

    2017-01-01

    Fusarium oxysporum f. sp. cubense (Foc) is one of the most important threats to global banana production. Strategies to control the pathogen are lacking, with plant resistance offering the only long-term solution, if sources of resistance are available. Prevention of introduction of Foc into disease-free areas thus remains a key strategy to continue sustainable banana production. In recent years, strains of Foc affecting Cavendish bananas have destroyed plantations in a number of countries in Asia and in the Middle East, and one African country. One vegetative compatibility group (VCG), 01213/16, is considered the major threat to bananas in tropical and subtropical climatic conditions. However, other genetically related VCGs, such as 0121, may potentially jeopardize banana cultures if they were introduced into disease-free areas. To prevent the introduction of these VCGs into disease-free Cavendish banana-growing countries, a real-time PCR test was developed to accurately detect both VCGs. A previously described putative virulence gene was used to develop a specific combination of hydrolysis probe/primers for the detection of tropical Foc race 4 strains. The real-time PCR parameters were optimized by following a statistical approach relying on orthogonal arrays and the Taguchi method in an attempt to enhance sensitivity and ensure high specificity of the assay. This study also assessed critical performance criteria, such as repeatability, reproducibility, robustness, and specificity, with a large including set of 136 F. oxysporum isolates, including 73 Foc pathogenic strains representing 24 VCGs. The validation data demonstrated that the new assay could be used for regulatory testing applications on banana plant material and can contribute to preventing the introduction and spread of Foc strains affecting Cavendish bananas in the tropics. PMID:28178348

  19. Development of a strain-specific real-time PCR assay for enumeration of a probiotic Lactobacillus reuteri in chicken feed and intestine.

    Directory of Open Access Journals (Sweden)

    Verity Ann Sattler

    Full Text Available A strain-specific real-time PCR assay was developed for quantification of a probiotic Lactobacillus reuteri (DSM 16350 in poultry feed and intestine. The specific primers were designed based on a genomic sequence of the strain derived from suppression subtractive hybridization with the type strain L. reuteri DSM 20016. Specificity was tested using a set of non-target strains from several sources. Applicability of the real-time PCR assay was evaluated in a controlled broiler feeding trial by using standard curves specific for feed and intestinal matrices. The amount of the probiotic L. reuteri was determined in feed from three feeding phases and in intestinal samples of the jejunum, ileum, and caecum of three, 14, and 39 day old birds. L. reuteri DSM 16350 cells were enumerated in all feeds supplemented with the probiotic close to the inclusion rate of 7.0 × 10(3 cfu/g, however, were not detected in L. reuteri DSM 16350 free feed. In three day old birds L. reuteri DSM 16350 was only detected in intestinal samples from probiotic fed animals ranging from 8.2 ± 7.8 × 10(5 cfu/g in the jejunum, 1.0 ± 1.1×10(7 cfu/g in the ileum, and 2.5 ± 5.7 × 10(5 cfu/g in the caecum. Similar results were obtained for intestinal samples of older birds (14 and 39 days. With increasing age of the animals the amount of L. reuteri signals in the control animals, however, also increased, indicating the appearance of highly similar bacterial genomes in the gut microbiota. The L. reuteri DSM 16350 qPCR assay could be used in future for feeding trials to assure the accurate inclusion of the supplement to the feed and to monitor it's uptake into the GIT of young chicken.

  20. Development of a hydrolysis probe-based real-time assay for the detection of tropical strains of Fusarium oxysporum f. sp. cubense race 4.

    Science.gov (United States)

    Aguayo, Jaime; Mostert, Diane; Fourrier-Jeandel, Céline; Cerf-Wendling, Isabelle; Hostachy, Bruno; Viljoen, Altus; Ioos, Renaud

    2017-01-01

    Fusarium oxysporum f. sp. cubense (Foc) is one of the most important threats to global banana production. Strategies to control the pathogen are lacking, with plant resistance offering the only long-term solution, if sources of resistance are available. Prevention of introduction of Foc into disease-free areas thus remains a key strategy to continue sustainable banana production. In recent years, strains of Foc affecting Cavendish bananas have destroyed plantations in a number of countries in Asia and in the Middle East, and one African country. One vegetative compatibility group (VCG), 01213/16, is considered the major threat to bananas in tropical and subtropical climatic conditions. However, other genetically related VCGs, such as 0121, may potentially jeopardize banana cultures if they were introduced into disease-free areas. To prevent the introduction of these VCGs into disease-free Cavendish banana-growing countries, a real-time PCR test was developed to accurately detect both VCGs. A previously described putative virulence gene was used to develop a specific combination of hydrolysis probe/primers for the detection of tropical Foc race 4 strains. The real-time PCR parameters were optimized by following a statistical approach relying on orthogonal arrays and the Taguchi method in an attempt to enhance sensitivity and ensure high specificity of the assay. This study also assessed critical performance criteria, such as repeatability, reproducibility, robustness, and specificity, with a large including set of 136 F. oxysporum isolates, including 73 Foc pathogenic strains representing 24 VCGs. The validation data demonstrated that the new assay could be used for regulatory testing applications on banana plant material and can contribute to preventing the introduction and spread of Foc strains affecting Cavendish bananas in the tropics.

  1. A new real-time PCR assay for rapid identification of the S. aureus/MRSA strains

    Directory of Open Access Journals (Sweden)

    Ivan Manga

    2013-01-01

    Full Text Available The Methicillin-resistant Staphylococcus aureus (MRSA with the livestock-associated MRSA (LA-MRSA are of great interest to scientists and general public. The aim of our study was to present a new more rapid and reliable diagnostic method working on the RT-PCR platform applicable for monitoring of MRSA/S. aureus. The parallel testing of the S. aureus specific nuc gene sequence and the mecA gene sequence was utilised for this purpose. A collection of ten S. aureus/MRSA reference strains, fifteen genetically related non S. aureus reference strains and fifty-six environmental samples was employed for estimation of the assay performance and parameters. The environmental samples acquired in the Czech livestock farms were represented with the livestock and human nasal mucosae or skin swabs, the slaughter meat swabs and were chosen preferentially from individuals with previously confi rmed or suspected positive MRSA/S. aureus cases. The classic selective cultivation approach with the biochemical test and agar disk diffusion test was accepted as reference diagnostic method. As there were no culture positive samples that were negative using RT-PCR, our method featured with 100% sensitivity in comparison to reference method. The limit of detection allowed to identify from tens to hundreds copies of S. aureus/MRSA genome. Further, the RT-PCR assay featured with 100% inclusivity and 95% exclusivity at Cq value below 30. These parameters suggested on powerful and reliable diagnostic method with real potential of practical utilisation. We consider our method as ideal for testing of individual suspected colonies, when the results can be acquired in less than 1.5 hour.

  2. Strain distribution in thin concrete pavement panels under three-point loading to failure with pre-pulse-pump Brillouin optical time domain analysis (Presentation Video)

    Science.gov (United States)

    Bao, Yi; Cain, John; Chen, Yizheng; Huang, Ying; Chen, Genda; Palek, Leonard

    2015-04-01

    Thin concrete panels reinforced with alloy polymer macro-synthetic fibers have recently been introduced to rapidly and cost-effectively improve the driving condition of existing roadways by laying down a fabric sheet on the roadways, casting a thin layer of concrete, and then cutting the layer into panels. This study is aimed to understand the strain distribution and potential crack development of concrete panels under three-point loading. To this end, six full-size 6ft×6ft×3in concrete panels were tested to failure in the laboratory. They were instrumented with three types of single-mode optical fiber sensors whose performance and ability to measure the strain distribution and detect cracks were compared. Each optical fiber sensor was spliced and calibrated, and then attached to a fabric sheet using adhesive. A thin layer of mortar (0.25 ~ 0.5 in thick) was cast on the fabric sheet. The three types of distributed sensors were bare SM-28e+ fiber, SM-28e+ fiber with a tight buffer, and concrete crack cable, respectively. The concrete crack cable consisted of one SM-28e+ optical fiber with a tight buffer, one SM-28e+ optical fiber with a loose buffer for temperature compensation, and an outside protective tight sheath. Distributed strains were collected from the three optical fiber sensors with pre-pulse-pump Brillouin optical time domain analysis in room temperature. Among the three sensors, the bare fiber was observed to be most fragile during construction and operation, but most sensitive to strain change or micro-cracks. The concrete crack cable was most rugged, but not as sensitive to micro-cracks and robust in micro-crack measurement as the bare fiber. The ruggedness and sensitivity of the fiber with a tight buffer were in between the bare fiber and the concrete crack cable. The strain distribution resulted from the three optical sensors are in good agreement, and can be applied to successfully locate cracks in the concrete panels. It was observed that the

  3. Detection of Atypical H-Type Bovine Spongiform Encephalopathy and Discrimination of Bovine Prion Strains by Real-Time Quaking-Induced Conversion.

    Science.gov (United States)

    Masujin, Kentaro; Orrú, Christina D; Miyazawa, Kohtaro; Groveman, Bradley R; Raymond, Lynne D; Hughson, Andrew G; Caughey, Byron

    2016-03-01

    Prion diseases of cattle include the classical bovine spongiform encephalopathy (C-BSE) and the atypical H-type BSE (H-BSE) and L-type BSE (L-BSE) strains. Although the C- and L-BSE strains can be detected and discriminated by ultrasensitive real-time quaking-induced conversion (RT-QuIC) assays, no such test has yet been described for the detection of H-BSE or the discrimination of each of the major bovine prion strains. Here, we demonstrate an RT-QuIC assay for H-BSE that can detect as little as 10(-9) dilutions of brain tissue and neat cerebrospinal fluid samples from clinically affected cattle. Moreover, comparisons of the reactivities with different recombinant prion protein substrates and/or immunoblot band profiles of proteinase K-treated RT-QuIC reaction products indicated that H-, L-, and C-BSE have distinctive prion seeding activities and can be discriminated by RT-QuIC on this basis.

  4. Job Strain as a Risk Factor for Leisure-Time Physical Inactivity: An Individual-Participant Meta-Analysis of Up to 170,000 Men and Women

    Science.gov (United States)

    Fransson, Eleonor I.; Heikkilä, Katriina; Nyberg, Solja T.; Zins, Marie; Westerlund, Hugo; Westerholm, Peter; Väänänen, Ari; Virtanen, Marianna; Vahtera, Jussi; Theorell, Töres; Suominen, Sakari; Singh-Manoux, Archana; Siegrist, Johannes; Sabia, Séverine; Rugulies, Reiner; Pentti, Jaana; Oksanen, Tuula; Nordin, Maria; Nielsen, Martin L.; Marmot, Michael G.; Magnusson Hanson, Linda L.; Madsen, Ida E. H.; Lunau, Thorsten; Leineweber, Constanze; Kumari, Meena; Kouvonen, Anne; Koskinen, Aki; Koskenvuo, Markku; Knutsson, Anders; Kittel, France; Jöckel, Karl-Heinz; Joensuu, Matti; Houtman, Irene L.; Hooftman, Wendela E.; Goldberg, Marcel; Geuskens, Goedele A.; Ferrie, Jane E.; Erbel, Raimund; Dragano, Nico; De Bacquer, Dirk; Clays, Els; Casini, Annalisa; Burr, Hermann; Borritz, Marianne; Bonenfant, Sébastien; Bjorner, Jakob B.; Alfredsson, Lars; Hamer, Mark; Batty, G. David; Kivimäki, Mika

    2012-01-01

    Unfavorable work characteristics, such as low job control and too high or too low job demands, have been suggested to increase the likelihood of physical inactivity during leisure time, but this has not been verified in large-scale studies. The authors combined individual-level data from 14 European cohort studies (baseline years from 1985–1988 to 2006–2008) to examine the association between unfavorable work characteristics and leisure-time physical inactivity in a total of 170,162 employees (50% women; mean age, 43.5 years). Of these employees, 56,735 were reexamined after 2–9 years. In cross-sectional analyses, the odds for physical inactivity were 26% higher (odds ratio = 1.26, 95% confidence interval: 1.15, 1.38) for employees with high-strain jobs (low control/high demands) and 21% higher (odds ratio = 1.21, 95% confidence interval: 1.11, 1.31) for those with passive jobs (low control/low demands) compared with employees in low-strain jobs (high control/low demands). In prospective analyses restricted to physically active participants, the odds of becoming physically inactive during follow-up were 21% and 20% higher for those with high-strain (odds ratio = 1.21, 95% confidence interval: 1.11, 1.32) and passive (odds ratio = 1.20, 95% confidence interval: 1.11, 1.30) jobs at baseline. These data suggest that unfavorable work characteristics may have a spillover effect on leisure-time physical activity. PMID:23144364

  5. Variation of B1 gene and AF146527 repeat element copy numbers according to Toxoplasma gondii strains assessed using real-time quantitative PCR.

    Science.gov (United States)

    Costa, Jean-Marc; Bretagne, Stéphane

    2012-04-01

    Using the multicopy B1 gene and AF146527 element for the amplification of Toxoplasma gondii DNA raises the issue of reliable quantification for clinical diagnosis. We applied relative quantification to reference strains using the single-copy P30 gene as a reference. According to the parasite type, the copy numbers for the B1 gene and AF146527 element were found to be 5 to 12 and 4 to 8 times lower than the previous estimations of 35 and 230 copies, respectively.

  6. Diagnostic real-time PCR assays for the detection of emetic Bacillus cereus strains in foods and recent food-borne outbreaks.

    Science.gov (United States)

    Fricker, Martina; Messelhäusser, Ute; Busch, Ulrich; Scherer, Siegfried; Ehling-Schulz, Monika

    2007-03-01

    Cereulide-producing Bacillus cereus can cause an emetic type of food-borne disease that mimics the symptoms provoked by Staphylococcus aureus. Based on the recently discovered genetic background for cereulide formation, a novel 5' nuclease (TaqMan) real-time PCR assay was developed to provide a rapid and sensitive method for the specific detection of emetic B. cereus in food. The TaqMan assay includes an internal amplification control and primers and a probe designed to target a highly specific part of the cereulide synthetase genes. Additionally, a specific SYBR green I assay was developed and extended to create a duplex SYBR green I assay for the one-step identification and discrimination of the two emesis-causing food pathogens B. cereus and S. aureus. The inclusivity and exclusivity of the assay were assessed using a panel of 100 strains, including 23 emetic B. cereus and 14 S. aureus strains. Different methods for DNA isolation from artificially contaminated foods were evaluated, and established real-time assays were used to analyze two recent emetic food poisonings in southern Germany. One of the food-borne outbreaks included 17 children visiting a day care center who vomited after consuming a reheated rice dish, collapsed, and were hospitalized; the other case concerned a single food-poisoning incident occurring after consumption of cauliflower. Within 2 h, the etiological agent of these food poisonings was identified as emetic B. cereus by using the real-time PCR assay.

  7. InSAR time-series constraints on inter-seismic strain accumulation and creep distribution along North Anatolian and Chaman Faults

    Science.gov (United States)

    Havazli, E.; Fattahi, H.; Amelung, F.

    2013-12-01

    In many aspects, the San Andreas and the North Anatolian fault zones show many similarities. They are similarly right-lateral, strike-slip faults, at the same time, are transforms. However, they vary in the maximum amount of lateral displacement and show different topographic features. The maximum offset is nearly 300 km along the San Andreas Fault whereas it is approximately 85-90 km along the North Anatolian Fault. In recent years, interseismic crustal velocities and strains have been determined for North Anatolian Fault Zone through repeated measurements using the Global Positioning System and satellite radar interferometry. The Chaman Fault in Pakistan and Afghanistan is the only major fault along the western India-Eurasia plate boundary zone and probably accommodates the entire relative plate motion of 30-35 mm/yr. Recent GPS and InSAR studies on the Chaman fault yield slip rates of 18 × 1 mm/yr. The inconsistency in geologic, geodetic and seismic slip rates along the Chaman Fault need investigations to better understand the geodynamic responses of the Indo-Asia collision along its western boundary. We use InSAR time-series analysis using archived and new SAR imagery to constrain strain accumulation across the North Anatolian Fault and Chaman Faults. We expect a relative accuracy of InSAR measurements better than 1 mm/yr over 100 km, made possible by recent advances in flattening residual, orbital error and atmospheric correction strategies [Fattahi & Amelung, 2013]. After validation of the technique in Southern San Andreas Fault, using GPS observations, we apply the same InSAR time-series approach to constrain strain accumulation across the North Anatolian and Chaman Faults. We will use the InSAR data to establish the first-order fault properties of the Chaman and North Anatolian Faults (creep distribution, locking depth) using analytical two-dimensional elastic strain accumulation models along different transects across the faults. Our preliminary results

  8. Non-invasive timing of gas gun-launched projectiles using external surface-mounted optical fiber-Bragg grating strain gauges.

    Science.gov (United States)

    Goodwin, Peter M; Marshall, Bruce R; Stevens, Gerald D; Dattelbaum, Dana M

    2013-03-01

    Non-invasive detection methods for tracking gun-launched projectiles are important not only for assessment of gun performance but are also essential for timing a variety of diagnostics, for example, to investigate plate-impact events for shock compression experiments. Measurement of the time of passage of a projectile moving inside of the gun barrel can be achieved by detection of the transient hoop strain induced in the barrel of a light-gas gun by the passage of the projectile using external, barrel surface-mounted optical fiber-Bragg grating strain gauges. Optical fiber-Bragg gratings have been implemented and their response characterized on single-stage and two-stage light gas guns routinely used for dynamic experimentation at Los Alamos National Laboratory. Two approaches, using either broadband or narrowband illumination, were used to monitor changes in the Bragg wavelength of the fiber-Bragg gratings. The second approach, using narrowband laser illumination, offered the highest sensitivity. The feasibility of using these techniques to generate early, pre-event signals useful for triggering high-latency diagnostics was demonstrated.

  9. A strain gauge

    DEFF Research Database (Denmark)

    2016-01-01

    The invention relates to a strain gauge of a carrier layer and a meandering measurement grid positioned on the carrier layer, wherein the strain gauge comprises two reinforcement members positioned on the carrier layer at opposite ends of the measurement grid in the axial direction....... The reinforcement members are each placed within a certain axial distance to the measurement grid with the axial distance being equal to or smaller than a factor times the grid spacing. The invention further relates to a multi-axial strain gauge such as a bi-axial strain gauge or a strain gauge rosette where each...... of the strain gauges comprises reinforcement members. The invention further relates to a method for manufacturing a strain gauge as mentioned above....

  10. High GUD incidence in the early 20 century created a particularly permissive time window for the origin and initial spread of epidemic HIV strains.

    Directory of Open Access Journals (Sweden)

    João Dinis de Sousa

    Full Text Available The processes that permitted a few SIV strains to emerge epidemically as HIV groups remain elusive. Paradigmatic theories propose factors that may have facilitated adaptation to the human host (e.g., unsafe injections, none of which provide a coherent explanation for the timing, geographical origin, and scarcity of epidemic HIV strains. Our updated molecular clock analyses established relatively narrow time intervals (roughly 1880-1940 for major SIV transfers to humans. Factors that could favor HIV emergence in this time frame may have been genital ulcer disease (GUD, resulting in high HIV-1 transmissibility (4-43%, largely exceeding parenteral transmissibility; lack of male circumcision increasing male HIV infection risk; and gender-skewed city growth increasing sexual promiscuity. We surveyed colonial medical literature reporting incidences of GUD for the relevant regions, concentrating on cities, suffering less reporting biases than rural areas. Coinciding in time with the origin of the major HIV groups, colonial cities showed intense GUD outbreaks with incidences 1.5-2.5 orders of magnitude higher than in mid 20(th century. We surveyed ethnographic literature, and concluded that male circumcision frequencies were lower in early 20(th century than nowadays, with low rates correlating spatially with the emergence of HIV groups. We developed computer simulations to model the early spread of HIV-1 group M in Kinshasa before, during and after the estimated origin of the virus, using parameters derived from the colonial literature. These confirmed that the early 20(th century was particularly permissive for the emergence of HIV by heterosexual transmission. The strongest potential facilitating factor was high GUD levels. Remarkably, the direct effects of city population size and circumcision frequency seemed relatively small. Our results suggest that intense GUD in promiscuous urban communities was the main factor driving HIV emergence. Low

  11. PLASTICITY AND NON-LINEAR ELASTIC STRAINS

    Science.gov (United States)

    conditions existing in plane waves in an extended medium to give the time rate of change of stress as a function of the time rate of change of strain, the stress invariants, the total strain and the plastic strain. (Author)

  12. Activity of ceftobiprole compared with those of other agents against Staphylococcus aureus strains with different resistotypes by time-kill analysis.

    Science.gov (United States)

    Lin, Gengrong; Appelbaum, Peter C

    2008-02-01

    Among 10 hospital- and community-acquired Staphylococcus aureus strains with differing methicillin and vancomycin resistotypes, all strains were susceptible to ceftobiprole at MICs Ceftobiprole, at 4x MIC, was bactericidal (99.9% killing) against 9 of 10 strains tested at 4x MIC after 24 h. Ceftobiprole also yielded significant activity at earlier periods, with 90% killing of all strains at 2x MIC at 6 and 12 h. Vancomycin was bactericidal against 6 of 8 strains tested at 2x MIC after 24 h. By contrast, linezolid and tigecycline were mainly bacteriostatic, and quinupristin/dalfopristin was bactericidal against 4 of 10 strains at 2x MIC after 24 h.

  13. Spatial and Temporal Control of Hyperthermia Using Real Time Ultrasonic Thermal Strain Imaging with Motion Compensation, Phantom Study.

    Directory of Open Access Journals (Sweden)

    Josquin Foiret

    Full Text Available Mild hyperthermia has been successfully employed to induce reversible physiological changes that can directly treat cancer and enhance local drug delivery. In this approach, temperature monitoring is essential to avoid undesirable biological effects that result from thermal damage. For thermal therapies, Magnetic Resonance Imaging (MRI has been employed to control real-time Focused Ultrasound (FUS therapies. However, combined ultrasound imaging and therapy systems offer the benefits of simple, low-cost devices that can be broadly applied. To facilitate such technology, ultrasound thermometry has potential to reliably monitor temperature. Control of mild hyperthermia was previously achieved using a proportional-integral-derivative (PID controller based on thermocouple measurements. Despite accurate temporal control of heating, this method is limited by the single position at which the temperature is measured. Ultrasound thermometry techniques based on exploiting the thermal dependence of acoustic parameters (such as longitudinal velocity can be extended to create thermal maps and allow an accurate monitoring of temperature with good spatial resolution. However, in vivo applications of this technique have not been fully developed due to the high sensitivity to tissue motion. Here, we propose a motion compensation method based on the acquisition of multiple reference frames prior to treatment. The technique was tested in the presence of 2-D and 3-D physiological-scale motion and was found to provide effective real-time temperature monitoring. PID control of mild hyperthermia in presence of motion was then tested with ultrasound thermometry as feedback and temperature was maintained within 0.3°C of the requested value.

  14. Transverse tectonic structural elements across Himalayan mountain front, eastern Arunachal Himalaya, India: Implication of superposed landform development on analysis of neotectonics

    Science.gov (United States)

    Bhakuni, S. S.; Luirei, Khayingshing; Kothyari, Girish Ch.; Imsong, Watinaro

    2017-04-01

    mountain front along the Sesseri, Siluk, Siku, Siang, Mingo, Sileng, Dikari, and Simen rivers. At some such junctions, landforms associated with the active right-lateral strike-slip faults are superposed over the earlier landforms formed by transverse normal faults. In addition to linear transverse features, we see evidence that the fold-thrust belt of the frontal part of the Arunachal Himalaya has also been affected by the neotectonically active NW-SE trending major fold known as the Siang antiform that again is aligned transverse to the mountain front. The folding of the HFT and MBT along this antiform has reshaped the landscape developed between its two western and eastern limbs running N-S and NW-SE, respectively. The transverse faults are parallel to the already reported deep-seated transverse seismogenic strike-slip fault. Therefore, a single take home message is that any true manifestation of the neotectonics and seismic hazard assessment in the Himalayan region must take into account the role of transverse tectonics.

  15. Gen-2 RFID compatible, zero down-time, programmable mechanical strain-monitors and mechanical impact detectors

    Science.gov (United States)

    Chakrabartty, Shantanu; Feng, Tao; Aono, Kenji

    2013-04-01

    A key challenge in structural health monitoring (SHM) sensors embedded inside civil structures is that elec- tronics need to operate continuously such that mechanical events of interest can be detected and appropriately analyzed. Continuous operation however requires a continuous source of energy which cannot be guaranteed using conventional energy scavenging techniques. The paper describes a hybrid energy scavenging SHM sensor which experiences zero down-time in monitoring mechanical events of interest. At the core of the proposed sensor is an analog floating-gate storage technology that can be precisely programmed at nano-watt and pico- watt power levels. This facilitates self-powered, non-volatile data logging of the mechanical events of interest by scavenging energy directly from the mechanical events itself. Remote retrieval of the stored data is achieved using a commercial off-the-shelf Gen-2 radio-frequency identification (RFID) reader which periodically reads an electronic product code (EPC) that encapsulates the sensor data. The Gen-2 interface also facilitates in simultaneous remote access to multiple sensors and also facilitates in determining the range and orientation of the sensor. The architecture of the sensor is based on a token-ring topology which enables sensor channels to be dynamically added or deleted through software control.

  16. The use of quantitative real time polymerase chain reaction to quantify some rumen bacterial strains in an in vitro rumen system

    Directory of Open Access Journals (Sweden)

    Lucy Onime

    2013-08-01

    Full Text Available The aim of this work was to quantify four rumen bacterial strains (Butyrivibrio fibrisolvens, Ruminococcus albus, Streptococcus bovis, Megasphaera elsdenii in an in vitro batch rumen fermentative system by quantitative real time polymerase chain reaction (qPCR. The experiment was a 2×2 factorial arrangement with two types of liquid rumen, collected from dairy cows (DC and fattening bulls (FB and two types of fermentation substrate (forage:concentrate ratios, 75:25 and 25:75 and was replicated in two fermentation runs. Fermentation fluids from FB compared to those from DC had lower pH, higher total VFA concentrations (averages of 0 and 24 h samplings, 6.70 vs 7.04 and 72.6 vs 42.7 mmol/l P<0.001 and contained less acetic (P=0.014 and more propionic (P<0.01 and butyric (P=0.029 acids. The two types of substrates incubated produced very small differences in the end fermentation products. B. fibrosolvens concentrations were higher (P<0.001 in the DC fermentation fluids compared to that from bulls (averages of 0 and 24 h sampling times, 3.47 vs 1.38 x109 copies /mL, while M. elsdenii was detected only in FB fermentation fluids. R. albus and S. bovis concentrations were not different between the two types of rumen liquid. With the only exception for B. fibrosolvens, bacteria strains considered in this study increased their concentrations in the fermentation fluid during the 24 h of in vitro incubation.

  17. Matrix-assisted laser desorption ionization-time of flight and comparative genomic analysis of M-18 group a Streptococcus strains associated with an acute rheumatic fever outbreak in northeast Italy in 2012 and 2013.

    Science.gov (United States)

    Gaibani, Paolo; Scaltriti, Erika; Foschi, Claudio; Baggio, Enrico; Tamburini, Maria Vittoria; Creti, Roberta; Pascucci, Maria Grazia; Fagioni, Marco; Ambretti, Simone; Comandatore, Francesco; Pongolini, Stefano; Landini, Maria Paola

    2015-05-01

    Acute rheumatic fever (ARF) is a postsuppurative sequela caused by Streptococcus pyogenes infections affecting school-age children. We describe here the occurrence of an ARF outbreak that occurred in Bologna province, northeastern Italy, between November 2012 and May 2013. Molecular analysis revealed that ARF-related group A Streptococcus (GAS) strains belonged to the M-18 serotype, including subtypes emm18.29 and emm18.32. All M-18 GAS strains shared the same antigenic profile, including SpeA, SpeB, SpeC, SpeL, SpeM, and SmeZ. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analysis revealed that M-18 GAS strains grouped separately from other serotypes, suggesting a different S. pyogenes lineage. Single nucleotide polymorphisms and phylogenetic analysis based on whole-genome sequencing showed that emm18.29 and emm18.32 GAS strains clustered in two distinct groups, highlighting genetic variations between these subtypes. Comparative analysis revealed a similar genome architecture between emm18.29 and emm18.32 strains that differed from noninvasive emm18.0 strains. The major sources of differences between M-18 genomes were attributable to the prophage elements. Prophage regions contained several virulence factors that could have contributed to the pathogenic potential of emm18.29 and emm18.32 strains. Notably, phage ΦSPBO.1 carried erythrogenic toxin A gene (speA1) in six ARF-related M-18 GAS strains but not in emm18.0 strains. In addition, a phage-encoded hyaluronidase gene (hylP.2) presented different variants among M-18 GAS strains by showing internal deletions located in the α-helical and TSβH regions. In conclusion, our study yielded insights into the genome structure of M-18 GAS strains responsible for the ARF outbreak in Italy, thus expanding our knowledge of this serotype.

  18. Wrinkle-to-fold transition in soft layers under equi-biaxial strain: A weakly nonlinear analysis

    Science.gov (United States)

    Ciarletta, P.

    2014-12-01

    Soft materials can experience a mechanical instability when subjected to a finite compression, developing wrinkles which may eventually evolve into folds or creases. The possibility to control the wrinkling network morphology has recently found several applications in many developing fields, such as scaffolds for biomaterials, stretchable electronics and surface micro-fabrication. Albeit much is known of the pattern initiation at the linear stability order, the nonlinear effects driving the pattern selection in soft materials are still unknown. This work aims at investigating the nature of the elastic bifurcation undertaken by a growing soft layer subjected to a equi-biaxial strain. Considering a skin effect at the free surface, the instability thresholds are found to be controlled by a characteristic length, defined by the ratio between capillary energy and bulk elasticity. For the first time, a weakly nonlinear analysis of the wrinkling instability is performed here using the multiple-scale perturbation method applied to the incremental theory in finite elasticity. The Ginzburg-Landau equations are derived for different superposing linear modes. This study proves that a subcritical pitchfork bifurcation drives the observed wrinkle-to-fold transition in swelling gels experiments, favoring the emergence of hexagonal creased patterns, albeit quasi-hexagonal patterns might later emerge because of an expected symmetry break. Moreover, if the surface energy is somewhat comparable to the bulk elastic energy, it has the same stabilizing effect as for fluid instabilities, driving the formation of stable wrinkles, as observed in elastic bi-layered materials.

  19. Novel multiplex real-time PCR diagnostic assay for identification and differentiation of Mycobacterium tuberculosis, Mycobacterium canettii, and Mycobacterium tuberculosis complex strains.

    Science.gov (United States)

    Reddington, Kate; O'Grady, Justin; Dorai-Raj, Siobhan; Maher, Majella; van Soolingen, Dick; Barry, Thomas

    2011-02-01

    Tuberculosis (TB) in humans is caused by members of the Mycobacterium tuberculosis complex (MTC). Rapid detection of the MTC is necessary for the timely initiation of antibiotic treatment, while differentiation between members of the complex may be important to guide the appropriate antibiotic treatment and provide epidemiological information. In this study, a multiplex real-time PCR diagnostics assay using novel molecular targets was designed to identify the MTC while simultaneously differentiating between M. tuberculosis and M. canettii. The lepA gene was targeted for the detection of members of the MTC, the wbbl1 gene was used for the differentiation of M. tuberculosis and M. canettii from the remainder of the complex, and a unique region of the M. canettii genome, a possible novel region of difference (RD), was targeted for the specific identification of M. canettii. The multiplex real-time PCR assay was tested using 125 bacterial strains (64 MTC isolates, 44 nontuberculosis mycobacteria [NTM], and 17 other bacteria). The assay was determined to be 100% specific for the mycobacteria tested. Limits of detection of 2.2, 2.17, and 0.73 cell equivalents were determined for M. tuberculosis/M. canettii, the MTC, and M. canettii, respectively, using probit regression analysis. Further validation of this diagnostics assay, using clinical samples, should demonstrate its potential for the rapid, accurate, and sensitive diagnosis of TB caused by M. tuberculosis, M. canettii, and the other members of the MTC.

  20. Interaction between recrystallization and strain-induced precipitation in a high Nb- and N-bearing austenitic stainless steel: Influence of the interpass time

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.B.R., E-mail: marianabdrs@gmail.com [Department of Materials Engineering, UFSCar, Via Washington Luis, Km 235, 13565-905 São Carlos, SP (Brazil); Gallego, J. [Department of Mechanical Engineering, UNESP, Avenida Brasil, 56, 15385-000 Ilha Solteira, SP (Brazil); Cabrera, J.M. [Department of Materials Science and Metallurgical Engineering, Polytechnic University of Catalunya, Avenida Diagonal 647, 08028 Barcelona (Spain); Fundacio CTM Centre Tecnologic, Plaza de la Ciencia 2, 08243 Manresa (Spain); Balancin, O. [Department of Materials Engineering, UFSCar, Via Washington Luis, Km 235, 13565-905 São Carlos, SP (Brazil); Jorge, A.M., E-mail: moreira@dema.ufscar.br [Department of Materials Engineering, UFSCar, Via Washington Luis, Km 235, 13565-905 São Carlos, SP (Brazil)

    2015-06-18

    In this work, we studied the influence of the interpass time (20 and 5 s) on the interaction between recrystallization and strain-induced precipitation occurring during multiple passes' deformations under continuous cooling conditions in a high niobium- and nitrogen-bearing austenitic stainless steel (ISO 5832-9). The correlation between microstructure evolution and hot mechanical properties was performed by physical simulation using hot torsion tests. The microstructure evolution was analyzed by optical microscopy, transmission electron microscopy and electron back scattered diffraction (EBSD). This technique indicated that dynamic recrystallization occurred at the first passes promoting an excellent grain refinement. On the other hand, shorter interpass time (5 s) allowed higher volume fraction of smallest precipitates than larger interpass time (20 s). After soaking, only TiNbN precipitates were found, whereas, Z-phase (CrNbN) and NbN were formed during thermomechanical processing. Particles with sizes between 20 and 50 nm were effective to pin grain boundaries and dislocations.

  1. Regional ejection fraction and regional area strain for left ventricular function assessment in male patients after first-time myocardial infarction.

    Science.gov (United States)

    Teo, Soo-Kng; Vos, F J A; Tan, Ru-San; Zhong, Liang; Su, Yi

    2015-04-01

    In this work, we present a method to assess left ventricle (LV) regional function from cardiac magnetic resonance (CMR) imaging based on the regional ejection fraction (REF) and regional area strain (RAS). CMR scans were performed for 30 patients after first-time myocardial infarction (MI) and nine age- and sex-matched healthy volunteers. The CMR images were processed to reconstruct three-dimensional LV geometry, and the REF and RAS in a 16-segment model were computed using our proposed methodology. The method of computing the REF was tested and shown to be robust against variation in user input. Furthermore, analysis of data was feasible in all patients and healthy volunteers without any exclusions. The REF correlated well with the RAS in a nonlinear manner (quadratic fit-R(2) = 0.88). In patients after first-time MI, the REF and RAS were significantly reduced across all 16 segments (REF: p function in the patients with preserved global ejection fraction with reasonable accuracy (more than 78%). These preliminary results confirmed the validity of our approach for accurate analysis of LV regional function. Our approach potentially offers physicians new insights into the local characteristics of the myocardial mechanics after a MI.

  2. Assessing the performance of novel software Strain Solution on automated discrimination of Escherichia coli serotypes and their mixtures using matrix-assisted laser desorption ionization-time of flight mass spectrometry.

    Science.gov (United States)

    Ojima-Kato, Teruyo; Yamamoto, Naomi; Iijima, Yoshio; Tamura, Hiroto

    2015-12-01

    O157, O26, and O111 are the most important O serogroups of enterohemorrhagic Escherichia coli worldwide. Recently we reported a strategy for discriminating these serotypes from the others using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) based on the S10-spc-alpha operon gene-encoded ribosomal protein mass spectrum (S10-GERMS) method. To realize the fully automated identification of microorganisms at species- or serotype-level with the concept of S10-GERMS method, novel software named Strain Solution for MALDI-TOF MS was developed. In this study, the Strain Solution was evaluated with a total of 45 E. coli isolates including O26, O91, O103, O111, O115, O121, O128, O145, O157, O159, and untyped serotypes. The Strain Solution could accurately discriminate 92% (11/12) of O157 strains, 100% (13/13) of O26 and O111 strains from the others with three biomarkers in an automated manner. In addition, this software could identify 2 different E. coli strains (K-12 as a non-O157 representative and O157) in mixed samples. The results suggest that Strain Solution will be useful for species- or serotype-level classification of microorganisms in the fields of food safety and diagnostics.

  3. Culture conditions of Roseobacter strain 27-4 affect its attachment and biofilm formation as quantified by real-time PCR

    DEFF Research Database (Denmark)

    Bruhn, Jesper Bartholin; Haagensen, Janus Anders Juul; Bagge-Ravn, D.;

    2006-01-01

    The fish probiotic bacterium Roseobacter strain 27-4 grows only as rosettes and produces its antibacterial compound under static growth conditions. It forms three-dimensional biofilms when precultured under static conditions. We quantified attachment of Roseobacter strain 27-4 using a direct real...

  4. Superinfection exclusion of the ruminant pathogen anaplasma marginale in the tick vector is dependent on time between exposures to the strains

    Science.gov (United States)

    The remarkable genetic diversity of vector-borne pathogens allows for the establishment of superinfection in the mammalian host. To have a long-term impact on population strain structure, the introduced strains must also be transmitted by a vector population that has been exposed to the existing pri...

  5. The strained state cosmology

    CERN Document Server

    Tartaglia, Angelo

    2015-01-01

    Starting from some relevant facts concerning the behaviour of the universe over large scale and time span, the analogy between the geometric approach of General Relativ- ity and the classical description of an elastic strained material continuum is discussed. Extending the elastic deformation approach to four dimensions it is shown that the accelerated expansion of the universe is recovered. The strain field of space-time repro- duces properties similar to the ones ascribed to the dark energy currently called in to explain the accelerated expansion. The strain field in the primordial universe behaves as radiation, but asymptotically it reproduces the cosmological constant. Subjecting the theory to a number of cosmological tests confirms the soundness of the approach and gives an optimal value for the one parameter of the model, i.e. the bulk modulus of the space-time continuum. Finally various aspects of the Strained State Cosmology (SSC) are discussed and contrasted with some non-linear massive gravity theor...

  6. Inoculum effect on growth-delay time of oxacillin-resistant strains of Staphylococcus aureus and Staphylococcus epidermidis exposed to cefamandole, cefazolin, and cefuroxime.

    Science.gov (United States)

    Yourassowsky, E; van der Linden, M P; Crokaert, F

    1990-04-01

    Cephalosporins have been recommended as prophylactic antibiotics in patients undergoing cardiovascular surgery. The major function of these antibiotics is to protect patients against Staphylococcus aureus and Staphylococcus epidermidis infections. The lowest inoculum amount responsible for infection during surgery is unknown but is probably low. To determine the comparative activities of cefazolin, cefuroxime, and cefamandole against S. aureus and S. epidermidis for prophylactic purposes, we selected five strains of S. aureus and S. epidermidis that presented homogeneous resistances to oxacillin. A continuously monitored turbidimetric method was used to evaluate cultures with variable inoculum sizes ranging from 10(6) to 1 CFU/ml and exposed to cefazolin, cefuroxime, and cefamandole at concentrations of 0.5, 1, 2, 4, 8, 16, and 32 micrograms/ml. Growth was defined as an increase of 0.1 optical density unit. The relationship between the time required for growth, the antibiotic concentration, and the initial bacterial density showed that cefamandole was more active than cefazolin, which, in turn, was revealed to be more active than cefuroxime against S. aureus and S. epidermidis.

  7. Real-Time PCR Quantification of Heteroplasmy in a Mouse Model with Mitochondrial DNA of C57BL/6 and NZB/BINJ Strains

    Science.gov (United States)

    Sangalli, Juliano Rodrigues; Rodrigues, Thiago Bittencourt; Smith, Lawrence Charles; Meirelles, Flávio Vieira; Chiaratti, Marcos Roberto

    2015-01-01

    Mouse models are widely employed to study mitochondrial inheritance, which have implications to several human diseases caused by mutations in the mitochondrial genome (mtDNA). These mouse models take advantage of polymorphisms between the mtDNA of the NZB/BINJ and the mtDNA of common inbred laboratory (i.e., C57BL/6) strains to generate mice with two mtDNA haplotypes (heteroplasmy). Based on PCR followed by restriction fragment length polymorphism (PCR-RFLP), these studies determine the level of heteroplasmy across generations and in different cell types aiming to understand the mechanisms underlying mitochondrial inheritance. However, PCR-RFLP is a time-consuming method of low sensitivity and accuracy that dependents on the use of restriction enzyme digestions. A more robust method to measure heteroplasmy has been provided by the use of real-time quantitative PCR (qPCR) based on allelic refractory mutation detection system (ARMS-qPCR). Herein, we report an ARMS-qPCR assay for quantification of heteroplasmy using heteroplasmic mice with mtDNA of NZB/BINJ and C57BL/6 origin. Heteroplasmy and mtDNA copy number were estimated in germline and somatic tissues, providing evidence of the reliability of the approach. Furthermore, it enabled single-step quantification of heteroplasmy, with sensitivity to detect as low as 0.1% of either NZB/BINJ or C57BL/6 mtDNA. These findings are relevant as the ARMS-qPCR assay reported here is fully compatible with similar heteroplasmic mouse models used to study mitochondrial inheritance in mammals. PMID:26274500

  8. Real-time structural integrity monitoring using a passive quadrature demodulated, localised Michelson optical fibre interferometer capable of simultaneous strain and acoustic emission sensing

    Science.gov (United States)

    Tapanes, Edward

    1991-12-01

    A Michelson Fiber optic sensor (MFOS) is described for in-situ strain and vibration monitoring as well as acoustic emission detection in composite material structures. The phase sensitive fiber optic sensor is localized, all-fiber, and intrinsic. The MFOS was successfully embedded in Kevlar/epoxy and graphite/epoxy thermosets as well as graphite/PEEK thermoplastic in order to perform local strain and vibration measurements at the lamina level. A technique allowing acoustic emission detection in parallel with strain and vibration monitoring is illustrated.

  9. Time series analysis of strain accumulation along the Haiyuan fault (Gansu, China) over the 1993-2009 period, from ERS and ENVISAT InSAR data

    Science.gov (United States)

    Jolivet, Romain; Lasserre, Cecile; Doin, Marie-Pierre; Guillaso, Stéphane; Cavalié, Olivier; Peltzer, Gilles; Sun, Jianbao; Rong, Dailu; Shen, Zheng-Kang; Xu, Xiwei

    2010-05-01

    We use SAR interferometry to measure the strain accumulation along the left-lateral Haiyuan fault system (HFS), that marks the north-eastern boundary of the tibetan plateau. The last major earthquakes that occured along the HFS are the M~8 1920 Haiyuan earthquake (strike-slip mechanism) and the Ml=8-8.3 1927 Gulang earthquake that ruptured a thrust fault system. No large earthquake is reported on the central section of the HFS, the "Tianzhu seismic gap", since ~1000 years. We first analyze the complete ENVISAT SAR data archive along 4 descending and 2 ascending tracks for the 2003-2009 period and construct an InSAR-based mean Line-Of-Sight (LOS) velocity map around the HFS from the eastern end of the Qilian shan (102° E), to the west, to the Liupan shan (106° E), to the east. Data are processed using a small baseline chain type. For each track, all radar images are coregistrated to a single master and interferograms are produced using a local adaptative range filtering. Residual orbital and atmospheric delays are jointly inverted and corrected for each unwrapped interferogram. Atmospheric corrections are validated using the ERA40 global atmospheric model (ECMWF). The interferograms series on each track are then inverted to obtain the increments of LOS radar delays between acquisition dates, adapting the Lopez-Quiroz et al. 2009 time series analysis. The obtained LOS mean velocity maps show a dominant left-lateral motion across the fault with along-strike variations: some fault sections are locked at shallow depth while others are creeping and local vertical movements are observed (subsidence in the "Jingtai" pull-apart basin). For various fault slip rates imposed below 20 km (4-10 mm/yr), we model the shallow velocity by inverting the mean LOS velocity maps for both strike-slip and dip-slip motion on vertical, 5km x 2.5km discretized patches, using a least-square method with an appropriate degree of smoothing. The fault geometry follows the surface trace of the

  10. Quantitative real-time reverse transcription-PCR analysis reveals stable and prolonged neurotoxin cluster gene activity in a Clostridium botulinum type E strain at refrigeration temperature.

    Science.gov (United States)

    Chen, Ying; Korkeala, Hannu; Lindén, Jere; Lindström, Miia

    2008-10-01

    The relative expression levels of six botulinum neurotoxin cluster genes in a group II Clostridium botulinum type E strain grown at 10 or 30 degrees C were investigated using quantitative real-time reverse transcription-PCR. An enzyme-linked immunosorbent assay was used to confirm neurotoxin expression. Distinct mRNA and toxin production patterns were observed at the two temperatures. The average relative mRNA levels at 10 degrees C were higher than (ntnh and p47), similar to (botE), or lower than (orfx1, orfx2, orfx3) those at 30 degrees C. The maximum botE expression levels and average neurotoxin levels at 10 degrees C were 45 to 65% of those at 30 degrees C. The relative mRNA levels at 10 degrees C declined generally slowly within 8 days, as opposed to the rapid decline observed at 30 degrees C within 24 h. Distinct expression patterns of the six genes at the two temperatures suggest that the type E neurotoxin cluster genes are transcribed as two tricistronic operons at 30 degrees C, whereas at 10 degrees C monocistronic (botE or orfx1 alone) and bicistronic (ntnh-p47 and orfx2-orfx3) transcription may dominate. Thus, type E botulinum neurotoxin production may be involved with various temperature-dependent regulatory events. In light of group II C. botulinum type E being a dangerous food-borne pathogen, these findings may be important in terms of the safety of refrigerated packaged foods of extended durability.

  11. Improvements of high-throughput culturing yielded novel SAR11 strains and other abundant marine bacteria from the Oregon coast and the Bermuda Atlantic Time Series study site.

    Science.gov (United States)

    Stingl, Ulrich; Tripp, Harry James; Giovannoni, Stephen J

    2007-08-01

    The introduction of high-throughput dilution-to-extinction culturing (HTC) of marine bacterioplankton using sterilized natural sea water as media yielded isolates of many abundant but previously uncultured marine bacterial clades. In early experiments, bacteria from the SAR11 cluster (class Alphaproteobacteria), which are presumed to be the most abundant prokaryotes on earth, were cultured. Although many additional attempts were made, no further strains of the SAR11 clade were obtained. Here, we describe improvements to the HTC technique, which led to the isolation of 17 new SAR11 strains from the Oregon coast and the Sargasso Sea, accounting for 28% and 31% of all isolates in these experiments. Phylogenetic analysis of the internal transcribed spacer (ITS) region showed that the isolates from the Oregon coast represent three different subclusters of SAR11, while isolates from the Sargasso Sea were more uniform and represented a single ITS cluster. A PCR assay proved the presence of proteorhodopsin (PR) in nearly all SAR11 isolates. Analysis of PR amino-acid sequences indicated that isolates from the Oregon coast were tuned to either green or blue light, while PRs from strains obtained from the Sargasso Sea were exclusively tuned to maximum absorbance in the blue. Interestingly, phylogenies based on PR and ITS did not correlate, suggesting lateral gene transfer. In addition to the new SAR11 strains, many novel strains belonging to clusters of previously uncultured or undescribed species of different bacterial phyla, including the first strain of the highly abundant alphaproteobacterial SAR116 clade, were isolated using the modified methods.

  12. Real-Time Wing-Vortex and Pressure Distribution Estimation on Wings Via Displacements and Strains in Unsteady and Transitional Flight Conditions

    Science.gov (United States)

    2016-09-07

    Lagrange strain tensor , defined as: εx = u/x + 1 2 ( u2/x + v 2 /x + w 2 /x ) (1.11a) εy = v/y + 1 2 ( u2/y + v 2 /y + w 2 /y ) (1.11b) γxy = u/y + v/x + u...is the known stress tensor , expressed as a function of the reconstructed strain tensor ε = ε(u), and δv is an appropriate vector test function...two-dimensional surface is characterized by two symmetric tensors , called the first and second fundamental forms of a surface. See Do Carmo [13] for

  13. Strain Pattern in Supercooled Liquids

    Science.gov (United States)

    Illing, Bernd; Fritschi, Sebastian; Hajnal, David; Klix, Christian; Keim, Peter; Fuchs, Matthias

    2016-11-01

    Investigations of strain correlations at the glass transition reveal unexpected phenomena. The shear strain fluctuations show an Eshelby-strain pattern [˜cos (4 θ ) /r2 ], characteristic of elastic response, even in liquids, at long times. We address this using a mode-coupling theory for the strain fluctuations in supercooled liquids and data from both video microscopy of a two-dimensional colloidal glass former and simulations of Brownian hard disks. We show that the long-ranged and long-lived strain signatures follow a scaling law valid close to the glass transition. For large enough viscosities, the Eshelby-strain pattern is visible even on time scales longer than the structural relaxation time τ and after the shear modulus has relaxed to zero.

  14. Identification and quantification of a toxigenic and non-toxigenic Aspergillus flavus strain in contaminated maize using quantitative real-time PCR

    Science.gov (United States)

    Aflatoxins, which are produced by the fungus Aspergillus flavus, are toxic to humans, livestock, and pets. The value of maize (Zea mays) grain is markedly reduced when contaminated with aflatoxin. Plant resistance and biological control using non-toxin producing strains are considered effective st...

  15. VALIDATION OF COOKING TIMES AND TEMPERATURES FOR THERMAL INACTIVATION OF YERSINIA PESTIS STRAINS KIM5 AND CDC-A1112 IN GROUND BEEF

    Science.gov (United States)

    The thermal stability of Yersinia pestis inoculated into retail ground beef (25 per cent fat) and heated in a temperature-controlled water bath or cooked on commercial grills was evaluated. Irradiated ground beef (3-g portions) was inoculated with ca. 6.7 log10 CFU/g of Y. pestis strain KIM5 and hea...

  16. Psychological strain between nurses

    Directory of Open Access Journals (Sweden)

    Andrea Obročníková

    2015-12-01

    Full Text Available Aim: The aim of the study was to identify differences in perception of work (mental workload among nurses providing acute and chronic nursing care. Design: Study design is cross-sectional and descriptive. Methods: The sample of respondents consisted of 97 nurses working in departments Neurology, Anesthesiology and Intensive Care Unit of the hospital St. James in Bardejov, University Hospital of L. Pasteur in Košice and University Hospital J. A. Reiman in Prešov. To measure psychological strain, Meister's questionnaire for neuropsychological strain was used. Results: Increased psychological strain was observed in nurses providing acute care versus nurses providing chronic care, particularly in job satisfaction, long-term tolerance, time constraints, high responsibility, nervousness, fatigue and satiety. In comparison with the population norm, nurses in acute care achieved significantly higher indicators of factor I (strain and gross score as nurses in neurological care. A statistically significant relationship between psychological stress and age of nurses working in anesthesiology and intensive care departments was confirmed. Nurses with long term practical experience are exposed to intense mental stress (especially in the areas of strain and monotony. Conclusion: The results of our study suggest the reality that variable qualities of work related strain among nurses can lead to physical and emotional exhaustion.

  17. Colony Dimorphism in Bradyrhizobium Strains

    Science.gov (United States)

    Sylvester-Bradley, Rosemary; Thornton, Philip; Jones, Peter

    1988-01-01

    Ten isolates of Bradyrhizobium spp. which form two colony types were studied; the isolates originated from a range of legume species. The two colony types differed in the amount of gum formed or size or both, depending on the strain. Whole 7-day-old colonies of each type were subcultured to determine the proportion of cells which had changed to the other type. An iterative computerized procedure was used to determine the rate of switching per generation between the two types and to predict proportions reached at equilibrium for each strain. The predicted proportions of the wetter (more gummy) or larger colony type at equilibrium differed significantly between strains, ranging from 0.9999 (strain CIAT 2383) to 0.0216 (strain CIAT 2469), because some strains switched faster from dry to wet (or small to large) and others switched faster from wet to dry (or large to small). Predicted equilibrium was reached after about 140 generations in strain USDA 76. In all but one strain (CIAT 3030) the growth rate of the wetter colony type was greater than or similar to that of the drier type. The mean difference in generation time between the two colony types was 0.37 h. Doubling times calculated for either colony type after 7 days of growth on the agar surface ranged from 6.0 to 7.3 h. The formation of two persistent colony types by one strain (clonal or colony dimorphism) may be a common phenomenon among Bradyrhizobium strains. Images PMID:16347599

  18. Respuesta serológica y tiempo de saneamiento en rebaños bovinos con brucelosis vacunados con Cepa 19 o Cepa RB-51; Xª Región, Chile Serologic response and time to eradication in herds with brucellosis vaccinated with strain 19 or strain RB-51; 10th Region, Chile

    Directory of Open Access Journals (Sweden)

    M RAMIREZ

    2002-01-01

    Full Text Available Se comparó la respuesta serológica y el tiempo de saneamiento en rebaños bovinos con brucelosis, vacunados con vacuna Cepa 19 o Cepa RB-51. Se estudiaron los registros serológicos de 79 rebaños de la provincia de Valdivia, Xª región de Chile. Los rebaños se habian incorporado al Programa de Erradicacion de Brucelosis Bovina entre 1996 y 1999, y al momento de este estudio se encontraban bajo la condicion de "rebaño saneado". Veintiséis rebaños, con 540 vacas y una seroprevalencia inicial de 14.1%, fueron vacunados con la vacuna Cepa 19 y 53 rebaños, con 1104 vacas y una seroprevalencia inicial de 7.6%, recibieron Cepa RB-51. Periódicamente se colectaron muestras de suero sanguíneo y se examinaron para anticuerpos de Brucella spp. usando las pruebas de Rosa de Bengala y Fijacion de Complemento. Se evaluaron las seroprevalencias, el tiempo de saneamiento y los intervalos de tiempo dentro de éste, el número de exámenes y el lapso de tiempo entre los exámenes. Sesenta y seis de 369, vacas, previamente negativas vacunadas con Cepa 19, seroconvirtieron, pero ninguna de las 917 vacas vacunadas con RB-51 seroconvirtió. El tiempo de saneamiento para los rebaños vacunados con Cepa 19 fluctuó desde 304 a 1025 días (mediana 481 días, y para los rebaños vacunados con Cepa RB-51 desde 140 a 753 días (mediana 401 días; p = 0.003. El tamaño del rebaño, las políticas de reemplazo, el tipo de asistencia veterinaria y la severidad de los signos clínicos de brucelosis no afectaron los lapsos de tiempo. Los rebaños con Cepa 19 fueron muestreados en promedio 4.4 veces y los rebaños con Cepa RB-51 fueron muestreados solo 3.4 veces (p The serologic response to brucellosis vaccination and the time to eradication of brucellosis from herds were compared in dairy cattle vaccinated with either vaccine strains 19 or RB-51. Serologic records from 79 herds from the Province of Valdivia, 10th region of Chile, were evaluated. Herds had been

  19. Formation of concentrated solid cluster in a liquid-solid mixture by ultrasonic wave. 3rd Report. Simulation by superposing Oseen`s flow field; Choonpa ni yoru suichu ryushi no cluster keisei. 3. Oseen sokudo kasaneawaseho ni yoru simulation

    Energy Technology Data Exchange (ETDEWEB)

    Asakura, K.; Nakajima, I. [Hokkaido University, Sapporo (Japan); Kaneko, T. [Science and Technology Agency, Tokyo (Japan); Hashimoto, T. [Hokkaido University, Sapporo (Japan). Faculty of Engineering; Imai, T. [Akita University, Akita (Japan). Faculty of Engineering

    1998-10-25

    The numerical calculation was carried out on the reported empirical result in the cluster formation of particles in water by ultrasonic wave. In addition, the attenuation of an ultrasonic wave was measured from sound pressure in a tube. Since the Reynolds number of the particles was less than 2, a method of using a local analytical solution was employed as the calculation method. A method superposing Oseen`s flow field was used for calculating the relative speed of the particles and the fluid. The following knowledge was obtained. It was observed from the actual measurement that the soundwave attenuated with the energy consumed through dispersion and absorption by the polyethylene particles in the fluid. The attenuation coefficient became larger in proportion to the particle concentration, with no difference caused by the particle size. Improvement was found necessary for the method of measuring attenuation factor in a high concentration area. It was judged possible, by verifying the mathematical method, to qualitatively calculate the interaction of the particles by the 1st order Oseen approximation. This method was applicable to a particle flow such as a standing wave in which particle movement is different in direction depending on the position. The method was effective to grasp the interaction of a discrete small number of particles but was limited in a large number. 14 refs., 16 figs.

  20. Novel Accurate Bacterial Discrimination by MALDI-Time-of-Flight MS Based on Ribosomal Proteins Coding in S10-spc-alpha Operon at Strain Level S10-GERMS

    Science.gov (United States)

    Tamura, Hiroto; Hotta, Yudai; Sato, Hiroaki

    2013-08-01

    Matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is one of the most widely used mass-based approaches for bacterial identification and classification because of the simple sample preparation and extremely rapid analysis within a few minutes. To establish the accurate MALDI-TOF MS bacterial discrimination method at strain level, the ribosomal subunit proteins coded in the S 10-spc-alpha operon, which encodes half of the ribosomal subunit protein and is highly conserved in eubacterial genomes, were selected as reliable biomarkers. This method, named the S10-GERMS method, revealed that the strains of genus Pseudomonas were successfully identified and discriminated at species and strain levels, respectively; therefore, the S10-GERMS method was further applied to discriminate the pathovar of P. syringae. The eight selected biomarkers (L24, L30, S10, S12, S14, S16, S17, and S19) suggested the rapid discrimination of P. syringae at the strain (pathovar) level. The S10-GERMS method appears to be a powerful tool for rapid and reliable bacterial discrimination and successful phylogenetic characterization. In this article, an overview of the utilization of results from the S10-GERMS method is presented, highlighting the characterization of the Lactobacillus casei group and discrimination of the bacteria of genera Bacillus and Sphingopyxis despite only two and one base difference in the 16S rRNA gene sequence, respectively.

  1. Novel accurate bacterial discrimination by MALDI-time-of-flight MS based on ribosomal proteins coding in S10-spc-alpha operon at strain level S10-GERMS.

    Science.gov (United States)

    Tamura, Hiroto; Hotta, Yudai; Sato, Hiroaki

    2013-08-01

    Matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is one of the most widely used mass-based approaches for bacterial identification and classification because of the simple sample preparation and extremely rapid analysis within a few minutes. To establish the accurate MALDI-TOF MS bacterial discrimination method at strain level, the ribosomal subunit proteins coded in the S10-spc-alpha operon, which encodes half of the ribosomal subunit protein and is highly conserved in eubacterial genomes, were selected as reliable biomarkers. This method, named the S10-GERMS method, revealed that the strains of genus Pseudomonas were successfully identified and discriminated at species and strain levels, respectively; therefore, the S10-GERMS method was further applied to discriminate the pathovar of P. syringae. The eight selected biomarkers (L24, L30, S10, S12, S14, S16, S17, and S19) suggested the rapid discrimination of P. syringae at the strain (pathovar) level. The S10-GERMS method appears to be a powerful tool for rapid and reliable bacterial discrimination and successful phylogenetic characterization. In this article, an overview of the utilization of results from the S10-GERMS method is presented, highlighting the characterization of the Lactobacillus casei group and discrimination of the bacteria of genera Bacillus and Sphingopyxis despite only two and one base difference in the 16S rRNA gene sequence, respectively.

  2. Work-family conflict, lack of time for personal care and leisure, and job strain in migraine: Results of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil).

    Science.gov (United States)

    Griep, Rosane Härter; Toivanen, Susanna; Santos, Itamar S; Rotenberg, Lucia; Juvanhol, Leidjaira Lopes; Goulart, Alessandra C; Aquino, Estela M; Benseñor, Isabela

    2016-11-01

    Work-family conflict and time scarcity may affect health. We investigated the association between these issues and migraine, taking into account job strain. Baseline data from ELSA-Brasil (6,183 women; 5,664 men) included four indicators of work-family conflict: time- and strain-based interference of work with family (TB-WFC, SB-WFC), interference of family with work (FWC) and lack of time for personal care and leisure (LOT). Migraine was classified according to International Headache Society criteria. Among women, definite migraine was associated with SB-WFC (odds ratio [OR] = 1.28; 95% confidence interval [CI] 1.06-1.55), FWC (OR = 1.32; 1.00-1.75), and LOT (OR = 1.30; 1.08-1.58). Probable migraine was associated with SB-WFC (OR = 1.17; 1.00-1.36). High psychological job demands and low social support interacted with LOT in association with definite migraine. Among men, probable migraine was associated with LOT (OR = 1.34; 1.09-1.64), and there were interactions between job strain and WFC for probable migraine. Balancing the demands of professional and domestic spheres could be highly relevant in the management of migraines. Am. J. Ind. Med. 59:987-1000, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  3. Development, validation and field evaluation of a quantitative real-time PCR able to differentiate between field Mycoplasma synoviae and the MS-H-live vaccine strain.

    Science.gov (United States)

    Dijkman, R; Feberwee, A; Landman, W J M

    2017-08-01

    A quantitative PCR (qPCR) able to differentiate between field Mycoplasma synoviae and MS-H vaccine strain was developed, validated and evaluated. It was developed using nucleotide differences in the obg gene. Analytical specificity and sensitivity assessed using DNA from 194 M. synoviae field samples, three different batches of MS-H vaccine and from 43 samples representing four other avian Mycoplasma species proved to be 100%. The detection limit for field M. synoviae and MS-H vaccine strain was 10(2-3) and 10(2) colony-forming units PCR equivalents/g trachea mucus, respectively. The qPCR was able to detect both, field M. synoviae and MS-H vaccine strain in ratios of 1:100 determined both using spiked and field samples. One hundred and twenty samples from M. synoviae-infected non-vaccinated birds, 110 samples from M. synoviae-vaccinated birds from a bird experiment and 224 samples from M. synoviae negative (serology and PCR) birds were used to determine the relative sensitivity and specificity using a previously described M. synoviae PCR as reference. The relative sensitivity and specificity for field M. synoviae were 95.0% and 99.6%, respectively, and 94.6% and 100% for the MS-H-live vaccine, respectively. Field validation and confirmation by multi locus sequence typing revealed that the qPCR correctly distinguished between MS-H and field M. synoviae. Evaluation of the differentiating M. synoviae qPCR in three commercial flocks suggested transmission of MS-H-live vaccine from vaccinated to non-vaccinated flocks at the same farm. Furthermore, it showed evidence for the colonization with field M. synoviae in MS-H-vaccinated flocks.

  4. DEVELOPMENT OF TEST KIT FOR DETECTION OF PANDEMIC STRAIN INFLUENZA VIRUS A (H1N1 2009 BY REAL TIME POLYMERASE CHAIN REACTION

    Directory of Open Access Journals (Sweden)

    S. V. Stepaniuk

    2013-04-01

    Full Text Available Influenza viruses A play an important role in the structure of the incidence of people with acute respiratory viral infection, which make up 90% from all other infectious diseases. According to the World Health Organization, only severe flu worldwide suffer annually 3.5 million, of which 45–60% are children. An economic loss from seasonal flu epidemic is in average about 85% of economic losses from infectious diseases in general. The experience of fighting the flu, accumulated over the years, has shown that to develop and deliver effective preventive measures necessary to build a system of permanent monitoring for influenza virus circulation, based on use of laboratory methods for accurate and rapid dentification and characterization of circulating strains of influenza virus A. Among the methods of laboratory diagnosis of influenza, the most effective is a method of polymerase chain reaction. Data on the evelopment of diagnostic test kits in the format of two-stage multiplex RTPCR-analysis for detection and genotyping of pandemic influenza virus A (H1N12009 are given. The results of laboratory and experimental research of «DIA Influenza H1N1» test system showed that it is effective and specific for detection of California pandemic influenza virus A (H1N12009 strains and can be used to diagnose disease caused by this strain of virus. Clinical trial of the course of the State registration by Ministry of Health of Ukraine have shown sensitivity and specificity of «DIA Influenza H1N1» test systems up to 100%.

  5. Comparison of two real-time RT-PCR assays for differentiation of C-strain vaccinated from classical swine fever infected pigs and wild boars

    DEFF Research Database (Denmark)

    Widén, F.; Everett, H.; Blome, S.

    2014-01-01

    Classical swine fever is one of the most important infectious diseases for the pig industry worldwide due to its economic impact. Vaccination is an effective means to control disease, however within the EU its regular use is banned owing to the inability to differentiate infected and vaccinated...... animals, the so called DIVA principle. This inability complicates monitoring of disease and stops international trade thereby limiting use of the vaccine in many regions. The C-strain vaccine is safe to use and gives good protection. It is licensed for emergency vaccination in the EU in event...

  6. Hip flexor strain - aftercare

    Science.gov (United States)

    ... flexor - aftercare; Hip flexor injury - aftercare; Hip flexor tear - aftercare; Iliopsoas strain - aftercare; Strained iliopsoas muscle - aftercare; Torn iliopsoas muscle - aftercare; Psoas strain - aftercare

  7. Echocardiographic assessment of myocardial strain.

    Science.gov (United States)

    Gorcsan, John; Tanaka, Hidekazu

    2011-09-27

    Echocardiographic strain imaging, also known as deformation imaging, has been developed as a means to objectively quantify regional myocardial function. First introduced as post-processing of tissue Doppler imaging velocity converted to strain and strain rate, strain imaging has more recently also been derived from digital speckle tracking analysis. Strain imaging has been used to gain greater understanding into the pathophysiology of cardiac ischemia and infarction, primary diseases of the myocardium, and the effects of valvular disease on myocardial function, and to advance our understanding of diastolic function. Strain imaging has also been used to quantify abnormalities in the timing of mechanical activation for heart failure patients undergoing cardiac resynchronization pacing therapy. Further advances, such as 3-dimensional speckle tracking strain imaging, have emerged to provide even greater insight. Strain imaging has become established as a robust research tool and has great potential to play many roles in routine clinical practice to advance the care of the cardiovascular patient. This perspective reviews the physiology of myocardial strain, the technical features of strain imaging using tissue Doppler imaging and speckle tracking, their strengths and weaknesses, and the state-of-the-art present and potential future clinical applications.

  8. Time-course investigation of infection with a low virulent Pasteurella multocida strain in normal and immune-suppressed 12-week-old free-range chickens.

    Science.gov (United States)

    Mbuthia, P G; Njagi, L W; Nyaga, P N; Bebora, L C; Minga, U; Christensen, J P; Olsen, J E

    2011-12-01

    Twelve-week-old indigenous chickens, either immune-suppressed using dexamethasone (IS) or non-immune-suppressed (NIS), were challenged with a low virulent strain, Pasteurella multocida strain NCTC 10322(T), and developed clinical signs and pathological lesions typical of chronic fowl cholera. NIS birds demonstrated much more severe signs of fowl cholera than IS birds. With few exceptions, signs recorded in IS and NIS birds were of the same types, but significantly milder in the IS birds, indicating that immune suppression does not change the course of infection but rather the severity of signs in fowl cholera. P. multocida signals by fluorescent in situ hybridization (FISH) were observed between 1 h and 14 days in the lungs, trachea, air sacs, liver, spleen, bursa of Fabricius and caecal tonsils, while signals from other organs mostly were observed after 24 h. More organs had FISH signals in NIS birds than in IS birds and at higher frequency per organ. Many organs were positive by FISH even 14 days post infection, and it is suggested that these organs may be likely places for long-term carriage of P. multocida following infection. The present study has demonstrated the spread of P. multocida in different tissues in chickens and distribution of lesions associated with chronic fowl cholera, and pointed to a decrease of pathology in IS birds. Since dexamethasone mostly affects heterophils, the study suggests that these cells play a role in the development of lesions associated with chronic fowl cholera in chickens.

  9. Co-axial superposed folding and inverted regional metamorphism in the Tonga Formation: Cretaceous accretionary thrust tectonics in the Cascades crystalline core

    Science.gov (United States)

    Luke, Jensen; Lebit, Hermann; Paterson, Scott; Miller, Robert; Vernon, Ron

    2017-04-01

    context, the Tonga Formation, on the westernmost boundary of the Cascades crystalline core, records Cretaceous plutonism, contact to regional metamorphism, and multiple episodes of folding, evidencing intense, arc-perpendicular contractional deformation, similar to that observed in the neighboring Chiwaukum Schist to the east (Miller and Paterson, 1992; Miller et al., 1993; Paterson and Miller, 1998; Miller et al., 2006). Building on previous extensive mapping and metamorphic and petrologic analysis in the Cascades, we use the Tonga Formation as a means to a comprehensive tectonic synthesis incorporating detailed analysis of the kinematics and timing of structural evolution, magma emplacement, and metamorphism.

  10. Rapid change in the ciprofloxacin resistance pattern among Neisseria gonorrhoeae strains in Nuuk, Greenland: time to reconsider preventive and treatment strategies.

    Science.gov (United States)

    Rolskov, Anne Skjerbæk; Bjorn-Mortensen, Karen; Mulvad, Gert; Poulsen, Peter; Jensen, Jørgen Skov; Pedersen, Michael Lynge

    2015-01-01

    Sexually transmitted infections (STIs), including infections with Neisseria gonorrhoeae (GC), are highly incident in Greenland. Since January 2011, GC testing has been performed on urine with nucleic acid amplification tests (NAATs) by strand displacement amplification (Becton Dickinson ProbeTec). Monitoring of GC antibiotic susceptibility by culture was introduced in Nuuk in 2012. Until 2014, no cases of ciprofloxacin-resistant GC strains were reported. In this paper, we report the finding of ciprofloxacin-resistant GC and describe the most recent incidence of GC infections in Greenland. The number of urine NAATs and culture-positive swabs from January to October 2014 were obtained from the Central Laboratory at Queens Ingrid's Hospital in Nuuk and stratified on gender, place and period of testing. Incidence rates were estimated as number of urine NAAT * (12/10) per 100,000 inhabitants. Men in Nuuk with a positive NAAT for GC were encouraged to provide a urethral swab for culture and susceptibility testing. From January to October 2014, a total of 5,436 urine GC NAATs were performed on patients from Nuuk and 9,031 from the rest of Greenland. Of these, 422 (8%) and 820 (9%) were positive, respectively. From January to August, 6 (15%) cultures from Nuuk were ciprofloxacin resistant while in September and October, 26 (59%) were ciprofloxacin resistant (presistance. GC incidence in Nuuk was 3,017 per 100,000 inhabitants per year, compared to 2,491 per 100,000 inhabitants per year in the rest of Greenland. Within a short period, a rapid and dramatic change in ciprofloxacin susceptibility among GC strains isolated in Nuuk was documented and recommendation for first line treatments has changed. Continued monitoring and rethinking of primary and secondary preventive initiatives is highly recommended in this high GC incidence setting.

  11. Rapid change in the ciprofloxacin resistance pattern among Neisseria gonorrhoeae strains in Nuuk, Greenland: time to reconsider preventive and treatment strategies

    Directory of Open Access Journals (Sweden)

    Anne Skjerbæk Rolskov

    2015-05-01

    Full Text Available Objectives: Sexually transmitted infections (STIs, including infections with Neisseria gonorrhoeae (GC, are highly incident in Greenland. Since January 2011, GC testing has been performed on urine with nucleic acid amplification tests (NAATs by strand displacement amplification (Becton Dickinson ProbeTec. Monitoring of GC antibiotic susceptibility by culture was introduced in Nuuk in 2012. Until 2014, no cases of ciprofloxacin-resistant GC strains were reported. In this paper, we report the finding of ciprofloxacin-resistant GC and describe the most recent incidence of GC infections in Greenland. Methods: The number of urine NAATs and culture-positive swabs from January to October 2014 were obtained from the Central Laboratory at Queens Ingrid's Hospital in Nuuk and stratified on gender, place and period of testing. Incidence rates were estimated as number of urine NAAT * (12/10 per 100,000 inhabitants. Men in Nuuk with a positive NAAT for GC were encouraged to provide a urethral swab for culture and susceptibility testing. Results: From January to October 2014, a total of 5,436 urine GC NAATs were performed on patients from Nuuk and 9,031 from the rest of Greenland. Of these, 422 (8% and 820 (9% were positive, respectively. From January to August, 6 (15% cultures from Nuuk were ciprofloxacin resistant while in September and October, 26 (59% were ciprofloxacin resistant (p<0.01. In total, 35 (40% of 88 culture-positive isolates showed ciprofloxacin resistance. GC incidence in Nuuk was 3,017 per 100,000 inhabitants per year, compared to 2,491 per 100,000 inhabitants per year in the rest of Greenland. Conclusion: Within a short period, a rapid and dramatic change in ciprofloxacin susceptibility among GC strains isolated in Nuuk was documented and recommendation for first line treatments has changed. Continued monitoring and rethinking of primary and secondary preventive initiatives is highly recommended in this high GC incidence setting.

  12. Proteomic analysis of small acid soluble proteins in the spore core of Bacillus subtilis ΔprpE and 168 strains with predictions of peptides liquid chromatography retention times as an additional tool in protein identification

    Directory of Open Access Journals (Sweden)

    Obuchowski Michał

    2010-11-01

    Full Text Available Abstract Background Sporulation, characteristic for some bacteria such as Bacillus subtilis, has not been entirely defined yet. Protein phosphatase E (PrpE and small, acid soluble spore proteins (SASPs influence this process. Nevertheless, direct result of PrpE interaction on SASPs content in spore coat of B. subtilis has not been evidenced so far. As proteomic approach enables global analysis of occurring proteins, therefore it was chosen in this experiment to compare SASPs occurrence in two strains of B. subtilis, standard 168 and ΔprpE, lacking PrpE phosphatase. Proteomic analysis is still a challenge, and despite of big approach in mass spectrometry (MS field, the identification reliability remains unsatisfactory. Therefore there is a rising interest in new methods, particularly bioinformatic tools that would harden protein identification. Most of currently applied algorithms are based on MS-data. Information from separation steps is not still in routine usage, even though they also provide valuable facts about analyzed structures. The aim of this research was to apply a model for peptides retention times prediction, based on quantitative structure-retention relationships (QSRR in SASPs analysis, obtained from two strains of B. subtilis proteome digests after separation and identification of the peptides by LC-ESI-MS/MS. The QSRR approach was applied as the additional constraint in proteomic research verifying results of MS/MS ion search and confirming the correctness of the peptides identifications along with the indication of the potential false positives and false negatives. Results In both strains of B. subtilis, peptides characteristic for SASPs were found, however their identification confidence varied. According to the MS identity parameter Xcorr and difference between predicted and experimental retention times (ΔtR four groups could be distinguished: correctly and incorrectly identified, potential false positives and false

  13. Monoclonal antibodies to Toxoplasma gondii strain 119 identify recently isolated Danish strains as one group

    DEFF Research Database (Denmark)

    Jensen, L.; Petersen, E.; Henriksen, S.A.;

    1998-01-01

    Four mAb raised against the Danish Toxoplasma gondii strain 119, were selected by screening hybridoma supernatants by indirect immunofluorescence against tachyzoites of the RH strain in order to obtain strain restricted markers. Strain restriction extended beyond discrimination of the 119 and RH...... strains, as demonstrated on a further six T. gondii reference strains [BK and GT1 (group A), NTE and 561 (group B), and NED and C56 (group C)]. The bradyzoite-specific mAb, 4.3, reacted to the GT1, NTE and 561 strains, but not to the BK, NED or C56 strains. The tachyzoite-specific mAb, 4.25, reacted....... gondii strain collection representative for a small geographic area (Denmark) was established within a short time span from a variety of animal species. Using the mAb as typing reagents to this Danish strain collection, all 36 animal and two human strains were identified as having the same reaction...

  14. Proof of Principle for a Real-Time Pathogen Isolation Media Diagnostic: The Use of Laser-Induced Breakdown Spectroscopy to Discriminate Bacterial Pathogens and Antimicrobial-Resistant Staphylococcus aureus Strains Grown on Blood Agar

    Directory of Open Access Journals (Sweden)

    Rosalie A. Multari

    2013-01-01

    Full Text Available Laser-Induced Breakdown Spectroscopy (LIBS is a rapid, in situ, diagnostic technique in which light emissions from a laser plasma formed on the sample are used for analysis allowing automated analysis results to be available in seconds to minutes. This speed of analysis coupled with little or no sample preparation makes LIBS an attractive detection tool. In this study, it is demonstrated that LIBS can be utilized to discriminate both the bacterial species and strains of bacterial colonies grown on blood agar. A discrimination algorithm was created based on multivariate regression analysis of spectral data. The algorithm was deployed on a simulated LIBS instrument system to demonstrate discrimination capability using 6 species. Genetically altered Staphylococcus aureus strains grown on BA, including isogenic sets that differed only by the acquisition of mutations that increase fusidic acid or vancomycin resistance, were also discriminated. The algorithm successfully identified all thirteen cultures used in this study in a time period of 2 minutes. This work provides proof of principle for a LIBS instrumentation system that could be developed for the rapid discrimination of bacterial species and strains demonstrating relatively minor genomic alterations using data collected directly from pathogen isolation media.

  15. Strain and phase identification of the U.S. category B agent Coxiella burnetii by matrix assisted laser desorption/ionization time-of-flight mass spectrometry and multivariate pattern recognition.

    Science.gov (United States)

    Pierce, Carrie Y; Barr, John R; Woolfitt, Adrian R; Moura, Hercules; Shaw, Edward I; Thompson, Herbert A; Massung, Robert F; Fernandez, Facundo M

    2007-01-30

    Accurate bacterial identification is important in diagnosing disease and in microbial forensics. Coxiella burnetii, a highly infective microorganism causative of the human disease Q fever, is now considered a U.S. category B potential bioterrorism agent. We report here an approach for the confirmatory identification of C. burnetii at the strain level which involves the combined use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and supervised pattern recognition via Partial Least Squares-Discriminant Analysis (PLS-DA). C. burnetii isolates investigated in this study included the following prototype strains from different geographical and/or historical origins and with different antigenic properties: Nine Mile I, Australian QD, M44, KAV, PAV, Henzerling, and Ohio. After culture and purification following standard protocols, linear MALDI-TOF mass spectra of pure bacterial cultures were acquired in positive ion mode. Mass spectral data were normalized, baseline-corrected, denoised, binarized and modeled by PLS-DA under crossvalidation conditions. Robustness with respect to uncontrolled variations in the sample preparation and MALDI analysis protocol was assessed by repeating the experiment on five different days spanning a period of 6 months. The method was validated by the prediction of unknown C. burnetii samples in an independent test set with 100% sensitivity and specificity for five out of six strain classes.

  16. Extreme multi-millennial slip rate variations on the Garlock fault, California: Strain super-cycles, potentially time-variable fault strength, and implications for system-level earthquake occurrence

    Science.gov (United States)

    Dolan, James F.; McAuliffe, Lee J.; Rhodes, Edward J.; McGill, Sally F.; Zinke, Robert

    2016-07-01

    Pronounced variations in fault slip rate revealed by new measurements along the Garlock fault have basic implications for understanding how faults store and release strain energy in large earthquakes. Specifically, dating of a series of 26.0+3.5/-2.5 m fault offsets with a newly developed infrared-stimulated luminescence method shows that the fault was slipping at >14.0+2.2/-1.8 mm /yr, approximately twice as fast as the long-term average rate, during a previously documented cluster of four earthquakes 0.5-2.0 ka. This elevated late Holocene rate must be balanced by periods of slow or no slip such as that during the ca. 3300-yr-long seismic lull preceding the cluster. Moreover, whereas a comparison of paleoseismic data and stress modeling results suggests that individual Garlock earthquakes may be triggered by periods of rapid San Andreas fault slip or very large-slip events, the ;on-off; behavior of the Garlock suggests a longer-term mechanism that may involve changes in the rate of elastic strain accumulation on the fault over millennial time scales. This inference is consistent with most models of the geodetic velocity field, which yield slip-deficit rates that are much slower than the average latest Pleistocene-early Holocene (post-8-13 ka) Garlock slip rate of 6.5 ± 1.5 mm /yr. These observations indicate the occurrence of millennia-long strain ;super-cycles; on the Garlock fault that may be associated with temporal changes in elastic strain accumulation rate, which may in turn be controlled by variations in relative strength of the various faults in the Garlock-San Andreas-Eastern California Shear Zone fault system and/or changes in relative plate motion rates.

  17. Persistence of uropathogenic Escherichia coli strains in the host for long periods of time: relationship between phylogenetic groups and virulence factors.

    Science.gov (United States)

    Narciso, A; Nunes, F; Amores, T; Lito, L; Melo-Cristino, J; Duarte, A

    2012-06-01

    Escherichia coli cause the majority of urinary tract infections (UTIs). Virulence plays an important role in the initial stages of interaction with the host, facilitating colonization of the urinary tract tissue. The purpose of this study was to assess whether there is a relationship between virulence and antibiotic resistance in the persistence of uropathogenic E. coli strains. This study included five patients with UTI between 2001 and 2009. The antibiotic resistance phenotype of 29 E. coli isolates was determined by the disk diffusion method. Clonal relationship was determined through M13 polymerase chain reaction (PCR) fingerprinting. Phylogeny, virulence factors, β-lactamases, and replicon typing were studied through PCR. Antibiogram profiles were found from different patients and corresponded to CTX-M-2, CTX-M-15, CTX-M-32, and TEM-52 enzymes. Plasmids belonged essentially to incompatibility group IncF. No clonal relationship was observed among isolates from different patients, except for patients 4 and 5. Phylogenetic group A was predominant. Our work showed that commensal group A possesses the same virulence factors as the pathogenic groups B1 and D. E. coli common pilus and type 1 fimbriae could play an important role in the persistence in the host and in symptomatic UTI, respectively, which, combined with extended-spectrum β-lactamases (ESBLs), are a cause of the dissemination of microorganisms in the hospital and the community.

  18. Time resolved studies of the addition reactions of silylenes and unsaturated hydrocarbons in the gas phase (an investigation of the strain energies of silirane and silirene rings)

    CERN Document Server

    Dormer, G

    1999-01-01

    This thesis reports the measurement of absolute rate constants for number of silylene addition reactions with unsaturated hydrocarbons. The reactions of SiH sub 2 , SiD sub 2 and Me sub 2 Si with alkene and alkynes were studied. The silylenes were formed, in situ, by the photolysis of an organosilicon precursor, and the rate constants obtained by the direct observation of the absorption decay of the silylene reactant. The reactions were studied in the gas phase and their temperature and pressure dependence investigated. The reaction of SiH sub 2 and 1,3-butadiene was investigated and found to be pressure dependent. The following Arrhenius equation was yielded at infinite pressure; log(k supinfinity/cm sup 3 molecule sup - sup 1 s sup - sup 1) = (-9.57 +- 0.05) + (3.22 +- 0.35) kJmol sup - sup 1 /RT ln 10. The reaction was found to proceed via a two-channel pathway, leading to the products vinylsilirane and silacyclopentane. RRKM modelling of the system was carried out and led to the calculation of the strain ...

  19. Using Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry to analyze differentially expressed brain polypeptides in scrapie strain 22L-infected BALB/c mice

    Institute of Scientific and Technical Information of China (English)

    Xiangyu Liao; Chuanjing Ju; Jiayu Wan; Wensen Liu; Xin Tang; Wufei Zhu; Na Xu; Jing Xu; Nan Li; Yaping Chang

    2011-01-01

    Differentially expressed polypeptides in the brain of a BALB/c mouse model infected with scrapie strain 22L were analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results showed that 21 peptides were down-regulated, with peptides of mass-to-charge ratio 758.772 5 and mass-to-charge ratio 5 432.206 9, demonstrating the most significant decreases. These finding suggest that these peptides are candidate biomarkers and may play an important role in the pathogenesis of prion disease.

  20. Strain correction in interleaved strain-encoded (SENC) cardiac MR

    Science.gov (United States)

    Motaal, Abdallah G.; Osman, Nael F.

    2010-03-01

    The strain encoding (SENC) technique directly encodes regional strain of the heart into the acquired MR images and produces two images with two different tunings so that longitudinal strain, on the short-axis view, or circumferential strain on the long-axis view, are measured. Interleaving acquisition is used to shorten the acquisition time of the two tuned images by 50%, but it suffers from errors in the strain calculations due to inter-tunings motion of the heart. In this work, we propose a method to correct for the inter-tunings motion by estimating the motion-induced shift in the spatial frequency of the encoding pattern, which depends on the strain rate. Numerical data was generated to test the proposed method and real images of human subjects were used for validation. The proposed method corrected the measured strain values so they became nearly identical to the original ones. The results show an improvement in strain calculations so as to relax the imaging constraints on spatial and temporal resolutions and improve image quality.

  1. Real-Time TaqMan PCR Assay for the Detection of Heat-Labile and Heat-Stable Enterotoxin Genes in a Geographically Diverse Collection of Enterotoxigenic Escherichia coli Strains and Stool Specimens.

    Science.gov (United States)

    Pattabiraman, Vaishnavi; Parsons, Michele B; Bopp, Cheryl A

    2016-04-01

    Enterotoxigenic Escherichia coli (ETEC) are an important cause of diarrhea in children under the age of 5 years in developing countries and are the leading bacterial agent of traveler's diarrhea in persons traveling to these countries. ETEC strains secrete heat-labile (LT) and/or heat-stable (ST) enterotoxins that induce diarrhea by causing water and electrolyte imbalance. We describe the validation of a real-time TaqMan PCR (RT-PCR) assay to detect LT, ST1a, and ST1b enterotoxin genes in E. coli strains and in stool specimens. We validated LT/ST1b duplex and ST1a single-plex RT-PCR assay using a conventional PCR assay as a gold standard with 188 ETEC strains and 42 non-ETEC strains. We validated LT/ST1b duplex and ST1a single-plex RT-PCR assay in stool specimens (n = 106) using traditional culture as the gold standard. RT- PCR assay sensitivities for LT, ST1a, and ST1b detection in strains were 100%, 100%, and 98%; specificities were 95%, 98%, and 99%, and Pearson correlation coefficient r was 0.9954 between RT-PCR assay and the gold standard. In stool specimens, RT-PCR assay sensitivities for LT, ST1a, and ST1b detection were 97%, 100%, and 97%; and specificities were 99%, 94%, and 97%. Pearson correlation coefficient r was 0.9975 between RT-PCR results in stool specimens and the gold standard. Limits of detection of LT, ST1a, and ST1b by RT-PCR assay were 0.1 to1.0 pg/μL and by conventional PCR assay were 100 to1000 pg/μL. The accuracy, rapidity and sensitivity of this RT-PCR assay is promising for ETEC detection in public health/clinical laboratories and for laboratories in need of an independent method to confirm results of other culture independent diagnostic tests.

  2. Piezoelectric field in strained GaAs.

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Weng Wah; Wieczorek, Sebastian Maciej

    2005-11-01

    This report describes an investigation of the piezoelectric field in strained bulk GaAs. The bound charge distribution is calculated and suitable electrode configurations are proposed for (1) uniaxial and (2) biaxial strain. The screening of the piezoelectric field is studied for different impurity concentrations and sample lengths. Electric current due to the piezoelectric field is calculated for the cases of (1) fixed strain and (2) strain varying in time at a constant rate.

  3. Geobacteraceae strains and methods

    Science.gov (United States)

    Lovley, Derek R.; Nevin, Kelly P.; Yi, Hana

    2015-07-07

    Embodiments of the present invention provide a method of producing genetically modified strains of electricigenic microbes that are specifically adapted for the production of electrical current in microbial fuel cells, as well as strains produced by such methods and fuel cells using such strains. In preferred embodiments, the present invention provides genetically modified strains of Geobacter sulfurreducens and methods of using such strains.

  4. Mercury retention in several strains and strain crosses of chickens

    Energy Technology Data Exchange (ETDEWEB)

    Miller, V.L.; Bearse, G.E.; Csonka, E.

    1970-01-01

    The retention of mercury from injections of mercuric chloride was determined in 32 samples of chicks from various strains and strain crosses of egg type stock. The chicks retaining the most mercury had some four times as much mercury in the liver and kidneys as the chicks retaining the lowest amount. The chicks selected for resistance to leukosis retained more mercury than the susceptible chicks within several leukosis breeding programs.

  5. Novel multiplex real-time PCR diagnostic assay for identification and differentiation of Mycobacterium tuberculosis, Mycobacterium canettii, and Mycobacterium tuberculosis complex strains.

    NARCIS (Netherlands)

    Reddington, K.; O'Grady, J.; Dorai-Raj, S.; Maher, M.; Soolingen, D. van; Barry, T.

    2011-01-01

    Tuberculosis (TB) in humans is caused by members of the Mycobacterium tuberculosis complex (MTC). Rapid detection of the MTC is necessary for the timely initiation of antibiotic treatment, while differentiation between members of the complex may be important to guide the appropriate antibiotic treat

  6. Dynamic strain aging in magnesium oxide single crystals

    Science.gov (United States)

    Srinivasan, M.; Stoebe, T. G.

    1973-01-01

    Strain rate change transients are considered together with aspects of serrated flow, questions of flow stress and work hardening during dynamic strain aging, and time, temperature, and prestrain dependence of strain aging. On continuing the deformation process after aging for certain periods of time for a particular strain, a subsidiary load drop is sometimes observed in addition to the main yield drops.

  7. The L2b real-time PCR targeting the pmpH gene of Chlamydia trachomatis used for the diagnosis of lymphogranuloma venereum is not specific to L2b strains.

    Science.gov (United States)

    Touati, A; Peuchant, O; Hénin, N; Bébéar, C; de Barbeyrac, B

    2016-06-01

    The French Reference Centre for chlamydiae uses two real-time PCRs targeting the pmpH gene of Chlamydia trachomatis to differentiate between L strains and variant L2b, responsible for a lymphogranuloma venereum outbreak in Europe. We compared the results obtained for 122 L2b C. trachomatis-positive specimens, using the two real-time PCRs, with the sequencing of the ompA gene. Only 91 specimens were confirmed as L2b. Our results demonstrate that the lymphogranuloma venereum outbreak is no longer dominated by the variant L2b, and that many L-positive specimens were misidentified as L2b with the method used, which raises the question of its specificity. Copyright © 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  8. A finite difference technique for solving a time strain separable K-BKZ constitutive equation for two-dimensional moving free surface flows

    Science.gov (United States)

    Tomé, M. F.; Bertoco, J.; Oishi, C. M.; Araujo, M. S. B.; Cruz, D.; Pinho, F. T.; Vynnycky, M.

    2016-04-01

    This work is concerned with the numerical solution of the K-BKZ integral constitutive equation for two-dimensional time-dependent free surface flows. The numerical method proposed herein is a finite difference technique for simulating flows possessing moving surfaces that can interact with solid walls. The main characteristics of the methodology employed are: the momentum and mass conservation equations are solved by an implicit method; the pressure boundary condition on the free surface is implicitly coupled with the Poisson equation for obtaining the pressure field from mass conservation; a novel scheme for defining the past times t‧ is employed; the Finger tensor is calculated by the deformation fields method and is advanced in time by a second-order Runge-Kutta method. This new technique is verified by solving shear and uniaxial elongational flows. Furthermore, an analytic solution for fully developed channel flow is obtained that is employed in the verification and assessment of convergence with mesh refinement of the numerical solution. For free surface flows, the assessment of convergence with mesh refinement relies on a jet impinging on a rigid surface and a comparison of the simulation of a extrudate swell problem studied by Mitsoulis (2010) [44] was performed. Finally, the new code is used to investigate in detail the jet buckling phenomenon of K-BKZ fluids.

  9. Sprains and Strains

    Science.gov (United States)

    ... wrestling put people at risk for strains. Gymnastics, tennis, rowing, golf, and other sports that require extensive gripping can increase the risk of hand and forearm strains. Elbow strains sometimes occur in people who participate in ...

  10. Muscle strain treatment

    Science.gov (United States)

    Treatment - muscle strain ... Question: How do you treat a muscle strain ? Answer: Rest the strained muscle and apply ice for the first few days after the injury. Anti-inflammatory medicines or acetaminophen ( ...

  11. Muscle strain (image)

    Science.gov (United States)

    A muscle strain is the stretching or tearing of muscle fibers. A muscle strain can be caused by sports, exercise, a ... something that is too heavy. Symptoms of a muscle strain include pain, tightness, swelling, tenderness, and the ...

  12. Time series analysis of strain accumulation across the Haiyuan fault, Gansu, China, over the 2003-2009 period from ENVISAT InSAR data

    Science.gov (United States)

    Jolivet, R.; Lasserre, C.; Doin, M.; Guillaso, S.; Cavalie, O.; Peltzer, G.; Sun, J.; Shen, Z.

    2009-12-01

    We use sar interferometry to characterize the present-day behaviour of the left-lateral Haiyuan fault system (HFS), one of the main geological structure at the north-eastern boundary of the tibetan plateau that accomodates the eastward movement of Tibet relative to the Gobi-Ala Shan platform. The last major earthquakes that occured along the HFS are the M~8 1920 Haiyuan earthquake (strike-slip mechanism) and the Ml=8-8.3 1927 Gulang earthquake that ruptured a nearby thrust fault system. A ~260 km-long seismic gap has been identified on the central part of the HFS, along which creep may occur. We propose to further investigate the relationships between the present day deformation processes observed along the HFS and its seismic history and segmentation. We construct an extended InSAR-based map of the deformation around the Haiyuan fault from the eastern end of the Qilian Shan (102° E), to the west, to the junction with the Liupan Shan (106° E), to the east. We use monthly ENVISAT acquisitions along 4 descending and 2 ascending tracks, spanning the 2003-2009 time period. Data are processed using a small baseline chain type. For each track, all radar images are coregistrated to a single master and interferograms are produced using a local adaptative range filtering. Residual orbital and atmospheric effects are jointly inverted and corrected for each unwrapped interferogram. Atmospheric corrections are validated “a posteriori” , using the most recent global atmospheric model. We also investigate the potential improvements of these models for “a priori” atmospheric corrections. The interferograms series on each track are then inverted to obtain the increments of Line Of Sight (LOS) radar delays between acquisition dates, adapting the Lopez-Quiroz et al. 2009 time series analysis. We derive LOS mean velocity maps, that show along-strike variations including local shallow creep and vertical movements (subsidence in the Jingtai pull-apart basin). These features

  13. A multiplex, internally controlled real-time PCR assay for detection of toxigenic Clostridium difficile and identification of hypervirulent strain 027/ST-1

    DEFF Research Database (Denmark)

    Hoegh, A M; Nielsen, J B; Lester, A

    2012-01-01

    The purpose of this study was to validate a multiplex real-time PCR assay capable of detecting toxigenic Clostridium difficile and simultaneously identifying C. difficile ribotype 027/ST-1 by targeting the toxin genes tcdA, tcdB and cdtA in one reaction and in a separate reaction identifying the Δ...... to confirm the correct identification of the Δ117 deletion in tcdC and C. difficile ribotype 027/ST-1, respectively. The PCR assay displayed a sensitivity, specificity, PPV and NPV of 99.0%, 97.4%, 87.4% and 99.8%, respectively, compared to toxigenic culture on 665 samples evaluable both by PCR and culture....... Sequencing of tcdC, ribotyping and MLST of cultured isolates validated the genotyping assay and confirmed the ability of the assay to correctly identify C. difficile ribotype 027/ST-1 in our current epidemiological setting. We describe the use of a combination of two separate PCR assays for sensitive...

  14. A strain gauge

    DEFF Research Database (Denmark)

    2017-01-01

    The invention relates to a strain gauge of a carrier layer and a meandering measurement grid (101) positioned on the carrier layer, wherein the measurement grid comprises a number of measurement grid sections placed side by side with gaps in between, and a number of end loops (106) interconnecting...... the measurement grid sections at their ends. The end loops at both ends of the measurement grid extend a length (L, 500) in the axial direction in millimetres of a factor times a ratio between a width of a grid section and the gap distance, wherein the factor is larger or equal to 1.5. The invention further...

  15. Spontaneous abortion and physical strain around implantation

    DEFF Research Database (Denmark)

    Hjollund, N H; Jensen, Tina Kold; Bonde, Jens Peter

    2000-01-01

    Existing studies of physical strain and spontaneous abortion are mainly retrospective or based only on pregnancies that have survived the first trimester. Furthermore, almost all studies have relied on averaged measures of physical strain, which tend to blur an effect if peak values during short...... pregnancy the women recorded physical strain prospectively in a structured diary. Physical strain around the time of implantation was associated with later spontaneous abortion. The adjusted risk ratio for women who reported physical strain higher than average at day 6 to 9 after the estimated date...

  16. Spontaneous abortion and physical strain around implantation

    DEFF Research Database (Denmark)

    Hjøllund, Niels Henrik Ingvar; Jensen, T.K.; Bonde, J.P.

    2000-01-01

    Existing studies of physical strain and spontaneous abortion are mainly retrospective or based only on pregnancies that have survived the first trimester. Furthermore, almost all studies have relied on averaged measures of physical strain, which tend to blur an effect if peak values during short...... pregnancy the women recorded physical strain prospectively in a structured diary. Physical strain around the time of implantation was associated with later spontaneous abortion. The adjusted risk ratio for women who reported physical strain higher than average at day 6 to 9 after the estimated date...

  17. Evaluation of matrix-assisted laser desorption ionization-time of flight mass spectrometry for species identification of Acinetobacter strains isolated from blood cultures.

    Science.gov (United States)

    Kishii, K; Kikuchi, K; Matsuda, N; Yoshida, A; Okuzumi, K; Uetera, Y; Yasuhara, H; Moriya, K

    2014-05-01

    The clinical relevance of Acinetobacter species, other than A. baumannii, as human pathogens has not been sufficiently assessed owing to the insufficiency of simple phenotypic clinical diagnostic laboratory tests. Infections caused by these organisms have different impacts on clinical outcome and require different treatment and management approaches. It is therefore important to correctly identify Acinetobacter species. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been introduced to identify a wide range of microorganisms in clinical laboratories, but only a few studies have examined its utility for identifying Acinetobacter species, particularly those of the non-Acinetobacter baumannii complex. We therefore evaluated MALDI-TOF MS for identification of Acinetobacter species by comparing it with sequence analysis of rpoB using 123 isolates of Acinetobacter species from blood. Of the isolates examined, we identified 106/123 (86.2%) to species, and 16/123 (13.0%) could only be identified as acinetobacters. The identity of one isolate could not be established. Of the 106 species identified, 89/106 (84.0%) were confirmed by rpoB sequence analysis, and 17/106 (16.0%) were discordant. These data indicate correct identification of 89/123 (72.4%) isolates. Surprisingly, all blood culture isolates were identified as 13 species of Acinetobacter, and the incidence of Acinetobacter pittii was unexpectedly high (42/123; 34.1%) and exceeded that of A. baumannii (22/123; 17.9%). Although the present identification rate using MALDI-TOF MS is not acceptable for species-level identification of Acinetobacter, further expansion of the database should remedy this situation.

  18. Real-time RT-PCR expression analysis of chitinase and endoglucanase genes in the three-way interaction between the biocontrol strain Clonostachys rosea IK726, Botrytis cinera and strawberry

    DEFF Research Database (Denmark)

    Mamarabadi, Mojtaba; Jensen, Birgit; Jensen, Søren Dan Funck

    2008-01-01

    Clonostachys rosea is a well-known biocontrol agent against Botrytis cinerea, the causal agent of gray mold in strawberry. The activity of cell wall-degrading enzymes might play a significant role for successful biocontrol by C. rosea. The expression pattern of four chitinases, and two...... endoglucanase genes from C. rosea strain IK726 was analyzed using real-time RT-PCR in vitro and in strawberry leaves during interaction with B. cinerea. Specific primers were designed for ß-tubulin genes from C. rosea and B. cinerea, respectively, and a gene encoding a DNA-binding protein (DBP) from strawberry......, allowing in situ activity assessment of each fungus in vitro and during their interaction on strawberry leaves. Growth of B. cinerea was inhibited in all pathogen-antagonist interactions while the activity of IK726 was slightly increased. In all in vitro interactions, four of the six genes were upregulated...

  19. Serologic response of roosters to gradient dosage levels of a commercially available live F strain-derived Mycoplasma gallisepticum vaccine over time.

    Science.gov (United States)

    Purswell, J L; Evans, J D; Branton, S L

    2011-09-01

    Spray application is a commonly used, time- and labor-efficient means to deliver live Mycoplasma gallisepticum (MG) vaccine to laying hens in commercial production facilities. The dosage of vaccine received by spray-vaccinated birds can vary due to variation in the spray plume and the vaccine suspension droplet trajectory. In this study, a total of 48 Hy-Line W-36 males were placed individually in isolation units following eye-drop application of gradient levels (1 x, 10(-1) x, 10(-2) x, 10(-3) x, 10(-4) x, 10(-5) x, 10(-6) x, and unvaccinated control) of the MG vaccine. The determined titer associated with a 1 x dose was 2 x 10(6) colony-forming units/dose. Serologic response was assessed weekly following vaccination via serum plate agglutination (SPA) for weeks one through seven postvaccination (p.v.). In addition, immunologic response was assessed at 5, 6, and 7 wk p.v. via MG enzyme-linked immunosorbent assay (ELISA). As indicated by SPA analyses, a 1 x dose of vaccine resulted in 100% seroconversion, and dose levels of 10(-1) x and 10(-2) x resulted in 75% and 37.5% seroconversion, respectively, at 6 wk p.v. The MG ELISA results at 6 wk p.v. demonstrated immunologic responses in 100%, 57.1%, and 28.6% of the 1 x, 10(-1) x, and 10(-2) x dosed birds, respectively. The lower dosage levels of 10(-3) x, 10(-4) x, 10(-5) x, and 10(-6) x did not elicit a response from any bird at 6 wk p.v. Utilizing the SPA data, a logistic regression model was used to determine the relationship between dosage level and seroconversion rate (R2 = 0.999 with a standard error of prediction of 1.6%). The model predicted a required effective dosage of 0.26 x for 90% seroconversion at 6 wk p.v. under test conditions.

  20. Development and validation of a real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay for investigation of wild poliovirus type 1-South Asian (SOAS) strain reintroduced into Israel, 2013 to 2014.

    Science.gov (United States)

    Hindiyeh, M Y; Moran-Gilad, J; Manor, Y; Ram, D; Shulman, L M; Sofer, D; Mendelson, E

    2014-02-20

    In February 2013, wild poliovirus type 1 (WPV1) was reintroduced into southern Israel and resulted in continuous silent circulation in the highly immune population. As a part of the public health emergency response, a novel real time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay was developed, to allow for the sensitive and specific detection of the circulatingWPV1-South Asian (SOAS) strain. Specific primers and probes derived from the VP-1 region were designed, based on sequenced sewage isolates, and used to simultaneously amplify this WPV1-SOAS sequence together with bacteriophage MS-2 as internal control. High titre WPV1-SOAS stock virus was used for assay optimisation and 50 processed sewage samples collected from southern Israel and tested by reference culture based methods were used for analytical validation of the assay’s performance. The limit of detection of the multiplex qRT-PCR (SOAS/MS-2) assay was 0.1 plaque-forming unit (pfu)/reaction (20 pfu/mL) for WPV1-SOAS RNA with 100% sensitivity, specificity, positive and negative predictive values when compared to the culture based method. The turnaround time was rapid, providing results for environmental samples within 24 to 48 hours from completion of sewage processing, instead of five to seven days by culture-based analysis. Direct sewage testing by qRT-PCR assay proved to be a useful tool for rapid detection and environmental surveillance of WPV1-SOAS circulating strain during emergency response. Application of the approach for detection of WPV1-SOAS in stool samples obtained during acute flaccid paralysis (AFP) surveillance or field surveys should be further evaluated.

  1. Strain localization band width evolution by electronic speckle pattern interferometry strain rate measurement

    Energy Technology Data Exchange (ETDEWEB)

    Guelorget, Bruno [Institut Charles Delaunay-LASMIS, Universite de technologie de Troyes, FRE CNRS 2848, 12 rue Marie Curie, B.P. 2060, 10010 Troyes Cedex (France)], E-mail: bruno.guelorget@utt.fr; Francois, Manuel; Montay, Guillaume [Institut Charles Delaunay-LASMIS, Universite de technologie de Troyes, FRE CNRS 2848, 12 rue Marie Curie, B.P. 2060, 10010 Troyes Cedex (France)

    2009-04-15

    In this paper, electronic speckle pattern interferometry strain rate measurements are used to quantify the width of the strain localization band, which occurs when a sheet specimen is submitted to tension. It is shown that the width of this band decreases with increasing strain. Just before fracture, this measured width is about five times wider than the shear band and the initial sheet thickness.

  2. Comparison of the Abbott RealTime CT new formulation assay with two other commercial assays for detection of wild-type and new variant strains of Chlamydia trachomatis

    DEFF Research Database (Denmark)

    Møller, Jens Kjølseth; Pedersen, Lisbeth Nørum; Persson, Kenneth

    2010-01-01

    In an analytical methods comparison study on clinical samples, the Abbott RealTime CT new formulation assay (m2000 real-time PCR) consisting of a duplex PCR targeting different parts of the cryptic plasmid in Chlamydia trachomatis was compared with version 2 of the Roche COBAS(R) TaqMan(R) CT assay...... comprising a duplex PCR for a target in the cryptic plasmid and the omp1 gene, and compared with the Gen-Probe APTIMA COMBO 2(R) assay (AC2) targeting the C. trachomatis 23S rRNA molecule. First-catch urine samples from Sweden were tested in Malmoe for C. trachomatis with the m2000 real-time PCR assay......, and with an in-house PCR for the new variant C. trachomatis strain with a deletion in the cryptic plasmid. Aliquots of the urine samples were sent to Aarhus, Denmark and further examined with the TaqMan CT and the AC2 assay. A positive prevalence of 9.1% (148/1,632 urine samples examined) was detected according...

  3. Variabilidade de produção de aflatoxinas por linhagens de Aspergillus flavus em diferentes tempos de manutenção Aflatoxin production variability by Aspergillus flavus strains after different storage times

    Directory of Open Access Journals (Sweden)

    M.H. Taniwaki

    1993-05-01

    Full Text Available O presente trabalho fui realizado com a finalidade de se estudar a produção de aflatoxinas por linhagens de A. flavus, recém isoladas, em diferentes tempos de manutenção, a fim de contribuir para um melhor entendimento do mecanismo de variação na produção de aflatoxinas. Para isso, foram utilizadas três linhagens de A. flavus produtoras de aflatoxinas, classificadas como: a grande produtora; b média produtora e c baixa produtora. Neste experimento, que se estendeu por 280 dias, os fungos foram estudados em dois métodos de preservação: mantido em óleo mineral, no meio Czapeck, e repicado periodicamente em meio Czapeck modificado. A análise da produção de aflatoxinas foi efetuada de 30 em 30 dias. A quantificação da toxina foi feita por cromatografía em camada delgada, pela técnica de avaliação visual, de diluição até extinção. Foi constatada uma variação na produção de toxina em todas as linhagens, contudo elas não perderam suas características originais.Aflatoxin production by strains recently isolated of Aspergillus flavus was studied, after different storage times understand the mechanisms of possible variations in aflatoxin production. Three A. flavus aflatoxin producing strains were utilized, classified as: a high producer; b medium producer and c low producer. The experiment lasted 280 days and the moulds were studied by two preservation methods: oil covered slants on Czapeck's medium and periodic transfer on Czapeck's modified medium. Quantification of the aflatoxin produced was made at 30 day intervals, on thin-layer chromatography and visual determination by the dilution-to-extinction technique. The production of aflatoxin by all strains varied but they did not lose their initial characteristics. Microscopic examinations revealed thickened zones and hifal enlargements over some globous structures that may be related to aflatoxin production sites.

  4. Asymptomatic bacteriuria Escherichia coli strains

    DEFF Research Database (Denmark)

    Hancock, Viktoria; Nielsen, E.M.; Klemm, Per

    2006-01-01

    Urinary tract infections (UTIs) affect millions of people each year. Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU) in humans. Persons affected by ABU may carry a particular E. coli strain for extended periods of time without any symptoms. In contrast...

  5. Asymptomatic bacteriuria Escherichia coli strains

    DEFF Research Database (Denmark)

    Hancock, Viktoria; Nielsen, E.M.; Klemm, Per

    2006-01-01

    Urinary tract infections (UTIs) affect millions of people each year. Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU) in humans. Persons affected by ABU may carry a particular E. coli strain for extended periods of time without any symptoms. In contrast...

  6. Obturator internus muscle strains

    Directory of Open Access Journals (Sweden)

    Caoimhe Byrne, MB BCh, BAO

    2017-03-01

    Full Text Available We report 2 cases of obturator internus muscle strains. The injuries occurred in young male athletes involved in kicking sports. Case 1 details an acute obturator internus muscle strain with associated adductor longus strain. Case 2 details an overuse injury of the bilateral obturator internus muscles. In each case, magnetic resonance imaging played a crucial role in accurate diagnosis.

  7. Intergranular strains in textured steel

    Energy Technology Data Exchange (ETDEWEB)

    Daymond, M.R. [Los Alamos Neutron Science Center (LANSCE), Los Alamos, NM (United States); Tome, C.N. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.; Bourke, M.A.M. [Los Alamos Neutron Science Center (LANSCE), Los Alamos, NM (United States); Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

    2000-07-01

    Tensile specimens were machined from heat treated austenitic stainless steel plate prior to and after 70% reduction by uni-directional rolling. In addition to a specimen from the as-received plate, two specimens were cut from the rolled plate, with axes parallel and perpendicular to the rolling direction respectively. In situ measurements of the strain response of multiple hkl lattice planes to an applied uniaxial tensile load were made using neutron diffraction. The experimental results are compared with predictions from a self-consistent Hill-Hutchinson model. The measured texture in the plate was approximately 3 times random, however its effect on the hkl response was small compared to the residual strains left by rolling. The apparent elastic modulus and Poisson's ratios of the planes is affected by the residual strains, which is attributed to the effect of micro-plasticity. Interpretation of residual stress measurements is considered in light of these results. (orig.)

  8. Temperature inactivation of Feline calicivirus vaccine strain FCV F-9 in comparison with human noroviruses using an RNA exposure assay and reverse transcribed quantitative real-time polymerase chain reaction-A novel method for predicting virus infectivity.

    Science.gov (United States)

    Topping, J R; Schnerr, H; Haines, J; Scott, M; Carter, M J; Willcocks, M M; Bellamy, K; Brown, D W; Gray, J J; Gallimore, C I; Knight, A I

    2009-03-01

    A one-step reverse transcription quantitative real-time polymerase chain reaction (RT-QPCR) method in combination with RNase treatment and low copy number samples was developed in order to examine the effect of temperature on the ability of virus capsids to protect their RNA content. The method was applied to a non-cultivable virus (GII.4 norovirus) and Feline calicivirus vaccine strain F-9 (FCV) which is often used as a norovirus surrogate. Results demonstrated that FCV RNA is exposed maximally after 2min at 63.3 degrees C and this correlated with a greater than 4.5log reduction in infectivity as assessed by plaque assay. In contrast human GII.4 norovirus RNA present in diluted clinical specimens was not exposed maximally until 76.6 degrees C, at least 13.3 degrees C greater than that for FCV. These data suggest that norovirus possesses greater thermostability than this commonly used surrogate. Further, these studies indicate that current food processing regimes for pasteurisation are insufficient to achieve inactivation of GII.4 NoVs. The method provides a novel molecular method for predicting virus infectivity.

  9. Left ventricular layer function in hypertension assessed by myocardial strain rate using novel one-beat real-time three-dimensional speckle tracking echocardiography with high volume rates.

    Science.gov (United States)

    Saeki, Maki; Sato, Noriaki; Kawasaki, Masanori; Tanaka, Ryuhei; Nagaya, Maki; Watanabe, Takatomo; Ono, Koji; Noda, Toshiyuki; Zile, Michael R; Minatoguchi, Shinya

    2015-08-01

    We recently developed novel software to measure phasic strain rate (SR) using automated one-beat real-time three-dimensional speckle tracking echocardiography (3D-STE) with high volume rates. We tested the hypothesis that left ventricular (LV) systolic function and relaxation analyzed by SR with the novel 3D-STE in hypertension (HTN) with hypertrophy may be impaired in the endocardium before there is LV systolic dysfunction. We measured LV longitudinal, radial and circumferential SR in patients with HTN (n=80, 69±7 years) and age-matched normotensive controls (n= 60, 69±10 years) using 3D-STE. HTN patients were divided into four groups according to LV geometry: normal, concentric remodeling, concentric hypertrophy and eccentric hypertrophy. We measured SR during systole as an index of systolic function, SR during isovolumic relaxation (IVR) as an index of relaxation and E/e' as an index of filling pressure. Endocardial SR during systole in HTN with concentric and eccentric hypertrophy decreased compared with that in controls despite no reduction in ejection fraction or epicardial SR. Endocardial radial SR during IVR decreased even in normal geometry, and it was further reduced in concentric remodeling and hypertrophy despite no reduction in epicardial SR. LV phasic SR assessed by 3D-STE with high volume rates is a useful index to detect early decreases in LV systolic function and to predict subclinical LV layer dysfunction in patients with HTN.

  10. Effective heat strain index using pocket computer.

    Science.gov (United States)

    Kamon, E; Ryan, C

    1981-08-01

    An effective heat strain index (EHSI) using a hand calculator with memory is suggested for on-site evaluation of prevailing hot ambient conditions. The inputs to the programmed calculator include dry-bulb, wet-bulb and globe temperatures, and estimates of metabolism and air movements. The index is based on a program for calculation of the total heat balance and on the efficiency of sweating. The display of information on the ambient conditions EHSI display is one of following: no strain; low strain; high strain; or time limits of exposure.

  11. Sensor for Measuring Strain in Textile

    Directory of Open Access Journals (Sweden)

    Gerhard Tröster

    2008-06-01

    Full Text Available In this paper a stain sensor to measure large strain (80% in textiles is presented. It consists of a mixture of 50wt-% thermoplastic elastomer (TPE and 50wt-% carbon black particles and is fiber-shaped with a diameter of 0.315mm. The attachment of the sensor to the textile is realized using a silicone film. This sensor configuration was characterized using a strain tester and measuring the resistance (extension-retraction cycles: It showed a linear resistance response to strain, a small hysteresis, no ageing effects and a small dependance on the strain velocity. The total mean error caused by all these effects was +/-5.5% in strain. Washing several times in a conventional washing machine did not influence the sensor properties. The paper finishes by showing an example application where 21 strain sensors were integrated into a catsuit. With this garment, 27 upper body postures could be recognized with an accuracy of 97%.

  12. Real Time Superresolution by Means of an Ultrasonic Light Diffractor and TV System.

    Science.gov (United States)

    Sato, T; Ueda, M; Ikeda, T

    1974-06-01

    The change of angle and the shift of frequency of light by an ultrasonic light diffractor are used for real time realization of a holographic superresolution system. A TV system and an electrical filter are used to pick up the desired image hologram from the superposed, images, which are obtained by a number of object-beam lights and reference beams. For two-dimensional as well as one-dimensional objects, images superresolved three to five times are displayed on a TV monitor in real time.

  13. Measurement of Sorption-Induced Strain

    Energy Technology Data Exchange (ETDEWEB)

    Eric P. Robertson; Richard L. Christiansen

    2005-05-01

    Strain caused by the adsorption of gases was measured in samples of subbituminous coal from the Powder River basin of Wyoming, U.S.A. and high-volatile bituminous coal from east-central Utah, U.S.A. using an apparatus developed jointly at the Idaho National Laboratory (Idaho Falls, Idaho, U.S.A.) and Colorado School of Mines (Golden, Colorado, U.S.A.). The apparatus can be used to measure strain on multiple small coal samples based on the optical detection of the longitudinal strain instead of the more common usage of strain gauges, which require larger samples and longer equilibration times. With this apparatus, we showed that the swelling and shrinkage processes were reversible and that accurate strain data could be obtained in a shortened amount of time. A suite of strain curves was generated for these coals using gases that included carbon dioxide, nitrogen, methane, helium, and various mixtures of these gases. A Langmuir-type equation was applied to satisfactorily model the strain data obtained for pure gases. The sorption-induced strain measured in the subbituminous coal was larger than the high-volatile bituminous coal for all gases tested over the range of pressures used in the experimentation, with the CO2-induced strain for the subbituminous coal over twice as great at the bituminous coal.

  14. Human immunodeficiency virus type 1 Brazilian subtype B variant showed an increasing avidity of the anti-V3 antibodies over time compared to the subtype B US/European strain in São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Casseb Jorge

    2004-01-01

    Full Text Available The Brazilian variant of human immunodeficiency virus type 1 (HIV-1 subtype B, (serotype B"-GWGR, has a tryptophan replacing the proline in position 328 the HIV-1 envelope. A longer median time period from infection to acquired immunodeficiency syndrome (AIDS for serotype B (B"-GWGR infected subjects compared to the B-GPGR US/European strain was reported. In a cohort study, in São Paulo city, 10 B"-GWGR patients had a statistically significant increased avidity of the anti-V3 antibodies, from 79% ± 33% to 85% ± 75%, versus from 48% ± 59% to 32% ± 17% for the 10 B-GPGR subjects (p = 0.02. The T CD4+ cells showed a mean increase of + 0.45 cells/month for the B-GPGR subjects and for B"-GWGR the slope was + 1.24 cells/month (p = 0.06, for 62 and 55 months of follow up, respectively. RNA plasma viral load decreased from 3.98 ± 1.75 to 2.16 ± 1.54 log10 in the B"-GWGR group while B-GPGR patients showed one log10 reduction in viral load from 4.09 ± 0.38 to 3.17 ± 1.47 log10 over time (p = 0.23, with a decreasing slope of 0.0042 ± log10,/month and 0.0080 ± log10/month, for B-GPGR and B"-GWGR patients, respectively (p = 0.53. Neither group presented any AIDS defining events during the study, according to Center for Diseases Control criteria. Although the sample size is small, these results may indicate that differences in the pathogenicity of the 2 HIV-1 B serotypes which co-circulate in Brazil may be correlated to the avidity of anti-V3 antibodies.

  15. Characterization of the time-dependent strain field at seismogenic depths using first-motion focal mechanisms: Observations of large-scale decadal variations in stress along the San Andrea fault system

    Science.gov (United States)

    Sipkin, S.A.; Silver, P.G.

    2003-01-01

    We present a method for summing moment tensors derived from first-motion focal mechanisms to study temporal dependence in features of the subsurface regional strain field. Time-dependent processes are inferred by comparing mechanisms summed over differing time periods. We apply this methodology to seismogenic zones in central and southern California using focal mechanisms produced by the Northern and Southern California Seismograph Networks for events during 1980-1999. We find a consistent pattern in both the style of deformation (strike-slip versus compressional) and seismicity rate across the entire region. If these temporal variations are causally related, it suggests a temporal change in the regional-scale stress field. One change consistent with the observations is a rotation in the regional maximum horizontal compressive stress direction, followed by a reversal to the original direction. Depending upon the dominant style of deformation locally, this change in orientation of the regional stress will tend to either enhance or hinder deformation. The mode of enhanced deformation can range from increased microseismicity and creep to major earthquakes. We hypothesize that these temporal changes in the regional stress field are the result of subtle changes in apparent relative plate motion between the Pacific and North American plates, perhaps due to long-range postseismic stress diffusion. Others have hypothesized that small changes in plate motion over thousands of years, and/or over decades, are responsible for changes in the style of deformation in southern California. We propose that such changes, over the course of just a few years, also affect the style of deformation.

  16. Strain y strain rate para dummies

    Directory of Open Access Journals (Sweden)

    Pastor Olaya, MD

    2011-11-01

    Full Text Available Desarrollos recientes en el campo de la ecocardiografía han permitido a los cardiólogos cuantificar de manera objetiva la función miocárdica regional y global con base en los conceptos de deformación (strain y velocidad de deformación (strain rate que pueden calcularse de manera no invasiva tanto en el ventrículo izquierdo como en el derecho, y suministrar valiosa información en múltiples escenarios clínicos. Dado que esta técnica novedosa y promisoria se utiliza cada vez más en la clínica y en estudios de investigación, se hace necesario el conocimiento adecuado de sus principios, así como de sus aspectos técnicos, alcances y limitaciones para una mejor implementación. En este artículo se busca dar explicación a los conceptos fundamentales y las potenciales aplicaciones clínicas de la strain y la strain rate derivados por speckle tracking (strain 2D.

  17. Vorticity and strain analyses: using rotated boudins and drag folds in the HP-LT Sanandaj-Sirjan metamorphic belt, Southwestern Iran

    Science.gov (United States)

    Sarkarinejad, K.; Keshavarz, S.

    2009-04-01

    The Seh-Ghalatoun area, in the southwestern Iran, is part of the HP-LT Sanandaj -Sirjan metamorphic belt within the Zagros orogenic belt. The area exhum high- grade metamorphic rocks along thrusts and shear zones which reveals the HP-LT conditions of metamorphism. This high strain zone affected by the polyphase deformation. Mesoscopic and microscopic structures such as rotated porphyroclasts, boudins, veins, drag folds and superposed folds have been used to estimate quantitative finite strain, kinematic vorticity number and sense of shear. axial plane of the asymmetrical folds give an orientation of N30˚W,40˚NE to N45˚W,39˚NE. clockwise rotation of asymetrical fold hinges indicates dextral sense of shear. The superposed folding patterns in this area indicates type 2 and type 3 interference patterns. Boudin trains in the quartzo-feldespatic gneises layers are symmetric and asymmetric and they have been classified as the domino boudins, drawn boudins, shear band and torn boudins. The boudin obliquity with respect to the fabric attractor is considerable so that the domino boudins are either parallel or oblique to the S1 foliations, their mean orientation is N70˚W. In addition modified or complex boudins consist of two categories: the sequential boudins and reworked boudins is a clear reason for subsequent deformation. Based on these structures, three phases of deformation were recognized in the Seh-Ghalatoun area. First phase of deformation (D1) led to the formation of the main foliation (S1) with NW-SE direction and have formed at the peak of metamorphism. Presence of weaker and less penetrative foliation superposed on the S1 foliation which form S2 foliation. Third phase of deformation (D3) developed by shearing along the shear zones and thrusts which give rise to the S/C shear band cleavage (S3) during lateral exhumation High-grade and high strain metamorphic rocks on top of the subducting Thethyan oceanic crust.

  18. First Complete Genome Sequence of Marinilactibacillus piezotolerans Strain 15R, a Marine Lactobacillus Isolated from Coal-Bearing Sediment 2.0 Kilometers below the Seafloor, Determined by PacBio Single-Molecule Real-Time Technology

    Science.gov (United States)

    Wei, Yuli; Cao, Junwei; Kato, Chiaki; Cui, Weicheng

    2017-01-01

    ABSTRACT   Marinilactibacillus piezotolerans strain 15R is a facultatively anaerobic heterotrophic lactobacillus isolated from deep marine subsurface sediment nearly 2 km below the seafloor in the northwestern Pacific. We report here the first whole-genome sequence of strain 15R. The identified genome sequence has 2,767,908 bp, 35.4% G+C content, and predicted 2,552 candidate protein-coding sequences, with no identified plasmids. PMID:28209827

  19. Three dimensional strained semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Voss, Lars; Conway, Adam; Nikolic, Rebecca J.; Leao, Cedric Rocha; Shao, Qinghui

    2016-11-08

    In one embodiment, an apparatus includes a three dimensional structure comprising a semiconductor material, and at least one thin film in contact with at least one exterior surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the three dimensional structure. In another embodiment, a method includes forming a three dimensional structure comprising a semiconductor material, and depositing at least one thin film on at least one surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the structure.

  20. Strain-engineered MOSFETs

    CERN Document Server

    Maiti, CK

    2012-01-01

    Currently strain engineering is the main technique used to enhance the performance of advanced silicon-based metal-oxide-semiconductor field-effect transistors (MOSFETs). Written from an engineering application standpoint, Strain-Engineered MOSFETs introduces promising strain techniques to fabricate strain-engineered MOSFETs and to methods to assess the applications of these techniques. The book provides the background and physical insight needed to understand new and future developments in the modeling and design of n- and p-MOSFETs at nanoscale. This book focuses on recent developments in st

  1. Distributed strain monitoring for bridges: temperature effects

    Science.gov (United States)

    Regier, Ryan; Hoult, Neil A.

    2014-03-01

    To better manage infrastructure assets as they reach the end of their service lives, quantitative data is required to better assess structural behavior and allow for more informed decision making. Distributed fiber optic strain sensors are one sensing technology that could provide comprehensive data for use in structural assessments as these systems potentially allow for strain to be measured with the same accuracy and gage lengths as conventional strain sensors. However, as with many sensor technologies, temperature can play an important role in terms of both the structure's and sensor's performance. To investigate this issue a fiber optic distributed strain sensor system was installed on a section of a two span reinforced concrete bridge on the TransCanada Highway. Strain data was acquired several times a day as well as over the course of several months to explore the effects of changing temperature on the data. The results show that the strain measurements are affected by the bridge behavior as a whole. The strain measurements due to temperature are compared to strain measurements that were taken during a load test on the bridge. The results show that even a small change in temperature can produce crack width and strain changes similar to those due to a fully loaded transport truck. Future directions for research in this area are outlined.

  2. Myocardial Strain and Strain Rate Imaging: Comparison between Doppler Derived Strain Imaging and Speckle Tracking Echocardiography

    Directory of Open Access Journals (Sweden)

    Anita Sadeghpour

    2013-05-01

    Full Text Available Regional myocardial function has been traditionally assessed by visual estimation (1. Echocardiographic strain imaging which is known as deformation imaging, has been emerged as a quantitative technique to accurately estimate regional myocardial function and contractility. Currently, strain imaging has been regarded as a research tool in the most echocardiography laboratories. However, in recent years, strain imaging has gain momentum in daily clinical practice (2. The following two techniques have dominated the research arena of echocardiography: (1 Doppler based tissue velocity measurements, frequently referred to tissue Doppler or myocardial Doppler, and (2 speckle tracking on the basis of displacement measurements (3. Over the past two decades, Tissue Doppler Imaging (TDI and Doppler –derived strain (S and strain rate (SR imaging were introduced to quantify regional myocardial function. However, Doppler–derived strain variables faced criticisms, with regard to the angle dependency, noise interference, and substantial intraobserver and interobserver variability. The angle dependency is the major weakness of Doppler based methodology; however, it has the advantage of online measurements of velocities and time intervals with excellent temporal resolution, which is essential for the assessment of ischemia (4. Speckle-tracking echocardiography (STE or Non Doppler 2D strain echocardiography is a relatively new, largely angle-independent technique that analyzes motion by tracking natural acoustic reflections and interference patterns within an ultrasonic window. The image-processing algorithm tracks elements with approximately 20 to 40 pixels containing stable patterns and are described as ‘‘speckles’’ or ‘‘fingerprints’’. The speckles seen in grayscale B-mode (2D images are tracked consecutively frame to frame (5, 6. Assessment of 2D strain by STE is a semiautomatic method that requires definition of the myocardium

  3. Rapid detection of carbapenemase-producing Klebsiella pneumoniae strains derived from blood cultures by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS).

    Science.gov (United States)

    Sakarikou, Christina; Ciotti, Marco; Dolfa, Camilla; Angeletti, Silvia; Favalli, Cartesio

    2017-03-08

    Carbapenemase-producing Enterobacteriaceae (CPE), particularly carbapenemase-producing Klebsiella pneumoniae isolates, are important causative agents of nosocomial infections associated with significant mortality rates mostly in critical wards. The rapid detection and typing of these strains is critical either for surveillance purposes and to prevent outbreaks and optimize antibiotic therapy. In this study, the MALDI-TOF MS method was used to detect rapidly these isolates from blood cultures (BCs) and to obtain proteomic profiles enable to discriminate between carbapenemase-producing and non-carbapenemase-producing strains. Fifty-five K. pneumoniae strains were tested. Identification and carbapenemase-production detection assay using Ertapenem were performed both from bacterial pellets extracted directly from BCs flasks and from subcultures of these strains. For all isolates, a complete antimicrobial susceptibility testing and a genotypic characterization were performed. We found 100% agreement between the carbapenemase-producing profile generated by MALDI TOF MS and that obtained using conventional methods. The assay detected and discriminated different carbapenemase-producing K. pneumoniae isolates within 30 min to 3 h after incubation with Ertapenem. MALDI-TOF MS is a promising, rapid and economical method for the detection of carbapenemase-producing K. pneumoniae strains that could be successfully introduced into the routine diagnostic workflow of clinical microbiology laboratories.

  4. Sprains and Strains

    Science.gov (United States)

    ... and chronic. An acute strain occurs when a muscle becomes strained or pulled — or may even tear — when it stretches unusually far or abruptly. Acute ... and increases joint range of motion, making the muscles less tight and less prone to trauma ... Environmental conditions. Slippery or uneven surfaces can make ...

  5. Highly Strained Organophosphorus Compounds

    NARCIS (Netherlands)

    Slootweg, J.C.

    2005-01-01

    In our research on small, strained organophosphorus ring systems we became interested in the synthesis and applications of species that are even more strained than the parent phosphirane, by introducing an exocyclic double bond (methylenephosphirane), and by cyclopropyl spirofusion to the edge (e.g

  6. Influences of misfit strains on liquid phase heteroepitaxial growth

    Science.gov (United States)

    Lu, Yanli; Peng, Yingying; Yu, Genggeng; Chen, Zheng

    2017-10-01

    Influences of misfit strains with different signs on liquid phase heteroepitaxial growth are studied by binary phase field crystal model. It is amazing to find that double islands are formed because of lateral and vertical separation. The morphological evolution of epitaxial layer depends on signs of misfit strains. The maximum atomic layer thickness of double islands under negative misfit strain is larger than that of under positive misfit strain at the same evolutional time, and size differences between light and dark islands is much smaller under negative misfit strain than that of under positive misfit strain. In addition, concentration field and density field approximately have similar variational law along x direction under the same misfit strain but show opposite variational trend under misfit strains with different signs. Generally, free energy of epitaxial growth systems keeps similar variational trend under misfit strains with different signs.

  7. Strain y strain rate para dummies Strain and strain rate for dummies

    Directory of Open Access Journals (Sweden)

    Pastor Olaya

    2011-12-01

    Full Text Available Desarrollos recientes en el campo de la ecocardiografía han permitido a los cardiólogos cuantificar de manera objetiva la función miocárdica regional y global con base en los conceptos de deformación (strain y velocidad de deformación (strain rate que pueden calcularse de manera no invasiva tanto en el ventrículo izquierdo como en el derecho, y suministrar valiosa información en múltiples escenarios clínicos. Dado que esta técnica novedosa y promisoria se utiliza cada vez más en la clínica y en estudios de investigación, se hace necesario el conocimiento adecuado de sus principios, así como de sus aspectos técnicos, alcances y limitaciones para una mejor implementación. En este artículo se busca dar explicación a los conceptos fundamentales y las potenciales aplicaciones clínicas de la strain y la strain rate derivados por speckle tracking (strain 2D.Recent developments in the field of echocardiography have allowed cardiologists to objectively quantify regional and global myocardial function based on the deformation (strain and strain rate which can be calculated non-invasively in both the left or right ventricle, and provide valuable information in multiple clinical settings. Since this new technique is promising and is being increasingly used in clinical and research studies, the adequate knowledge of its principles and its technical aspects, scope and limitations are necessary for its better implementation. This article seeks to explain fundamental concepts and potential clinical applications of strain and strain rate derived by speckle tracking (2D strain.

  8. Strain rate effects in stress corrosion cracking

    Energy Technology Data Exchange (ETDEWEB)

    Parkins, R.N. (Newcastle upon Tyne Univ. (UK). Dept. of Metallurgy and Engineering Materials)

    1990-03-01

    Slow strain rate testing (SSRT) was initially developed as a rapid, ad hoc laboratory method for assessing the propensity for metals an environments to promote stress corrosion cracking. It is now clear, however, that there are good theoretical reasons why strain rate, as opposed to stress per se, will often be the controlling parameter in determining whether or not cracks are nucleated and, if so, are propagated. The synergistic effects of the time dependence of corrosion-related reactions and microplastic strain provide the basis for mechanistic understanding of stress corrosion cracking in high-pressure pipelines and other structures. However, while this may be readily comprehended in the context of laboratory slow strain tests, its extension to service situations may be less apparent. Laboratory work involving realistic stressing conditions, including low-frequency cyclic loading, shows that strain or creep rates give good correlation with thresholds for cracking and with crack growth kinetics.

  9. Atlas of stress-strain curves

    CERN Document Server

    2002-01-01

    The Atlas of Stress-Strain Curves, Second Edition is substantially bigger in page dimensions, number of pages, and total number of curves than the previous edition. It contains over 1,400 curves, almost three times as many as in the 1987 edition. The curves are normalized in appearance to aid making comparisons among materials. All diagrams include metric (SI) units, and many also include U.S. customary units. All curves are captioned in a consistent format with valuable information including (as available) standard designation, the primary source of the curve, mechanical properties (including hardening exponent and strength coefficient), condition of sample, strain rate, test temperature, and alloy composition. Curve types include monotonic and cyclic stress-strain, isochronous stress-strain, and tangent modulus. Curves are logically arranged and indexed for fast retrieval of information. The book also includes an introduction that provides background information on methods of stress-strain determination, on...

  10. Dark field electron holography for strain measurement

    Energy Technology Data Exchange (ETDEWEB)

    Beche, A., E-mail: armand.beche@fei.com [CEA-Grenoble, INAC/SP2M/LEMMA, F-38054 Grenoble (France); Rouviere, J.L. [CEA-Grenoble, INAC/SP2M/LEMMA, F-38054 Grenoble (France); Barnes, J.P.; Cooper, D. [CEA-LETI, Minatec Campus, F-38054 Grenoble (France)

    2011-02-15

    Dark field electron holography is a new TEM-based technique for measuring strain with nanometer scale resolution. Here we present the procedure to align a transmission electron microscope and obtain dark field holograms as well as the theoretical background necessary to reconstruct strain maps from holograms. A series of experimental parameters such as biprism voltage, sample thickness, exposure time, tilt angle and choice of diffracted beam are then investigated on a silicon-germanium layer epitaxially embedded in a silicon matrix in order to obtain optimal dark field holograms over a large field of view with good spatial resolution and strain sensitivity. -- Research Highlights: {yields} Step by step explanation of the dark field electron holography technique. {yields} Presentation of the theoretical equations to obtain quantitative strain map. {yields} Description of experimental parameters influencing dark field holography results. {yields} Quantitative strain measurement on a SiGe layer embedded in a silicon matrix.

  11. EVALUATION OF LOCAL STRAIN EVOLUTION FROM METALLIC WHISKER FORMATION

    Energy Technology Data Exchange (ETDEWEB)

    Hoffman, E.; Lam, P.

    2011-05-11

    Evolution of local strain on electrodeposited tin films upon aging has been monitored by digital image correlation (DIC) for the first time. Maps of principal strains adjacent to whisker locations were constructed via comparing pre- and post-growth scanning electron microscopy (SEM) images. Results showed that the magnitude of the strain gradient plays an important role in whisker growth. DIC visualized the dynamic growth process in which the alteration of strain field has been identified to cause growth of subsequent whiskers.

  12. Design and evaluation of two-stage multiplex real-time PCR method for detecting O157:H7 and non-O157 STEC strains from beef samples

    Science.gov (United States)

    Introduction: E. coli O157:H7 was first recognized as a human pathogen in 1982 and until recently was the only E. coli strain mandated for testing by the USDA. In June 2012, the USDA declared six additional Shiga-toxin producing E. coli serogroups (O26, O45, O103, O111, O121, and O145) as adulterant...

  13. Modelling to very high strains

    Science.gov (United States)

    Bons, P. D.; Jessell, M. W.; Griera, A.; Evans, L. A.; Wilson, C. J. L.

    2009-04-01

    Ductile strains in shear zones often reach extreme values, resulting in typical structures, such as winged porphyroclasts and several types of shear bands. The numerical simulation of the development of such structures has so far been inhibited by the low maximum strains that numerical models can normally achieve. Typical numerical models collapse at shear strains in the order of one to three. We have implemented a number of new functionalities in the numerical platform "Elle" (Jessell et al. 2001), which significantly increases the amount of strain that can be achieved and simultaneously reduces boundary effects that become increasingly disturbing at higher strain. Constant remeshing, while maintaining the polygonal phase regions, is the first step to avoid collapse of the finite-element grid required by finite-element solvers, such as Basil (Houseman et al. 2008). The second step is to apply a grain-growth routine to the boundaries of polygons that represent phase regions. This way, the development of sharp angles is avoided. A second advantage is that phase regions may merge or become separated (boudinage). Such topological changes are normally not possible in finite element deformation codes. The third step is the use of wrapping vertical model boundaries, with which optimal and unchanging model boundaries are maintained for the application of stress or velocity boundary conditions. The fourth step is to shift the model by a random amount in the vertical direction every time step. This way, the fixed horizontal boundary conditions are applied to different material points within the model every time step. Disturbing boundary effects are thus averaged out over the whole model and not localised to e.g. top and bottom of the model. Reduction of boundary effects has the additional advantage that model can be smaller and, therefore, numerically more efficient. Owing to the combination of these existing and new functionalities it is now possible to simulate the

  14. Hamstring strain - aftercare

    Science.gov (United States)

    ... Elsevier Saunders; 2015:chap 88. Reider B, Davies GJ, Provencher MT. Muscle strains about the hip and thigh. In: Reider B, Davies GJ, Provencher MT, eds. Orthopaedic Rehabilitation of the Athlete . ...

  15. Digital Eye Strain Reduction Techniques: A Review

    OpenAIRE

    PREETHI J SEEGEHALLI

    2016-01-01

    Digital eye strain or computer vision syndrome (CVS) is caused when we spend considerable amount of time in staring at digital screens of desktop computer, laptop, e-readers, tablets and mobile phones. This paper discusses the different the causes for visual fatigue and digital eye strain reduction techniques like usage of optical glass, flicker free screen, color filtering, fuzzy logic based brightness adaption technique, bias lighting screens, optimizing monitor’s color temperature and Auto...

  16. Photothermal strain imaging

    Science.gov (United States)

    Choi, Changhoon; Ahn, Joongho; Jeon, Seungwan; Kim, Chulhong

    2017-07-01

    Vulnerable plaques are the major cause of cardiovascular disease, but they are difficult to detect with conventional intravascular imaging techniques. Techniques are needed to identify plaque vulnerability based on the presence of lipids in plaque. Thermal strain imaging (TSI) is an imaging technique based on ultrasound (US) wave propagation speed, which varies with the medium temperature. In TSI, the strain that occurs during tissue temperature change can be used for lipid detection because it has a different tendency depending on the type of tissue. Here, we demonstrate photothermal strain imaging (pTSI) using an intravascular ultrasound catheter. pTSI is performed by slightly and selectively heating lipid using a relatively inexpensive continuous laser source. We applied a speckle-tracking algorithm to US B-mode images for strain calculations. As a result, the strain produced in porcine fat was different from the strain produced in water-bearing gelatin phantom, which made it possible to distinguish the two. This suggests that pTSI could potentially be a way of differentiating lipids in coronary artery.

  17. Time-course investigation of infection with a low virulent Pasteurella multocida strain in normal and immune-suppressed 12-week-old free-range chickens

    DEFF Research Database (Denmark)

    Mbuthia, P.G.; Njagi, L.W.; Nyaga, P.N.;

    2011-01-01

    Twelve-week-old indigenous chickens, either immune-suppressed using dexamethasone (IS) or non-immune-suppressed (NIS), were challenged with a low virulent strain, Pasteurella multocida strain NCTC 10322(T), and developed clinical signs and pathological lesions typical of chronic fowl cholera. NIS...... birds demonstrated much more severe signs of fowl cholera than IS birds. With few exceptions, signs recorded in IS and NIS birds were of the same types, but significantly milder in the IS birds, indicating that immune suppression does not change the course of infection but rather the severity of signs...... in fowl cholera. P. multocida signals by fluorescent in situ hybridization (FISH) were observed between 1 h and 14 days in the lungs, trachea, air sacs, liver, spleen, bursa of Fabricius and caecal tonsils, while signals from other organs mostly were observed after 24 h. More organs had FISH signals...

  18. Strain: Fact or Fiction?

    Science.gov (United States)

    Heilbronner, Renée

    2017-04-01

    2017 marks the 50th anniversary of the publication of John Ramsay's well known textbook "Folding and Fracturing of Rocks" - ... and the 30th anniversary of the rejection of a rather less well known paper entitled "Strain: Fact or Fiction?" submitted by Renée Panozzo to the Journal of Structural Geology. The gist of the paper was simple and straight forward: it was argued that not every fabric that can be observed in deformed rocks is necessarily a measure of the amount of strain the rock incurred. A distinction was made between a general "fabric", i.e., the traceable geometry of grain boundaries, for example, and a so-called "strain fabric", i.e., the model geometry that would result from homogeneously straining an initially isotropic fabric and that would exhibit at least orthorhombic symmetry. To verify if a given fabric was indeed a strain fabric it was therefore suggested to use the SURFOR method (published by Panozzo) and to carry out a so-called strain test, i.e., a check of symmetry, before interpreting the results of a fabric analysis in terms of strain. The problem with the paper was that it was very obviously written out of frustration. The frustration came form having reviewed a number of manuscripts which tried to use the then novel SURFOR method for strain analysis without first checking if the the fabric was a indeed a "strain fabric" or not, and then blaming the SURFOR method for producing ambiguous results. As a result, the paper was not exactly well balanced and carefully thought out. It was considered "interesting but not scholarly" by one of the reviewers and down-right offensive by the second. To tell the truth, however, the paper was not formally rejected. The editor Sue Treagus strongly encouraged Panozzo to revise the paper, ... and 30 years later, I will follow her advise and offer a revised paper as a tribute to John Ramsay. To quote from the original manuscript: "We should be a little more impressed that strain works so well, and less

  19. Strain analysis of nonlocal viscoelastic Kelvin bar in tension

    Institute of Scientific and Technical Information of China (English)

    ZHAO Xue-chuan; LEI Yong-jun; ZHOU Jian-ping

    2008-01-01

    Based on viscoelastic Kelvin model and nonlocal relationship of strain and stress, a nonlocal constitutive relationship of viscoelasticity is obtained and the strain response of a bar in tension is studied. By transforming governing equation of the strain analysis into Volterra integration form and by choosing a symmetric exponential form of kernel function and adapting Neumann series, the closed-form solution of strain field of the bar is obtained. The creep process of the bar is presented. When time approaches infinite, the strain of bar is equal to the one of nonlocal elasticity.

  20. Job strain and the risk of stroke

    DEFF Research Database (Denmark)

    Fransson, Eleonor I; Nyberg, Solja T; Heikkilä, Katriina

    2015-01-01

    BACKGROUND AND PURPOSE: Psychosocial stress at work has been proposed to be a risk factor for cardiovascular disease. However, its role as a risk factor for stroke is uncertain. METHODS: We conducted an individual-participant-data meta-analysis of 196 380 males and females from 14 European cohort...... studies to investigate the association between job strain, a measure of work-related stress, and incident stroke. RESULTS: In 1.8 million person-years at risk (mean follow-up 9.2 years), 2023 first-time stroke events were recorded. The age- and sex-adjusted hazard ratio for job strain relative to no job....... CONCLUSION: Job strain may be associated with an increased risk of ischemic stroke, but further research is needed to determine whether interventions targeting job strain would reduce stroke risk beyond existing preventive strategies....

  1. 3D Morphing Using Strain Field Interpolation

    Institute of Scientific and Technical Information of China (English)

    Han-Bing Yan; Shi-Min Hu; Ralph R Martin

    2007-01-01

    In this paper, we present a new technique based on strain fields to carry out 3D shape morphing for applicationsin computer graphics and related areas.Strain is an important geometric quantity used in mechanics to describe the deformation of objects.We apply it in a novel way to analyze and control deformation in morphing.Using position vector fields, the strain field relating source and target shapes can be obtained.By interpolating this strain field between zero and a final desired value we can obtain the position field for intermediate shapes.This method ensures that the 3D morphing process is smooth.Locally, volumes suffer minimal distortion, and no shape jittering or wobbling happens: other methods do not necessarily have these desirable properties.We also show how to control the method so that changes of shape (in particular, size changes) vary linearly with time.

  2. Muscle strain injuries.

    Science.gov (United States)

    Garrett, W E

    1996-01-01

    One of the most common injuries seen in the office of the practicing physician is the muscle strain. Until recently, little data were available on the basic science and clinical application of this basic science for the treatment and prevention of muscle strains. Studies in the last 10 years represent action taken on the direction of investigation into muscle strain injuries from the laboratory and clinical fronts. Findings from the laboratory indicate that certain muscles are susceptible to strain injury (muscles that cross multiple joints or have complex architecture). These muscles have a strain threshold for both passive and active injury. Strain injury is not the result of muscle contraction alone, rather, strains are the result of excessive stretch or stretch while the muscle is being activated. When the muscle tears, the damage is localized very near the muscle-tendon junction. After injury, the muscle is weaker and at risk for further injury. The force output of the muscle returns over the following days as the muscle undertakes a predictable progression toward tissue healing. Current imaging studies have been used clinically to document the site of injury to the muscle-tendon junction. The commonly injured muscles have been described and include the hamstring, the rectus femoris, gastrocnemius, and adductor longus muscles. Injuries inconsistent with involvement of a single muscle-tendon junction proved to be at tendinous origins rather than within the muscle belly. Important information has also been provided regarding injuries with poor prognosis, which are potentially repairable surgically, including injuries to the rectus femoris muscle, the hamstring origin, and the abdominal wall. Data important to the management of common muscle injuries have been published. The risks of reinjury have been documented. The early efficacy and potential for long-term risks of nonsteroidal antiinflammatory agents have been shown. New data can also be applied to the field

  3. Screening of flocculant-producing strains by NTG mutagenesis

    Institute of Scientific and Technical Information of China (English)

    HUANG Xiao-wu; CHENG Wen; HU Yong-you

    2005-01-01

    Screening of new microorganism being able to produce efficiently flocculants was carried out. A new model for screening efficient flocculant-producing strains was designed and tested. The results showed that this model for screening efficient flocculant-producing strains is very reliable and can greatly shorten the screening period. 13 flocculant-producing strains were isolated from activated sludge by conventional method. A strain, designated as HHE6, produced the bioflocculant with the turbidity removal 98% for kaolin suspension. Six of 13 strains selected as the original strains were treated with NTG as mutagen, and five mutant strains(HHE-P7, HHE-A8, HHE-P21,HHE-P24, HHE-A26) with high flocculation efficiency was obtained by selection, which exhibited the flocculation rate for kaolin suspension above 90%. Strains HHE6, HHE-P7, and HHE-P24 were classified as Penicillium purpurogenum, HHE-P21 as Penicillium cyclopium,HHE-A26 as Aspergillus versicolor and HHE-A8 as Aspergillus fumigatus, and it is hitherto unreported for biofloccutant-producing strains of Penicillium. The growth of the six strains(HHE6, HHE-P7, HHE-A8, HHE-P21, HHE-P24, HHE-A26) had similar curves, i.e. firstly increasing rapidly, keeping relatively constant then and finally decreasing gradually with cultivation time. The production of bioflocculants by strains showed the similar pattern to strain growth.

  4. Unsteady Aerodynamic Force Sensing from Strain Data

    Science.gov (United States)

    Pak, Chan-Gi

    2017-01-01

    A simple approach for computing unsteady aerodynamic forces from simulated measured strain data is proposed in this study. First, the deflection and slope of the structure are computed from the unsteady strain using the two-step approach. Velocities and accelerations of the structure are computed using the autoregressive moving average model, on-line parameter estimator, low-pass filter, and a least-squares curve fitting method together with analytical derivatives with respect to time. Finally, aerodynamic forces over the wing are computed using modal aerodynamic influence coefficient matrices, a rational function approximation, and a time-marching algorithm.

  5. Well Conductor Strain Monitoring

    Science.gov (United States)

    2014-05-06

    comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE JUL 2014 2. REPORT TYPE 3. DATES...849,429; filed on June 26, 2013 by the inventor, Dr. Anthony Ruffa and entitled “ SUBSEA WELL CONDUCTOR STRAIN MONITORING”. STATEMENT OF

  6. Exploration and research of rapidly identifying escherichia coli and detecting ESBLs strains by matrix-assisted laser desorption ionization-time of flight mass spectrometry%MALDI-TOF MS方法快速鉴定大肠杆菌及ESBLs菌株检测探索研究

    Institute of Scientific and Technical Information of China (English)

    战晓微; 杜影; 王宏伟; 吴远高; 郑秋月

    2015-01-01

    Objective The strains of Escherichia coli was tested by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). ESBLs strains were distinguished, and different type ESBLs strains was differentiated by clustering analysis. Feasibility of identification was explored by MALDI-TOF MS for E.coli and ESBLs strains. Methods Peptide mass fingerprints were obtained via collecting mass spectrometric data of 47 E.coli. Their species were identified by biotyper sortware, and drug resistance results were studied. ESBLs strains of E.coli were researched by clustering analysis. Feasibility of identification was confirmed by MALDI-TOF MS for E.coli and ESBLs strains. Results The identification results were coincident with conventional method and PCR method. There were 9 ESBLs stains in 10 E.coli that were prompted for ESBLs strains by MALDI-TOF MS. It had good distinguishing capability for OXA type ESBLs E.coli by cluster analysis. Conclusion E.coli strains could be rapidly, accurately identified by MALDI-TOF MS, and there was a certain screening capacity for ESBLs strains.%目的:研以基质辅助激光解析电离飞行时间质谱(matrix assisted laser desorption ionization-time of flight mass spectrometry, MALDI-TOF MS)方法检测大肠杆菌,并利用MALDI-TOF MS方法鉴别ESBLs菌株及聚类分析法区分不同分型的ESBLs菌株,探索MALDI-TOF MS方法鉴定大肠杆菌及ESBLs菌株的可行性。方法利用MALDI-TOF MS采集47株大肠杆菌分离株的质谱数据,生成肽指纹图谱,并利用biotyper软件进行菌种鉴定,同时研究其耐药性鉴定结果,并利用聚类分析法研究大肠杆菌 ESBLs 菌株,最终确定MALDI-TOF MS对大肠杆菌菌种鉴定及ESBLs菌株鉴别的可行性。结果 MALDI-TOF MS方法鉴定大肠杆菌的结果与传统方法及PCR方法检测结果均符合,经MALDI-TOF MS鉴定方法提示为ESBLs菌株的10株大肠杆菌中有9株为 ESBLs 菌株,且聚类分析法对 OXA

  7. Developing a Biosensor for Estrogens in Water Samples: Study ofthe Real-time Response of Live Cells of the Estrogen-sensitive YeastStrain RMY/ER-ERE using Fluorescence Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wozei, E.; Hermanowicz, S.W.; Holman, H-Y.N.

    2006-01-01

    Using a fluorescein di-{beta}-d-galactopyranoside (FDG) substrate we show that in live cells of an estrogen-sensitive yeast strain RMY/ER-ERE with human estrogen receptor (ER{alpha}) gene and the lacZ gene which encodes {beta}-galactosidase, the uptake of 17{beta}-estradiol (E2) and the subsequent production of {beta}-galactosidase enzyme occur quite rapidly, with maximal enzyme-catalyzed product formation evident after about 30 min of exposure to E2. This finding which agrees with the well-known rates of enzyme-catalyzed reactions could have implications for shortening the duration of environmental sample screening and monitoring regimes using yeast-based estrogen assays, and the development of biosensors for environmental estrogens to complement quantification methods.

  8. Developing a Biosensor for Estrogens in Water Samples: Study ofthe Real-time Response of Live Cells of the Estrogen-sensitive YeastStrain RMY/ER-ERE using Fluorescence Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wozei, E.; Hermanowicz, S.W.; Holman, H-Y.N.

    2005-07-13

    Using a fluorescein di-{beta}-D-galactopyranoside (FDG) substrate we show that in live cells of an estrogen-sensitive yeast strain RMY/ER-ERE with human estrogen receptor (ER{alpha}) gene and the lacZ gene which encodes {beta}-galactosidase, the uptake of 17 {beta}-estradiol (E2) and the subsequent production of {beta}-galactosidase enzyme occur quite rapidly, with maximal enzyme-catalyzed product formation evident after about 30 minutes of exposure to E2. This finding which agrees with the well-known rates of enzyme-catalyzed reactions could have implications for shortening the duration of environmental sample screening and monitoring regimes using yeast-based estrogen assays, and the development of biosensors for environmental estrogens to complement quantification methods.

  9. Multivariate Time Series Decomposition into Oscillation Components.

    Science.gov (United States)

    Matsuda, Takeru; Komaki, Fumiyasu

    2017-08-01

    Many time series are considered to be a superposition of several oscillation components. We have proposed a method for decomposing univariate time series into oscillation components and estimating their phases (Matsuda & Komaki, 2017 ). In this study, we extend that method to multivariate time series. We assume that several oscillators underlie the given multivariate time series and that each variable corresponds to a superposition of the projections of the oscillators. Thus, the oscillators superpose on each variable with amplitude and phase modulation. Based on this idea, we develop gaussian linear state-space models and use them to decompose the given multivariate time series. The model parameters are estimated from data using the empirical Bayes method, and the number of oscillators is determined using the Akaike information criterion. Therefore, the proposed method extracts underlying oscillators in a data-driven manner and enables investigation of phase dynamics in a given multivariate time series. Numerical results show the effectiveness of the proposed method. From monthly mean north-south sunspot number data, the proposed method reveals an interesting phase relationship.

  10. Strains in General Relativity

    CERN Document Server

    Bini, Donato; Geralico, Andrea

    2014-01-01

    The definition of relative accelerations and strains among a set of comoving particles is studied in connection with the geometric properties of the frame adapted to a "fiducial observer." We find that a relativistically complete and correct definition of strains must take into account the transport law of the chosen spatial triad along the observer's congruence. We use special congruences of (accelerated) test particles in some familiar spacetimes to elucidate such a point. The celebrated idea of Szekeres' compass of inertia, arising when studying geodesic deviation among a set of free-falling particles, is here generalized to the case of accelerated particles. In doing so we have naturally contributed to the theory of relativistic gravity gradiometer. Moreover, our analysis was made in an observer-dependent form, a fact that would be very useful when thinking about general relativistic tests on space stations orbiting compact objects like black holes and also in other interesting gravitational situations.

  11. AERODYNAMIC BEHAVIOR AIRCRAFT CAUSED BY RESIDUAL STRAIN WINGS

    Directory of Open Access Journals (Sweden)

    Sergiy Ishchenko

    2011-03-01

    Full Text Available Abstract. The influence of residual strain on the airframe aerodynamic characteristics of aircraft wasconsidered. The possibility of estimation of changes in deformation of airframe using data of leveling wasshown. The method of estimating the change of aerodynamic characteristics caused by the influence ofresidual strain airframe was proposed. Technique can be used in the operation and overhaul of aircraft withlarge operating time.Keywords: aerodynamic characteristics, residual strain construction asymmetric moments, thedistribution of circulation, the scheme of leveling, trigonometric series.

  12. AERODYNAMIC BEHAVIOR AIRCRAFT CAUSED BY RESIDUAL STRAIN WINGS

    OpenAIRE

    Ishchenko, Sergiy; Tofil, Arkadiush

    2011-01-01

    Abstract. The influence of residual strain on the airframe aerodynamic characteristics of aircraft wasconsidered. The possibility of estimation of changes in deformation of airframe using data of leveling wasshown. The method of estimating the change of aerodynamic characteristics caused by the influence ofresidual strain airframe was proposed. Technique can be used in the operation and overhaul of aircraft withlarge operating time.Keywords: aerodynamic characteristics, residual strain constr...

  13. The need to generate realistic strain signals at an automotive coil spring for durability simulation leading to fatigue life assessment

    Science.gov (United States)

    Putra, T. E.; Abdullah, S.; Schramm, D.; Nuawi, M. Z.; Bruckmann, T.

    2017-09-01

    This study aims to accelerate fatigue tests using simulated strain signals. Strain signals were acquired from a coil spring involving car movements. Using a mathematical expression, the measured strain signals yielded acceleration signals, and were considered as disturbances on generating strain signals. The simulated strain signals gave the testing time deviation by only 1.5%. The wavelet-based data editing was applied to shorten the strain signals time up to 36.7% and reduced the testing time up to 33.9%. In conclusion, the simulated strain signals were able to maintain the majority of fatigue damage and decreased the testing time.

  14. What Are Sprains and Strains?

    Science.gov (United States)

    ... hands and arms a lot. Examples are gymnastics, tennis, rowing, and golf. People who play these sports sometimes strain their hand or arm. Elbow strains can also happen when playing sports. What ...

  15. Strain measurement based battery testing

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jeff Qiang; Steiber, Joe; Wall, Craig M.; Smith, Robert; Ng, Cheuk

    2017-05-23

    A method and system for strain-based estimation of the state of health of a battery, from an initial state to an aged state, is provided. A strain gauge is applied to the battery. A first strain measurement is performed on the battery, using the strain gauge, at a selected charge capacity of the battery and at the initial state of the battery. A second strain measurement is performed on the battery, using the strain gauge, at the selected charge capacity of the battery and at the aged state of the battery. The capacity degradation of the battery is estimated as the difference between the first and second strain measurements divided by the first strain measurement.

  16. Modified 16S-23S rRNA intergenic region restriction endonuclease analysis for species identification of Enterococcus strains isolated from pigs, compared with identification using classical methods and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Nowakiewicz, Aneta; Ziółkowska, Grażyna; Zięba, Przemysław; Trościańczyk, Aleksandra; Banach, Tomasz; Kowalski, Cezary

    2015-03-01

    Fast and reliable identification of bacteria to at least the species level is currently the basis for correct diagnosis and appropriate treatment of infections. This is particularly important in the case of bacteria of the genus Enterococcus, whose resistance profile is often correlated with their species (e.g. resistance to vancomycin). In this study, we evaluated restriction endonuclease analysis of the 16S-23S rRNA gene intergenic transcribed spacer (ITS) region for species identification of Enterococcus. The utility of the method was compared with that of phenotypic methods [biochemical profile evaluation and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)]. Identification was based on 21 Enterococcus reference strains, of the species E. faecalis, E. faecium, E. hirae, E. durans, E. casseliflavus, E. gallinarum, E. avium, E. cecorum and E. columbae, and 47 Enterococcus field strains isolated from pigs. Restriction endonuclease analysis of the ITS-PCR product using HinfI, RsaI and MboI, in the order specified, enabled species differentiation of the Enterococcus reference and field strains, and in the case of the latter, the results of species identification were identical (47/47) to those obtained by MALDI-TOF MS. Moreover, as a result of digestion with MboI, a unique restriction profile was also obtained for the strains (3/3) identified by MALDI-TOF MS as E. thailandicus. In our opinion, restriction endonuclease analysis of the 16S-23S rRNA gene ITS region of Enterococcus may be a simple and relatively fast (less than 4 h) alternative method for identifying the species occurring most frequently in humans and animals.

  17. Perceptual strain index for heat strain assessment in an experimental study: an application to construction workers.

    Science.gov (United States)

    Yang, Y; Chan, Albert P C

    2015-02-01

    Although the physiological strain index (PhSI) is universal and comprehensive, its restrictions are recognized in terms of invasive on-site measurements and the requirement of accurate instruments. The perceptual strain index (PeSI) has been proposed as a user-friendly and practical indicator for heat strain. However, the application of this index in assessing the heat strain of construction workers has yet to be examined and documented. This study aims to ascertain the reliability and applicability of PeSI in an experimental setting that simulates a stressful working environment (i.e., environment, work uniform, and work pace) experienced by construction workers. Ten males and two females performed intermittent exercise on a treadmill while wearing a summer work uniform at 34.5 °C and 75% relative humidity in a climatic chamber. Physiological parameters (core temperature, heart rate) and perceptual variables (thermal sensation, perceived exertion) were collated synchronously at 3 min intervals. The results of two-way repeated measures analysis of variance (clothing×time) revealed that the PeSI was useful in differentiating the heat strain levels between different work uniforms. Not only did the PeSI change in the same general manner with the PhSI, but it was also powerful in reflecting different levels of physiological strain. Thus, the PeSI offers considerable promise for heat strain assessment under simulated working conditions.

  18. Electronic and optical properties of strained graphene and other strained 2D materials: a review

    Science.gov (United States)

    Naumis, Gerardo G.; Barraza-Lopez, Salvador; Oliva-Leyva, Maurice; Terrones, Humberto

    2017-09-01

    This review presents the state of the art in strain and ripple-induced effects on the electronic and optical properties of graphene. It starts by providing the crystallographic description of mechanical deformations, as well as the diffraction pattern for different kinds of representative deformation fields. Then, the focus turns to the unique elastic properties of graphene, and to how strain is produced. Thereafter, various theoretical approaches used to study the electronic properties of strained graphene are examined, discussing the advantages of each. These approaches provide a platform to describe exotic properties, such as a fractal spectrum related with quasicrystals, a mixed Dirac–Schrödinger behavior, emergent gravity, topological insulator states, in molecular graphene and other 2D discrete lattices. The physical consequences of strain on the optical properties are reviewed next, with a focus on the Raman spectrum. At the same time, recent advances to tune the optical conductivity of graphene by strain engineering are given, which open new paths in device applications. Finally, a brief review of strain effects in multilayered graphene and other promising 2D materials like silicene and materials based on other group-IV elements, phosphorene, dichalcogenide- and monochalcogenide-monolayers is presented, with a brief discussion of interplays among strain, thermal effects, and illumination in the latter material family.

  19. An outbreak of infections caused by extensively drug-resistant Klebsiella pneumoniae strains during a short period of time in a Chinese teaching hospital: epidemiology study and molecular characteristics.

    Science.gov (United States)

    Zhou, Tieli; Zhang, Yapei; Li, Meimei; Yu, Xiao; Sun, Yao; Xu, Jiru

    2015-07-01

    In this study, we comprehensively described the clinical risk factors, outcome, epidemiology, and molecular basis associated with an outbreak of extensively drug-resistant KPC-2-producing Klebsiella pneumoniae involving 15 patients in a teaching hospital from May 1 to June 27, 2013. Most of the patients were elderly and received long-term hospital treatment, and 40.0% (6/15) of them were dead. All strains carried bla(KPC-2), rmtB, bla(CTX-M-65), bla(SHV-11), oqxA, oqxB, and aac(6')-Ib-cr and even harbored additional other resistance genes, such as armA, bla(CTX-M-1), bla(TEM-1). bla(KPC-2), rmtB, and bla(CTX-M-65) were located on the same ~54.2-kb plasmid, and conjugation experiments further proved the cotransferable characteristic. Alterations of outer membrane proteins were confirmed by sodium dodecyl sulfate--olyacrylamide gelelectrophoresis and sequencing, which can lead to a drastic change in the permeability of cells. All isolates belonged to the clone complex 258, spreading rapidly across the world. Our study demonstrated that a high degree of awareness and surveillance of those drug resistance determinants is urgently needed.

  20. Uniaxial tension test on Rubber at constant true strain rate

    Directory of Open Access Journals (Sweden)

    Sourne H.L.

    2012-08-01

    Full Text Available Elastomers are widely used for damping parts in different industrial contexts because of their remarkable dissipation properties. Indeed, they can undergo severe mechanical loading conditions, i.e., high strain rates and large strains. Nevertheless, the mechanical response of these materials can vary from purely rubber-like to glassy depending on the strain rate undergone. Classically, uniaxial tension tests are made in order to find a relation between the stress and the strain in the material at various strain rates. However, even if the strain rate is searched to be constant, it is the nominal strain rate that is considered. Here we develop a test at constant true strain rate, i.e. the strain rate that is experienced by the material. In order to do such a test, the displacement imposed by the machine is an exponential function of time. This test has been performed with a high speed hydraulic machine for strain rates between 0.01/s and 100/s. A specific specimen has been designed, yielding a uniform strain field (and so a uniform stress field. Furthermore, an instrumented aluminum bar has been used to take into account dynamic effects in the measurement of the applied force. A high speed camera enables the determination of strain in the sample using point tracking technique. Using this method, the stress-strain curve of a rubber-like material during a loading-unloading cycle has been determined, up to a stretch ratio λ = 2.5. The influence of the true strain rate both on stiffness and on dissipation of the material is then discussed.

  1. Tighter spots of light with superposed orbital angular momentum beams

    CERN Document Server

    Woźniak, Paweł; Bouchard, Frédéric; Karimi, Ebrahim; Leuchs, Gerd; Boyd, Robert W

    2016-01-01

    The possibility of focusing light to an ever tighter spot has important implications for many applications and fields of optics research, such as nano-optics and plasmonics, laser-scanning microscopy, optical data storage and many more. The size of lateral features of the field at the focus depends on several parameters, including the numerical aperture of the focusing system, but also the wavelength and polarization, phase and intensity distribution of the input beam. Here, we study the smallest achievable focal feature sizes of coherent superpositions of two co-propagating beams carrying opposite orbital angular momentum. We investigate the feature sizes for this class of beams not only in the scalar limit, but also use a fully vectorial treatment to discuss the case of tight focusing. Both our numerical simulations and our experimental results confirm that lateral feature sizes considerably smaller than those of a tightly focused Gaussian light beam can be observed. These findings may pave the way for impr...

  2. Intramyocardial strain estimation from cardiac cine MRI.

    Science.gov (United States)

    Elnakib, Ahmed; Beache, Garth M; Gimel'farb, Georgy; El-Baz, Ayman

    2015-08-01

    Functional strain is one of the important clinical indicators for the quantification of heart performance and the early detection of cardiovascular diseases, and functional strain parameters are used to aid therapeutic decisions and follow-up evaluations after cardiac surgery. A comprehensive framework for deriving functional strain parameters at the endocardium, epicardium, and mid-wall of the left ventricle (LV) from conventional cine MRI data was developed and tested. Cine data were collected using short TR-/TE-balanced steady-state free precession acquisitions on a 1.5T Siemens Espree scanner. The LV wall borders are segmented using a level set-based deformable model guided by a stochastic force derived from a second-order Markov-Gibbs random field model that accounts for the object shape and appearance features. Then, the mid-wall of the segmented LV is determined based on estimating the centerline between the endocardium and epicardium of the LV. Finally, a geometrical Laplace-based method is proposed to track corresponding points on successive myocardial contours throughout the cardiac cycle in order to characterize the strain evolutions. The method was tested using simulated phantom images with predefined point locations of the LV wall throughout the cardiac cycle. The method was tested on 30 in vivo datasets to evaluate the feasibility of the proposed framework to index functional strain parameters. The cine MRI-based model agreed with the ground truth for functional metrics to within 0.30 % for indexing the peak systolic strain change and 0.29 % (per unit time) for indexing systolic and diastolic strain rates. The method was feasible for in vivo extraction of functional strain parameters. Strain indexes of the endocardium, mid-wall, and epicardium can be derived from routine cine images using automated techniques, thereby improving the utility of cine MRI data for characterization of myocardial function. Unlike traditional texture-based tracking, the

  3. Apt strain measurement technique for impulsive loading applications

    Science.gov (United States)

    Ranjan Nanda, Soumya; Kulkarni, Vinayak; Sahoo, Niranjan

    2017-03-01

    The necessity of precise measurement of strain time history for impulsive loading applications has been addressed in the present investigation. Finite element modeling is initially carried out for a hemispherical test model and stress bar assembly to arrive at an appropriate location for strain measurement. In dynamic calibration experiments, strain measurements are performed using two wire and three wire quarter bride arrangements along with half bridge circuit. Usefulness of these arrangements has been verified by analyzing strain signals in time and frequency domains. Comparison of recovered force time histories proved that the half bridge circuit is the most suitable for such applications. Actual shock tube testing of the instrumented hemispherical test model confirmed the applicability of half bridge circuit for short duration strain measurements.

  4. Prediction of swelling rocks strain in tunneling

    Science.gov (United States)

    Parsapour, D.; Fahimifar, A.

    2016-05-01

    Swelling deformations leading to convergence of tunnels may result in significant difficulties during the construction, in particular for long term use of tunnels. By extracting an experimental based explicit analytical solution for formulating swelling strains as a function of time and stress, swelling strains are predicted from the beginning of excavation and during the service life of tunnel. Results obtained from the analytical model show a proper agreement with experimental results. This closed-form solution has been implemented within a numerical program using the finite element method for predicting time-dependent swelling strain around tunnels. Evaluating effects of swelling parameters on time-dependent strains and tunnel shape on swelling behavior around the tunnel according to this analytical solution is considered. The ground-support interaction and consequent swelling effect on the induced forces in tunnel lining is considered too. Effect of delay in lining installation on swelling pressure which acting on the lining and its structural integrity, is also evaluated. A MATLAB code of " SRAP" is prepared and applied to calculate all swelling analysis around tunnels based on analytical solution.

  5. Time-resolved ultraviolet spectroscopy of the compact interacting binary QU Car

    CERN Document Server

    Hartley, L E; Long, K S

    2002-01-01

    We present HST/STIS (1160--1700A) echelle spectra of the cataclysmic variable (CV) star, QU Car, observed in time-tag mode at three epochs. In catalogues this binary is classified as a nova-like variable. We find evidence of a high-state non-magnetic CV at low inclination, with unusually high ionisation. We observed narrow absorption lines (few hundred km/s wide) in N V1240, O V1371 and Si IV1398, as well as broader (HWZI ~1000km/s) emission in C III1176, C IV1549 and He II1640, all with a superposed absorption component. High ionisation is indicated by the unusually string He II emission and the relative strength of the O V absorption line. The dereddened UV SED of, on average, -2.3 suggests that disc accretion dominates the spectral energy distribution. In two observations velocity shifting is noted in the absorption lines on a timescale long enough not to repeat within the ~2600-sec exposures. The absorption superposed on the C IV emission line moves coherently with the N V and Si IV absorption, suggesting...

  6. Material characterization at high strain by adapted tensile tests

    NARCIS (Netherlands)

    Emmens, W.C.; van den Boogaard, Antonius H.

    2012-01-01

    The strength of materials at high strain levels has been determined using the so-called Continuous-Bendingunder- Tension (CBT) test. This is a modified tensile test where the specimen is subjected to repetitive bending at the same time. This test enables to create high levels of uniform strain. A

  7. Passive microrheology in the effective time domain: analyzing time dependent colloidal dispersions.

    Science.gov (United States)

    Vyas, Bhavna M; Orpe, Ashish V; Kaushal, Manish; Joshi, Yogesh M

    2016-10-21

    We studied the aging dynamics of an aqueous suspension of LAPONITE®, a model time dependent soft glassy material, using a passive microrheology technique. This system is known to undergo physical aging during which its microstructure evolves progressively to explore lower free energy states. Optical microscopy is used to monitor the motion of micron-sized tracer probes embedded in a sample kept between two glass plates. The mean square displacements (MSD) obtained from the motion of the tracer particles show a systematic change from a purely diffusive behavior at short aging times to a subdiffusive behavior as the material ages. Interestingly, the MSDs at all the aging times as well as different LAPONITE® concentrations superpose remarkably to show a time-aging time master curve when the system is transformed from the real time domain to the effective time domain, which is obtained by rescaling the material clock to account for the age dependent relaxation time. The transformation of the master curve from the effective time domain to the real time domain leads to the prediction of the MSD in real time over a span of 5 decades when the measured data at individual aging times are only over 2 decades. Since the MSD obtained from microrheology is proportional to the creep compliance of a material, by using the Boltzmann superposition principle along with the convolution relation in the effective time domain, we predict the stress relaxation behavior of the system in real time. This work shows that the effective time approach applied to microrheology facilitates the prediction of long time creep and relaxation dynamics of a time dependent soft material by carrying out short time experiments at different aging times.

  8. Antimicrobial drug susceptibility of Neisseria meningitidis strains isolated from carriers

    Directory of Open Access Journals (Sweden)

    Dayamí García

    2000-06-01

    Full Text Available When it is necessary to determine the susceptibility of Neisseria meningitidis (Nm strains to antimicrobial drugs, it is important to consider that it should be analyzed in a double context. One of them related to the use of drugs in a specific medical treatment; and the other; to chemoprophylatic drugs, both with the same purpose: the accurate selection of the “in vivo” antimicrobial agent. This requires the study of the sensitivity and resistance of strains isolated in both carriers and patients. With the aim of further studying the behavior of the strains that currently circulate in Cuba, an antimicrobial drug susceptibility study was conducted in 90 strains isolated from carriers during the first half of 1998. The agar dilution method was used to determine the minimum inhibitory concentrations (MICs to: penicillin, ampicillin, rifampin, sulfadiazine, chloramphenicol, ciprofloxacin, ceftriaxone, cefotaxime. The study of the three latter drugs was done for the first time in our country. The search for β- lactamase-producer strains was also performed. There was a predominance of penicillin sensitive strains (82,2% with an intermediate sensitivity to ampicillin (57,8%, while 70% of the strains were sensitive to sulfadiazine. Regarding the rest of the antimicrobial drugs, 100% of the strains were sensitive. The paper shows the MICs for each drug as well as the phenotypic characteristics of the strains with the penicillin and sulfadiazine sensitivity and resistance patterns. No β-lactamase-producer strains were found.

  9. Laboratory evaluation of three strains of the entomopathogenic fungus Metarhizium anisopliae for controlling Dermanyssus gallinae.

    Science.gov (United States)

    Tavassoli, M; Ownag, A; Pourseyed, S H; Mardani, K

    2008-06-01

    The pathogenicity of three strains of the entomopathogenic fungus Metarhizium anisopliae on different life stages of Dermanyssus gallinae was evaluated in the laboratory. All the strains tested were virulent to D. gallinae but pathogenicity varied among the strains. Strain V245 induced a higher mortality rate using different concentrations than other two strains. The estimated median lethal concentration of different strains of M. anisopliae against D. gallinae varied depending on the exposure time of D. gallinae to M. anisopliae. It was concluded that the pathogenicity of the entomopathogenic fungus M. anisopliae on different life stages of D. gallinae was concentration and time dependent.

  10. Sadovskii vortex in strain

    Science.gov (United States)

    Freilich, Daniel; Llewellyn Smith, Stefan

    2014-11-01

    A Sadovskii vortex is a patch of fluid with uniform vorticity surrounded by a vortex sheet. Using a boundary element type method, we investigate the steady states of this flow in an incompressible, inviscid straining flow. Outside the vortex, the fluid is irrotational. In the limiting case where the entire circulation is due to the vortex patch, this is a patch vortex (Moore & Saffman, Aircraft wake turbulence and its detection 1971). In the other limiting case, where all the circulation is due to the vortex sheet, this is a hollow vortex (Llewellyn Smith and Crowdy, J. Fluid Mech. 691, 2012). This flow has two governing nondimensional parameters, relating the strengths of the straining field, vortex sheet, and patch vorticity. We study the relationship between these two parameters, and examine the shape of the resulting vortices. We also work towards a bifurcation diagram of the steady states of the Sadovskii vortex in an attempt to understand the connection between vortex sheet and vortex patch desingularizations of the point vortex. Support from NSF-CMMI-0970113.

  11. Real-time PCR detection and quantification of fish probiotic Phaeobacter strain 27-4 and fish pathogenic Vibrio in microalgae, rotifer, Artemia and first feeding turbot (Psetta maxima) larvae

    DEFF Research Database (Denmark)

    Prol, M.J.; Bruhn, Jesper Bartholin; Pintado, J.

    2009-01-01

    and in presence of microalgae (Isochrysis galbana), rotifers (Brachionus plicatilis), Artemia nauplii or turbot (Psetta maxima) larvae by real-time PCR based on primers directed at genetic loci coding for antagonistic and virulence-related functions respectively. The optimized protocol was used to study...

  12. In vitro activity of trovafloxacin against Bacteroides fragilis in mixed culture with either Escherichia coli or a vancomycin- resistant strain of Enterococcus faecium determined by an anaerobic time-kill technique.

    NARCIS (Netherlands)

    L.E.T. Stearne (Lorna); C. Kooi; W.H.F. Goessens (Wil); I.A.J.M. Bakker-Woudenberg (Irma); I.C. Gyssens (Inge)

    2001-01-01

    textabstractTo determine the efficacy of trovafloxacin as a possible treatment for intra-abdominal abscesses, we have developed an anaerobic time-kill technique using different inocula to study the in vitro killing of Bacteroides fragilis in pure culture or in mixed cul

  13. Photonic skin for pressure and strain sensing

    Science.gov (United States)

    Chen, Xianfeng; Zhang, C.; van Hoe, B.; Webb, D. J.; Kalli, K.; van Steenberge, G.; Peng, G.-D.

    2010-04-01

    In this paper, we report on the strain and pressure testing of highly flexible skins embedded with Bragg grating sensors recorded in either silica or polymer optical fibre. The photonic skins, with a size of 10cm x 10cm and thickness of 1mm, were fabricated by embedding the polymer fibre or silica fibre containing Bragg gratings in Sylgard 184 from Dow Corning. Pressure sensing was studied using a cylindrical metal post placed on an array of points across the skin. The polymer fibre grating exhibits approximately 10 times the pressure sensitivity of the silica fibre and responds to the post even when it is placed a few centimetres away from the sensing fibre. Although the intrinsic strain sensitivities of gratings in the two fibre types are very similar, when embedded in the skin the polymer grating displayed a strain sensitivity approximately 45 times greater than the silica device, which also suffered from considerable hysteresis. The polymer grating displayed a near linear response over wavelength shifts of 9nm for 1% strain. The difference in behaviour we attribute to the much greater Young's modulus of the silica fibre (70 GPa) compared to the polymer fibre (3 GPa).

  14. Irreversible Flow of Particle Suspensions with Non-uniform Strain

    Science.gov (United States)

    Gollub, J. P.; Guasto, Jeffrey S.; Ross, Andrew S.

    2010-03-01

    Despite the time reversibility of their governing equations (Stokes equations), particle trajectories in concentrated, periodically-sheared suspensions are irreversible above a critical strain amplitude [Pine et al., Nature (2005)]. Many-body interactions between particles are responsible for the chaotic dynamics, and a phase transition is observed between reversible and irreversible states [Corte et al., Nature Physics (2008)]. We extend previous experiments to a system with inhomogeneous strain: an oscillatory, rectangular channel flow. Deviations from reversible particle trajectories are parameterized by the mean square particle displacements sampled once per cycle, and by the particle fluctuation relaxation time, studied as a function of strain amplitude. We find that irreversibility increases roughly exponentially with the wall strain, and strikingly, the particle motions across the entire channel become irreversible simultaneously, despite the spatially varying strain. Random particle motion and shear-induced migration apparently produce reorganization of the suspension leading to a global onset of irreversibility.

  15. Creep Strain and Strain Rate Response of 2219 Al Alloy at High Stress Levels

    Science.gov (United States)

    Taminger, Karen M. B.; Wagner, John A.; Lisagor, W. Barry

    1998-01-01

    As a result of high localized plastic deformation experienced during proof testing in an International Space Station connecting module, a study was undertaken to determine the deformation response of a 2219-T851 roll forging. After prestraining 2219-T851 Al specimens to simulate strains observed during the proof testing, creep tests were conducted in the temperature range from ambient temperature to 107 C (225 F) at stress levels approaching the ultimate tensile strength of 2219-T851 Al. Strain-time histories and strain rate responses were examined. The strain rate response was extremely high initially, but decayed rapidly, spanning as much as five orders of magnitude during primary creep. Select specimens were subjected to incremental step loading and exhibited initial creep rates of similar magnitude for each load step. Although the creep rates decreased quickly at all loads, the creep rates dropped faster and reached lower strain rate levels for lower applied loads. The initial creep rate and creep rate decay associated with primary creep were similar for specimens with and without prestrain; however, prestraining (strain hardening) the specimens, as in the aforementioned proof test, resulted in significantly longer creep life.

  16. Filter Paper Degrading Ability of a Trichoderma Strain With Multinucleate Conidia

    Science.gov (United States)

    Toyama, Hideo; Yano, Makiko; Hotta, Takeshi; Toyama, Nobuo

    The multinucleate conidia were produced from the green mature conidia of Trichoderma reesei Rut C-30 strain by colchicine treatment. The strain with higher Filter paper degrading ability was selected among those conidia using a double layer selection medium. The selected strain, JS-2 was able to collapse the filter paper within 15 min but the original strain took 25 min to collapse it completely. Moreover, the amount of reducing sugar in the L-type glass tube of the strain, JS-2, was greater than that of the original strain. The Avicel, CMC-Na, and Salicin hydrolyzing activity of the strain, JS-2, increased 2.1 times, 1.2 times, and 3.6 times higher than that of the original strain.

  17. Hydrogen production from microbial strains

    Science.gov (United States)

    Harwood, Caroline S; Rey, Federico E

    2012-09-18

    The present invention is directed to a method of screening microbe strains capable of generating hydrogen. This method involves inoculating one or more microbes in a sample containing cell culture medium to form an inoculated culture medium. The inoculated culture medium is then incubated under hydrogen producing conditions. Once incubating causes the inoculated culture medium to produce hydrogen, microbes in the culture medium are identified as candidate microbe strains capable of generating hydrogen. Methods of producing hydrogen using one or more of the microbial strains identified as well as the hydrogen producing strains themselves are also disclosed.

  18. Evaluation of Strain Hardening Parameters

    Institute of Scientific and Technical Information of China (English)

    DING Zong-hai; Pavel Huml; YANG Wei

    2004-01-01

    The plane-strain compression test for three kinds of materials was carried out in a temperature range between room temperature and 400 ℃. The σ - ε curves and strain-hardening rate at different temperatures were simulated and a reasonable fit to the experimental data was obtained. A modified model created by data inference and computer simulation was developed to describe the strain hardening at a large deformation, and the predicted strain hardening are in a good agreement with that observed in a large range of stress. The influences of different parameters on strain hardening behaviour under large deformation were analysed. The temperature increase within the test temperatures for stainless steel 18/8 Ti results in dropping of flow stress and strain-hardening rate. For favourable γ-fibre texture to obtain high r, the cold rolling was applied at large reduction. In the experimental procedure, the X-ray diffraction test was carried out to compare the strain hardening and microstructure under large deformation for a bcc steel (low carbon steel SS-1142). The results indicate that the high strain-hardening rate possibly occurs when the primary slip plane {110} is parallel to the rolling plane and the strain-hardening rate decreases when lots of {110} plane rotate out from the orientation {110}∥RP.

  19. Strain index: a new visualizing parameter for US elastography

    Science.gov (United States)

    Sosa-Cabrera, Dario; de Luis-García, R.; Tristán-Vega, A.; Alberola-López, Carlos; Ruiz-Alzola, Juan

    2008-03-01

    Elastography, an ultrasound modality based on the relation between tissue strain and its mechanical properties, has a strong potential in the diagnosis and prognosis of tumors. For instance, tissue affected by breast and prostate cancer undergoes a change in its elastic properties. These changes can be measured using ultrasound signals. The standard way to visualize the elastic properties of tissues in elastography is the representation of the axial strain. Other approaches investigate the information contained in shear strain elastograms, vorticity or the representation of the full strain tensor. In this paper, we propose to represent the elastic behaviour of tissues through the visualization of the Strain Index, related with the trace of the strain tensor. Based on the mathematical interpretation of the strain tensor, this novel parameter is equivalent to the sum of the eigenvalues of the strain tensor, and constitutes a measure of the total amount of strain of the soft tissue. In order to show the potential of this visualization approach, a tissue-mimicking phantom was modeled as a 10x10x5 cm region containing a centered 10mm cylindrical inclusion three times stiffer than the surrounding material, and its elastic behavior was simulated using finite elements software. Synthetic pre- and post-compression (1.25%) B-mode images were computer-generated with ultrasound simulator. Results show that the visualization of the tensor trace significantly improves the representation and detection of inclusions, and can help add insight in the detection of different types of tumors.

  20. Will the swine strain crowd out the seasonal influenza strain?

    CERN Document Server

    Schinazi, Rinaldo B

    2010-01-01

    We use spatial and non spatial models to argue that competition alone may explain why two influenza strains do not usually coexist. The more virulent strain is likely to crowd out the less virulent one. This can be seen as a consequence of the Exclusion Principle of Ecology. We exhibit, however, a spatial model for which coexistence is possible.

  1. Storm time equatorial magnetospheric ion temperature derived from TWINS ENA flux

    Science.gov (United States)

    Katus, R. M.; Keesee, A. M.; Scime, E.; Liemohn, M. W.

    2017-04-01

    The plasma sheet plays an integral role in the transport of energy from the magnetotail to the ring current. We present a comprehensive study of the equatorial magnetospheric ion temperatures derived from Two Wide-angle Imaging Neutral-atom Spectrometers (TWINS) energetic neutral atom (ENA) measurements during moderate to intense (Dstpeak Los Alamos National Laboratory magnetospheric plasma analyzer. The ion temperatures are analyzed as a function of storm time, local time, and L shell. We perform a normalized superposed epoch analysis of 48 geomagnetic storms and examine the spatial and temporal evolution of the plasma as a function of storm phase. This analysis illustrates the spatial and temporal variation of the ions from the plasma sheet into the inner magnetosphere. We find that the ion temperature increases approaching the storm peak. This enhancement has the largest magnetic local time extent near 12 RE distance downtail.

  2. Development of bioluminescent Salmonella strains for use in food safety

    Directory of Open Access Journals (Sweden)

    Bailey R Hartford

    2008-01-01

    Full Text Available Abstract Background Salmonella can reside in healthy animals without the manifestation of any adverse effects on the carrier. If raw products of animal origin are not handled properly during processing or cooked to a proper temperature during preparation, salmonellosis can occur. In this research, we developed bioluminescent Salmonella strains that can be used for real-time monitoring of the pathogen's growth on food products. To accomplish this, twelve Salmonella strains from the broiler production continuum were transformed with the broad host range plasmid pAKlux1, and a chicken skin attachment model was developed. Results Salmonella strains carrying pAKlux1 constitutively expressed the luxCDABE operon and were therefore detectable using bioluminescence. Strains were characterized in terms of bioluminescence properties and plasmid stability. To assess the usefulness of bioluminescent Salmonella strains in food safety studies, we developed an attachment model using chicken skin. The effect of washing on attachment of Salmonella strains to chicken skin was tested using bioluminescent strains, which revealed the attachment properties of each strain. Conclusion This study demonstrated that bioluminescence is a sensitive and effective tool to detect Salmonella on food products in real-time. Bioluminescence imaging is a promising technology that can be utilized to evaluate new food safety measures for reducing Salmonella contamination on food products.

  3. Cells as strain-cued automata

    Science.gov (United States)

    Cox, Brian N.; Snead, Malcolm L.

    2016-02-01

    homogeneous populations and network formation by invaders, morphological outcomes are governed by the ratio of the rates of two competing time dependent processes, one a migration velocity and the other a relaxation velocity related to the propagation of strain information. Relaxation velocities are approximately constant for different species and organs, whereas cell migration rates vary by three orders of magnitude. We conjecture that developmental processes use rapid cell migration to achieve certain outcomes, and slow migration to achieve others. We infer from analysis of host relaxation during network formation that a transition exists in the mechanical response of a host cell from animate to inanimate behavior when its strain changes at a rate that exceeds 10-4-10-3 s-1. The transition has previously been observed in experiments conducted in vitro.

  4. Nonlinear time dependent behaviour of epoxy resins

    Science.gov (United States)

    Marotzke, C.; Feldmann, T.

    2016-07-01

    The nonlinear behaviour of epoxy resins is studied on standard tensile tests. A strain field measurement system is applied (Aramis) in order to monitor local strains. The residual strain is measured by recovering the specimens for up to 68 hours after unloading. The time span the specimen is exposed to load has a large influence on the creeping process and the residual strain after recovering. This is studied by comparison of instantaneous unloading with keeping the specimen under permanent load for thirty minutes. It is shown that moderate differences in the initial strain can lead to large differences in the creep behaviour as well as in the residual strain.

  5. Strained graphene Hall bar

    Science.gov (United States)

    Milovanović, S. P.; Peeters, F. M.

    2017-02-01

    The effects of strain, induced by a Gaussian bump, on the magnetic field dependent transport properties of a graphene Hall bar are investigated. The numerical simulations are performed using both classical and quantum mechanical transport theory and we found that both approaches exhibit similar characteristic features. The effects of the Gaussian bump are manifested by a decrease of the bend resistance, R B, around zero-magnetic field and the occurrence of side-peaks in R B. These features are explained as a consequence of bump-assisted scattering of electrons towards different terminals of the Hall bar. Using these features we are able to give an estimate of the size of the bump. Additional oscillations in R B are found in the quantum description that are due to the population/depopulation of Landau levels. The bump has a minor influence on the Hall resistance even for very high values of the pseudo-magnetic field. When the bump is placed outside the center of the Hall bar valley polarized electrons can be collected in the leads.

  6. High strain rate behaviour of polypropylene microfoams

    Science.gov (United States)

    Gómez-del Río, T.; Garrido, M. A.; Rodríguez, J.; Arencón, D.; Martínez, A. B.

    2012-08-01

    Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc.) or personal safety (helmets, knee-pads, etc.). In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry) is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of strain rates (0.001 to 3000 s-1) in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB). Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

  7. High strain rate behaviour of polypropylene microfoams

    Directory of Open Access Journals (Sweden)

    Martínez A.B.

    2012-08-01

    Full Text Available Microcellular materials such as polypropylene foams are often used in protective applications and passive safety for packaging (electronic components, aeronautical structures, food, etc. or personal safety (helmets, knee-pads, etc.. In such applications the foams which are used are often designed to absorb the maximum energy and are generally subjected to severe loadings involving high strain rates. The manufacture process to obtain polymeric microcellular foams is based on the polymer saturation with a supercritical gas, at high temperature and pressure. This method presents several advantages over the conventional injection moulding techniques which make it industrially feasible. However, the effect of processing conditions such as blowing agent, concentration and microfoaming time and/or temperature on the microstructure of the resulting microcellular polymer (density, cell size and geometry is not yet set up. The compressive mechanical behaviour of several microcellular polypropylene foams has been investigated over a wide range of strain rates (0.001 to 3000 s−1 in order to show the effects of the processing parameters and strain rate on the mechanical properties. High strain rate tests were performed using a Split Hopkinson Pressure Bar apparatus (SHPB. Polypropylene and polyethylene-ethylene block copolymer foams of various densities were considered.

  8. Residual strains in conduit arteries.

    Science.gov (United States)

    Rachev, A; Greenwald, S E

    2003-05-01

    Residual strains and stresses are those that exist in a body when all external loads are removed. Residual strains in arteries can be characterized by the opening angle of the sector-like cross-section which arises when an unloaded ring segment is radially cut. A review of experimental methods for measuring residual strains and the main results about the variation of the opening angle with arterial localization, age, smooth muscle activity, mechanical environment and certain vascular pathologies are presented and discussed. It is shown that, in addition to their well-established ability to homogenize the stress field in the arterial wall, residual strains make arteries more compliant and thereby improve their performance as elastic reservoirs and ensure more effective local control of the arterial lumen by smooth muscle cells. Finally, evidence that, in some cases, residual strains remain in arteries even after they have been cut radially is discussed.

  9. New Insights into Various Production Characteristics of Streptococcus thermophilus Strains

    Science.gov (United States)

    Cui, Yanhua; Xu, Tingting; Qu, Xiaojun; Hu, Tong; Jiang, Xu; Zhao, Chunyu

    2016-01-01

    Streptococcus thermophilus is one of the most valuable homo-fermentative lactic acid bacteria, which, for a long time, has been widely used as a starter for the production of fermented dairy products. The key production characteristics of S. thermophilus, for example the production of extracellular polysaccharide, proteolytic enzymes and flavor substances as well as acidifying capacity etc., have an important effect on the quality of dairy products. The acidification capacity of the strains determines the manufacturing time and quality of dairy products. It depends on the sugar utilization ability of strains. The production of extracellular polysaccharide is beneficial for improving the texture of dairy products. Flavor substances increase the acceptability of dairy products. The proteolytic activity of the strain influences not only the absorption of the nitrogen source, but also the formation of flavor substances. Different strains have obvious differences in production characteristics via long-time evolution and adaptation to environment. Gaining new strains with novel and desirable characteristics is an important long-term goal for researchers and the fermenting industry. The understanding of the potential molecular mechanisms behind important characteristics of different strains will promote the screening and breeding of excellent strains. In this paper, key technological and functional properties of different S. thermophilus strains are discussed, including sugar metabolism, proteolytic system and amino acid metabolism, and polysaccharide and flavor substance biosynthesis. At the same time, diversity of genomes and plasmids of S. thermophilus are presented. Advances in research on key production characteristics and molecular levels of S. thermophilus will increase understanding of molecular mechanisms of different strains with different important characteristics, and improve the industrialization control level for fermented foods. PMID:27754312

  10. Constitutive Relation of Yunjialing Anthracite Under Medium Strain Rate

    Institute of Scientific and Technical Information of China (English)

    GAO Wen-jiao; SHAN Ren-liang; WANG Gong-cheng; CHENG Rui-qiang

    2007-01-01

    By means of the split Hopkinson pressure bar (SHPB) testing system, this paper presents a dynamic constitutive relation of anthracite at a strain rate of ε =5-85s-1. Generally, the dynamic stress-strain curve for this kind of anthracite under uni-axial compression has the following four stages: a non-linear loading stage, a plastic yielding stage, a strain-strengthening stage and an unloading breakage stage. Correspondingly, the initial elastic modulus Eb, the yielding strength σs and the ultimate strength σb increase along with an increasing strain rate. The time-dependent elasticity was identified when we analyzed the mechanical properties of anthracite. Based on characteristics of measured dynamic stress-strain curves and an analysis of existing rock dynamic constitutive models, as well as a preparatory simulation, a new visco-elastic damage model has been introduced in this paper. A linear spring is put parallel to two Maxwell units with different relaxation times to express two distinct plastic flows. The damage D is equal to [Eb- E(εi)]/Eb, where Eb is the beginning modulus and the E(εi) is the slope of a connected line between the origin point and any other point on a tested stress-strain curve. In the new constitutive model, one Maxwell unit with low relaxation time (ψ)1 is used to describe the response of anthracite to a low strain rate, while the other, with a high relaxation time (ψ)2 describes the response of anthracite to a high strain rate. Simulated stress-strain curves from the new model are consistent with the measured curves.

  11. Family-supportive work environments and psychological strain: a longitudinal test of two theories.

    Science.gov (United States)

    Odle-Dusseau, Heather N; Herleman, Hailey A; Britt, Thomas W; Moore, Dewayne D; Castro, Carl A; McGurk, Dennis

    2013-01-01

    Based on the Job Demands-Resources (JDR) model (E. Demerouti, A. B. Bakker, F. Nachreiner, & W. B. Schaufeli, 2001, The job demands-resources model of burnout. Journal of Applied Psychology, 86, 499-512) and Conservation of Resources (COR) theory (S. E. Hobfoll, 2002, Social and psychological resources and adaptation. Review of General Psychology, 6, 307-324), we tested three competing models that predict different directions of causation for relationships over time between family-supportive work environments (FSWE) and psychological strain, with two waves of data from a military sample. Results revealed support for both the JDR and COR theories, first in the static model where FSWE at Time 1 predicted psychological strain at Time 2 and when testing the opposite direction, where psychological strain at Time 1 predicted FSWE at Time 2. For change models, FSWE predicted changes in psychological strain across time, although the reverse causation model was not supported (psychological strain at Time 1 did not predict changes in FSWE). Also, changes in FSWE across time predicted psychological strain at Time 2, whereas changes in psychological strain did not predict FSWE at Time 2. Theoretically, these results are important for the work-family interface in that they demonstrate the application of a systems approach to studying work and family interactions, as support was obtained for both the JDR model with perceptions of FSWE predicting psychological strain (in both the static and change models), and for COR theory where psychological strain predicts FSWE across time.

  12. Changes in Fetal Left and Right Ventricular Strain Mechanics during Normal Pregnancy.

    NARCIS (Netherlands)

    Kapusta, L.; Mainzer, G.; Weiner, Z.; Deutsch, L.; Khoury, A.; Haddad, S.; Lorber, A.

    2013-01-01

    BACKGROUND: The aim of this study was to detect normal changes in fetal two-dimensional speckle-tracking echocardiography-derived values for global and regional longitudinal left and right ventricular strain, strain rate, and time to peak (T2P) global strain during pregnancy. METHODS: Forty-four hea

  13. Visualizing surface strain distribution of facial skin using stereovision

    Directory of Open Access Journals (Sweden)

    Nagisa Miura

    2016-07-01

    Full Text Available An experimental technique has been developed for measuring and visualizing strain distribution on facial skin. A stereovision technique based on digital image correlation is employed for obtaining the displacement distribution on the human face. Time-variation of the movement of the facial skin surface is obtained from consecutive images obtained using a pair of high-speed cameras. The strains on the facial skin surface are then obtained from the measured displacements. The performance of the developed system is demonstrated by applying it to the measurement of the strain on facial skin during the production of sound. Results show that the strains on facial skin can be visualized. Further discussion on the relationship between the creation of wrinkles and strains is possible with the help of the developed system.

  14. Exploring new strains of dye-decolorizing bacteria.

    Science.gov (United States)

    Han, Jing-Long; Ng, I-Son; Wang, Yanni; Zheng, Xuesong; Chen, Wen-Ming; Hsueh, Chung-Chuan; Liu, Shi-Qi; Chen, Bor-Yann

    2012-04-01

    This study unveiled a new strategy to explore new indigenous strains with excellent decolorization capabilities from freshwaters and seawaters. Two new bacterial decolorizers DX2b and SH7b, which have the capability to decolorize textile dyes, were isolated from Cross-Strait Taiwan and China. According to PCR-augmented 16S rRNA gene analyses for strain identification, >99% of nucleotide sequences in isolated strains were identical to type strains Rahnella aquatilis, Acinetobacter guillouiae, Microvirgula aerodenitrificans, and Pseudomonas sp. Time-series inspection upon azoreductase activity assay and generation of decolorized intermediates all confirmed in parallel with reductive decolorization of new decolorizers DX2b and SH7b. The result also showed that bacterial decolorization of these new strains was mainly catalyzed via the enzymatic expression of azoreductase and riboflavin reductase, and biosorption seemed not to play a crucial role color removal (approximately <10%).

  15. Estimating the plastic strain with the use of acoustic anisotropy

    Science.gov (United States)

    Belyaev, A. K.; Lobachev, A. M.; Modestov, V. S.; Pivkov, A. V.; Polyanskii, V. A.; Semenov, A. S.; Tret'yakov, D. A.; Shtukin, L. V.

    2016-09-01

    Experimental verification is used to show that reference specimens and structure unloading do not permit obtaining an adequate estimate of plastic strain by measuring the acoustic anisotropy. Analytic estimates of the speed of propagation of a plane acoustic wave of various polarizations in an elastoplastic material in the direction orthogonal to the action of preliminary uniaxial stress are obtained. An analysis of the obtained relations reveala an advantage of using absolute values of the velocity of longitudinal and transverse waves for the plastic strain identification. In contrast to acoustic anisotropy, the velocities vary monotonically in a wider range of plastic strains. At the same time, the elastic strain does not affect the longitude wave velocity, which allows one to use the measurement results to estimate the character of strains.

  16. Biodegradation of furfural by Bacillus subtilis strain DS3.

    Science.gov (United States)

    Zheng, Dan; Bao, Jianguo; Lu, Jueming; Lv, Quanxi

    2015-07-01

    An aerobic bacterial strain DS3, capable of growing on furfural as sole carbon source, was isolated from actived sludge of wastewater treatment plant in a diosgenin factory after enrichment. Based on morphological physiological tests as well as 16SrDNA sequence and Biolog analyses it was identified as Bacillus subtilis. The study revealed that strain DS3 utilized furfural, as analyzed by high-performance liquid chromatography (HPLC). Under following conditions: pH 8.0, temperature 35 degrees C, 150 rpm and 10% inoculum, strain DS3 showed 31.2% furfural degradation. Furthermore, DS3 strain was found to tolerate furfural concentration as high as 6000 mg(-1). The ability of Bacillus subtilis strain DS3 to degrade furfural has been demonstrated for the first time in the present study.

  17. A distributed optical fiber bi-directional strain-displacement sensor

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A distributed optical fiber strain-displacement sensor is developed, which consists of an optical fiber gauge of strain-displacement and an optical time domain reflectometer (OTDR). The operational principle is the modulation of fiber loss in OTDR, i.e. the strain and displacement in monitoring position are obtained from the bending loss of optical fiber bonded on the optical fiber gauge of strain-displacement. After examining the strain and displacement in the cantilever and the micro displacement rack respectively, the result indicates that the distributed optical fiber gauge of strain-displacement can monitor strains or displacements in different sensitive lengths. The key technique for measuring bi-directional strain-displacement is the pretreatment of bending of the freely suspended optical fibers, which can be identified with OTDR by inserting time delay optical fiber.

  18. Sprains, Strains, and Tears

    Science.gov (United States)

    ... Both can result in significant lost time from sports. A COMPLETE PHYSICAL ACTIVITY PROGRAM A well-rounded physical activity program includes aerobic exercise and strength training exercise, but not necessarily in the same session. ...

  19. High temperature strain measurement with a resistance strain gage

    Science.gov (United States)

    Lei, Jih-Fen; Fichtel, ED; Mcdaniel, Amos

    1993-01-01

    A PdCr based electrical resistance strain gage was demonstrated in the laboratory to be a viable sensor candidate for static strain measurement at high temperatures. However, difficulties were encountered while transferring the sensor to field applications. This paper is therefore prepared for recognition and resolution of the problems likely to be encountered with PdCr strain gages in field applications. Errors caused by the measurement system, installation technique and lead wire attachment are discussed. The limitations and some considerations related to the temperature compensation technique used for this gage are also addressed.

  20. Strain and strain rate: An emerging technology in the perioperative period.

    Science.gov (United States)

    Malik, Vishwas; Subramaniam, Arun; Kapoor, Poonam Malhotra

    2016-01-01

    Newer noninvasive parameters are being used for perioperative detection of myocardial ischaemia. TDI and global strain rate are some of these parameters. TDI signal is a modification of the routine Doppler flow signal. It is obtained by using thresholding and filtering algorithms that reject echoes originating from the blood pool (by-passing the high pass filter). Set-Up of the machine by activating the TDI function allows decreasing the system gain using a low pass filter and eliminates the signal produced by blood flow. Doppler shift obtained from myocardial tissue motion are of higher amplitudes (reflectivity 40 dB higher) and move about 10 times slower than blood (velocity range: 0.06 to 0.24 m/s). Speckle tracking echocardiography (tissue tracking, 2D strain) utilizes routine gray-scale 2D echo images to calculate myocardial strain. Interactions of ultrasound with myocardium result in reflection and scattering. These interactions generate a finely gray-shaded, speckled pattern (acoustic marker). This speckled pattern is unique for each myocardial region and relatively stable throughout the cardiac cycle. Spatial and temporal image processing of acoustic speckles in both 2D and 3D allows for the calculation of myocardial velocity, strain, and Strain rate.

  1. Evaluation of left ventricular regional myocardial systolic function in patients with diastolic heart failure using real-time triplane strain rate imaging%实时三平面应变率成像评价舒张性心力衰竭患者左心室局部心肌收缩功能

    Institute of Scientific and Technical Information of China (English)

    姜海燕; 王志斌; 聂晶; 李艳

    2011-01-01

    目的:应用实时三平面应变率成像检测舒张性心力衰竭患者左心室局部心肌收缩功能,探讨其临床意义.方法:选取舒张性心力衰竭患者29例、收缩性心力衰竭患者26例和正常人30例,应用实时三平面应变率成像测定左心室各壁基底段和中间段收缩期峰值应变率(SRs).结果:舒张性心力衰竭组、收缩性心力衰竭组左心室壁各节段SRs均小于正常组相应节段(P<0.05或P<0.01),且正常组、舒张性心力衰竭组、收缩性心力衰竭组各组SRs逐渐减小(P<0.05或P<0.01).结论:舒张性心力衰竭患者存在左心室局部心肌收缩功能异常,实时三平面应变率成像检测左心室局部心肌收缩功能在心力衰竭患者心脏功能评价中具有重要价值.%Objective: To evaluate the left ventricular regional myocardial systolic function in patients with diastolic heart failure using real-time triplane strain rate imaging and investigate its clinical significance.Methods: Twenty-nine patients with diastolic heart failure, 26 patients with systolic heart failure and 30 healthy subjects as control group were enrolled.The systolic peak strain rate (SRs) were measured at basal and middle segments in different left ventricular walls using real-time triplane strain rate imaging.Results: SRs in diastolic heart failure and systolic heart failure groups were significantly lower than in control group(P<0.05 or P<0.01).There was a significantly step-down change among normal, diastolic heart failure and systolic heart failure in SRs (P<0.05 or P<0.01).Conclusions: The left ventricular regional myocardial systolic dysfunction existed in patients with diastolic heart failure.Thus, assessing left ventricular regional myocardial systolic function using real-time triplane strain rate imaging has important clinical value in the comprehensive evaluation of cardiac function in heart failure.

  2. PROPERTIES OF NEW STRAINS CHEMOLITHOTROPHIC BACTERIA ISOLATED FROM INDUSTRIAL SUBSTRATES

    Directory of Open Access Journals (Sweden)

    I. A.

    2015-12-01

    Full Text Available The purpose of the research was determination of strains Acidithiobacillus ferrooxidans MFLv37 and Acidithiobacillus ferrooxidans MFLad27, isolated from aboriginal consortium of coal beneficiation dumps and fly ash from coal combustion, resistance to heavy metals, forming part of these waste, as well as adaption ability of the strains to new substrates. New strains increased resistance to heavy metal ions as compared to A. ferrooxidans standard and collection strains is found; minimal inhibitory concentrations of heavy and toxic metals are determined; a number of metals that have negative impact on growth of isolated cultures are identified. It is shown that the minimal metals concentrations, at which strains growth still happens, are several times higher than their concentrations in technogenic waste. It has been established that isolated strains differed in their ability to adapt, as well as in growth rate and substrates oxidation. This is due to the specific conditions of microbiocenoses formation in making and further storage of rock dumps and fly ash, whereof the appropriate strains are isolated. The investigations indicate the necessity in directional selection of strains that are resistant to the toxic compounds and are able to oxidize various mineral substrates, as well as in their adaptation to new substrates for the extraction of heavy metals.

  3. [Study on relationship between coping resources and strain in mental workers].

    Science.gov (United States)

    Xiao, Yuan-Mei; Wang, Zhi-Ming; Wang, Mian-Zhen; Lan, Ya-Jia

    2005-01-01

    To study the effects of mental workers' coping resources on their strain. Strain (vocational strain, psychological strain, interpersonal strain, physical strain) and coping resources (recreation, self-care, social support, rational coping) were measured on 3379 mental workers with personal strain questionnaire (PSQ) and personal resources questionnaire (PRQ). There existed significantly negative correlations between PRQ and PSQ (P social support (SS) and rational coping (RC) had the closest relationships with PSQ. In the items of SS, those related to feeling support had more remission on strain. In the items of RC, those related to reasonable arrangement of time and anti-interference had more remission on strain. In the items of recreation (RE), those related to self-determination had more effects on the remission of strain, while indulging in watching TV could cause the strength of strain, and there was a positive correlation between watching TV and strain (P support and reasonable arrangement of time, were the important measures for the remission of mental worker' strain.

  4. Roll bonding of strained aluminium

    DEFF Research Database (Denmark)

    Staun, Jakob M.

    2003-01-01

    This report investigates roll bonding of pre-strained (å ~ 4) aluminium sheets to produce high strain material from high purity aluminium (99.996%) and commercial pure aluminium (99.6%). The degree of bonding is investigated by optical microscopy and ultrasonic scanning. Under the right...... of the cross rolled volume fraction is found. To further asses this effect, and the anisotropy, it is necessary to acquire knowledge about both texture and microstructure, e.g. by TEM. Roll bonding of pre-strained aluminium is found to be a possible alternative to ARB in the quest for ultra-fine grained...

  5. Roll bonding of strained aluminium

    DEFF Research Database (Denmark)

    Staun, Jakob M.

    2003-01-01

    This report investigates roll bonding of pre-strained (å ~ 4) aluminium sheets to produce high strain material from high purity aluminium (99.996%) and commercial pure aluminium (99.6%). The degree of bonding is investigated by optical microscopy and ultrasonic scanning. Under the right...... of the cross rolled volume fraction is found. To further asses this effect, and the anisotropy, it is necessary to acquire knowledge about both texture and microstructure, e.g. by TEM. Roll bonding of pre-strained aluminium is found to be a possible alternative to ARB in the quest for ultra-fine grained...

  6. Detection and Differentiation of Vaccine and Wild-type Strains of PPRV by Duplex Real-time RT-PCR%实时荧光RT-PCR鉴别小反刍兽疫病毒疫苗株和野毒株

    Institute of Scientific and Technical Information of China (English)

    李林; 吴晓东; 刘春菊; 王清华; 包静月; 王志亮

    2016-01-01

    To differentiate vaccine virus and wild-type peste des petits ruminants virus(PPRV)by duplex real-time RT-PCR,one pair of primers and two TaqMan probes were designed based on the comparison of PPRV genome sequences available in GenBank. The duplex real-time RT-PCR results showed that the detection limits for vaccine strain and wild-type strains were both 10 copies per reaction. The developed assay also showed high ampliifcation efifciency,linearity and speciifcity in discriminating the two PPRV types. A total of 136 clinical samples tested by the conventional RT-PCR were run again by the duplex real-time RT-PCR. The results were conifrmed subsequently by sequencing the positive conventional RT-PCR products. This reliable and rapid duplex real-time RT-PCR assay would be feasible and attractive for diagnostic laboratories,both for clinical purpose in active surveillance and for epidemiological investigations.%为快速鉴别小反刍兽疫病毒的疫苗株和野毒株,本研究通过分析GenBank中已发布的小反刍兽疫病毒全基因组序列,设计了1对通用引物以及疫苗株和野毒株特异性探针各1条,建立了小反刍兽疫病毒鉴别实时荧光RT-PCR方法。结果显示,该方法对疫苗株和野毒株的检测灵敏度均可以检测至10拷贝/反应,在108至101拷贝/反应之间具有良好的线性关系,扩增效率均接近1。该方法具有良好的特异性,能够区分不同谱系的野毒株株和疫苗株。使用该方法对136份临床疑似样品检测,检出的阳性数量与普通RT-PCR相同,并且测序后的区分结果也相同。本方法的建立为该病的实验室鉴别检测和流行病学调查提供了技术支持。

  7. Evaluation in vitro of the infection times of engorged females of Rhipicephalus (Boophilus microplus by the entomopathogenic nematode Steinernema glaseri CCA strain Avaliação in vitro dos tempos de infecção de fêmeas ingurgitadas de Rhipicephalus (Boophilus microplus pelo nematoide entomopatogênico Steinernema glaseri estirpe CCA

    Directory of Open Access Journals (Sweden)

    Leandro Barbiéri de Carvalho

    2010-04-01

    Full Text Available Studies have shown that ticks are susceptible to infection by entomopathogenic nematodes. These studies indicate different susceptibilities of ticks to infection by these fungi, depending on the tick species, development phase, entomopathogenic nematodes species and strains and the time the ticks are exposed to them. Usually this period ranges from 24 to 72 hours. The aim of this study was to evaluate the infection times in vitro of engorged Rhipicephalus (Boophilus microplus females by the entomopathogenic nematodes Steinernema glaseri CCA strain, by analysis of the ticks' biological parameters. The results show that a 2-hour exposure time was sufficient for the engorged R. microplus females to be infected by S. glaseri CCA, but that a minimum exposure time of 24 hours was necessary to generate treatment efficacy above 90%.Os carrapatos são susceptíveis à infecção por nematoides entomopatogênicos. Essa susceptibilidade diverge quanto às espécies de carrapato estudadas, à fase evolutiva, às espécies e estirpes dos nematoides e ao tempo ao qual os carrapatos ficam expostos a estes. O presente trabalho teve como objetivo avaliar os tempos de infecção in vitro de fêmeas ingurgitadas de Rhipicephalus (Boophilus microplus pelo nematoide entomopatogênico Steinernema glaseri estirpe CCA, pela análise dos parâmetros biológicos do carrapato. Os resultados obtidos demonstraram que um período de duas horas de exposição foi suficiente para que fêmeas ingurgitadas de R. microplus fossem infectadas por S. glaseri CCA e que um período de exposição mínimo de 24h foi necessário para que houvesse infecção de fêmeas ingurgitadas de R. microplus por S. glaseri estirpe CCA, capaz de gerar, in vitro, eficácia no tratamento superior a 90%.

  8. Modulating thermal conduction by the axial strain

    Science.gov (United States)

    Jiang, Jianjun; Zhao, Hong

    2016-09-01

    Recent studies have revealed that the symmetry of interparticle potential plays an important role in the one-dimensional thermal conduction problem. Here we demonstrate that, by introducing strain into the Fermi-Pasta-Ulam-β lattice, the interparticle potential can be converted from symmetric to asymmetric, which leads to a change of the asymptotic decaying behavior of the heat current autocorrelation function. More specifically, such a change in the symmetry of the potential induces a fast decaying stage, in which the heat current autocorrelation function decays faster than power-law manners or in a power-law manner but faster than ~t -1, in the transient stage. The duration of the fast decaying stage increases with increasing strain ratio and decreasing of the temperature. As a result, the thermal conductivity calculated following the Green-Kubo formula may show a truncation-time independent behavior, suggesting a system-size independent thermal conductivity.

  9. Averaged hole mobility model of biaxially strained Si

    Institute of Scientific and Technical Information of China (English)

    Song Jianjun; Zhu He; Yang Jinyong; Zhang Heming; Xuan Rongxi; Hu Huiyong

    2013-01-01

    We aim to establisha model of the averaged hole mobility of strained Si grown on (001),(101),and (111) relaxed Si1-xGex substrates.The results obtained from our calculation show that their hole mobility values corresponding to strained Si (001),(101) and (111) increase by at most about three,two and one times,respectively,in comparison with the unstrained Si.The results can provide a valuable reference to the understanding and design of strained Si-based device physics.

  10. Relativistic Strain and Electromagnetic Photon-Like Objects

    CERN Document Server

    Donev, Stoil

    2014-01-01

    This paper aims to relate some properties of photon-like objects, considered as spatially finite time-stable physical entities with dynamical structure, to well defined properties of the corresponding electromagnetic strains defined as Lie derivatives of the Minkowski (pseudo)metric with respect to the eigen vector fields of the Maxwell-Minkowski stress-energy-momentum tensor. First we recall the geometric sense of the concept of strain, then we introduce and discuss the notion for photon-like objects (PhLO). We compute then the strains along the eigen vectors of the stress-energy-momentum tensor $T_{\\mu}^{\

  11. Spacecraft Dynamic Characterization by Strain Energies Method

    Science.gov (United States)

    Bretagne, J.-M.; Fragnito, M.; Massier, S.

    2002-01-01

    In the last years the significant increase in satellite broadcasting demand, with the wide band communication dawn, has given a great impulse to the telecommunication satellite market. The big demand is translated from operators (such as SES/Astra, Eutelsat, Intelsat, Inmarsat, EuroSkyWay etc.) in an increase of orders of telecom satellite to the world industrials. The largest part of these telecom satellite orders consists of Geostationary platforms which grow more and more in mass (over 5 tons) due to an ever longer demanded lifetime (up to 20 years), and become more complex due to the need of implementing an ever larger number of repeaters, antenna reflectors and feeds, etc... In this frame, the mechanical design and verification of these large spacecraft become difficult and ambitious at the same time, driven by the dry mass limitation objective. By the Finite Element Method (FEM), and on the basis of the telecom satellite heritage of a world leader constructor such as Alcatel Space Industries it is nowadays possible to model these spacecraft in a realistic and confident way in order to identify the main global dynamic aspects such as mode shapes, mass participation and/or dynamic responses. But on the other hand, one of the main aims consists in identifying soon in a program the most critical aspects of the system behavior in the launch dynamic environment, such as possible dynamic coupling between the different subsystems and secondary structures of the spacecraft (large deployable reflectors, thrusters, etc.). To this aim a numerical method has been developed in the frame of the Alcatel SPACEBUS family program, using MSC/Nastran capabilities and it is presented in this paper. The method is based on Spacecraft sub-structuring and strain energy calculation. The method mainly consists of two steps : 1) subsystem modal strain energy ratio (with respect to the global strain energy); 2) subsystem strain energy calculation for each mode according to the base driven

  12. Canning Tests on Mushroom Strain

    OpenAIRE

    Gormley, T. R. (Thomas Ronan); MacCanna, C.

    1980-01-01

    Canning tests were carried out on 5 mushroom strains from 2 flushes of 4 separate crops. Particular attention was given to the ratio of whole closed canned mushrooms to that of whole closed canned mushrooms plus canned stems and pieces - i.e. total yield. Factors considered in the tests included grading prior to processing, blanching and retort losses, shrinkage in size and mushroom whiteness. Cream and off-white strains had the highest level of open and misshapen mushrooms prior to processin...

  13. ASPECTS CONCERNING THE ENZYMATIC ACTIVITY IN SEVERAL THERMOACTINOMYCETE STRAINS

    Directory of Open Access Journals (Sweden)

    Simona Dunca

    2003-08-01

    Full Text Available In the thermoactinomycete strains subjected to examination the values of their recorded enzymatic activities (i.e. α-amy lase, protease, exo-β-1,4 – glucanase, endo -β-1,4 – glucanase and β-glucosidase were lower in the stationary cultures as compared to the stirred ones. The strain Thermomonospora fusca BB255 was found to be highly cellulase- producing and at the same time able to synthesize α-amy lases and proteases.

  14. Detecting strain in birefringent materials using spectral polarimetry

    Science.gov (United States)

    Ragucci, Anthony J. (Inventor); Cisar, Alan J. (Inventor); Huebschman, Michael L. (Inventor); Garner, Harold R. (Inventor)

    2010-01-01

    A method, computer program product and system for analyzing multispectral images from a plurality of regions of birefringent material, such as a polymer film, using polarized light and a corresponding polar analyzer to identify differential strain in the birefringent material. For example, the birefringement material may be low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyvinylidene chloride, polyester, nylon, or cellophane film. Optionally, the method includes generating a real-time quantitative strain map.

  15. The effects of academic and interpersonal stress on dating violence among college students: a test of classical strain theory.

    Science.gov (United States)

    Mason, Brandon; Smithey, Martha

    2012-03-01

    This study examines Merton's Classical Strain Theory (1938) as a causative factor in intimate partner violence among college students. We theorize that college students experience general life strain and cumulative strain as they pursue the goal of a college degree. We test this strain on the likelihood of using intimate partner violence. Strain due to unrealistic expectations of intimate partnership and economic strain are also examined. The analysis examines the following causative factors representing strain: 1) the College Undergraduate Stress Scale (Renner & Mackin, 1998); 2) cumulative academic strain measured by college classification; 3) cumulative intimate partner strain measured as the length of time in the relationship; 4) academic strain measured by number of hours studied weekly, and 5) economic strain measured by number of hours worked weekly. Additionally, we examine the extent to which gender and race/ethnicity differentially affect intimate partner in the context of these measures of strain. The Conflict Tactics Scales II (Straus et al, 1996) are used to measure dating violence and include indicators for sexual coercion, physical aggression, injury, and psychological aggression. Data were collected from 142 students in lower-division classes from Texas Tech University. Results show that general strain and cumulative intimate partner strain increase the use of dating violence among college students. The longer dating partners are in a relationship, the higher the chances of psychological aggression, physical assault, and sexual coercion. Converse to our expectations, time spent working reduces psychological aggression due to reducing time spent together rather than reflecting economic strain.

  16. Dual-phase cardiac diffusion tensor imaging with strain correction.

    Directory of Open Access Journals (Sweden)

    Christian T Stoeck

    Full Text Available In this work we present a dual-phase diffusion tensor imaging (DTI technique that incorporates a correction scheme for the cardiac material strain, based on 3D myocardial tagging.In vivo dual-phase cardiac DTI with a stimulated echo approach and 3D tagging was performed in 10 healthy volunteers. The time course of material strain was estimated from the tagging data and used to correct for strain effects in the diffusion weighted acquisition. Mean diffusivity, fractional anisotropy, helix, transverse and sheet angles were calculated and compared between systole and diastole, with and without strain correction. Data acquired at the systolic sweet spot, where the effects of strain are eliminated, served as a reference.The impact of strain correction on helix angle was small. However, large differences were observed in the transverse and sheet angle values, with and without strain correction. The standard deviation of systolic transverse angles was significantly reduced from 35.9±3.9° to 27.8°±3.5° (p<0.001 upon strain-correction indicating more coherent fiber tracks after correction. Myocyte aggregate structure was aligned more longitudinally in systole compared to diastole as reflected by an increased transmural range of helix angles (71.8°±3.9° systole vs. 55.6°±5.6°, p<0.001 diastole. While diastolic sheet angle histograms had dominant counts at high sheet angle values, systolic histograms showed lower sheet angle values indicating a reorientation of myocyte sheets during contraction.An approach for dual-phase cardiac DTI with correction for material strain has been successfully implemented. This technique allows assessing dynamic changes in myofiber architecture between systole and diastole, and emphasizes the need for strain correction when sheet architecture in the heart is imaged with a stimulated echo approach.

  17. Molecular characterization of Mycobacterium bovis strains isolated from cattle slaughtered at two abattoirs in Algeria

    Directory of Open Access Journals (Sweden)

    Ouzrout Rachid

    2009-01-01

    Full Text Available Abstract Background Bovine Tuberculosis is prevalent in Algeria despite governmental attempts to control the disease. The objective of this study was to conduct, for the first time, molecular characterization of a population sample of Mycobacterium bovis strains isolated from slaughter cattle in Algeria. Between August and November 2007, 7250 animals were consecutively screened at the abattoirs of Algiers and Blida. In 260 animals, gross visible granulomatous lesions were detected and put into culture. Bacterial isolates were subsequently analysed by molecular methods. Results Altogether, 101 bacterial strains from 100 animals were subjected to molecular characterization. M. bovis was isolated from 88 animals. Other bacteria isolated included one strain of M. caprae, four Rhodococcus equi strains, three Non-tuberculous Mycobacteria (NTM and five strains of other bacterial species. The M. bovis strains isolated showed 22 different spoligotype patterns; four of them had not been previously reported. The majority of M. bovis strains (89% showed spoligotype patterns that were previously observed in strains from European cattle. Variable Number of Tandem Repeat (VNTR typing supported a link between M. bovis strains from Algeria and France. One spoligotype pattern has also been shown to be frequent in M. bovis strains from Mali although the VNTR pattern of the Algerian strains differed from the Malian strains. Conclusion M. bovis infections account for a high amount of granulomatous lesions detected in Algerian slaughter cattle during standard meat inspection at Algiers and Blida abattoir. Molecular typing results suggested a link between Algerian and European strains of M. bovis.

  18. Molecular characterization of Mycobacterium bovis strains isolated from cattle slaughtered at two abattoirs in Algeria

    Science.gov (United States)

    Sahraoui, Naima; Müller, Borna; Guetarni, Djamel; Boulahbal, Fadéla; Yala, Djamel; Ouzrout, Rachid; Berg, Stefan; Smith, Noel H; Zinsstag, Jakob

    2009-01-01

    Background Bovine Tuberculosis is prevalent in Algeria despite governmental attempts to control the disease. The objective of this study was to conduct, for the first time, molecular characterization of a population sample of Mycobacterium bovis strains isolated from slaughter cattle in Algeria. Between August and November 2007, 7250 animals were consecutively screened at the abattoirs of Algiers and Blida. In 260 animals, gross visible granulomatous lesions were detected and put into culture. Bacterial isolates were subsequently analysed by molecular methods. Results Altogether, 101 bacterial strains from 100 animals were subjected to molecular characterization. M. bovis was isolated from 88 animals. Other bacteria isolated included one strain of M. caprae, four Rhodococcus equi strains, three Non-tuberculous Mycobacteria (NTM) and five strains of other bacterial species. The M. bovis strains isolated showed 22 different spoligotype patterns; four of them had not been previously reported. The majority of M. bovis strains (89%) showed spoligotype patterns that were previously observed in strains from European cattle. Variable Number of Tandem Repeat (VNTR) typing supported a link between M. bovis strains from Algeria and France. One spoligotype pattern has also been shown to be frequent in M. bovis strains from Mali although the VNTR pattern of the Algerian strains differed from the Malian strains. Conclusion M. bovis infections account for a high amount of granulomatous lesions detected in Algerian slaughter cattle during standard meat inspection at Algiers and Blida abattoir. Molecular typing results suggested a link between Algerian and European strains of M. bovis. PMID:19173726

  19. Enterobacter Strains Might Promote Colon Cancer.

    Science.gov (United States)

    Yurdakul, Dilşad; Yazgan-Karataş, Ayten; Şahin, Fikrettin

    2015-09-01

    Many studies have been performed to determine the interaction between bacterial species and cancer. However, there has been no attempts to demonstrate a possible relationship between Enterobacter spp. and colon cancer so far. Therefore, in the present study, it is aimed to investigate the effects of Enterobacter strains on colon cancer. Bacterial proteins were isolated from 11 Enterobacter spp., one Morganella morganii, and one Escherichia coli strains, and applied onto NCM460 (Incell) and CRL1790 (ATCC) cell lines. Cell viability and proliferation were determined in MTS assay. Flow Cytometry was used to detect CD24 level and apoptosis. Real-Time PCR studies were performed to determine NFKB and Bcl2 expression. Graphpad Software was used for statistical analysis. The results showed that proteins, isolated from the Enterobacter spp., have significantly increased cell viability and proliferation, while decreasing the apoptosis of the cell lines tested. The data in the present study indicated that Enterobacter strains might promote colon cancer. Moreover, Enterobacter spp. could be a clinically important factor for colon cancer initiation and progression. Studies can be extended on animal models in order to develop new strategies for treatment.

  20. Shape recovery and irrecoverable strain control in polyurethane shape-memory polymer

    Directory of Open Access Journals (Sweden)

    Hisaaki Tobushi et al

    2008-01-01

    Full Text Available In shape-memory polymers, large strain can be fixed at a low temperature and thereafter recovered at a high temperature. If the shape-memory polymer is held at a high temperature for a long time, the irrecoverable strain can attain a new intermediate shape between the shape under the maximum stress and the primary shape. Irrecoverable strain control can be applied to the fabrication of a shape-memory polymer element with a complex shape in a simple method. In the present study, the influence of the strain-holding conditions on the shape recovery and the irrecoverable strain control in polyurethane shape-memory polymer is investigated by tension test of a film and three-point bending test of a sheet. The higher the shape-holding temperature and the longer the shape-holding time, the higher the irrecoverable strain rate. The equation that expresses the characteristics of the irrecoverable strain control is formulated.

  1. Stretchable and Flexible High-Strain Sensors Made Using Carbon Nanotubes and Graphite Films on Natural Rubber

    Directory of Open Access Journals (Sweden)

    Sreenivasulu Tadakaluru

    2014-01-01

    Full Text Available Conventional metallic strain sensors are flexible, but they can sustain maximum strains of only ~5%, so there is a need for sensors that can bear high strains for multifunctional applications. In this study, we report stretchable and flexible high-strain sensors that consist of entangled and randomly distributed multiwall carbon nanotubes or graphite flakes on a natural rubber substrate. Carbon nanotubes/graphite flakes were sandwiched in natural rubber to produce these high-strain sensors. Using field emission scanning electron microscopy, the morphology of the films for both the carbon nanotube and graphite sensors were assessed under different strain conditions (0% and 400% strain. As the strain was increased, the films fractured, resulting in an increase in the electrical resistance of the sensor; this change was reversible. Strains of up to 246% (graphite sensor and 620% (carbon nanotube sensor were measured; these values are respectively ~50 and ~120 times greater than those of conventional metallic strain sensors.

  2. Stretchable and flexible high-strain sensors made using carbon nanotubes and graphite films on natural rubber.

    Science.gov (United States)

    Tadakaluru, Sreenivasulu; Thongsuwan, Wiradej; Singjai, Pisith

    2014-01-06

    Conventional metallic strain sensors are flexible, but they can sustain maximum strains of only ~5%, so there is a need for sensors that can bear high strains for multifunctional applications. In this study, we report stretchable and flexible high-strain sensors that consist of entangled and randomly distributed multiwall carbon nanotubes or graphite flakes on a natural rubber substrate. Carbon nanotubes/graphite flakes were sandwiched in natural rubber to produce these high-strain sensors. Using field emission scanning electron microscopy, the morphology of the films for both the carbon nanotube and graphite sensors were assessed under different strain conditions (0% and 400% strain). As the strain was increased, the films fractured, resulting in an increase in the electrical resistance of the sensor; this change was reversible. Strains of up to 246% (graphite sensor) and 620% (carbon nanotube sensor) were measured; these values are respectively ~50 and ~120 times greater than those of conventional metallic strain sensors.

  3. Visual Measurement of Suture Strain for Robotic Surgery

    Directory of Open Access Journals (Sweden)

    John Martell

    2011-01-01

    Full Text Available Minimally invasive surgical procedures offer advantages of smaller incisions, decreased hospital length of stay, and rapid postoperative recovery to the patient. Surgical robots improve access and visualization intraoperatively and have expanded the indications for minimally invasive procedures. A limitation of the DaVinci surgical robot is a lack of sensory feedback to the operative surgeon. Experienced robotic surgeons use visual interpretation of tissue and suture deformation as a surrogate for tactile feedback. A difficulty encountered during robotic surgery is maintaining adequate suture tension while tying knots or following a running anastomotic suture. Displaying suture strain in real time has potential to decrease the learning curve and improve the performance and safety of robotic surgical procedures. Conventional strain measurement methods involve installation of complex sensors on the robotic instruments. This paper presents a noninvasive video processing-based method to determine strain in surgical sutures. The method accurately calculates strain in suture by processing video from the existing surgical camera, making implementation uncomplicated. The video analysis method was developed and validated using video of suture strain standards on a servohydraulic testing system. The video-based suture strain algorithm is shown capable of measuring suture strains of 0.2% with subpixel resolution and proven reliability under various conditions.

  4. Effective Hamiltonian of strained graphene.

    Science.gov (United States)

    Linnik, T L

    2012-05-23

    Based on the symmetry properties of the graphene lattice, we derive the effective Hamiltonian of graphene under spatially nonuniform acoustic and optical strains. Comparison with the published results of the first-principles calculations allows us to determine the values of some Hamiltonian parameters, and suggests the validity of the derived Hamiltonian for acoustical strain up to 10%. The results are generalized for the case of graphene with broken plane reflection symmetry, which corresponds, for example, to the case of graphene placed on a substrate. Here, essential modifications to the Hamiltonian give rise, in particular, to the gap opening in the spectrum in the presence of the out-of-plane component of optical strain, which is shown to be due to the lifting of the sublattice symmetry. The developed effective Hamiltonian can be used as a convenient tool for analysis of a variety of strain-related effects, including electron-phonon interaction or pseudo-magnetic fields induced by the nonuniform strain.

  5. Finite Element Modeling of the Behavior of Armor Materials Under High Strain Rates and Large Strains

    Science.gov (United States)

    Polyzois, Ioannis

    For years high strength steels and alloys have been widely used by the military for making armor plates. Advances in technology have led to the development of materials with improved resistance to penetration and deformation. Until recently, the behavior of these materials under high strain rates and large strains has been primarily based on laboratory testing using the Split Hopkinson Pressure Bar apparatus. With the advent of sophisticated computer programs, computer modeling and finite element simulations are being developed to predict the deformation behavior of these metals for a variety of conditions similar to those experienced during combat. In the present investigation, a modified direct impact Split Hopkinson Pressure Bar apparatus was modeled using the finite element software ABAQUS 6.8 for the purpose of simulating high strain rate compression of specimens of three armor materials: maraging steel 300, high hardness armor (HHA), and aluminum alloy 5083. These armor materials, provided by the Canadian Department of National Defence, were tested at the University of Manitoba by others. In this study, the empirical Johnson-Cook visco-plastic and damage models were used to simulate the deformation behavior obtained experimentally. A series of stress-time plots at various projectile impact momenta were produced and verified by comparison with experimental data. The impact momentum parameter was chosen rather than projectile velocity to normalize the initial conditions for each simulation. Phenomena such as the formation of adiabatic shear bands caused by deformation at high strains and strain rates were investigated through simulations. It was found that the Johnson-Cook model can accurately simulate the behavior of body-centered cubic (BCC) metals such as steels. The maximum shear stress was calculated for each simulation at various impact momenta. The finite element model showed that shear failure first occurred in the center of the cylindrical specimen and

  6. Screening Three Strains of Pseudomonas aeruginosa: Prediction of Biosurfactant-Producer Strain

    Directory of Open Access Journals (Sweden)

    Gholamreza Dehghan-Noudeh

    2009-01-01

    Full Text Available Problem statement: The chemical surfactants have some disadvantages; especially, toxicity and no biodegradability. Approach: Biosurfactants were the structurally diverse group of surface-active molecules synthesize by micro-organisms. The microbial surfactants were interesting, because of the biodegradable and have many applications in industry, agriculture, medicine. Results: In the present study, the production of biosurfactant by three strains of Pseudomonas aeruginosa (PTCC 1074, 1310 and 1430 was investigated. The hemolytic and foam forming activity of different strains were studied and consequently, P. aeruginosa PTCC 1074 was selected as the suitable strain. P. aeruginosa PTCC 1074 was grown in the nutrient broth medium and biosurfactant production was evaluated every 24 h by emulsification index and surface tension for the best of production time. After that, in order to get maximum production of biosurfactant, the selected strain was grown with different additives in nutrient broth and the best culture medium was found. The biosurfactant was isolated from the supernatant and its amphipathic structure was confirmed by chemical methods. Conclusion: Biosurfactant produced by Pseudomonas aeruginosa PTCC 1074 would be considered as a suitable surfactant in industries due to its low toxicity.

  7. Prior Inoculation with Type B Strains of Francisella tularensis Provides Partial Protection against Virulent Type A Strains in Cottontail Rabbits.

    Directory of Open Access Journals (Sweden)

    Vienna R Brown

    Full Text Available Francisella tularensis is a highly virulent bacterium that is capable of causing severe disease (tularemia in a wide range of species. This organism is characterized into two distinct subspecies: tularensis (type A and holarctica (type B which vary in several crucial ways, with some type A strains having been found to be considerably more virulent in humans and laboratory animals. Cottontail rabbits have been widely implicated as a reservoir species for this subspecies; however, experimental inoculation in our laboratory revealed type A organisms to be highly virulent, resulting in 100% mortality following challenge with 50-100 organisms. Inoculation of cottontail rabbits with the same number of organisms from type B strains of bacteria was found to be rarely lethal and to result in a robust humoral immune response. The objective of this study was to characterize the protection afforded by a prior challenge with type B strains against a later inoculation with a type A strain in North American cottontail rabbits (Sylvilagus spp. Previous infection with a type B strain of organism was found to lengthen survival time and in some cases prevent death following inoculation with a type A2 strain of F. tularensis. In contrast, inoculation of a type A1b strain was uniformly lethal in cottontail rabbits irrespective of a prior type B inoculation. These findings provide important insight about the role cottontail rabbits may play in environmental maintenance and transmission of this organism.

  8. Strain Growth in Containment Vessels

    Institute of Scientific and Technical Information of China (English)

    DONG Q; LI Q M; ZHENG J Y

    2006-01-01

    Strain growth is a phenomenon observed in containment vessels subjected to internal blast loading.The elastic response of the vessel may become larger in a later stage compared to its response during the initial stage.The dynamic responses of infinitely long cylindrical containment vessels subjected to uniformly-distributed internal blast loading are studied using LS-DYNA.The development of bending modes and the interaction between the breathing mode and bending modes are observed.The methodology developed for dynamic elastic buckling analysis is employed to study the strain growth phenomenon in explosion containment vessels.It is shown that the dynamic instable vibration of a containment vessel is the basic mechanism of strain growth.

  9. Improvement of Bacillus strains by mutation for overproduction of exopolygalacturonases.

    Science.gov (United States)

    Muzzamal, Hira; Latif, Zakia

    2016-08-01

    Pectinases, produced by microorganisms, have wide range application in food industry, textile processing, paper making, coffee and tea fermentation, etc. It accounts for 10% of the global industrial enzymes produced. The most important and widely used commercial pectinase polygalacturonase is produced by alkalophilic strains of Bacillus sp. and Streptomyces sp. Here, we explored 29 bacterial strains isolated from rotten mango samples for polygalacturonase production and selected 16 strains through preliminary screening by well-plate method for enzyme activity. The maximum zone of inhibition of pectin was observed up to 28 mm in diameter but one strain ZM11 was exhibiting no activity. Quantitative dinitrisalicylic acid (DNS) assay for polygalacturonase enzyme was also performed for the selected bacterial isolates. All the strains bestowed significant enzyme activity with the highest activity of 2.4 U/µL exhibited by strain ZM3 (P ≤0.05). Characterization of the isolates was performed using different biochemical tests which also confirmed the isolates as members of the genus Bacillus. Mutation was induced to the selected strains by UV light and acridine orange for different periods of time. Qualitative and quantitative assays of the mutant bacterial isolates showed that the enzyme activity increased to 4.62 U/µL which clearly indicated that induced mutation enhanced the ability of Bacillus strains to produce more polygalacturonase enzyme up to 3-fold as compared to the wild strains (P ≤0.05). Molecular characterization by 16S rRNA sequences further confirmed that the bacterial isolates belong to Bacillus subtilis and B. amyloliquefaciens.

  10. Identification of Potato Virus Y Strains in Tobacco Crops

    Directory of Open Access Journals (Sweden)

    Jelena Zindović

    2007-01-01

    Full Text Available Five viruses: Potato Virus Y (PVY, Tomato Spotted Wilt Virus, Cucumber Mosaic Virus, Tobacco Mosaic Virus and Alfalfa Mosaic Virus, of which PVY was predominant, were detected by serological testing of tobacco samples collected from many localities in Vojvodina in 2006. Viruses are the most important pathogens in tobacco and PVY causes considerable economic damages all over the world. A PVY population comprises several different strain groups, strain subgroups and recombinant strains. Among these, PVYN (necrotic strain and PVYO (ordinary strain cause the greatest yield and quality losses in tobacco. Identification of a prevalent strain in a PVY population is the basis of proper tobacco genotype selection for resistance against this significant virus. Typical symptoms caused by PVY were observed by monitoring tobacco crops in our country in 2006. The symptoms occurred as changes in the general plant appearance, as well as necrotic areas on leaves, petiols, stems and flowers. The initial symptoms of veinal necrosis were expanded throughout the leaf, causing reddish-brown (copper plant color and premature death of lower leaves. Plants with these symptoms occurred in all monitoredlocalities and their frequency was high.In order to understand various epidemiological aspects of the diseases caused by PVY and to prevent its occurrence and spreading in tobacco crops, it is necessary to properly identify this virus in time. Biological, serological and molecular identification of the virus and its prevalent strain was carried out in order to determine tobacco disease ethiology. The results obtained suggest that this prevalent strain of PVY has been spreading progressively in our country in recent years. Although PVYN is widely spread in tobacco crops in Europe, its destructiveness, disease intensity and wide distribution in Serbia were established only in the last two years.PVY necrotic strain was detected mainly in single infections, although it was also

  11. Anaplasma marginale superinfection attributable to pathogen strains with distinct genomic backgrounds.

    Science.gov (United States)

    Microbial strain structure is dynamic over space and time; shifts in pathogen strain structure result in changing patterns of disease. The scale of change in space and time differs markedly among pathogens depending on multiple factors including pathogen-specific mechanisms of genetic change and the...

  12. Longitudinal Strain and Strain Rate Abnormalities Precede Invasive Diagnosis of Transplant Coronary Artery Vasculopathy in Pediatric Cardiac Transplant Patients.

    Science.gov (United States)

    Zoeller, Bridget B; Miyamoto, Shelley D; Younoszai, Adel K; Landeck, Bruce F

    2016-04-01

    Transplant coronary artery vasculopathy (TCAV) is the primary cause of late graft loss in pediatric heart transplant recipients. TCAV is diagnosed using angiography or intravascular ultrasound; however, noninvasive methods remain elusive. We sought to define patterns of myocardial mechanics in patients with TCAV and to determine whether this can detect TCAV before invasive methods. In this retrospective study, we queried our heart transplant database to identify all recipients with TCAV since 2006 (n = 41). Echoes were reviewed from the last normal catheterization and at TCAV diagnosis, and from time-matched transplant controls (n = 33) without TCAV. Peak global circumferential and longitudinal strain and systolic and diastolic strain rate (SSR and DSR) of the left ventricle were derived using velocity vector imaging. T tests were used to compare both groups longitudinally and between groups at both time points. Longitudinal strain, SSR, and DSR were diminished in the TCAV group compared to the transplant control group at both time points. No differences were found across time points in either group. Retrospective modeling using a longitudinal strain cutoff of 15 % on echoes 2 years prior to TCAV diagnosis predicted development or exclusion of TCAV with sensitivity of 53 %, specificity of 89 % with an area under the curve of 0.8. Decreases in longitudinal strain measurements demonstrate that alterations in myocardial mechanics occur in patients with TCAV at least 2 years prior to invasive diagnosis. These early changes may be due to microvascular disease. This modality could aid in earlier treatment and intervention for this challenging problem .

  13. Left ventricular strain and its pattern estimated from cine CMR and validation with DENSE.

    Science.gov (United States)

    Gao, Hao; Allan, Andrew; McComb, Christie; Luo, Xiaoyu; Berry, Colin

    2014-07-07

    Measurement of local strain provides insight into the biomechanical significance of viable myocardium. We attempted to estimate myocardial strain from cine cardiovascular magnetic resonance (CMR) images by using a b-spline deformable image registration method. Three healthy volunteers and 41 patients with either recent or chronic myocardial infarction (MI) were studied at 1.5 Tesla with both cine and DENSE CMR. Regional circumferential and radial left ventricular strains were estimated from cine and DENSE acquisitions. In all healthy volunteers, there was no difference for peak circumferential strain (- 0.18 ± 0.04 versus - 0.18 ± 0.03, p = 0.76) between cine and DENSE CMR, however peak radial strain was overestimated from cine (0.84 ± 0.37 versus 0.49 ± 0.2, p cine were similar to the patterns from DENSE, including the strain evolution related to recovery time and strain patterns related to MI scar extent. Furthermore, cine-derived strain disclosed different strain patterns in MI and non-MI regions, and regions with transmural and non-transmural MI as DENSE. Although there were large variations with radial strain measurements from cine CMR images, useful circumferential strain information can be obtained from routine clinical CMR imaging. Cine strain analysis has potential to improve the diagnostic yield from routine CMR imaging in clinical practice.

  14. Construction of an environmental safe Bacillus thuringiensis engineered strain against Coleoptera.

    Science.gov (United States)

    Yu, Yajun; Yuan, Yihui; Gao, Meiying

    2016-05-01

    Cloning of new toxic genes from Bacillus thuringiensis (Bt) and construction of Bt engineered strains are two key strategies for bio-control of coleopteran pests in agriculture and forestry. In this study, we cloned a new cry3Aa-type gene, cry3Aa8, from wild Bt strain YC-03 against coleopteran, and constructed a Bt engineered strain, ACE-38, containing insecticidal protein-encoding gene cry3Aa8. The engineered strain, with almost four times of Cry3Aa yield compared with strain YC-03, was an antibiotic marker-free strain. Though no selective pressure was presented in the medium, cry3Aa8 in the engineered strain ACE-38 remained stable. The yield of Cry3Aa by strain ACE-38 reached 2.09 mg/ml in the optimized fermentation medium. The activity of strain ACE-38 against Plagiodera versicolora was tested, and the LC50 of ACE-38 cultures in the optimized fermentation medium was 1.13 μl/ml. Strain ACE-38 is a non-antibiotic Bt engineered strain with high Chrysomelidae toxicity and exhibits good fermentation property. The modified indigenous site-specific recombination system constructed in this study might be useful for the construction of Bt engineered strains containing genes that cannot be expressed in the indigenous site-specific recombination system using plasmid pBMB1205R.

  15. Strain-dependent electronic and magnetic of Co-doped monolayer of WSe2

    Science.gov (United States)

    Wu, Ninghua; Zhao, Xu; Wang, Tianxing

    2016-10-01

    We perform first-principles calculation to investigate electronic and magnetic properties of Co-doped WSe2 monolayer with strains from -10% to 10%. We find that Co can induce magnetic moment about 0.894 μB, the Co-doped WSe2 monolayer is a magnetic semiconductor material without strain. The doped system shows half-metallic properties under tensile strain, and the largest half-metal gap is 0.147 eV at 8% strain. The magnetic moment (0.894 μB) increases slightly from 0% to 6%, and jumps into about 3 μB at 8% and 10%, which presents high-spin state configurations. When we applied compressive strain, the doped system shows a half-metallic feature at -2% strain, and the magnetic moment jumps into 1.623 μB at -4% strain, almost two times as the original moment 0.894 μB at 0% strain. The magnetic moment vanishes at -7% strain. The Co-doped WSe2 can endure strain from -6% to 10%. Strain changes the redistribution of charges and magnetic moment. Our calculation results show that the Co-doped WSe2 monolayer can transform from magnetic semiconductor to half-metallic material under strain.

  16. Left ventricular strain and its pattern estimated from cine CMR and validation with DENSE

    Science.gov (United States)

    Gao, Hao; Allan, Andrew; McComb, Christie; Luo, Xiaoyu; Berry, Colin

    2014-07-01

    Measurement of local strain provides insight into the biomechanical significance of viable myocardium. We attempted to estimate myocardial strain from cine cardiovascular magnetic resonance (CMR) images by using a b-spline deformable image registration method. Three healthy volunteers and 41 patients with either recent or chronic myocardial infarction (MI) were studied at 1.5 Tesla with both cine and DENSE CMR. Regional circumferential and radial left ventricular strains were estimated from cine and DENSE acquisitions. In all healthy volunteers, there was no difference for peak circumferential strain (- 0.18 ± 0.04 versus - 0.18 ± 0.03, p = 0.76) between cine and DENSE CMR, however peak radial strain was overestimated from cine (0.84 ± 0.37 versus 0.49 ± 0.2, p cine were similar to the patterns from DENSE, including the strain evolution related to recovery time and strain patterns related to MI scar extent. Furthermore, cine-derived strain disclosed different strain patterns in MI and non-MI regions, and regions with transmural and non-transmural MI as DENSE. Although there were large variations with radial strain measurements from cine CMR images, useful circumferential strain information can be obtained from routine clinical CMR imaging. Cine strain analysis has potential to improve the diagnostic yield from routine CMR imaging in clinical practice.

  17. Assessment of segmental myocardial viability using regional 2-dimensional strain echocardiography.

    Science.gov (United States)

    Migrino, Raymond Q; Zhu, Xiaoguang; Pajewski, Nicholas; Brahmbhatt, Tejas; Hoffmann, Raymond; Zhao, Ming

    2007-04-01

    We determined whether 2-dimensional strain echocardiography can identify viable from infarcted myocardium in a rat ischemia-reperfusion model. A total of 16 male Sprague-Dawley rats underwent left anterior descending coronary artery occlusion for 12 or 30 minutes followed by 60-minute reperfusion. Short-axis 2-dimensional strain echocardiography was performed at the mid-ventricle 60 minutes post-reperfusion. Post-sacrifice, triphenyl tetrazolium chloride was infused to the coronary circulation. Regional end-systolic radial and circumferential strain, and time to peak strain, were measured using software in all 96 segments and correlated with areas of infarct in corresponding histologic slices. Segments with greater than 50% area of infarct had lower end-systolic radial and circumferential strain and longer time to peak strain versus areas with 50% or less strain or no infarct. Extent of infarct correlates with radial and circumferential strain. End-systolic radial strain less than 2% has 88% sensitivity and 95% specificity for detecting infarcted area greater than 50%. Two-dimensional strain echocardiography-derived strain is useful in distinguishing infarcted from viable myocardium.

  18. Photoacoustic spectroscopy of Entamoeba histolytica strains

    Science.gov (United States)

    Acosta-Avalos, D.; Alvarado-Gil, J. J.; Silva, E. F.; Orozco, E.; de Menezes, L. F.; Vargas, H.

    2005-06-01

    Pathogenic and non-pathogenic strains of E. histolytica are studied using photoacoustic spectroscopy. It is shown that the pathogenic strain presents a spectrum similar to that of iron sulfur proteins. The non-pathogenic strain does not show any relevant absorption at the studied wavelength range. The differences observed between the optical absorption spectra of both strains opens the possibility of using photoacoustic spectroscopy as a reliable and simple technique to identify different types of E. histolytica strains.

  19. Recrystallization of High Carbon Steel during High Strain Rate

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The recrystallization of high carbon steel during high temperature and high speed rolling has been studied by analyzing the stress-strain curves and the austenite grain size.Isothermal multi-pass hot compression at high strain rate was carried out by Gleeble-2000. The austenite grain size was measured by IBAS image analysis system. The results show that static recrystallization occurred at interpass time under pre-finish rolling, and at the finish rolling stage, due to the brief interpass time, static recrystallization can not be found.

  20. [Selected properties of Bacteroides fragilis enterotoxigenic strains].

    Science.gov (United States)

    Rokosz, A; Meisel-Mikołajczyk, F

    1995-01-01

    Seven B. fragilis strains were examined. One strain was reference, non-enterotoxigenic, representing serotype E2 according to Beerens et al. (1971). Six strains produced enterotoxin (ETBF). Four of them were isolated from human feces and two of them from swine feces. All strains were investigated morphologically, biochemically (ATB Expression, France) and by means of direct immunofluorescence (Bacteroides--IF test, Poland). Their resistance to chemotherapeutics was tested (ATB Expression, France). The MIC values of clindamycin and metronidazole were determined using E test strips (AB Biodisk, Sweden). Each strain formed capsules. The percentage of encapsulated cells was high (80-100%). Some strains produced thick capsules. Biochemical patterns were similar and typical for B. fragilis rods. One enterotoxigenic strain produced gelatinase and three ETBF strains fermented trehalose. All strains reacted in direct immunofluorescence exclusively with conjugate against serotype E of BFG. Thus, each strain showed antigenic pattern E. Drug susceptibility of all strains was similar. One enterotoxigenic strain was resistant to clindamycin. All strains were susceptible to metronidazole. These studies indicate that on the basis of morphological, biochemical and serological features (IF), enterotoxigenic B. fragilis strains cannot be distinguished from the nonenterotoxigenic one. Also, the correlation between toxigenicity and drug sensitivity of the examined strains is not observed.

  1. Extreme Temperature Strain Measurement System

    Science.gov (United States)

    1990-08-01

    Road, Lantham, New York 12110, Phone (518) 785-2323, noncontacting, " Fotonic " fiber bundle sensor * Dual Core Fiber Optic Strain Gage with Laser input...Lantham, New York 12110, Phone (518) 456-4131, Reflective Light, Fiber bundles, " Fotonic Sensors", to 600°F "• Moire’ Technique, optical interference

  2. Bacteriocins and novel bacterial strains.

    Science.gov (United States)

    Poultry is thought to be a significant source of Campylobacter in human disease. We evaluated anti-Campylobacter activity among 365 Bacillus and Paenibacillus isolates from poultry. One novel antagonistic Bacillus circulans and three Paenibacillus polymyxa strains were identified and further studi...

  3. Job strain and alcohol intake

    DEFF Research Database (Denmark)

    Heikkilä, Katriina; Nyberg, Solja T; Fransson, Eleonor I

    2012-01-01

    The relationship between work-related stress and alcohol intake is uncertain. In order to add to the thus far inconsistent evidence from relatively small studies, we conducted individual-participant meta-analyses of the association between work-related stress (operationalised as self-reported job...... strain) and alcohol intake....

  4. Computational strain gradient crystal plasticity

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Kysar, Jeffrey W.

    2014-01-01

    of plane crystal plasticity are studied: pure shear of a single crystal between rigid platens as well as plastic deformation around cylindrical voids in hexagonal close packed and face centered cubic crystals. Effective in-plane constitutive slip parameters for plane strain deformation of specifically...

  5. Job strain and tobacco smoking

    DEFF Research Database (Denmark)

    Heikkilä, Katriina; Nyberg, Solja T; Fransson, Eleonor I

    2012-01-01

    Tobacco smoking is a major contributor to the public health burden and healthcare costs worldwide, but the determinants of smoking behaviours are poorly understood. We conducted a large individual-participant meta-analysis to examine the extent to which work-related stress, operationalised as job...... strain, is associated with tobacco smoking in working adults....

  6. A Novel Creep-Fatigue Life Prediction Model for P92 Steel on the Basis of Cyclic Strain Energy Density

    Science.gov (United States)

    Ji, Dongmei; Ren, Jianxing; Zhang, Lai-Chang

    2016-09-01

    A novel creep-fatigue life prediction model was deduced based on an expression of the strain energy density in this study. In order to obtain the expression of the strain energy density, the load-controlled creep-fatigue (CF) tests of P92 steel at 873 K were carried out. Cyclic strain of P92 steel under CF load was divided into elastic strain, applying and unloading plastic strain, creep strain, and anelastic strain. Analysis of cyclic strain indicates that the damage process of P92 steel under CF load consists of three stages, similar to pure creep. According to the characteristics of the strains above, an expression was defined to describe the strain energy density for each cycle. The strain energy density at stable stage is inversely proportional to the total strain energy density dissipated by P92 steel. However, the total strain energy densities under different test conditions are proportional to the fatigue life. Therefore, the expression of the strain energy density at stable stage was chosen to predict the fatigue life. The CF experimental data on P92 steel were employed to verify the rationality of the novel model. The model obtained from the load-controlled CF test of P92 steel with short holding time could predict the fatigue life of P92 steel with long holding time.

  7. A Novel Creep-Fatigue Life Prediction Model for P92 Steel on the Basis of Cyclic Strain Energy Density

    Science.gov (United States)

    Ji, Dongmei; Ren, Jianxing; Zhang, Lai-Chang

    2016-11-01

    A novel creep-fatigue life prediction model was deduced based on an expression of the strain energy density in this study. In order to obtain the expression of the strain energy density, the load-controlled creep-fatigue (CF) tests of P92 steel at 873 K were carried out. Cyclic strain of P92 steel under CF load was divided into elastic strain, applying and unloading plastic strain, creep strain, and anelastic strain. Analysis of cyclic strain indicates that the damage process of P92 steel under CF load consists of three stages, similar to pure creep. According to the characteristics of the strains above, an expression was defined to describe the strain energy density for each cycle. The strain energy density at stable stage is inversely proportional to the total strain energy density dissipated by P92 steel. However, the total strain energy densities under different test conditions are proportional to the fatigue life. Therefore, the expression of the strain energy density at stable stage was chosen to predict the fatigue life. The CF experimental data on P92 steel were employed to verify the rationality of the novel model. The model obtained from the load-controlled CF test of P92 steel with short holding time could predict the fatigue life of P92 steel with long holding time.

  8. Major flood related strains and pregnancy outcomes.

    Science.gov (United States)

    Hilmert, Clayton J; Kvasnicka-Gates, Lexi; Teoh, Ai Ni; Bresin, Konrad; Fiebiger, Siri

    2016-11-01

    To assess the impact of experiencing a major flood during pregnancy on fetal growth and length of gestation, and to consider how flood-related strains might contribute to these effects. The Red River Pregnancy Project was a prospective study carried out for 3 months immediately after the historic 2009 crest of the Red River in Fargo, North Dakota. Pregnant community residents who were at least 18 years old with a singleton, intrauterine pregnancy participated in the study (N = 169). Analyses examined if birth weight and length of gestation were associated with residential distance from flooding and gestational age at time of the flood crest. For pregnancies earlier in gestation during the crest (-1 SD = 12 weeks), birth weight decreased as distance from flooding decreased (-42.29 g/mi, p .10). Biparietal growth trajectories showed a decrease in growth after the crest of the flood but only for women early in pregnancy. However, various measures of flood related and general stress or strain did not explain these effects. Length of gestation was not associated with distance from or the timing of the flood. Pregnant women in the first trimester who experience a major flood near their homes are at risk of having lower birth weight neonates due to a reduction in fetal growth. The mechanisms of this effect deserve further attention in rapidly mounted investigations after disaster. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  9. Date of origin of the SARS coronavirus strains

    Directory of Open Access Journals (Sweden)

    Cai Lun

    2004-02-01

    Full Text Available Abstract Background A new respiratory infectious epidemic, severe acute respiratory syndrome (SARS, broke out and spread throughout the world. By now the putative pathogen of SARS has been identified as a new coronavirus, a single positive-strand RNA virus. RNA viruses commonly have a high rate of genetic mutation. It is therefore important to know the mutation rate of the SARS coronavirus as it spreads through the population. Moreover, finding a date for the last common ancestor of SARS coronavirus strains would be useful for understanding the circumstances surrounding the emergence of the SARS pandemic and the rate at which SARS coronavirus diverge. Methods We propose a mathematical model to estimate the evolution rate of the SARS coronavirus genome and the time of the last common ancestor of the sequenced SARS strains. Under some common assumptions and justifiable simplifications, a few simple equations incorporating the evolution rate (K and time of the last common ancestor of the strains (T0 can be deduced. We then implemented the least square method to estimate K and T0 from the dataset of sequences and corresponding times. Monte Carlo stimulation was employed to discuss the results. Results Based on 6 strains with accurate dates of host death, we estimated the time of the last common ancestor to be about August or September 2002, and the evolution rate to be about 0.16 base/day, that is, the SARS coronavirus would on average change a base every seven days. We validated our method by dividing the strains into two groups, which coincided with the results from comparative genomics. Conclusion The applied method is simple to implement and avoid the difficulty and subjectivity of choosing the root of phylogenetic tree. Based on 6 strains with accurate date of host death, we estimated a time of the last common ancestor, which is coincident with epidemic investigations, and an evolution rate in the same range as that reported for the HIV-1 virus.

  10. Processing plant persistent strains of Listeria monocytogenes appear to have a lower virulence potential than clinical strains in selected virulence models

    DEFF Research Database (Denmark)

    Jensen, Anne; Thomsen, L.E.; Jørgensen, R.L.

    2008-01-01

    cell line, Caco-2; time to death in a nematode model, Caenorhabditis elegans and in a fruit fly model, Drosophila melanogaster and fecal shedding in a guinea pig model. All strains adhered to and grew in Caco-2 cells in similar levels. When exposed to 10(6) CFU/ml, two strains representing...

  11. High-resolution melt PCR analysis for rapid identification of Chlamydia abortus live vaccine strain 1B among C. abortus strains and field isolates.

    Science.gov (United States)

    Vorimore, Fabien; Cavanna, Noémie; Vicari, Nadia; Magnino, Simone; Willems, Hermann; Rodolakis, Annie; Siarkou, Victoria I; Laroucau, Karine

    2012-09-01

    We describe a novel high-resolution melt assay that clearly differentiates Chlamydia abortus live vaccine strain 1B from field C. abortus strains and field wild-type isolates based on previously described single nucleotide polymorphisms. This modern genotyping technique is inexpensive, easy to use, and less time-consuming than PCR-RFLP.

  12. Short communication: heat resistance of Escherichia coli strains in raw milk at different subpasteurization conditions.

    Science.gov (United States)

    Peng, S; Hummerjohann, J; Stephan, R; Hammer, P

    2013-06-01

    A commonly applied treatment of raw milk to reduce bacterial loads is the short-time application of heat at subpasteurization levels under continuous flow, generally referred to as thermization, because this method retains some of the beneficial properties of raw milk. In a previous study, Escherichia coli strains exhibiting increased thermotolerance were found, demanding investigations into their ability to survive thermization. Nine E. coli strains, including 4 Shiga toxin-producing E. coli (STEC) strains, were investigated for their reduction during a thermization treatment in raw milk using a pilot-plant pasteurizer to reflect typically applied commercial conditions. Six of the 9 E. coli strains, including the 4 STEC strains, were similarly inactivated at 60, 62.5, and 65°C, whereas increased thermotolerance was observed for 3 E. coli strains. All strains were reduced to thermization treatment.

  13. High Strain, Strain Rate Behavior of PTFE/Al/W

    Science.gov (United States)

    Addiss, John; Cai, Jing; Walley, Steve; Proud, William; Nesterenko, Vitali

    2007-06-01

    Conventional dropweight technique was modified to accommodate low amplitude signals from low strength, cold isostatically pressed energetic ``heavy'' composites of polytetrafluoroethylene (PTFE)/AL/W. The fracture strength, strain and post-critical behaviour of fractured samples were measured for samples of different porosity and W grain size (the masses of each component being the same in each case). Unusual phenomenon of significantly higher strength (55 MPa) of porous composites (density 5.9 g/cc) with small tungsten particles (1 micron) in comparison with strength (32 MPa) of dense composites (7.1 g/cc) with larger tungsten particles (20 micron) was observed. This is attributed to force chains created by a network of small tungsten particles. Interrupted tests at the different level of strains revealed mechanism of fracture under dynamic compression.

  14. A NEW STRAIN OF TRANSMISSIBLE LEUCEMIA IN FOWLS (STRAIN H).

    Science.gov (United States)

    Ellermann, V

    1921-03-31

    1. A new strain of fowl leucosis has been transmitted through twelve generations of fowls. 2. An increase in virulence was observed during its passage. This was shown in a shortening of the interval between inoculation and death. The increase in virulence does not affect the number of successful inoculations, which remains approximately constant in from 20 to 40 per cent of the birds employed. 3. As with former strains, the disease manifests itself in various forms; i.e., myeloid and intravascular lymphoid types. A single lymphatic case was observed. 4. In several intravascular cases a diminution in the hemolytic power of the serum was established. This phenomenon was absent in a number of myeloid cases. 5. Active immunization cannot be produced by means of the subcutaneous injection of virulent material. 6. The finding of previous experiments that the virus is filterable has been confirmed. 7. The inoculation of human leucemic material into fowls gave negative results.

  15. Physiologic and genetic characterization of Bacillus sphaericus native strains

    Directory of Open Access Journals (Sweden)

    Jenny Dussen Garzón

    2012-06-01

    Full Text Available Eighteen pathogenic native strains of Bacillus sphaericus that were pathogens to mosquito larvae were isolated from different Colombia regions. The objective of this study was to evaluate at physiological and molecular level pathogenic strains and to compare them with the reference 2362 one. Cellular growth, sporulation percentage, pathogenic activity against third instar larvae of Culex quinquejasciaius, the presence of toxigenic proteins, the size of native plasmids and the genetic polymorphism among pathogenic and non pathogenic isolations was evaluated. The evaluated strains of Bs presented a latency stage ranging from 2 to 3 h and one logarithmic phase of 7 h; the sporulation in BHI was lower than 1% to 40 h of incubation, in NYSM medium was obtained ten times more production of biomass and spores, 26% of the population showed sporulation percentage higher than 90%; the isolations were classified in three groups of pathogenicity with [Formula] and [Formula]. Punctual mutations on the genes which encoding for native toxins were detected and was found a exclusive protein of 30 kDa in pathogenic native strains. The isolations of Bs presented a plasmid of 118Kb that was not related to the toxicity; pathogenic strains are a homogenous group with a similarity between 90 to 100%, whereas non-pathogenic ones are genetically heterogeneous group and conform a cluster aside. The native strains have a great potential in biological control of mosquito larvae that transmitting diseases such as dengue, malaria, encephalitis and filariasis among others.

  16. Antibiotic Susceptibilities of Acinetobacter Baumanii Strains Isolated from Clinical Samples

    Directory of Open Access Journals (Sweden)

    Harun Aðca

    2013-01-01

    Full Text Available      Aim :  In this study it was aimed to investigate the antibiotic susceptibilities of Acinetobacter baumanii strains isolated from various clinical samples sent to Tavsanli State Hospital Microbiology Laboratory retrospectively. Material and Method: All of the cultures were examined for the agent and antibiotic susceptibilities. For the identification of bacteria, various chemical tests and BBL Crystal E/NF (Beckton Dickinson, ABD system was used. Antibiotic susceptibilities were investigated according to CLSI criteria on Mueller Hinton agar by disc diffusion method. Results: There were 74 strains isolated and identified as Acinetobacter baumanii. Most of the strains were isolated from  tracheal aspirate specimens (46 % Most of the strains were isolated from nosocomial infections. Antibiotic resistance was high among strains. The most susceptible antibiotic was gentamicin (30%. Discussion: To prevent the development of resistance, antibiotics should be used carefully in appropriate doses and time, empirical  antibiotherapy should be determined for each centre according to resistance rates of the centre and should be regulated according to the antibiogram results. Increasing resistance rates in Acinetobacter strains leads to the usage of new alternative antibiotics.  

  17. Fumonisin production by Gibberella fujikuroi strains from Pinus species.

    Science.gov (United States)

    Mirete, S; Patiño, B; Vázquez, C; Jiménez, M; Hinojo, M J; Soldevilla, C; González-Jaén, M T

    2003-12-31

    Fumonisins are important mycotoxins basically produced by strains from the Gibberella fujikuroi species complex (with anamorphs in Fusarium genus) which contaminate food and feed products representing a risk to human and animal health. In this work, we report for the first time the fumonisin production of Fusarium moniliforme Sheldon strains associated to edible pine nuts of Pinus pinea. P. pinea is an important and widely distributed Pinus species in the Mediterranean area where their pine nuts are consumed raw or slightly processed in diverse food products. In this work, characterization and further identification of those strains were performed by polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLPs) of the intergenic spacer region of the rDNA (IGS) with the aid of the eight mating populations (A-H) described for G. fujikuroi species complex. The method was powerful to detect polymorphism, allowing discrimination between individuals and could be used to study the genetic relationships among them and within the G. fujikuroi species complex. Fusarium strains associated to Pinus radiata were also included in the present study. These strains did not produce fumonisins and showed no close relation with the strains isolated from P. pinea. The approach used in this work was rapid and proved to be efficient to assist identification and to characterize and analyse relatedness of new isolates within the G. fujikuroi species complex.

  18. Strains

    Science.gov (United States)

    ... N, Rodeo SA, Alini M, Maher S, et al. Physiology and pathophysiology of musculoskeletal tissues. In: Miller MD, Thompson SR, eds. DeLee and Drez's Orthopaedic Sports Medicine . 4th ed. Philadelphia, PA: Elsevier Saunders; 2015: ...

  19. Two-strain competition in quasineutral stochastic disease dynamics

    Science.gov (United States)

    Kogan, Oleg; Khasin, Michael; Meerson, Baruch; Schneider, David; Myers, Christopher R.

    2014-10-01

    We develop a perturbation method for studying quasineutral competition in a broad class of stochastic competition models and apply it to the analysis of fixation of competing strains in two epidemic models. The first model is a two-strain generalization of the stochastic susceptible-infected-susceptible (SIS) model. Here we extend previous results due to Parsons and Quince [Theor. Popul. Biol. 72, 468 (2007), 10.1016/j.tpb.2007.04.002], Parsons et al. [Theor. Popul. Biol. 74, 302 (2008), 10.1016/j.tpb.2008.09.001], and Lin, Kim, and Doering [J. Stat. Phys. 148, 646 (2012), 10.1007/s10955-012-0479-9]. The second model, a two-strain generalization of the stochastic susceptible-infected-recovered (SIR) model with population turnover, has not been studied previously. In each of the two models, when the basic reproduction numbers of the two strains are identical, a system with an infinite population size approaches a point on the deterministic coexistence line (CL): a straight line of fixed points in the phase space of subpopulation sizes. Shot noise drives one of the strain populations to fixation, and the other to extinction, on a time scale proportional to the total population size. Our perturbation method explicitly tracks the dynamics of the probability distribution of the subpopulations in the vicinity of the CL. We argue that, whereas the slow strain has a competitive advantage for mathematically "typical" initial conditions, it is the fast strain that is more likely to win in the important situation when a few infectives of both strains are introduced into a susceptible population.

  20. Wireless Zigbee strain gage sensor system for structural health monitoring

    Science.gov (United States)

    Ide, Hiroshi; Abdi, Frank; Miraj, Rashid; Dang, Chau; Takahashi, Tatsuya; Sauer, Bruce

    2009-05-01

    A compact cell phone size radio frequency (ZigBee) wireless strain measurement sensor system to measure the structural strain deformation was developed. The developed system provides an accurate strain measurement data stream to the Internet for further Diagnostic and Prognostic (DPS) correlation. Existing methods of structural measurement by strain sensors (gauges) do not completely satisfy problems posed by continuous structural health monitoring. The need for efficient health monitoring methods with real-time requirements to bidirectional data flow from sensors and to a commanding device is becoming critical for keeping our daily life safety. The use of full-field strain measurement techniques could reduce costly experimental programs through better understanding of material behavior. Wireless sensor-network technology is a monitoring method that is estimated to grow rapidly providing potential for cost savings over traditional wired sensors. The many of currently available wireless monitoring methods have: the proactive and constant data rate character of the data streams rather than traditional reactive, event-driven data delivery; mostly static node placement on structures with limited number of nodes. Alpha STAR Electronics' wireless sensor network system, ASWN, addresses some of these deficiencies, making the system easier to operate. The ASWN strain measurement system utilizes off-the-shelf sensors, namely strain gauges, with an analog-to-digital converter/amplifier and ZigBee radio chips to keep cost lower. Strain data is captured by the sensor, converted to digital form and delivered to the ZigBee radio chip, which in turn broadcasts the information using wireless protocols to a Personal Data Assistant (PDA) or Laptop/Desktop computers. From here, data is forwarded to remote computers for higher-level analysis and feedback using traditional cellular and satellite communication or the Ethernet infrastructure. This system offers a compact size, lower cost

  1. Characteristics of Yersinia enterocolitica biotype 1A strains isolated from patients and asymptomatic carriers.

    Science.gov (United States)

    Stephan, R; Joutsen, S; Hofer, E; Säde, E; Björkroth, J; Ziegler, D; Fredriksson-Ahomaa, M

    2013-07-01

    Yersinia enterocolitica biotype 1A strains are frequently isolated from the environment, foods, and animals, and also from humans with yersiniosis. There are controversial reports on the pathogenicity of biotype 1A strains. In this study, 811 fecal samples from asymptomatic humans from Switzerland were studied for the presence of Y. enterocolitica. Nine (1.1%) of the 811 samples were positive for Y. enterocolitica 1A. These strains were compared with 12 Y. enterocolitica 1A strains from Swiss patients with diarrhea isolated in the same year. Almost all (20/21) Y. enterocolitica 1A strains carried the ystB gene, seven strains carried the hreP gene, and none carried the ail, ystA, myfA, yadA, or virF genes. Most (17/21) Y. enterocolitica 1A strains belonged to two major clusters, A and B, by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Strains of cluster B were only isolated from humans with diarrhea; however, ystB and hreP genes were detected in strains from both clinical and non-clinical samples and from strains of clusters A and B. Using ribotyping, six restriction patterns among biotype 1A strains were obtained with HindIII enzyme. The most common ribotype (RT I) was found in strains isolated from humans with and without diarrhea. All biotype 1A strains had a unique NotI profile by pulsed-field gel electrophoresis (PFGE), showing a very high genetic diversity. In this study, Y. enterocolitica 1A strains from clinical and non-clinical samples could not be clearly differentiated from each other. More research is needed in order to prove that biotype 1A strains are a primary cause for human yersiniosis and not only a secondary finding.

  2. 实时三维超声心动图斑点追踪技术评价正常人左心室心肌应变%Evaluation of left ventricular strain by real-time three-dimensional speckle tracking imaging in healthy adults

    Institute of Scientific and Technical Information of China (English)

    汤乔颖; 邓又斌; 黄润青; 杨好意; 王婷

    2012-01-01

    目的 评价三维超声斑点追踪技术测量正常人左室心肌应变的能力,并对心肌总应变矢量的大小和角度进行初步研究.方法 使用三维超声斑点追踪和二维超声斑点追踪技术对31例健康志愿者进行了心肌运动分析,测量左室的纵向、圆周向及径向应变,并通过纵向及圆周向应变计算心肌总应变矢量的大小及角度.结果 三维斑点追踪测得的纵向及圆周向应变在左室整体及各短轴水平均小于二维应变,而径向应变则相反.三维斑点追踪测得的心肌应变在左室不同水平间存在差异,左室中部水平的纵向、圆周向及径向应变均大于基底部及心尖部水平,而二维应变在不同水平间的差异未显示出明显规律.通过测量的纵向及圆周向应变计算得到心肌总应变矢量大小和角度,应用三维应变计算出的心肌总应变矢量绝对值在左室中部水平最大,而总应变矢量角度在不同水平间无明显差异.结论 三维斑点追踪可通过测量心肌应变对左室局部功能进行准确评价且重复性良好,具有潜在的临床应用价值.%Objective To investigate the ability of three-dimensional(3D) speckle tracking imaging (STI) for assessing left ventricular (LV) strain,and measure the value and angle of myocardial main strain vector.Methoods Longitudinal,circumferential and radial strain of LV were measured in 31 healthy adults by 3D-STI and two-dimensional(2D) STI.The main strain vector and the angle between main strain vector and the LV short-axis plane were calculated from longitudinal and circumferential strains.Results The global longitudinal,circumferential strains and strains at basal,middle,apical level of LV by 3D-STI were significantly smaller than those by 2D-STI,whereas radial strain showed an opposite trend.The 3D strains presented significant difference between different levels of LV,longitudinal,circumferential and radial 3D strains were greater at

  3. Engineering piezoresistivity using biaxially strained silicon

    DEFF Research Database (Denmark)

    Pedersen, Jesper Goor; Richter, Jacob; Brandbyge, Mads;

    2008-01-01

    We calculate the shear piezocoefficient of p-type silicon with grown-in biaxial strain using a 66 k·p method. We find a significant increase in the value of the shear piezocoefficient for compressive grown-in biaxial strain, while tensile strain decreases the piezocoefficient. The dependence...... of the piezocoefficient on temperature and dopant density is altered qualitatively for strained silicon. In particular, we find that a vanishing temperature coefficient may result for silicon with grown-in biaxial tensile strain. These results suggest that strained silicon may be used to engineer the iezoresistivity...

  4. Whole genome analysis of Vietnamese G2P[4] rotavirus strains possessing the NSP2 gene sharing an ancestral sequence with Chinese sheep and goat rotavirus strains.

    Science.gov (United States)

    Do, Loan Phuong; Doan, Yen Hai; Nakagomi, Toyoko; Gauchan, Punita; Kaneko, Miho; Agbemabiese, Chantal; Dang, Anh Duc; Nakagomi, Osamu

    2015-10-01

    Because imminent introduction into Vietnam of a vaccine against Rotavirus A is anticipated, baseline information on the whole genome of representative strains is needed to understand changes in circulating strains that may occur after vaccine introduction. In this study, the whole genomes of two G2P[4] strains detected in Nha Trang, Vietnam in 2008 were sequenced, this being the last period during which virtually no rotavirus vaccine was used in this country. The two strains were found to be >99.9% identical in sequence and had a typical DS-1 like G2-P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2 genotype constellation. Analysis of the Vietnamese strains with >184 G2P[4] strains retrieved from GenBank/EMBL/DDBJ DNA databases placed the Vietnamese strains in one of the lineages commonly found among contemporary strains, with the exception of the NSP2 and NSP4 genes. The NSP2 genes were found to belong to a previously undescribed lineage that diverged from Chinese sheep and goat rotavirus strains, including a Chinese rotavirus vaccine strain LLR with 95% nucleotide identity; the time of their most recent common ancestor was 1975. The NSP4 genes were found to belong, together with Thai and USA strains, to an emergent lineage (VIII), adding further diversity to ever diversifying NSP4 lineages. Thus, there is a need to enhance surveillance of locally-circulating strains from both children and animals at the whole genome level to address the effect of rotavirus vaccines on changing strain distribution.

  5. Effect of transient change in strain rate on plastic flow behaviour of low carbon steel

    Indian Academy of Sciences (India)

    A Ray; P Barat; P Mukherjee; A Sarkar; S K Bandyopadhyay

    2007-02-01

    Plastic flow behaviour of low carbon steel has been studied at room temperature during tensile deformation by varying the initial strain rate of 3.3 × 10-4 s-1 to a final strain rate ranging from 1.33 × 10-3 s-1 to 2 × 10-3 s-1 at a fixed engineering strain of 12%. Haasen plot revealed that the mobile dislocation density remained almost invariant at the juncture where there was a sudden increase in stress with a change in strain rate and the plastic flow was solely dependent on the velocity of mobile dislocations. In that critical regime, the variation of stress with time was fitted with a Boltzmann type Sigmoid function. The increase in stress was found to increase with final strain rate and the time elapsed in attaining these stress values showed a decreasing trend. Both of these parameters saturated asymptotically at a higher final strain rate.

  6. Micro-electromechanical Systems for Probing Novel Strain Physics and Innovative Strain Devices in 2D Materials

    Science.gov (United States)

    Christopher, Jason; Vutukuru, Mounika; Bishop, David; Swan, Anna; Goldberg, Bennett

    Straining 2D materials can dramatically change electrical, thermal and optical properties and can even cause unconventional behavior such as generating pseudo-magnetic fields. However attempts at probing these effects have been hindered by the difficulty involved with precisely straining these materials. Here we present micro-electromechanical systems (MEMS) as an ideal platform for straining 2D materials because they are readily compatible with existing electronics and their size makes them compatible with 2D materials. Additionally the MEMS platform does more than facilitate experimentation; by freeing us to think of strain as dynamical it makes a whole new class of devices practical for next generation technology. To demonstrate the power of this platform we have for the first time measured the strain response of the Raman and photoluminescence spectra of suspended MoS2, and measured the friction force between MoS2 and the MEMS structure. This talk will touch on the basics of designing MEMS structures for straining 2D materials, how to transfer 2D materials onto MEMS without break either, proof of concept experimental results, and next steps in developing the MEMS platform. This work is supported by NSF DMR Grant 1411008, and author J. Christopher thanks the NDSEG program for its support.

  7. Quantitative analysis of left ventricular strain using cardiac computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Buss, Sebastian J., E-mail: sebastian.buss@med.uni-heidelberg.de [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany); Schulz, Felix; Mereles, Derliz [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany); Hosch, Waldemar [Department of Diagnostic and Interventional Radiology, University of Heidelberg, 69120 Heidelberg (Germany); Galuschky, Christian; Schummers, Georg; Stapf, Daniel [TomTec Imaging Systems GmbH, Munich (Germany); Hofmann, Nina; Giannitsis, Evangelos; Hardt, Stefan E. [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany); Kauczor, Hans-Ulrich [Department of Diagnostic and Interventional Radiology, University of Heidelberg, 69120 Heidelberg (Germany); Katus, Hugo A.; Korosoglou, Grigorios [Department of Cardiology, University of Heidelberg, 69120 Heidelberg (Germany)

    2014-03-15

    Objectives: To investigate whether cardiac computed tomography (CCT) can determine left ventricular (LV) radial, circumferential and longitudinal myocardial deformation in comparison to two-dimensional echocardiography in patients with congestive heart failure. Background: Echocardiography allows for accurate assessment of strain with high temporal resolution. A reduced strain is associated with a poor prognosis in cardiomyopathies. However, strain imaging is limited in patients with poor echogenic windows, so that, in selected cases, tomographic imaging techniques may be preferable for the evaluation of myocardial deformation. Methods: Consecutive patients (n = 27) with congestive heart failure who underwent a clinically indicated ECG-gated contrast-enhanced 64-slice dual-source CCT for the evaluation of the cardiac veins prior to cardiac resynchronization therapy (CRT) were included. All patients underwent additional echocardiography. LV radial, circumferential and longitudinal strain and strain rates were analyzed in identical midventricular short axis, 4-, 2- and 3-chamber views for both modalities using the same prototype software algorithm (feature tracking). Time for analysis was assessed for both modalities. Results: Close correlations were observed for both techniques regarding global strain (r = 0.93, r = 0.87 and r = 0.84 for radial, circumferential and longitudinal strain, respectively, p < 0.001 for all). Similar trends were observed for regional radial, longitudinal and circumferential strain (r = 0.88, r = 0.84 and r = 0.94, respectively, p < 0.001 for all). The number of non-diagnostic myocardial segments was significantly higher with echocardiography than with CCT (9.6% versus 1.9%, p < 0.001). In addition, the required time for complete quantitative strain analysis was significantly shorter for CCT compared to echocardiography (877 ± 119 s per patient versus 1105 ± 258 s per patient, p < 0.001). Conclusion: Quantitative assessment of LV strain

  8. Beryllium strain under dynamic loading

    Directory of Open Access Journals (Sweden)

    Pushkov Victor

    2015-01-01

    Full Text Available There are some data (not much on dynamic characteristics of beryllium that are important, for example, when estimating construction performance at NPP emergencies. A number of data on stress-strain curves, spall strength, shear strength, fracture and structure responses of shock loaded beryllium have obtained in US and Russian laboratories. For today the model description of this complex metal behavior does not have a reasonable agreement with the experimental data, thus a wider spectrum of experimental data is required. This work presents data on dynamic compression-test diagrams of Russian beryllium. Experiments are performed using Hopkinson bar method (SHPB. Strain rates were ε ∼ 103 s−1.

  9. Microtwin formation in the {alpha} phase of duplex titanium alloys affected by strain rate

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yi-Hsiang; Wu, Shu-Ming [Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, No. 2 Pei Ning Road, Keelung 20224, Taiwan (China); Kao, Fang-Hsin [Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Wang, Shing-Hoa, E-mail: shwang@ntou.edu.tw [Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, No. 2 Pei Ning Road, Keelung 20224, Taiwan (China); Yang, Jer-Ren [Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Yang, Chia-Chih [Department of Mechanical and Mechatronic Engineering, National Taiwan Ocean University, No. 2 Pei Ning Road, Keelung 20224, Taiwan (China); Chiou, Chuan-Sheng [Department of Mechanical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan (China)

    2011-03-15

    Research highlights: {yields} The long and dense twins in {alpha} phase of SP700 alloy occurring at lower strain rates promote a good ductility. {yields} The deformation in SP700 alloy changed to micro twins-controlled mechanism in {alpha} as the strain rate decreases. {yields} The material has time to redistribute the deformed strain between {alpha} and {beta} as the strain rate decreases. - Abstract: The effect of tensile strain rate on deformation microstructure was investigated in Ti-6-4 (Ti-6Al-4V) and SP700 (Ti-4.5Al-3V-2Mo-2Fe) of the duplex titanium alloys. Below a strain rate of 10{sup -2} s{sup -1}, Ti-6-4 alloy had a higher ultimate tensile strength than SP700 alloy. However, the yield strength of SP700 was consistently greater than Ti-6-4 at different strain rates. The ductility of SP700 alloy associated with twin formation (especially at the slow strain rate of 10{sup -4} s{sup -1}), always exceeded that of Ti-6-4 alloy at different strain rates. It is caused by a large quantity of deformation twins took place in the {alpha} phase of SP700 due to the lower stacking fault energy by the {beta} stabilizer of molybdenum alloying. In addition, the local deformation more was imposed on the {alpha} grains from the surrounding {beta}-rich grains by redistributing strain as the strain rate decreased in SP700 duplex alloy.

  10. Using Predictions Based on Geostatistics to Monitor Trends in Aspergillus flavus Strain Composition.

    Science.gov (United States)

    Orum, T V; Bigelow, D M; Cotty, P J; Nelson, M R

    1999-09-01

    ABSTRACT Aspergillus flavus is a soil-inhabiting fungus that frequently produces aflatoxins, potent carcinogens, in cottonseed and other seed crops. A. flavus S strain isolates, characterized on the basis of sclerotial morphology, are highly toxigenic. Spatial and temporal characteristics of the percentage of the A. flavus isolates that are S strain (S strain incidence) were used to predict patterns across areas of more than 30 km(2). Spatial autocorrelation in S strain incidence in Yuma County, AZ, was shown to extend beyond field boundaries to adjacent fields. Variograms revealed both short-range (2 to 6 km) and long-range (20 to 30 km) spatial structure in S strain incidence. S strain incidence at 36 locations sampled in July 1997 was predicted with a high correlation between expected and observed values (R = 0.85, P = 0.0001) by kriging data from July 1995 and July 1996. S strain incidence at locations sampled in October 1997 and March 1998 was markedly less than predicted by kriging data from the same months in prior years. Temporal analysis of four locations repeatedly sampled from April 1995 through July 1998 also indicated a major reduction in S strain incidence in the Texas Hill area after July 1997. Surface maps generated by kriging point data indicated a similarity in the spatial pattern of S strain incidence among all sampling dates despite temporal changes in the overall S strain incidence. Geostatistics provided useful descriptions of variability in S strain incidence over space and time.

  11. [Breeding of robust industrial ethanol-tolerant Saccharomyces cerevisiae strain by artificial zinc finger protein library].

    Science.gov (United States)

    Ma, Cui; Zhao, Xinqing; Li, Qian; Zhang, Mingming; Kim, Jin Soo; Bai, Fengwu

    2013-05-01

    Breeding of robust industrial Saccharomyces cerevisiae strains with high ethanol tolerance is of great significance for efficient fuel ethanol production. Zinc finger proteins play important roles in gene transcription and translation, and exerting control on the regulation of multiple genes. The sequence and localization of the zinc finger motif can be designed and engineered, and the artificial zinc finger protein can be used to regulate celluar metabolism. Stress tolerance of microbial strains is related to multiple genes. Therefore, it is possible to use artificially-designed zinc finger proteins to breed stress tolerant strains. In this study, a library containing artificial zinc finger protein encoding genes was transformed into the model yeast strain S288c. A recombinant strain named M01 with improved ethanol tolerance was obtained. The plasmid in M01 was isolated, and then transformed into the industrial yeast strain Sc4126. Ethanol tolerance of the recombinant strain of Sc4126 were significantly improved. When high gravity ethanol fermentation using 250 g/L glucose was performed, comparing with the wild-type strain, fermentation time of the recombinant strain was decreased by 24 h and the final ethanol concentration was enhanced by 6.3%. The results of this study demonstrate that artificial zinc finger proteins are able to exert control on stress tolerance of yeast strains, and these results provide basis to construct robust industrial yeast strains for efficient ethanol fermentation.

  12. Effect of various Portland cement paste compositions on early-age strain

    Science.gov (United States)

    Guzzetta, Alana G.

    Early-age strain in paste, mortar, and concrete mixtures was investigated using a new method where the specimen shape was a cone frustum. Strain of the specimen from both the horizontal and vertical directions was captured by height change measurement. The volumetric strain was then calculated as a function of the height change and was plotted versus time. A correlation was found between the slopes of the volumetric strain curve resulting from this test method and the initial setting time of the tested material. An initial evaluation of the repeatability of this innovative test method was conducted. The early-age strain effects of aggregate volume, shrinkage reducing admixture, water-cementitious ratio (w/cm), and partial cement replacement with supplementary cementitious materials were tested and individually compared. From these comparisons, it was observed that ambient temperature, bleed water development, and rheological properties had a significant impact on the volumetric strain results. Data showed increased strain as aggregate volume was reduced and as the w/cm was changed from 0.25 up to 0.50. The addition of shrinkage reducing admixture generally caused an increase in the 36-hour volumetric strain value. In most of the mixtures, cement replacement with 20% fly ash or 10% metakaolin reduced the measured volumetric strain when the w/cm was 0.30. Replacement of cement with 10% silica fume caused an insignificant change in volumetric strain results.

  13. Strain-Detecting Composite Materials

    Science.gov (United States)

    Wallace, Terryl A. (Inventor); Smith, Stephen W. (Inventor); Piascik, Robert S. (Inventor); Horne, Michael R. (Inventor); Messick, Peter L. (Inventor); Alexa, Joel A. (Inventor); Glaessgen, Edward H. (Inventor); Hailer, Benjamin T. (Inventor)

    2016-01-01

    A composite material includes a structural material and a shape-memory alloy embedded in the structural material. The shape-memory alloy changes crystallographic phase from austenite to martensite in response to a predefined critical macroscopic average strain of the composite material. In a second embodiment, the composite material includes a plurality of particles of a ferromagnetic shape-memory alloy embedded in the structural material. The ferromagnetic shape-memory alloy changes crystallographic phase from austenite to martensite and changes magnetic phase in response to the predefined critical macroscopic average strain of the composite material. A method of forming a composite material for sensing the predefined critical macroscopic average strain includes providing the shape-memory alloy having an austenite crystallographic phase, changing a size and shape of the shape-memory alloy to thereby form a plurality of particles, and combining the structural material and the particles at a temperature of from about 100-700.degree. C. to form the composite material.

  14. Distributed fiber optic strain sensor based on the Sagnac and Michelson interferometers

    Science.gov (United States)

    Udd, Eric

    1996-04-01

    By placing fiber optic gratings in a Sagnac loop a distributed strain sensor may be formed by using the light reflected from the fiber gratings as sources for balanced Michelson and Mach- Zehnder interferometers. In this manner the resulting fiber optic sensor is capable of measuring integrated strain over lengths determined by the fiber grating position, point strain and temperature at the fiber grating locations and localizing and measuring the position of a time varying signal such as an acoustic wave.

  15. Suppression of dislocations at high strain rate deformation in a twinning-induced plasticity steel

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Z.Y. [Shenzhen Institute of Research and Innovation, The University of Hong Kong, Shenzhen (China); Department of Mechanical Engineering, The University of Hong Kong, Hong Kong (China); Huang, W., E-mail: whuang@szu.edu.cn [Department of Civil Engineering, Shenzhen University, Shenzhen (China); Huang, M.X., E-mail: mxhuang@hku.hk [Shenzhen Institute of Research and Innovation, The University of Hong Kong, Shenzhen (China); Department of Mechanical Engineering, The University of Hong Kong, Hong Kong (China)

    2015-03-25

    The increase of strain rate generally enhances dislocation evolution in face-centred cubic (FCC) metals. However, by synchrotron X-ray diffraction experiments, the present work demonstrates for the first time that a higher strain rate leads to a lower dislocation density in a twinning-induced plasticity steel with an FCC structure. This unexpected suppression of dislocation evolution has been attributed to the temperature increase due to dissipative heating at high strain rate deformation.

  16. Shrinkage strain – Rates study of dental composites based on (BisGMA/TEGDMA monomers

    Directory of Open Access Journals (Sweden)

    A. Amirouche-Korichi

    2017-02-01

    The results revealed that the fraction of opaque filler had no significant effect on the shrinkage strain-rate and on the time at maximum shrinkage strain-rate but these two parameters are closely related to the monomer ratios and viscosity of the organic matrix. The results have confirmed the proportionality of the shrinkage strain and DC and showed that the filler contents and monomer ratios would not affect this proportionality.

  17. Stress, strain rate and anisotropy in Kyushu, Japan

    Science.gov (United States)

    Savage, M. K.; Aoki, Y.; Unglert, K.; Ohkura, T.; Umakoshi, K.; Shimizu, H.; Iguchi, M.; Tameguri, T.; Ohminato, T.; Mori, J.

    2016-04-01

    Seismic anisotropy, the directional dependence of wave speeds, may be caused by stress-oriented cracks or by strain-oriented minerals, yet few studies have quantitatively compared anisotropy to stress and strain over large regions. Here we compare crustal stress and strain rates on the Island of Kyushu, Japan, as measured from inversions of focal mechanisms, GPS and shear wave splitting. Over 85,000 shear wave splitting measurements from local and regional earthquakes are obtained from the NIED network between 2004 and 2012, and on Aso, Sakurajima, Kirishima and Unzen volcano networks. Strain rate measurements are made from the Japanese Geonet stations. JMA-determined S arrival times processed with the MFAST shear wave splitting code measure fast polarisations (Φ), related to the orientation of the anisotropic medium and time delays (dt), related to the path length and the percent anisotropy. We apply the TESSA 2-D delay time tomography and spatial averaging code to the highest quality events, which have nearly vertical incidence angles, separating the 3455 shallow (depth = 40 km) earthquakes. Using square grids with 30 km sides for all the inversions, the best correlations are observed between splitting from shallow earthquakes and stress. Axes of maximum horizontal stress (SHmax) and Φ correlate with a coefficient c of 0.56, significant at the 99% confidence level. Their mean difference is 31.9°. Axes of maximum compressional strain rate and SHmax are also well aligned, with an average difference of 28°, but they do not correlate with each other, meaning that where they differ, the difference is not systematic. Anisotropy strength is negatively correlated with the stress ratio parameter determined from focal mechanism inversion (c = - 0.64; significant at the 99% confidence level). The anisotropy and stress results are consistent with stress-aligned microcracks in the crust in a dominantly strike-slip regime. Eigenvalues of maximum horizontal strain rate

  18. In-situ strain observation in high power laser cladding

    NARCIS (Netherlands)

    Ocelik, V.; Bosgra, J.; de Hosson, J. Th. M.

    2009-01-01

    The modern experimental technique - so called Digital Image Correlation - is applied during high power laser surface treatments for in-situ observation of displacements and strains near the processing area during and a short time after laser processing. An experimental setup has been designed and

  19. In-situ strain observation in high power laser cladding

    NARCIS (Netherlands)

    Ocelik, V.; Bosgra, J.; de Hosson, J. Th. M.

    2009-01-01

    The modern experimental technique - so called Digital Image Correlation - is applied during high power laser surface treatments for in-situ observation of displacements and strains near the processing area during and a short time after laser processing. An experimental setup has been designed and te

  20. In-situ strain observation in high power laser cladding

    NARCIS (Netherlands)

    Ocelik, V.; Bosgra, J.; de Hosson, J. Th. M.

    2009-01-01

    The modern experimental technique - so called Digital Image Correlation - is applied during high power laser surface treatments for in-situ observation of displacements and strains near the processing area during and a short time after laser processing. An experimental setup has been designed and te

  1. Dynamics of a seismogenic fault subject to variable strain rate

    Directory of Open Access Journals (Sweden)

    M. Dragoni

    2011-06-01

    Full Text Available The behaviour of seismogenic faults is generally investigated under the assumption that they are subject to a constant strain rate. We consider the effect of a slowly variable strain rate on the recurrence times of earthquakes generated by a single fault. To this aim a spring-block system is employed as a low-order analog of the fault. Two cases are considered: a sinusoidal oscillation in the driver velocity and a monotonic change from one velocity value to another. In the first case, a study of the orbit of the system in the state space suggests that the seismic activity of the equivalent fault is organized into cycles that include several earthquakes and repeat periodically. Within each cycle the recurrence times oscillate about an average value equal to the recurrence period for constant strain rate. In the second case, the recurrence time changes gradually from the value before the transition to the value following it. Asymptotic solutions are also given, approximating the case when the amplitude of the oscillation or of the monotonic change is much smaller than the average driver velocity and the period of oscillation or the duration of the transition is much longer than the recurrence times of block motions. If the system is not isolated but is subject to perturbations in stress, the perturbation anticipates or delays the subsequent earthquake. The effects of stress perturbations in the two cases of strain rate oscillations and monotonic change are considered.

  2. Survival characteristics of environmental and clinically derived strains of Cronobacter sakazakii in infant milk formula (IMF) and ingredients.

    Science.gov (United States)

    Walsh, D; Molloy, C; Iversen, C; Carroll, J; Cagney, C; Fanning, S; Duffy, G

    2011-03-01

    The study aimed to compare survival of Cronobacter sakazakii strains in plant-derived infant milk formula (IMF) ingredients and their thermotolerance in reconstituted IMF. Inulin and lecithin were inoculated with isolates of C. sakazakii including the typed clinical strains, NCTC 11467(T) and BAA 894; a mutant strain in which the wcaD gene had been disrupted; and two environmental strains isolated from IMF processing facilities. Samples were stored and examined for C. sakazakii. All strains were still detectable in both matrices after 338 days storage, except for the mutant strain that was no longer detectable at that time. Higher numbers of the environmental strains were recoverable after 338 days than the clinical strains. The thermotolerance of the five strains was investigated in reconstituted IMF at 55, 60 and 65°C. The clinically derived type strain, NCTC 11467(T), and the mutant strain were shown to be significantly more thermotolerant than other strains tested. Environmental strains were more persistent than the clinical strains in inulin and lecithin, indicating that patho-adaptation may have contributed to a reduction in the desiccation tolerance phenotype. However, the thermotolerance results could indicate that the ability to produce extracellular polysaccharide decreases thermotolerance. These results indicate that desiccation resistance may play a role in survival of C. sakazakii in dry IMF ingredients and processing plants; however, this trait may be of less importance in clinical environs. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

  3. Old times Old times

    Directory of Open Access Journals (Sweden)

    Ubiratan Paiva de Oliveira

    2008-04-01

    Full Text Available In Pinter: A Study of His Plays, Martin Esslin mentions three levels of possible interpretation for Old Times. According to him, Pinter's play could be interpreted on a realistic level, or either representing the male character's dream or a ritual game. He correctly remarks, though, that none of those levels excludes the others, because "... they must co-exist to create the atmosphere of poetic ambivalence on which the image of the play rests..1 In Pinter: A Study of His Plays, Martin Esslin mentions three levels of possible interpretation for Old Times. According to him, Pinter's play could be interpreted on a realistic level, or either representing the male character's dream or a ritual game. He correctly remarks, though, that none of those levels excludes the others, because "... they must co-exist to create the atmosphere of poetic ambivalence on which the image of the play rests..1

  4. Aseismic strain episodes at Campi Flegrei, Italy

    Science.gov (United States)

    Scarpa, Roberto; Amoruso, Antonella; Bilham, Roger; Di Lieto, Bellina; Errico, Antonio; Linde, Alan; Sacks, Selwyn

    2014-05-01

    Since spring 2004 a research project has been developed in Italy to install borehole Sacks-Evertson strainmeters (dilatometers) aimed to improve monitoring systems of the Italian volcanoes. 6 borehole dilatometers have been installed around Campi Flegrei and Vesuvius during 2004-2005 (Scarpa et al., 2007). This small network has been implemented by two arrays of long-baseline water tube tiltmeters installed in underground tunnels since 2008. Relevant strainmeter and tiltmeter data have been collected and analyzed at the instruments installed at Campi Flegrei during the recent unrest episodes. Renewed activity started since 2004-2005, characterized by a quite low rate of vertical vertical displacement, amounting initially to a few cm/year. A long term strain episode occurred during summer 2006, in correspondence to an increase of CO2 emission and displacements measured also by tiltmeters and GPS transducers. This strain episode preceded the seismic activity by few months, as also observed during the 1982 most significant unrest. Other aseismic slip episodes have been recorded in 2009, in correspondence of the renewal of gas emission activity at Solfatara, in 2010, one day before a seismic swarm, and in September 2012, few days before the most significant seismic swarm occurred after the 1982-1984 uplift. The time scale of these phenomena is ranging from some hours to several days, putting further constraints on the origin of ground uplifts at Campi Flegrei. Their location is compatible with the source inferred from long term deformation signals, at about 4 km depth beneath Pozzuoli.

  5. Fermentation characteristics of Dekkera bruxellensis strains.

    Science.gov (United States)

    Blomqvist, Johanna; Eberhard, Thomas; Schnürer, Johan; Passoth, Volkmar

    2010-07-01

    The influence of pH, temperature and carbon source (glucose and maltose) on growth rate and ethanol yield of Dekkera bruxellensis was investigated using a full-factorial design. Growth rate and ethanol yield were lower on maltose than on glucose. In controlled oxygen-limited batch cultivations, the ethanol yield of the different combinations varied from 0.42 to 0.45 g (g glucose)(-1) and growth rates varied from 0.037 to 0.050 h(-1). The effect of temperature on growth rate and ethanol yield was negligible. It was not possible to model neither growth rate nor ethanol yield from the full-factorial design, as only marginal differences were observed in the conditions tested. When comparing three D. bruxellensis strains and two industrial isolates of Saccharomyces cerevisiae, S. cerevisiae grew five times faster, but the ethanol yields were 0-13% lower. The glycerol yields of S. cerevisiae strains were up to six-fold higher compared to D. bruxellensis, and the biomass yields reached only 72-84% of D. bruxellensis. Our results demonstrate that D. bruxellensis is robust to large changes in pH and temperature and may have a more energy-efficient metabolism under oxygen limitation than S. cerevisiae.

  6. Spectral Psychoanalysis of Speech under Strain | Sharma ...

    African Journals Online (AJOL)

    Spectral Psychoanalysis of Speech under Strain. ... Different voice features from the speech signal to be influenced by strain are: loudness, fundamental frequency, jitter, zero-crossing rate, ... EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  7. Strain Monitoring of Flexible Structures

    Science.gov (United States)

    Litteken, Douglas A.

    2017-01-01

    , such as tensile testing, fatigue testing, and shear testing, but common measurement techniques cannot be used on fabric. Measuring strain in a material and during a test is a critical parameter for an engineer to monitor the structure during the test and correlate to an analytical model. The ability to measure strain in fabric structures is a challenge for NASA. Foil strain gauges, for example, are commonplace on metallic structures testing, but are extremely difficult to interface with a fabric substrate. New strain measuring techniques need to be developed for use with fabric structures. This paper investigates options for measuring strain in fabric structures for both ground testing and in-space structural health monitoring. It evaluates current commercially available options and outlines development work underway to build custom measurement solutions for NASA's fabric structures.

  8. Pulsar Timing Arrays

    OpenAIRE

    Joshi, Bhal Chandra

    2013-01-01

    In the last decade, the use of an ensemble of radio pulsars to constrain the characteristic strain caused by a stochastic gravitational wave background has advanced the cause of detection of very low frequency gravitational waves significantly. This electromagnetic means of gravitational wave detection, called Pulsar Timing Array(PTA), is reviewed in this article. The principle of operation of PTA, the current operating PTAs and their status is presented along-with a discussion of the main ch...

  9. Dynamic damage and stress-strain relations of ultra-high performance cementitious composites subjected to repeated impact

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Ultra-high performance cementitious composites (UHPCC) were prepared by replacing 60% of cement with ultra-fine industrial waste powders.The dynamic damage and compressive stress-strain relations of UHPCC were studied using split Hopkinson pressure bar (SHPB).The damage of UHPCC subjected to repeated impact was measured by the ultrasonic pulse velocity method.Results show that the dynamic damage of UHPCC increases linearly with impact times and the abilities of repeated impact resistance of UHPCC are improved with increasing fiber volume fraction.The stress waves on impact were recorded and the average stress,strain and strain rate of UHPCC were calculated based on the wave propagation theory.The effects of strain rate,fibers volume fraction and impact times on the stress-strain relations of UHPCC were studied.Results show that the peak stress and elastic modulus decrease while the strain rate and peak strain increase gradually with increasing impact times.

  10. EFFECTIVE STRESS AND STRAIN IN FINITE DEFORMATION

    Institute of Scientific and Technical Information of China (English)

    周喆; 秦伶俐; 黄文彬; 王红卫

    2004-01-01

    Whether the concept of effective stress and strain in elastic-plastic theory is still valid under the condition of finite deformation was mainly discussed. The uni-axial compression experiments in plane stress and plane strain states were chosen for study. In the two kinds of stress states, the stress- strain curve described by logarithm strain and rotated Kirchhoff stress matches the experiments data better than the curves defined by other stressstrain description.

  11. Haemophilus ducreyi Cutaneous Ulcer Strains Are Nearly Identical to Class I Genital Ulcer Strains.

    Directory of Open Access Journals (Sweden)

    Dharanesh Gangaiah

    Full Text Available Although cutaneous ulcers (CU in the tropics is frequently attributed to Treponema pallidum subspecies pertenue, the causative agent of yaws, Haemophilus ducreyi has emerged as a major cause of CU in yaws-endemic regions of the South Pacific islands and Africa. H. ducreyi is generally susceptible to macrolides, but CU strains persist after mass drug administration of azithromycin for yaws or trachoma. H. ducreyi also causes genital ulcers (GU and was thought to be exclusively transmitted by microabrasions that occur during sex. In human volunteers, the GU strain 35000HP does not infect intact skin; wounds are required to initiate infection. These data led to several questions: Are CU strains a new variant of H. ducreyi or did they evolve from GU strains? Do CU strains contain additional genes that could allow them to infect intact skin? Are CU strains susceptible to azithromycin?To address these questions, we performed whole-genome sequencing and antibiotic susceptibility testing of 5 CU strains obtained from Samoa and Vanuatu and 9 archived class I and class II GU strains. Except for single nucleotide polymorphisms, the CU strains were genetically almost identical to the class I strain 35000HP and had no additional genetic content. Phylogenetic analysis showed that class I and class II strains formed two separate clusters and CU strains evolved from class I strains. Class I strains diverged from class II strains ~1.95 million years ago (mya and CU strains diverged from the class I strain 35000HP ~0.18 mya. CU and GU strains evolved under similar selection pressures. Like 35000HP, the CU strains were highly susceptible to antibiotics, including azithromycin.These data suggest that CU strains are derivatives of class I strains that were not recognized until recently. These findings require confirmation by analysis of CU strains from other regions.

  12. Haemophilus ducreyi Cutaneous Ulcer Strains Are Nearly Identical to Class I Genital Ulcer Strains.

    Directory of Open Access Journals (Sweden)

    Dharanesh Gangaiah

    Full Text Available Although cutaneous ulcers (CU in the tropics is frequently attributed to Treponema pallidum subspecies pertenue, the causative agent of yaws, Haemophilus ducreyi has emerged as a major cause of CU in yaws-endemic regions of the South Pacific islands and Africa. H. ducreyi is generally susceptible to macrolides, but CU strains persist after mass drug administration of azithromycin for yaws or trachoma. H. ducreyi also causes genital ulcers (GU and was thought to be exclusively transmitted by microabrasions that occur during sex. In human volunteers, the GU strain 35000HP does not infect intact skin; wounds are required to initiate infection. These data led to several questions: Are CU strains a new variant of H. ducreyi or did they evolve from GU strains? Do CU strains contain additional genes that could allow them to infect intact skin? Are CU strains susceptible to azithromycin?To address these questions, we performed whole-genome sequencing and antibiotic susceptibility testing of 5 CU strains obtained from Samoa and Vanuatu and 9 archived class I and class II GU strains. Except for single nucleotide polymorphisms, the CU strains were genetically almost identical to the class I strain 35000HP and had no additional genetic content. Phylogenetic analysis showed that class I and class II strains formed two separate clusters and CU strains evolved from class I strains. Class I strains diverged from class II strains ~1.95 million years ago (mya and CU strains diverged from the class I strain 35000HP ~0.18 mya. CU and GU strains evolved under similar selection pressures. Like 35000HP, the CU strains were highly susceptible to antibiotics, including azithromycin.These data suggest that CU strains are derivatives of class I strains that were not recognized until recently. These findings require confirmation by analysis of CU strains from other regions.

  13. Strain Imaging Using Terahertz Waves and Metamaterials

    Science.gov (United States)

    2016-11-01

    TECHNICAL REPORT RDMR-WD-16-48 STRAIN IMAGING USING TERAHERTZ WAVES AND METAMATERIALS Henry O. Everitt and Martin S...TITLE AND SUBTITLE Strain Imaging Using Terahertz Waves and Metamaterials 5. FUNDING NUMBERS 6. AUTHOR(S) Henry O. Everitt, Martin S...technique to measure strain in opaque objects. Experiments were conducted utilizing metamaterials on polydimethylsiloxane (PDMS) sheets to produce

  14. Isolation and purification of Gallid herpesvirus 2 strains currently distributed in Japan.

    Science.gov (United States)

    Machida, Yuka; Murata, Shiro; Matsuyama-Kato, Ayumi; Isezaki, Masayoshi; Taneno, Akira; Sakai, Eishi; Konnai, Satoru; Ohashi, Kazuhiko

    2017-01-20

    Gallid herpesvirus 2 (GaHV-2) causes malignant lymphomas in chickens (Marek's disease, MD). Although MD is controlled through vaccination efforts, field isolates of GaHV-2 have increased in virulence worldwide and even cause MD in vaccinated chickens. GaHV-2 strains are classified into four categories (mild, virulent, very virulent and very virulent +) based on the virulence exhibited in experimental infection in unvaccinated or MD-vaccinated susceptible chickens. Although MD cases are sporadically reported in Japan, the recent field strains of GaHV-2 in Japan have not been characterized. During isolation of recent field strains by using primary chicken kidney cell cultures, a method classically used for GaHV-2 isolation, vaccine strains were simultaneously isolated. Therefore, it is necessary to separate vaccine strains to characterize the virulence and pathogenicity of the GaHV-2 strains currently distributed in Japan. In this study, we prepared cell suspensions from the spleens of MD-symptomatic chickens, inoculated day-old-chicks and isolated GaHV-2 strains by primary chicken kidney cell cultures at 2-3 weeks post inoculation. The isolated strains were passaged several times on chicken embryo fibroblast cells, and PCR analysis revealed that the isolated strains were not contaminated with vaccine strains. Moreover, the contaminant vaccine strains were completely removed by the purification of plaques observed in chicken kidney cells. These procedures are necessary to isolate GaHV-2 field strains from vaccine strains in order to carry out future studies to characterize these strains and glean insights into GaHV-2 virulence and pathogenicity.

  15. In-situ strain observation in high power laser cladding

    OpenAIRE

    Ocelik, V.; Bosgra, J.; De Hosson, J. Th. M.

    2009-01-01

    The modern experimental technique - so called Digital Image Correlation - is applied during high power laser surface treatments for in-situ observation of displacements and strains near the processing area during and a short time after laser processing. An experimental setup has been designed and tested to measure in-situ the strain during treatment with a high power 2 kW CW Nd:YAG laser, i.e. laser hardening, surface remelting, and laser cladding with Nanosteel, Eutroloy 16012 and MicroMelt ...

  16. Temporal evolution of strain rates at western Greenland moulins

    Science.gov (United States)

    Poinar, Kristin; Andrews, Lauren; Chu, Vena; Moon, Twila; Nowicki, Sophie

    2017-04-01

    Moulins are key sources for subglacial water across western Greenland. The rate and timing at which they deliver surface meltwater to the subglacial system are crucial inputs for ice-sheet hydrology models. Intensive field campaigns coupled to remote sensing efforts have provided, to date, information on the timing of supraglacial lake drainages and water flux through the consequent moulins, but predicting the dates of moulin activation has remained an area of active research. This is vital for the construction of spatially variable basal-input hydrographs for models that will predict the future evolution of Greenland ice flow and sliding. In this study, we combine multiple remote sensing datasets to investigate the degree to which local strain rates can predict moulin activation dates, as indicated by supraglacial lake drainage events. We find that over the period 2009-2011 in the Pâkitsoq region, moulins with more-tensile background (wintertime InSAR-derived) strain rates tend to activate first, followed by moulins in less-tensile background strain regimes. This pattern is relatively consistent across years, although we find that background strain rates are less important in explaining the date of moulin activation than are moulin elevation or cumulative days of runoff. In the Russell Glacier area, we examine the temporal evolution of summertime, Landsat-derived strain rates at moulin locations. Principal component analysis shows that strain rates at moulin locations increased abruptly over June 2012, independent of moulin elevation; strain rates in localities without moulins varied more smoothly in time. We also compare the strain rate time series at each moulin to lake drainage dates derived from MODIS and Landsat imagery from 2012. We hypothesize that the contrasting bedrock topography of the regions (Pâkitsoq is rougher than Russell at the few-km scale) may drive variations in moulin opening patterns across the two regions. Our results will have

  17. Antigenic differentiation of classical swine fever vaccinal strain PAV-250 from other strains, including field strains from Mexico.

    Science.gov (United States)

    Mendoza, Susana; Correa-Giron, Pablo; Aguilera, Edgar; Colmenares, Germán; Torres, Oscar; Cruz, Tonatiuh; Romero, Andres; Hernandez-Baumgarten, Eliseo; Ciprián, Abel

    2007-10-10

    Twenty-nine classical swine fever virus (CSFv) strains were grown in the PK15 or SK6 cell lines. Antigenic differentiation studies were performed using monoclonal antibodies (McAbs), produced at Lelystad (CDI-DLO), The Netherlands. The monoclonals which were classified numerically as monoclonals 2-13. Epitope map patterns that resulted from the reactivity with McAbs were found to be unrelated to the pathogenicity of the viruses studied. Antigenic determinants were recognized by McAbs 5 and 8, were not detected in some Mexican strains; however, sites for McAb 6 were absent in all strains. The PAV-250 vaccine strain was recognized by all MAbs, except by MAb 6. Furthermore, the Chinese C-S vaccine strain was found to be very similar to the GPE(-) vaccine. None of the studied Mexican vaccines or field strains was found to be similar to the PAV-250 vaccine strain.

  18. STRESS AND STRAIN STATE OF REPAIRING SECTION OF PIPELINE

    Directory of Open Access Journals (Sweden)

    V. V. Nikolaev

    2015-01-01

    Full Text Available Reliability of continuous operation of pipelines is an actual problem. For this reason should be developed an effective warning system of the main pipelines‘  failures and accidents not only in design and operation but also in selected repair. Changing of linear, unloaded by bending position leads to the change of stress and strain state of pipelines. And besides this, the stress and strain state should be determined and controlled in the process of carrying out the repair works. The article presents mathematical model of pipeline’s section straining in viscoelastic setting taking into account soils creep and high-speed stress state of pipeline with the purpose of stresses evaluation and load-supporting capacity of repairing section of pipeline, depending on time.  Stress and strain state analysis of pipeline includes longitudinal and circular stresses calculation  with  account of axis-asymmetrical straining and  was  fulfilled  on  the base of momentless theory of shells. To prove the consistency of data there were compared the calcu- lation results and the solution results by analytical methods for different cases (long pipeline’s section strain only under influence of cross-axis action; long pipeline’s section strain under in- fluence of longitudinal stress; long pipeline’s section strain; which is on the elastic foundation, under influence of cross-axis action. Comparison results shows that the calculation error is not more than 3 %.Analysis of stress-strain state change of pipeline’s section was carried out with development  of  this  model,  which  indicates  the  enlargement  of  span  deflection  in  comparison with problem’s solution in elastic approach. It is also proved, that for consistent assessment of pipeline maintenance conditions, it is necessary to consider the areolas of rheological processes of soils. On the base of complex analysis of pipelines there were determined stresses and time

  19. Analysis of Changing Swarm Rate using Volumetric Strain

    Science.gov (United States)

    Kumazawa, T.; Ogata, Y.; Kimura, K.; Maeda, K.; Kobayashi, A.

    2015-12-01

    Near the eastern coast of Izu peninsula is an active submarine volcanic region in Japan, where magma intrusions have been observed many times. The forecast of earthquake swarm activities and eruptions are serious concern particularly in nearby hot spring resort areas. It is well known that temporal durations of the swarm activities have been correlated with early volumetric strain changes at a certain observation station of about 20 km distance apart. Therefore the Earthquake Research Committee (2010) investigated some empirical statistical relations to predict sizes of the swarm activity. Here we looked at the background seismicity rate changes during these swarm periods using the non-stationary ETAS model (Kumazawa and Ogata, 2013, 2014), and have found the followings. The modified volumetric strain data, by removing the effect of earth tides, precipitation and coseismic jumps, have significantly higher cross-correlations to the estimated background rates of the ETAS model than to the swarm rate-changes. Specifically, the background seismicity rate synchronizes clearer to the strain change by the lags around a half day. These relations suggest an enhanced prediction of earthquakes in this region using volumetric strain measurements. Hence we propose an extended ETAS model where the background rate is modulated by the volumetric strain data. We have also found that the response function to the strain data can be well approximated by an exponential functions with the same decay rate, but that their intersects are inversely proportional to the distances between the volumetric strain-meter and the onset location of the swarm. Our numerical results by the same proposed model show consistent outcomes for the various major swarms in this region.

  20. Virulence of Serovar C-1 Strains of Avibacterium paragallinarum.

    Science.gov (United States)

    Trujillo-Ruíz, H H; Shivaprasad, H L; Morales-Erasto, V; Talavera-Rojas, M; Salgado-Miranda, C; Salazar-García, F; Blackall, P J; Soriano-Vargas, E

    2016-12-01

    The bacterium Avibacterium paragallinarum is the etiologic agent of infectious coryza of chickens. There are nine serovars of A. paragallinarum , and serovar C-1 has emerged in outbreaks of infectious coryza in layer hens in the Americas, with all isolates having been obtained from infectious coryza-vaccinated chickens. In the current study, the clinical and histopathologic outcomes of experimental infections in chickens with A. paragallinarum of serovar C-1 were investigated. The Japanese serovar reference strain, H-18, and a Mexican isolate, ESV-135, were included in the study. No differences in clinical sign scores or morbidity were observed between the two strains. The two bacterial strains caused microscopic lesions of lymphoplasmacytic inflammation in the mucosa of the nasal cavity, infraorbital sinus, and trachea. Similar severe lesions were observed in birds inoculated with both H-18 and ESV-135 strains. The lesions were present 48 hr after inoculation and persisted until day 10 after inoculation. Slight to severe, extensive hemorrhages were observed in the lumen, mucous membranes, and lamina propria of the nasal cavity and infraorbital sinus in most of the chickens inoculated with either the reference strain H-18 or the ESV-135 isolate. Hemorrhages in the upper respiratory tract of chickens experimentally infected with A. paragallinarum are reported here for the first time. The results have confirmed the high virulence of the reference strain H-18 as previously reported and have shown that the Mexican isolate was as virulent as the reference strain. The virulence of A. paragallinarum isolates may play a role in explaining why severe infectious coryza outbreaks are being seen in both vaccinated and nonvaccinated chicken flocks.

  1. Isolation and identification of the thermophilic alkaline desulphuricant strain

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A desulfurization strain that belongs to the thermophilic alkaline desulphuricant is designated as strain GDJ-3 and isolated from Inner Mongolia, China. The colony of the strain shows tiny, yellow, or white-yellow, and it becomes henna with the protracting of cultivated time. The cells are bacilliform (0.3 -0.6 × 1.0-1.2 μm), motive, and Gram negative. The strain GDJ-3 is able to utilize respectively the thiosulphate, sulfate, sulfite, or sulfide as sulfur source, utilize the carbon dioxide as the carbon source, and utilize the ammonium or nitrate as the nitrogen source. According to GenBank data, 16s RNA results of GDJ-3 are in good agreement with Alpha proteobacterrium sp. (97%) and Ochrobactrum sp. (98%). For GDJ-3, the optimum growth temperature is at 45℃, the optimum pH is at 8.5-8.8, and the optimum rocking speed of sorting table is at 150 r/min. Under the optimum culture condition, the cells of the strain can live for about 18 h. In the desulfurization solution, which is prepared according to the composition of DDS solution, the objectionable constituents of sodium thiosulphate and sodium sulfide were added factitiously, and the bacterial cell concentration was set at 107/mL. After the regeneration of the above desulfurization solution by the strain cells, the concentration of sodium thiosulphate was decreased by 14.75 g/L (percentage loss of content 13.21%), the concentration of sodium sulfide was decreased by 0.76 g/L (percentage loss of content 87.36%) in the desulfurization solution in 9.5 hours, and sulfur appeared. Maybe, this kind of strain can be used as the regeneration’s bacterial source of DDS solution.

  2. Symbiotic efficiency of selected indigenous Bradyrhizobium japonicum strains

    Directory of Open Access Journals (Sweden)

    Branka Komesarović

    2007-12-01

    Full Text Available Symbiotic nitrogen fixation has a unique role in a sustainable agriculture because the utilization of this natural process enables significant reduction of mineral nitrogen fertilization. Thereby, selection of highly efficient symbiotic nitrogen fixators is of great importance for successful legume inoculation due to the fact that the strains of nodule bacteria strongly differ in their symbiotic efficiency, competitiveness and compatibility. The main aim of the present study was to evaluate the symbiotic characteristics of indigenous and reference Bradyrhizobium japonicum and Bradyrhizobium elkanii strains and their compatibility with different soybean cultivars in agroecological conditions of eastern Slavonia. During two years of investigations, twofactorial field trials were set up in a randomized complete block design with five replicates. The results obtained in this study show that all B. japonicum strains had positive effect on all analyzed properties and particularly on seed yield as the most important parameter in soybean production. The highest values for nodule dry weight were obtained by application of indigenous B.japonicum strain S69 that was isolated from the similar agroecologicalconditions. Although the application of B. elkanii strain S76T resulted in the most abundant nodulation, at the same time it induced chlorosis on leaves in full blossom stage. Regarding the tested soybean cultivars, Ika and Nada, significant differences in nodulation were determined. Considerable rainfall deficiency in 2002 had strong influence on all tested properties. The highest nitrogen content in soybean aerial parts as well as the seed yield were determined in application of indigenous B. japonicum strains S69 and S75. The obtained results suggest that these two indigenous strains can becharacterized as the most efficient ones and could be used for soybean inoculant production for that region.

  3. Easy storage strategies for Sporothrix spp. strains.

    Science.gov (United States)

    Brilhante, Raimunda Sâmia Nogueira; Silva, Natalya Fechine; Lima, Rita Amanda Chaves de; Caetano, Érica Pacheco; Alencar, Lucas Pereira de; Castelo-Branco, Débora de Souza Collares Maia; Moreira, José Luciano Bezerra; Bandeira, Silviane Praciano; Camargo, Zoilo Pires de; Rodrigues, Anderson Messias; Bandeira, Tereza de Jesus Pinheiro Gomes; Monteiro, André Jalles; Cordeiro, Rossana de Aguiar; Sidrim, José Júlio Costa; Rocha, Marcos Fábio Gadelha

    2015-04-01

    The present study evaluated the maintenance of Sporothrix spp. (6 Sporothrix brasiliensis; 6 S. schenckii; 5 S. mexicana, and 3 S. globosa) in saline at 4°C, and in 10% glycerol plus either 10% lactose or 10% sucrose, at -20°C and -80°C. Viability was assessed after 3, 6, and 9 months of storage, through the recovery of strains on potato dextrose agar and analysis of macro- and micromorphological features. Conidium quantification was performed before and after storage, at 3, 6 and 9 months. 100% viability was observed, regardless of storage conditions or time period. Storage at 4°C and at -20°C did not alter the number of conidia, but lower conidium counts were observed at -80°C. This study shows that the combination of glycerol with lactose or sucrose is effective to maintain Sporothrix spp. at freezing temperatures.

  4. Distributed perfluorinated POF strain sensor using OTDR and OFDR techniques

    Science.gov (United States)

    Liehr, Sascha; Wendt, Mario; Krebber, Katerina

    2009-10-01

    This paper presents the latest advances in distributed strain sensing using perfluorinated (PF) polymer optical fibers (POF). Compared to previously introduced PMMA POF strain sensors, PF POF have the advantage of lower loss and therefore extended measurement length of more than 500 m at increased spatial resolution of 10 cm. It is shown that PF POF can measure strain distributed up to 100 %. The characteristic backscatter signature of this fiber type provides additional evaluation possibilities. We show that, by applying a cross-correlation algorithm to the backscatter signal, the distributed length change can be measured along the fiber. We also present, to our knowledge for the first time, incoherent Optical Frequency Domain Reflectometry (OFDR) in POF to measure distributed reflections and loss along the fiber. The OFDR technique proves superior to existing OTDR techniques in measurement speed, resolution and potential instrument costs.

  5. Recombinant brewer's yeast strains suitable for accelerated brewing.

    Science.gov (United States)

    Suihko, M L; Blomqvist, K; Penttilä, M; Gisler, R; Knowles, J

    1990-06-01

    Four brewer's yeast strains carrying the alpha-ald gene of Klebsiella terrigena (ex. Aerobacter aerogenes) or of Enterobacter aerogenes on autonomously replicating plasmids were constructed. The alpha-ald genes were linked either to the ADC1 promoter or to the PGK1 promoter of yeast Saccharomyces cerevisiae. In pilot scale brewing (50 l) with three of these recombinant yeasts the formation of diacetyl in beer was so low during fermentation that lagering was not required. All other brewing properties of the strains were unaffected and the quality of finished beers was as good as that of finished beer prepared with the control strain. The total process time of beer production could therefore be reduced to 2 weeks, in contrast to about 5 weeks required in the conventional process.

  6. Fatigue crack identification method based on strain amplitude changing

    Science.gov (United States)

    Guo, Tiancai; Gao, Jun; Wang, Yonghong; Xu, Youliang

    2017-09-01

    Aiming at the difficulties in identifying the location and time of crack initiation in the castings of helicopter transmission system during fatigue tests, by introducing the classification diagnostic criteria of similar failure mode to find out the similarity of fatigue crack initiation among castings, an engineering method and quantitative criterion for detecting fatigue cracks based on strain amplitude changing is proposed. This method is applied on the fatigue test of a gearbox housing, whose results indicates: during the fatigue test, the system alarms when SC strain meter reaches the quantitative criterion. The afterwards check shows that a fatigue crack less than 5mm is found at the corresponding location of SC strain meter. The test result proves that the method can provide accurate test data for strength life analysis.

  7. Strain Assessment in Surgically Resected Inflammatory and Neoplastic Bowel Lesions

    DEFF Research Database (Denmark)

    Havre, R F; Leh, S; Gilja, O H

    2014-01-01

    Purpose: To investigate whether ultrasound-based strain imaging can discriminate between colorectal adenocarcinomas and stenotic Crohn's lesions in newly resected surgical specimens.Materials and Methods: Resected surgical specimens from 27 patients electively operated for colorectal tumors...... or stenotic lesions from Crohn's disease were prospectively examined with ultrasonography using a Hitachi HV 900 US scanner with real-time elastography (RTE). Three different methods were applied to assess tissue strain: A four-level categorical visual classification, a continuous visual analog scale (VAS, 0...... - 100) and a strain ratio (SR) measurement between the lesion and surrounding reference tissue. The imaged sections were marked and subsequently examined by a pathologist. Results from RTE were evaluated according to diagnosis, degree of fibrosis, inflammatory parameters, tumor stage and grade...

  8. Strain System for the Motion Base Shuttle Mission Simulator

    Science.gov (United States)

    Huber, David C.; Van Vossen, Karl G.; Kunkel, Glenn W.; Wells, Larry W.

    2010-01-01

    The Motion Base Shuttle Mission Simulator (MBSMS) Strain System is an innovative engineering tool used to monitor the stresses applied to the MBSMS motion platform tilt pivot frames during motion simulations in real time. The Strain System comprises hardware and software produced by several different companies. The system utilizes a series of strain gages, accelerometers, orientation sensor, rotational meter, scanners, computer, and software packages working in unison. By monitoring and recording the inputs applied to the simulator, data can be analyzed if weld cracks or other problems are found during routine simulator inspections. This will help engineers diagnose problems as well as aid in repair solutions for both current as well as potential problems.

  9. Thermal-Work Strain and Energy Expenditure during Marine Rifle Squad Operations in Afghanistan (August 2013)

    Science.gov (United States)

    2015-08-10

    TECHNICAL REPORT NO. T15-7 DATE August 2015 ADA THERMAL-WORK STRAIN AND ENERGY EXPENDITURE ...USARIEM TECHNICAL REPORT T15-7 THERMAL-WORK STRAIN AND ENERGY EXPENDITURE DURING MARINE RIFLE SQUAD OPERATIONS IN AFGHANISTAN...0704-0188 The public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for

  10. CHARACTERIZATION OF A NEW BACILLUS-STEAROTHERMOPHILUS ISOLATE - A HIGHLY THERMOSTABLE ALPHA-AMYLASE-PRODUCING STRAIN

    NARCIS (Netherlands)

    WIND, RD; BUITELAAR, RM; EGGINK, G; HUIZING, HJ; DIJKHUIZEN, L

    A novel strain of Bacillus stearothermophilus was isolated from samples of a potato-processing industry. Compared to known alpha-amylases from other B. stearothermophilus strains, the isolate was found to produce a highly thermostable alpha-amylase. The half-time of inactivation of this

  11. CHARACTERIZATION OF A NEW BACILLUS-STEAROTHERMOPHILUS ISOLATE - A HIGHLY THERMOSTABLE ALPHA-AMYLASE-PRODUCING STRAIN

    NARCIS (Netherlands)

    WIND, RD; BUITELAAR, RM; EGGINK, G; HUIZING, HJ; DIJKHUIZEN, L

    1994-01-01

    A novel strain of Bacillus stearothermophilus was isolated from samples of a potato-processing industry. Compared to known alpha-amylases from other B. stearothermophilus strains, the isolate was found to produce a highly thermostable alpha-amylase. The half-time of inactivation of this alpha-amylas

  12. Characterization of a new Bacillus stearothermophilus isolate : a highly thermostable α-amylase-producing strain

    NARCIS (Netherlands)

    Wind, R.D.; Buitelaar, R.M.; Eggink, G.; Huizing, H.J.; Dijkhuizen, L.

    1994-01-01

    A novel strain of Bacillus stearothermophilus was isolated from samples of a potato-processing industry. Compared to known α-amylases from other B. stearothermophilus strains, the isolate was found to produce a highly thermostable α-amylase. The half-time of inactivation of this α-amylase was 5.1 h

  13. Survival and resuscitation of ten strains of Campylobacter jejuni and Campylobacter coli under acid conditions

    NARCIS (Netherlands)

    Chaveerach, P.; Huurne, ter A.A.H.M.; Lipman, L.J.A.; Knapen, van F.

    2003-01-01

    The culturability of 10 strains of Campylobacter jejuni and Campylobacter coli was studied after the bacteria were exposed to acid conditions for various periods of time. Campylobacter cells could not survive 2 h under acid conditions (formic acid at pH 4). The 10 Campylobacter strains could not be

  14. Survival and resuscitation of ten strains of Campylobacter jejuni and Campylobacter coli under acid conditions

    NARCIS (Netherlands)

    Chaveerach, P.; Huurne, ter A.A.H.M.; Lipman, L.J.A.; Knapen, van F.

    2003-01-01

    The culturability of 10 strains of Campylobacter jejuni and Campylobacter coli was studied after the bacteria were exposed to acid conditions for various periods of time. Campylobacter cells could not survive 2 h under acid conditions (formic acid at pH 4). The 10 Campylobacter strains could not be

  15. Critical current degradation in HTS wires due to cyclic mechanical strain

    NARCIS (Netherlands)

    Ryan, David T.; Li, Liang; Huang, Xianrui; Bray, J.W.; Laskaris, Evangelos T.; Sivasubramaniam, Kiruba; Gadre, Aniruddha D.; Fogerty, James M.; Harley, E.J.; Otto, A.; Ouden, den A.

    2005-01-01

    HTS wires, which may be used in many devices such as magnets and rotating machines, may be subjected to mechanical strains from electromagnetic, thermal and centripetal forces. In some applications these strains will be repeated several thousand times during the lifetime of the device. We have measu

  16. On lower order strain gradient plasticity theories

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Hutchinson, J. W.

    2003-01-01

    the tangent moduli governing increments of stress and strain. It is shown that the modification is far from benign from a mathematical standpoint, changing the qualitative character of solutions and leading to a new type of localization that is at odds with what is expected from a strain gradient theory......By way of numerical examples, this paper explores the nature of solutions to a class of strain gradient plasticity theories that employ conventional stresses, equilibrium equations and boundary conditions. Strain gradients come into play in these modified conventional theories only to alter....... The findings raise questions about the physical acceptability of this class of strain gradient theories....

  17. Validation of a novel fiber optic strain gauge in a cryogenic and high magnetic field environment

    Science.gov (United States)

    Baxter, Scott; Lakrimi, M.'hamed; Thomas, Adrian M.; Gao, Yunxin; Blakes, Hugh; Gibbens, Paul; Looi, Mengche

    2010-10-01

    We report on the first operation of an easy to use low cost novel fiber optic strain gauge (FOSG) in cryogenic and magnetic field environments. The FOSGs were mounted on a superconducting coil and resin impregnated. The gauges detected resin shrinkage upon curing. On cooldown, the FOSG monitored the thermal contraction strains of the coil and the electromagnetic strain during energization. The coil was deliberately quenched, in excess of 175 times, and again the FOSG detected the quenches and measured the thermal expansion-induced strains and subsequent re-cooling of the coil after a quench. Agreement with FEA predictions was very good.

  18. Compressive and tensile strain sensing using a polymer planar Bragg grating.

    Science.gov (United States)

    Rosenberger, M; Hessler, S; Belle, S; Schmauss, B; Hellmann, R

    2014-03-10

    A polymer planar Bragg grating sensor is used for measuring both mechanical compressive and tensile strain. The planar waveguide with integrated Bragg grating is fabricated in bulk Polymethylmethacrylate in a single writing step using combined amplitude and phase mask technique. After butt coupling of a single-mode optical fiber the planar structure can be applied for measuring both mechanical tensile and compressive strain alongside the integrated waveguide without the need of further modifications. In this respect, we particularly report for the first time compressive strain measurements using a polymer Bragg grating. Furthermore, the sensitivity of the sensor against tensile and compressive strain, its reproducibility and hysteresis are investigated and discussed.

  19. Sports related hamstring strains--two cases with different etiologies and injury sites.

    Science.gov (United States)

    Askling, C; Tengvar, M; Saartok, T; Thorstensson, A

    2000-10-01

    Hamstring strains are common injuries in sports. Knowledge about their etiology and localization is, however, limited. The two cases described here both had acute hamstring strains, but the etiologies were entirely different. The sprinter was injured when running at maximal speed, whereas the hamstring strain in the dancer occurred during slow stretching. Also the anatomical localizations of the injuries clearly differed. Magnetic resonance imaging (MRI) revealed pathological changes in the distal semitendinosus muscle in the sprinter and the proximal tendon of the semimembranosus muscle in the dancer. Subjectively, both athletes severely underestimated the recovery time. These case observations suggest a possible link between etiology and localization of hamstring strains.

  20. Myocardial strain and strain rate from speckle-tracking echocardiography are unable to differentiate asymptomatic biopsy-proven cellular rejection in the first year after cardiac transplantation.

    Science.gov (United States)

    Ambardekar, Amrut V; Alluri, Nitya; Patel, Amit C; Lindenfeld, JoAnn; Dorosz, Jennifer L

    2015-04-01

    Cellular rejection after cardiac transplantation is treatable with timely diagnosis. Because noninvasive methods for diagnosis are limited, surveillance endomyocardial biopsies are routinely performed in the first year after transplantation. The aim of this study was to test whether myocardial strain and strain rate as assessed by speckle-tracking echocardiography would be a sensitive noninvasive method for the detection of asymptomatic rejection. Surveillance biopsies and echocardiograms obtained in the first year after transplantation were retrospectively reviewed, and patients with asymptomatic biopsy-proven cellular rejection were identified, as well as control transplantation patients without rejection or cardiac complications. Circumferential and longitudinal strain and strain rate were measured using Velocity Vector Imaging software from echocardiograms performed at three time points for patients with rejection-baseline (no rejection), rejection, and resolution (of rejection)-and three time points for control patients-baseline (within the first month after transplantation), 6 months, and 12 months after transplantation. Speckle-tracking strain and strain rate measurements were obtained from 30 patients with asymptomatic biopsy-proven rejection and 14 control transplantation patients. There were no significant differences in circumferential and longitudinal strain or strain rate between the baseline, rejection, and resolution studies. Furthermore, there were no significant differences in strain and strain rate in control transplantation patients during the first year after transplantation or compared with patients with rejection. Speckle-tracking analysis was unable to detect changes on serial studies from patients with asymptomatic rejection and thus cannot replace biopsy. Other noninvasive methods for the diagnosis of cellular-mediated rejection are needed. Copyright © 2015 American Society of Echocardiography. Published by Elsevier Inc. All rights

  1. Molecular characterization of Salmonella Typhimurium highly successful outbreak strains.

    Science.gov (United States)

    Petersen, Randi Føns; Litrup, Eva; Larsson, Jonas T; Torpdahl, Mia; Sørensen, Gitte; Müller, Luise; Nielsen, Eva M

    2011-06-01

    Three large clusters of Salmonella Typhimurium infections in Denmark in 2008 and 2009 were defined by multilocus variable number of tandem repeat analysis (MLVA). One of these proved to be the hereto largest Danish cluster of salmonellosis with 1446 cases. Two smaller clusters with a total of 197 and 89 cases, respectively, were seen concurrently. These clusters shared epidemiological characteristics such as age distribution, geography, and time. To investigate the possible genetic relationship between the cluster strains, these were further characterized by phage typing, pulsed-field gel electrophoresis, and Optical Mapping. Although the MLVA method proved robust and well-performing in detecting and defining clusters, the employment of a second typing method detected an additional fourth cluster among the isolates. The cluster strains were stable throughout the almost 2-year period, even though we detected changes in three of five MLVA loci in a small fraction of isolates. These changes were mainly due to the gain or loss of single repeats. Optical Mapping of the large cluster strain indicated no increased content of virulence genes; however, Optical Mapping did reveal a large insert, a probable prophage, in the main cluster. This probable prophage may give the cluster strain a competitive advantage. The molecular methods employed suggested that the four clusters represented four distinct strains, although they seemed to be epidemiologically linked and shared genotypic characteristics.

  2. Test-retest repeatability of the Strain Index.

    Science.gov (United States)

    Stephens, John-Paul; Vos, Gordon A; Stevens, Edward M; Moore, J Steven

    2006-05-01

    Fifteen raters individually, and in five teams of three, evaluated the test-retest repeatability of published data collection and rating methods of the Strain Index by analyzing 61 job video files twice over a 5-month period. Raters estimated average and peak hand forces, measured Duration of Exertion, cycle time, and exertions per job cycle, calculated percent Duration of Exertion and Efforts per Minute, and assigned ratings for five of the six Strain Index task variables. Twelve additional jobs were analyzed to determine Strain Index Score and hazard classification. Intraclass correlation (ICC) coefficients for task variable ratings and accompanying data ranged from 0.66 to 0.95 for both individuals and teams. The Strain Index Score ICC(2,1) for individuals and teams were 0.56 and 0.82, respectively. Intra-rater reliability for the hazard classification was 0.81 for individuals and 0.88 for teams. The results indicate that the Strain Index has good test-retest reliability.

  3. Ultrasound strain imaging for quantification of tissue function: cardiovascular applications

    Science.gov (United States)

    de Korte, Chris L.; Lopata, Richard G. P.; Hansen, Hendrik H. G.

    2013-03-01

    With ultrasound imaging, the motion and deformation of tissue can be measured. Tissue can be deformed by applying a force on it and the resulting deformation is a function of its mechanical properties. Quantification of this resulting tissue deformation to assess the mechanical properties of tissue is called elastography. If the tissue under interrogation is actively deforming, the deformation is directly related to its function and quantification of this deformation is normally referred as `strain imaging'. Elastography can be used for atherosclerotic plaques characterization, while the contractility of the heart or skeletal muscles can be assessed with strain imaging. We developed radio frequency (RF) based ultrasound methods to assess the deformation at higher resolution and with higher accuracy than commercial methods using conventional image data (Tissue Doppler Imaging and 2D speckle tracking methods). However, the improvement in accuracy is mainly achieved when measuring strain along the ultrasound beam direction, so 1D. We further extended this method to multiple directions and further improved precision by using compounding of data acquired at multiple beam steered angles. In arteries, the presence of vulnerable plaques may lead to acute events like stroke and myocardial infarction. Consequently, timely detection of these plaques is of great diagnostic value. Non-invasive ultrasound strain compounding is currently being evaluated as a diagnostic tool to identify the vulnerability of plaques. In the heart, we determined the strain locally and at high resolution resulting in a local assessment in contrary to conventional global functional parameters like cardiac output or shortening fraction.

  4. Relatedness of medically important strains of Saccharomyces cerevisiae as revealed by phylogenetics and metabolomics.

    Science.gov (United States)

    MacKenzie, Donald A; Defernez, Marianne; Dunn, Warwick B; Brown, Marie; Fuller, Linda J; de Herrera, Santiago R M Seco; Günther, Andreas; James, Steve A; Eagles, John; Philo, Mark; Goodacre, Royston; Roberts, Ian N

    2008-07-01

    Ten medically important Saccharomyces strains, comprising six clinical isolates of Saccharomyces cerevisiae and four probiotic strains of Saccharomyces boulardii, were characterized at the genetic and metabolic level and compared with non-medical, commercial yeast strains used in baking and wine-making. Strains were compared by genetic fingerprinting using amplified fragment length polymorphism (AFLP) analysis, by ribosomal DNA ITS1 sequencing and by metabolic footprinting using both direct injection mass spectrometry (DIMS) and gas chromatography-time of flight-mass spectrometry (GC-ToF-MS). Overall, the clinical isolates fell into different groupings when compared with the non-medical strains, with good but not perfect correlation amongst strains at both the genetic and metabolic levels. Probiotic strains of S. boulardii that are used therapeutically to treat human gastro-intestinal tract disorders showed tight clustering both genetically and metabolically. Metabolomics was found to be of value both as a taxonomic tool and as a means to investigate anomalous links between genotype and phenotype. Key discriminatory metabolites were identified when comparing the three main groups of clinical, probiotic and non-medical strains and included molecules such as trehalose, myo-inositol, lactic acid, fumaric acid and glycerol 3-phosphate. This study confirmed the link between a subset of clinical isolates and baking or probiotic strains but also highlighted that in general the clinical strains were more diverse at both the genomic and metabolic levels.

  5. Enhanced ethanol fermentation by engineered Saccharomyces cerevisiae strains with high spermidine contents.

    Science.gov (United States)

    Kim, Sun-Ki; Jo, Jung-Hyun; Jin, Yong-Su; Seo, Jin-Ho

    2017-05-01

    Construction of robust and efficient yeast strains is a prerequisite for commercializing a biofuel production process. We have demonstrated that high intracellular spermidine (SPD) contents in Saccharomyces cerevisiae can lead to improved tolerance against various fermentation inhibitors, including furan derivatives and acetic acid. In this study, we examined the potential applicability of the S. cerevisiae strains with high SPD contents under two cases of ethanol fermentation: glucose fermentation in repeated-batch fermentations and xylose fermentation in the presence of fermentation inhibitors. During the sixteen times of repeated-batch fermentations using glucose as a sole carbon source, the S. cerevisiae strains with high SPD contents maintained higher cell viability and ethanol productivities than a control strain with lower SPD contents. Specifically, at the sixteenth fermentation, the ethanol productivity of a S. cerevisiae strain with twofold higher SPD content was 31% higher than that of the control strain. When the SPD content was elevated in an engineered S. cerevisiae capable of fermenting xylose, the resulting S. cerevisiae strain exhibited much 40-50% higher ethanol productivities than the control strain during the fermentations of synthetic hydrolysate containing high concentrations of fermentation inhibitors. These results suggest that the strain engineering strategy to increase SPD content is broadly applicable for engineering yeast strains for robust and efficient production of ethanol.

  6. Myocardial strain imaging: how useful is it in clinical decision making?

    Science.gov (United States)

    Smiseth, Otto A; Torp, Hans; Opdahl, Anders; Haugaa, Kristina H; Urheim, Stig

    2016-04-14

    Myocardial strain is a principle for quantification of left ventricular (LV) function which is now feasible with speckle-tracking echocardiography. The best evaluated strain parameter is global longitudinal strain (GLS) which is more sensitive than left ventricular ejection fraction (LVEF) as a measure of systolic function, and may be used to identify sub-clinical LV dysfunction in cardiomyopathies. Furthermore, GLS is recommended as routine measurement in patients undergoing chemotherapy to detect reduction in LV function prior to fall in LVEF. Intersegmental variability in timing of peak myocardial strain has been proposed as predictor of risk of ventricular arrhythmias. Strain imaging may be applied to guide placement of the LV pacing lead in patients receiving cardiac resynchronization therapy. Strain may also be used to diagnose myocardial ischaemia, but the technology is not sufficiently standardized to be recommended as a general tool for this purpose. Peak systolic left atrial strain is a promising supplementary index of LV filling pressure. The strain imaging methodology is still undergoing development, and further clinical trials are needed to determine if clinical decisions based on strain imaging result in better outcome. With this important limitation in mind, strain may be applied clinically as a supplementary diagnostic method.

  7. Demonstration test of burner liner strain measurements using resistance strain gages

    Science.gov (United States)

    Grant, H. P.; Anderson, W. L.

    1984-01-01

    A demonstration test of burner liner strain measurements using resistance strain gages as well as a feasibility test of an optical speckle technique for strain measurement are presented. The strain gage results are reported. Ten Kanthal A-1 wire strain gages were used for low cycle fatigue strain measurements to 950 K and .002 apparent strain on a JT12D burner can in a high pressure (10 atmospheres) burner test. The procedure for use of the strain gages involved extensive precalibration and postcalibration to correct for cooling rate dependence, drift, and temperature effects. Results were repeatable within + or - .0002 to .0006 strain, with best results during fast decels from 950 K. The results agreed with analytical prediction based on an axisymmetric burner model, and results indicated a non-uniform circumferential distribution of axial strain, suggesting temperature streaking.

  8. Enhanced dopant solubility in strained silicon

    Energy Technology Data Exchange (ETDEWEB)

    Adey, J [School of Physics, University of Exeter, Exeter EX4 4QL (United Kingdom); Jones, R [School of Physics, University of Exeter, Exeter EX4 4QL (United Kingdom); Briddon, P R [Physics Centre, School of Natural Science, Newcastle upon Tyne NE1 7RU (United Kingdom)

    2004-12-22

    The effect of biaxial strain on the solubility of the common donor arsenic and acceptor boron is calculated using spin-polarized local density functional theory. The change in solubility with strain is considered in terms of contributions from the change in total energy and Fermi energy with strain. The solubility of boron is found to be enhanced by compressive biaxial strain due to a reduction in the total energy of the small substitutional impurity and an increase in the Fermi energy for compressive strain. The solubility of arsenic is shown to be enhanced by tensile strain and this is due entirely to the change in Fermi energy. For boron as well as arsenic the change in Fermi energy with strain is shown to make the dominant contribution.

  9. Quantitative determination of gibberellins by high performance liquid chromatography from various gibberellins producing Fusarium strains.

    Science.gov (United States)

    Bhalla, Kirti; Singh, Shashi Bala; Agarwal, Rashmi

    2010-08-01

    High performance liquid chromatographic (HPLC) method was developed for analysis of seven gibberellins, i.e., GA3, GA4, GA7, GA3 methyl ester, GA7 methyl ester 3,13 diacetate, GA7 methyl ester, and fusaric acid, using an isocratic system. Method was used for estimation of gibberellins from different Fusarium strains. Gibberellins were extracted from 28 strains of Fusarium, out of which six strains of Fusarium were isolated from soil of different parts of India and 22 strains were procured from the Indian Type Culture Collection, Indian Agricultural Research Institute, New Delhi. Extracts were analyzed for qualitative and quantitative estimation of gibberellins by thin layer chromatography and HPLC, respectively. On the basis of quantitative analysis of produced gibberellins by HPLC, they were categorized as low, moderate, and high gibberellin producing strain. For the first time, Fusarium solani was also reported as high GA3 producing strain.

  10. Thermoresistive strain sensor and positioning method for roll-to-roll processes.

    Science.gov (United States)

    Liao, Kuan-Hsun; Lo, Cheng-Yao

    2014-05-05

    This study uses the Joule heating effect-generated temperature difference to monitor in real-time and localize both compressive and tensile strains for the polymer substrates used in the roll-to-roll process. A serpentine gold (Au) line was patterned on a polyethylenenaphthalate (PEN) substrate to form the strain sensor based on thermoresistive behavior. This strain sensor was then subjected to either current or voltage to induce the Joule heating effect on the Au resistor. An infrared (IR) detector was used to monitor the strain-induced temperature difference on the Au and PEN surfaces and the minimal detectable bending radius was 0.9 mm with a gauge factor (GF) of 1.46. The proposed design eliminates the judgment ambiguity from conventional resistive strain sensors where resistance is the only physical quantity monitored. This study precisely and successfully indicated the local strain quantitatively and qualitatively with complete simulations and measurements.

  11. Thermoresistive Strain Sensor and Positioning Method for Roll-to-Roll Processes

    Directory of Open Access Journals (Sweden)

    Kuan-Hsun Liao

    2014-05-01

    Full Text Available This study uses the Joule heating effect-generated temperature difference to monitor in real-time and localize both compressive and tensile strains for the polymer substrates used in the roll-to-roll process. A serpentine gold (Au line was patterned on a polyethylenenaphthalate (PEN substrate to form the strain sensor based on thermoresistive behavior. This strain sensor was then subjected to either current or voltage to induce the Joule heating effect on the Au resistor. An infrared (IR detector was used to monitor the strain-induced temperature difference on the Au and PEN surfaces and the minimal detectable bending radius was 0.9 mm with a gauge factor (GF of 1.46. The proposed design eliminates the judgment ambiguity from conventional resistive strain sensors where resistance is the only physical quantity monitored. This study precisely and successfully indicated the local strain quantitatively and qualitatively with complete simulations and measurements.

  12. Structural Damage Identification via Pseudo Strain Energy Density and Wavelet Packet Transform

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao-qiang; ZHU Hong-ping; GE Dong-dong

    2009-01-01

    Based on strain signals,a new time-domain methodology for detecting the beam local damage has been developed.The pseudo strain energy density (PSED) is defined and used to build two major damage indexes,the average pseudo strain energy density (APSED) and the average pseudo strain energy density rate (APSEDR).Probability and mathematical statistics are utilized to derive a standardized damage index.Furthermore,by applying the analytic relation between the strain energy release rate and the stress intensity factor,an analytic solution of crack depth is derived.For the dynamic strain signals,the wavelet packet transform is used to pre-process measured data.Finally,a numerical simulation indicates that this method can effectively identify the damage location and its absolute severity.

  13. Strain diversity plays no major role in the varying efficacy of rotavirus vaccines: an overview.

    Science.gov (United States)

    Velasquez, Daniel E; Parashar, Umesh D; Jiang, Baoming

    2014-12-01

    While a monovalent Rotarix® [RV1] and a pentavalent RotaTeq® [RV5] have been extensively tested and found generally safe and equally efficacious in clinical trials, the question still lingers about the evolving diversity of circulating rotavirus strains over time and their relationship with protective immunity induced by rotavirus vaccines. We reviewed data from clinical trials and observational studies that assessed the efficacy or field effectiveness of rotavirus vaccines against different rotavirus strains worldwide. RV1 provided broad clinical efficacy and field effectiveness against severe diarrhea due to all major circulating strains, including the homotypic G1P[8] and the fully heterotypic G2P[4] strains. Similarly, RV5 provided broad efficacy and effectiveness against RV5 and non-RV5 strains throughout different locations. Rotavirus vaccination provides broad heterotypic protection; however continuing surveillance is needed to track the change of circulating strains and monitor the effectiveness and safety of vaccines.

  14. Evidence for co-infection of ovine prion strains in classical scrapie isolates.

    Science.gov (United States)

    Thackray, A M; Lockey, R; Beck, K E; Spiropoulos, J; Bujdoso, R

    2012-01-01

    The diversity of strains of ovine prions within classical scrapie isolates was investigated by transmission studies in wild type mice. To determine the maximum diversity of prion strains present in each ovine scrapie isolate examined, isolates from mice having the shortest and longest incubation times for terminal disease after primary inoculation were passaged serially. Serial passage of ARQ/ARQ scrapie isolates in RIII mice revealed the ME7 prion strain in mice with short incubation times for terminal prion disease and the 87A strain in those mice with long incubation times. Serial passage of VRQ/VRQ scrapie isolates in RIII mice led to emergence of the 221C prion strain in mice with short incubation times and a variant of the 221C strain in those mice with long incubation times. RIII mice with short incubation times had higher levels of total and proteinase K-resistant PrP(Sc) compared with those RIII mice with long incubation times, while mice with long incubation times had large aggregates and plaques of PrP(Sc). ME7 PrP(Sc) differed in stability compared with the 87A prion strain, while PrP(Sc) associated with 221C had similar stability to that of the 221C variant. Serial passage in VM mice led to identification of ME7 and 87V in the same scrapie isolate. The data show that different prion strains can emerge from the same ovine scrapie isolate following serial passage in wild type mice and that the transmission properties of these strains correlate with distinct patterns of PrP(Sc) deposition.

  15. Model-based testing for space-time interaction using point processes: An application to psychiatric hospital admissions in an urban area

    CERN Document Server

    Meyer, Sebastian; Rössler, Wulf; Held, Leonhard

    2015-01-01

    Spatio-temporal interaction is inherent to cases of infectious diseases and occurrences of earthquakes, whereas the spread of other events, such as cancer or crime, is less evident. Statistical significance tests of space-time clustering usually assess the correlation between the spatial and temporal (transformed) distances of the events. Although appealing through simplicity, these classical tests do not adjust for the underlying population nor can they account for a distance decay of interaction. We propose to use the framework of an endemic-epidemic point process model to jointly estimate a background event rate explained by seasonal and areal characteristics, as well as a superposed epidemic component representing the hypothesis of interest. We illustrate this new model-based test for space-time interaction by analysing psychiatric inpatient admissions in Zurich, Switzerland (2007-2012). Several socio-economic factors were found to be associated with the admission rate, but there was no evidence of genera...

  16. Invariance of conductivity relaxation under pressure and temperature variations at constant conductivity relaxation time in 0.4Ca(NO₃)₂-0.6KNO₃.

    Science.gov (United States)

    Wojnarowska, Z; Ngai, K L; Paluch, M

    2014-12-01

    The article reports the dependence of the conductivity relaxation on temperature T and pressure P in the canonical ionic glass former 0.4Ca(NO(3))(2)-0.6KNO(3)(CKN). At constant conductivity relaxation time τ(σ), the entire conductivity relaxation spectra obtained at widely different combinations of T and P superpose almost perfectly, and thus it is the ion-ion interaction but not thermodynamics that determines the frequency dispersion. Moreover, on vitrifying CKN by either elevating P or decreasing T, changes of P or T dependence of τ(σ) at the glass transition pressure P(g) and temperature T(g) are observed to occur at the same value, i.e., τ(σ)(P(g))=τ(σ)(T(g)), indicating that the relation between τ(σ) and the structural relaxation time τ(α) is also independent of P and T.

  17. EDITORIAL: Excelling under strain: band engineering in nanomaterials Excelling under strain: band engineering in nanomaterials

    Science.gov (United States)

    Demming, Anna

    2013-08-01

    , 'We must be clear that when it comes to atoms, language can be used only as in poetry. The poet, too, is not nearly so concerned with describing facts as with creating images and establishing mental connections' [8]. Images have been central to the communication and description of the Bohr-Rutherford model described in 1913, yet the paper itself uses none, and is typical of scientific communications at the time. In fact the text itself makes an eloquent redundancy of accompanying figures but it is interesting to note in comparison with the more technologically advanced channels for current science communications that are so thankfully profuse in images and multimedia. Obviously there is now much more experimental work on systems at the nanoscale and below than a hundred years ago and this also contributes to the greater wealth of images in today's reports. The report by Nrauda and colleagues in this issue is a great example with a wide range of annotated atomic force and transmission electron microscope images, reciprocal space maps and line plots, each image speaking a thousand words and communicating the results with an immediacy that outstrips any narrative. Yet the text serves an indispensable function in relaying the insights derived from analysis of the data, suggesting growth mechanisms, driving forces and expanding the existing understanding of these systems—as Bohr might put it, adding the poetry. References [1] Bohr N 1913 On the constitution of atoms and molecules Phil. Mag 26 1 [2] Hrauda N, Zhang J J, Groiss H, Etzelstorfer T, Holý V, Bauer G, Deiter C, Seeck O H and Stangl J 2013 Strain relief and shape oscillations in site-controlled coherent SiGe islands Nanotechnology 24 335707 [3] Hall H H, Bardeen J and Pearson G L 1951 The effects of pressure and temperature on the resistance of p-n junctions in germanium Phys. Rev. 84 129-32 [4] Smith C S 1954 Piezoresistance effect in germanium and silicon Phys. Rev. 94 42-9 [5] Wei N, Xu L, Wang H-Q and Zheng

  18. 'Serious thigh muscle strains': beware the intramuscular tendon which plays an important role in difficult hamstring and quadriceps muscle strains.

    Science.gov (United States)

    Brukner, Peter; Connell, David

    2016-02-01

    Why do some hamstring and quadriceps strains take much longer to repair than others? Which injuries are more prone to recurrence? Intramuscular tendon injuries have received little attention as an element in 'muscle strain'. In thigh muscles, such as rectus femoris and biceps femoris, the attached tendon extends for a significant distance within the muscle belly. While the pathology of most muscle injures occurs at a musculotendinous junction, at first glance the athlete appears to report pain within a muscle belly. In addition to the musculotendinous injury being a site of pathology, the intramuscular tendon itself is occasionally injured. These injuries have a variety of appearances on MRIs. There is some evidence that these injuries require a prolonged rehabilitation time and may have higher recurrence rates. Therefore, it is important to recognise the tendon component of a thigh 'muscle strain'.

  19. Measuring and modelling straining of Escherichia coli in saturated porous media.

    Science.gov (United States)

    Foppen, Jan Willem; van Herwerden, Manon; Schijven, Jack

    2007-08-15

    Though coliform bacteria are used worldwide to indicate fecal pollution of groundwater, the parameters determining the transport of Escherichia coli in aquifers are relatively unknown. We evaluated the occurrence of both straining and attachment of E. coli ATCC25922 in columns of ultra-pure, angular, saturated quartz sand. The column experiments were conducted over a wide range of porous medium sizes, column heights, input concentrations, and pore water flow velocities. Straining and attachment were examined by modelling the breakthrough curves (with HYDRUS 1D). In addition, model output was compared with measured strained and attached bacteria via column extrusion experiments (in which sand was extruded from the column and placed in excess water) and flow reversal experiments (in which the pore water flow direction was reversed, thereby dislodging strained bacteria). Our model consisted of an attachment rate coefficient and a straining rate coefficient; both of these decreased with transport distance. The straining rate coefficient also decreased in a Langmuirian way, in response to the filling of available pore space, which in turn depended on influent bacteria concentration, quartz grain diameter, and transport distance. The maximum strained fraction was 25-30% of total bacteria mass applied to the column; the maximum attached fraction was 30-35%. The fit between modelled and measured (strained and attached) bacteria masses was acceptable, as was the sensitivity of the model output to fitted parameter values. Our results lead to a new description for the time-dependent mass balance of strained bacteria, which entails using three fitting parameters. The results also imply that column experiments in combination with retention profiles (or various column lengths) are not enough to explain the retention processes in a column. Column extrusion and flow reversal experiments provide vital additional information on the occurrence and magnitude of straining. Our

  20. A duplex PCR assay for the detection of Ralstonia solanacearum phylotype II strains in Musa spp.

    Directory of Open Access Journals (Sweden)

    Gilles Cellier

    Full Text Available Banana wilt outbreaks that are attributable to Moko disease-causing strains of the pathogen Ralstonia solanacearum (Rs remain a social and economic burden for both multinational corporations and subsistence farmers. All known Moko strains belong to the phylotype II lineage, which has been previously recognized for its broad genetic basis. Moko strains are paraphyletic and are distributed among seven related but distinct phylogenetic clusters (sequevars that are potentially major threats to Musaceae, Solanaceae, and ornamental crops in many countries. Although clustered within the Moko IIB-4 sequevar, strains of the epidemiologically variant IIB-4NPB do not cause wilt on Cavendish or plantain bananas; instead, they establish a latent infection in the vascular tissues of plantains and demonstrate an expanded host range and high aggressiveness toward Solanaceae and Cucurbitaceae. Although most molecular diagnostic methods focus on strains that wilt Solanaceae (particularly potato, no relevant protocol has been described that universally detects strains of the Musaceae-infecting Rs phylotype II. Thus, a duplex PCR assay targeting Moko and IIB-4NPB variant strains was developed, and its performance was assessed using an extensive collection of 111 strains representing the known diversity of Rs Moko-related strains and IIB-4NPB variant strains along with certain related strains and families. The proposed diagnostic protocol demonstrated both high accuracy (inclusivity and exclusivity and high repeatability, detected targets on either pure culture or spiked plant extracts. Although they did not belong to the Moko clusters described at the time of the study, recently discovered banana-infecting strains from Brazil were also detected. According to our comprehensive evaluation, this duplex PCR assay appears suitable for both research and diagnostic laboratories and provides reliable detection of phylotype II Rs strains that infect Musaceae.

  1. Measurement and Modeling of Sorption-Induced Strain and Permeability Changes in Coal

    Energy Technology Data Exchange (ETDEWEB)

    Eric P. Robertson

    2005-10-01

    Strain caused by the adsorption of gases was measured in samples of subbituminous coal from the Powder River basin of Wyoming, U.S.A., and high-volatile bituminous coal from the Uinta-Piceance basin of Utah, U.S.A. using a newly developed strain measurement apparatus. The apparatus can be used to measure strain on multiple small coal samples based on the optical detection of the longitudinal strain. The swelling and shrinkage (strain) in the coal samples resulting from the adsorption of carbon dioxide, nitrogen, methane, helium, and a mixture of gases was measured. Sorption-induced strain processes were shown to be reversible and easily modeled with a Langmuir-type equation. Extended Langmuir theory was applied to satisfactorily model strain caused by the adsorption of gas mixtures using the pure gas Langmuir strain constants. The amount of time required to obtain accurate strain data was greatly reduced compared to other strain measurement methods. Sorption-induced changes in permeability were also measured as a function of pres-sure. Cleat compressibility was found to be variable, not constant. Calculated variable cleat-compressibility constants were found to correlate well with previously published data for other coals. During permeability tests, sorption-induced matrix shrinkage was clearly demonstrated by higher permeability values at lower pore pressures while holding overburden pressure constant. Measured permeability data were modeled using three dif-ferent permeability models from the open literature that take into account sorption-induced matrix strain. All three models poorly matched the measured permeability data because they overestimated the impact of measured sorption-induced strain on permeabil-ity. However, by applying an experimentally derived expression to the measured strain data that accounts for the confining overburden pressure, pore pressure, coal type, and gas type, the permeability models were significantly improved.

  2. Temperature affects the morphology and calcification of Emiliania huxleyi strains

    Science.gov (United States)

    Rosas-Navarro, Anaid; Langer, Gerald; Ziveri, Patrizia

    2016-05-01

    The global warming debate has sparked an unprecedented interest in temperature effects on coccolithophores. The calcification response to temperature changes reported in the literature, however, is ambiguous. The two main sources of this ambiguity are putatively differences in experimental setup and strain specificity. In this study we therefore compare three strains isolated in the North Pacific under identical experimental conditions. Three strains of Emiliania huxleyi type A were grown under non-limiting nutrient and light conditions, at 10, 15, 20 and 25 °C. All three strains displayed similar growth rate versus temperature relationships, with an optimum at 20-25 °C. Elemental production (particulate inorganic carbon (PIC), particulate organic carbon (POC), total particulate nitrogen (TPN)), coccolith mass, coccolith size, and width of the tube element cycle were positively correlated with temperature over the sub-optimum to optimum temperature range. The correlation between PIC production and coccolith mass/size supports the notion that coccolith mass can be used as a proxy for PIC production in sediment samples. Increasing PIC production was significantly positively correlated with the percentage of incomplete coccoliths in one strain only. Generally, coccoliths were heavier when PIC production was higher. This shows that incompleteness of coccoliths is not due to time shortage at high PIC production. Sub-optimal growth temperatures lead to an increase in the percentage of malformed coccoliths in a strain-specific fashion. Since in total only six strains have been tested thus far, it is presently difficult to say whether sub-optimal temperature is an important factor causing malformations in the field. The most important parameter in biogeochemical terms, the PIC : POC ratio, shows a minimum at optimum growth temperature in all investigated strains. This clarifies the ambiguous picture featuring in the literature, i.e. discrepancies between PIC : POC

  3. Characterization of dynamic three-dimensional strain fields in the canine radius.

    Science.gov (United States)

    Coleman, John C; Hart, Richard T; Owan, Ichiro; Tankano, Yuichi; Burr, David B

    2002-12-01

    This note describes a method to approximate the 3-D mechanical environment of a long bone during a normal daily activity. Our specific goal was to characterize the temporal and spatial strain distributions in the mid-shaft region of the canine radius during gait. Direct measurement of strains along the entire surface of in vivo bone is not feasible, so we employed a combination of experimental measurements and numerical interpolation techniques to approximate the time-varying longitudinal strain distribution. Using standard in vivo strain gauging techniques, we measured dynamic strains at nine locations (three locations on each of three cross sections, data pooled from two experimental animals) on the canine radius during trotting gait. These in vivo strain measurements were then used to approximate the time course of the strain field for the entire radius mid-shaft region using a 3-D numerical interpolation scheme using finite element basis functions. Despite limitations in the present implementation of the method, the results show that there are considerable time-dependent variations in the strain distribution occurring at different transverse sections along the length of the diaphysis with substantial anteroposterior bending and rotation of neutral axis locations during the gait cycle.

  4. Multiplicative earthquake likelihood models incorporating strain rates

    Science.gov (United States)

    Rhoades, D. A.; Christophersen, A.; Gerstenberger, M. C.

    2017-01-01

    SUMMARYWe examine the potential for strain-rate variables to improve long-term earthquake likelihood models. We derive a set of multiplicative hybrid earthquake likelihood models in which cell rates in a spatially uniform baseline model are scaled using combinations of covariates derived from earthquake catalogue data, fault data, and strain-rates for the New Zealand region. Three components of the strain rate estimated from GPS data over the period 1991-2011 are considered: the shear, rotational and dilatational strain rates. The hybrid model parameters are optimised for earthquakes of M 5 and greater over the period 1987-2006 and tested on earthquakes from the period 2012-2015, which is independent of the strain rate estimates. The shear strain rate is overall the most informative individual covariate, as indicated by Molchan error diagrams as well as multiplicative modelling. Most models including strain rates are significantly more informative than the best models excluding strain rates in both the fitting and testing period. A hybrid that combines the shear and dilatational strain rates with a smoothed seismicity covariate is the most informative model in the fitting period, and a simpler model without the dilatational strain rate is the most informative in the testing period. These results have implications for probabilistic seismic hazard analysis and can be used to improve the background model component of medium-term and short-term earthquake forecasting models.

  5. Effect of Mn on strain accumulation in Nb microalloying steels

    Institute of Scientific and Technical Information of China (English)

    ZHU Guohui; S.V.Subramanian

    2007-01-01

    High Mn is added in line pipe steels to strengthen them.Also,Mn lowers the phase transformation temperature,which is an advantage because it lowers the rolling temperature for grain size control.However,Mn retards the kinetics of precipitation Of NbC in thermo-mechanical processing in Nb microalloying steels.In high-grade line pipe steels,the control of strain accumulation behavior is the key to the control of grain size.Strain accumulation can only be obtained when static recrystallization between passes could be suppressed.The effect of NbC precipitates on suppressing recrystallization has been widely investigated,mostly focusing on the Zener pinning of NbC on grain boundaries.However,it is applicable in large strain and long inter-pass time.In short inter-pass time,such as strip mill rolling,recrystallization behavior is controlled by the complicated interaction of precipitation with recovery and recrystallization.In this paper,the effect of Mn on strain accumulation during multi-pass strip mill rolling based on the interaction of precipitates with the activation energy of grain boundary migration and recovery,and the thermodynamics and kinetics of recrystallization are discussed systematically.

  6. Evaluation of left ventricular strain by real-time three-dimensional speckle tracking echocardiography in patients with hypertension and myocardial hypertrophy%实时三维超声心动图斑点追踪技术测量高血压心肌肥厚患者收缩期左室心肌应变

    Institute of Scientific and Technical Information of China (English)

    汤乔颖; 邓又斌; 黄润青; 刘琨; 孙杰; 邓琪

    2013-01-01

    Objective To investigate left ventricular (LV) strain in patients with hypertension (HT)and myocardial hypertrophy using three-dimensional speckle tracking echocardiography.Methods Myocardial movement was analyzed in 37 primary HT patients with myocardial hypertrophy and 27 healthy volunteers.LV longitudinal,circumferential,radial and area strains were measured.The correlation between each global strain parameter and LV ejection fraction (LVEF) was analyzed.Results LV global longitudinal strain(GSL),global radial strain (GSR) and global area strain (GSA) of HT patients with myocardial hypertrophy were significantly lower than the contrast group,whereas global circumferential strain(GSC) showed no significant difference between the two groups.Longitudinal,radial and area strains were decreased in LV basal and middle levels,while decreased circumferential strain was detected only in basal level.There were significant correlations between LVEF and GSL,GSC,GSR,GSA.Conclusions Impairment of LV regional myocardial contractility can be detected by three-dimensional speckle tracking echocardiography.%目的 采用实时三维超声心动图斑点追踪技术研究原发性高血压心肌肥厚患者的收缩期左室心肌应变特点.方法 采用三维超声心动图斑点追踪技术对37例原发性高血压心肌肥厚患者及27例健康志愿者进行了室壁运动分析,测量左室纵向、圆周向、径向、面积应变,比较两组间各应变参数的差异,并分析各项整体应变参数与左室射血分数(LVEF)的相关性.结果 高血压心肌肥厚患者的左室整体纵向、径向和面积应变较正常对照组明显减低,左室整体圆周向应变与对照组间无明显差异.纵向、径向、圆周向应变在左室基底段、中段明显减低,圆周向应变减低仅见于基底段.左室整体纵向、圆周向、径向、面积应变与LVEF具有相关性.结论 实时三维超声心动图斑点追踪技术可检测到高血压心

  7. Strain Measurement for Hollow Projectiles During Its Penetration of Concrete Targets

    Institute of Scientific and Technical Information of China (English)

    王琳; 王富耻; 王鲁; 李树奎

    2004-01-01

    Gives a new technique to measure the dynic deformation behavior and strain development of a hollow steel projectile during its penetration of concrete targets. Direct strain measurement was performed by applying strain gages attached to the inner walls of the hollow projectile, linked with on-board testing and storage recorder. This on-board test-record system is easy to operate, cost-effective and can provide reasonable, accurate and detailed information. Obverse ballistic experiments were carried out on ogival-nose hollow projectiles normally impacting concrete targets at velocities from 150 m/s to 300 m/s. The deformation process of projectiles was measured, recorded and played back. Profiles of voltage-time relationship were successively obtained and transfered to strain-time relationship with the aid of calibration tables. It was found that projectiles go through a series of compression and tension deformations intermittently. Relationships between strain development and projectile deformation process were discussed.

  8. Computational Strain Gradient Crystal Plasticity

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Kysar, Jeffrey W.

    2011-01-01

    A model for strain gradient crystal visco-plasticity is formulated along the lines proposed by Fleck andWillis (2009) for isotropic plasticity. Size-effects are included in the model due to the addition of gradient terms in both the free energy as well as through a dissipation potential. A finite...... element solution method is presented, which delivers the slip-rate field and the velocity-field based on two minimum principles. Some plane deformation problems relevant for certain specific orientations of a face centered cubic crystal under plane loading conditions are studied, and effective in......-plane parameters are developed based on the crystallographic properties of the material. The problem of cyclic shear of a single crystal between rigid platens is studied as well as void growth of a cylindrical void....

  9. Determining Micromechanical Strain in Nitinol

    Energy Technology Data Exchange (ETDEWEB)

    Strasberg, Matthew; /SLAC

    2006-09-27

    Nitinol is a superelastic alloy made of equal parts nickel and titanium. Due to its unique shape memory properties, nitinol is used to make medical stents, lifesaving devices used to allow blood flow in occluded arteries. Micromechanical models and even nitinol-specific finite element analysis (FEA) software are insufficient for unerringly predicting fatigue and resultant failure. Due to the sensitive nature of its application, a better understanding of nitinol on a granular scale is being pursued through X-ray diffraction techniques at the Stanford Synchrotron Radiation Laboratory (SSRL) at the Stanford Linear Accelerator Center (SLAC). Through analysis of powder diffraction patterns of nitinol under increasing tensile loads, localized strain can be calculated. We compare these results with micromechanical predictions in order to advance nitinol-relevant FEA tools. From this we hope to gain a greater understanding of how nitinol fatigues under multi-axial loads.

  10. Strain driven fast osseointegration of implants

    Directory of Open Access Journals (Sweden)

    Wiesmann Hans-Peter

    2005-09-01

    Full Text Available Abstract Background Although the bone's capability of dental implant osseointegration has clinically been utilised as early as in the Gallo-Roman population, the specific mechanisms for the emergence and maintenance of peri-implant bone under functional load have not been identified. Here we show that under immediate loading of specially designed dental implants with masticatory loads, osseointegration is rapidly achieved. Methods We examined the bone reaction around non- and immediately loaded dental implants inserted in the mandible of mature minipigs during the presently assumed time for osseointegration. We used threaded conical titanium implants containing a titanium2+ oxide surface, allowing direct bone contact after insertion. The external geometry was designed according to finite element analysis: the calculation showed that physiological amplitudes of strain (500–3,000 ustrain generated through mastication were homogenously distributed in peri-implant bone. The strain-energy density (SED rate under assessment of a 1 Hz loading cycle was 150 Jm-3 s-1, peak dislocations were lower then nm. Results Bone was in direct contact to the implant surface (bone/implant contact rate 90% from day one of implant insertion, as quantified by undecalcified histological sections. This effect was substantiated by ultrastructural analysis of intimate osteoblast attachment and mature collagen mineralisation at the titanium surface. We detected no loss in the intimate bone/implant bond during the experimental period of either control or experimental animals, indicating that immediate load had no adverse effect on bone structure in peri-implant bone. Conclusion In terms of clinical relevance, the load related bone reaction at the implant interface may in combination with substrate effects be responsible for an immediate osseointegration state.

  11. Job Strain in Shift and Daytime Workers.

    Science.gov (United States)

    Knutsson; Nilsson

    1997-07-01

    Cross-sectional questionnaire data were used to compare the levels of job strain in shift and daytime workers. Job strain was measured according to Karasek's Demands/Discretion model. Four occupational groups were included: drivers, industrial workers, policemen/watchmen, and cooks. The study subjects were a random sample of 508 daytime workers and 418 shift workers. Job demand did not differentiate between shift and daytime workers, comparing groups broken down by gender and by occupation. The daytime workers reported higher levels of job strain than the shift workers, and women experienced a higher level of job strain than did men. Multiple linear regression analysis showed that only occupational group and gender predicted job strain level. Shiftwork was not significantly associated with job strain in the regression model.

  12. The many shades of prion strain adaptation.

    Science.gov (United States)

    Baskakov, Ilia V

    2014-01-01

    In several recent studies transmissible prion disease was induced in animals by inoculation with recombinant prion protein amyloid fibrils produced in vitro. Serial transmission of amyloid fibrils gave rise to a new class of prion strains of synthetic origin. Gradual transformation of disease phenotypes and PrP(Sc) properties was observed during serial transmission of synthetic prions, a process that resembled the phenomenon of prion strain adaptation. The current article discusses the remarkable parallels between phenomena of prion strain adaptation that accompanies cross-species transmission and the evolution of synthetic prions occurring within the same host. Two alternative mechanisms underlying prion strain adaptation and synthetic strain evolution are discussed. The current article highlights the complexity of the prion transmission barrier and strain adaptation and proposes that the phenomenon of prion adaptation is more common than previously thought.

  13. Mortality among Patients Admitted to Strained Intensive Care Units

    Science.gov (United States)

    Gabler, Nicole B.; Ratcliffe, Sarah J.; Wagner, Jason; Asch, David A.; Rubenfeld, Gordon D.; Angus, Derek C.

    2013-01-01

    Rationale: The aging population may strain intensive care unit (ICU) capacity and adversely affect patient outcomes. Existing fluctuations in demand for ICU care offer an opportunity to explore such relationships. Objectives: To determine whether transient increases in ICU strain influence patient mortality, and to identify characteristics of ICUs that are resilient to surges in capacity strain. Methods: Retrospective cohort study of 264,401 patients admitted to 155 U.S. ICUs from 2001 to 2008. We used logistic regression to examine relationships of measures of ICU strain (census, average acuity, and proportion of new admissions) near the time of ICU admission with mortality. Measurements and Main Results: A total of 36,465 (14%) patients died in the hospital. ICU census on the day of a patient’s admission was associated with increased mortality (odds ratio [OR], 1.02 per standardized unit increase; 95% confidence interval [CI]: 1.00, 1.03). This effect was greater among ICUs employing closed (OR, 1.07; 95% CI: 1.02, 1.12) versus open (OR, 1.01; 95% CI: 0.99, 1.03) physician staffing models (interaction P value = 0.02). The relationship between census and mortality was stronger when the census was composed of higher acuity patients (interaction P value < 0.01). Averaging strain over the first 3 days of patients’ ICU stays yielded similar results except that the proportion of new admissions was now also associated with mortality (OR, 1.04 for each 10% increase; 95% CI: 1.02, 1.06). Conclusions: Several sources of ICU strain are associated with small but potentially important increases in patient mortality, particularly in ICUs employing closed staffing models. Although closed ICUs may promote favorable outcomes under static conditions, they are susceptible to being overwhelmed by patient influxes. PMID:23992449

  14. Study on cartilaginous and muscular strains of rat trachea

    Institute of Scientific and Technical Information of China (English)

    TENG Zhongzhao; LIU Zhaorong; LIN Yihan; WANG Yiqin; LI Fufeng; GONG Keqin

    2004-01-01

    This paper introduces a new method, termed Twice Cutting, for obtaining the zero-stress states of cartilage and muscle of trachea. The method applied cuts at the two junctions of tracheal cartilage and muscle perpendicular to the tangent lines of cartilage at its tips. The cartilaginous and muscular opening angles are defined for the first time in Twice Cutting methods. Based on the analysis of cartilaginous and muscular geometric information in no-load and zero-stress states, it is found that there are compressive and tensile residual strains in the inner and outer walls of the cartilage respectively. Residual strains at the muscular inner wall of tracheal rings near bifurcation are negative, whereas those of other rings are positive, and residual strains at outer wall of all rings are positive. This phenomenon of tracheal muscle residual strains is different from those of vessel etc. The results also show that the absolute values of cartilaginous strains are considerably smaller than that of muscular ones, with the ratio being around 0.05. The values of all the tracheal parameters, including residual strains and opening angles, are reducing with the increasing value of tracheal rings' position. So the consequences obtained in this paper not only indicate that the trachea is a non-uniform tissue along the circumferential and axial directions, but also reveal the differences between the trachea and other living tissues, such as vessel, esophagus. This is a basic research for further work, such as determining stress in trachea, to which the cartilaginous and muscular zero-stress states should be referred.

  15. Effect of strain rate and temperature at high strains on fatigue behavior of SAP alloys

    DEFF Research Database (Denmark)

    Blucher, J.T.; Knudsen, Per; Grant, N.J.

    1968-01-01

    Fatigue behavior of three SAP alloys of two nominal compositions (7 and 13% Al2O3) was studied in terms of strain rate and temperature at high strains; strain rate had no effect on life at 80 F, but had increasingly greater effect with increasing temperature above 500 F; life decreased with decre......Fatigue behavior of three SAP alloys of two nominal compositions (7 and 13% Al2O3) was studied in terms of strain rate and temperature at high strains; strain rate had no effect on life at 80 F, but had increasingly greater effect with increasing temperature above 500 F; life decreased...

  16. On inhomogeneous straining in compressed sylvinite

    Science.gov (United States)

    Barannikova, S. A.; Nadezhkin, M. V.; Zuev, L. B.; Zhigalkin, V. M.

    2010-06-01

    Spatiotemporal distributions of local components of the distortion tensor of quasi-plastic materials—saliferous rocks (sylvinite)—have been studied under active compressive straining conditions using double-exposure speckle photography techniques. The strain localization patterns are presented and the features of macroscopic strain inhomogeneity are considered for inelastic behavior of the material. Results obtained for the slow wave processes in deformed saliferous rocks are compared to analogous data available for ionic crystals.

  17. Dynamic Strain Conductivity of Compensated Silicon

    Science.gov (United States)

    Zainabidinov, S. Z.; Mamatkarimov, O. O.; Tursunov, I. G.; Tuychiev, U. A.

    In this paper the strain thermal Hall effect has been investigated in initial n-Si(P) and strongly compensated n-Si(Ni) samples of different compensation degree, which have been subject to uniform hydrostatic compression (UHC) under a pulse pressure regime ranging from 0 to 7×108 Pa. An experimental investigation of the strain thermal effect in the n-Si(Ni) sample leads to an essential strain conductivity increase, which is largely controlled by density variations of majority carriers.

  18. Snowball: Strain aware gene assembly of Metagenomes

    OpenAIRE

    Gregor, I.; Schönhuth, A.; McHardy, A. C.

    2015-01-01

    Gene assembly is an important step in functional analysis of shotgun metagenomic data. Nonetheless, strain aware assembly remains a challenging task, as current assembly tools often fail to distinguish among strain variants or require closely related reference genomes of the studied species to be available. We have developed Snowball, a novel strain aware and reference-free gene assembler for shotgun metagenomic data. It uses profile hidden Markov models (HMMs) of gene domains of interest to ...

  19. Method for generation of THz frequency radiation and sensing of large amplitude material strain waves in piezoelectric materials

    Science.gov (United States)

    Reed, Evan J.; Armstrong, Michael R.

    2010-09-07

    Strain waves of THz frequencies can coherently generate radiation when they propagate past an interface between materials with different piezoelectric coefficients. Such radiation is of detectable amplitude and contains sufficient information to determine the time-dependence of the strain wave with unprecedented subpicosecond, nearly atomic time and space resolution.

  20. Strain - The Heart of the Matter

    Science.gov (United States)

    Gapinski, Wendy R.

    2013-01-01

    Objective: Identify how much exercise is needed to maintain pre-bedrest / pre-spaceflight strength, minimize any flight complications and reduce time required to reacclimate to Earth's gravity. Subjects volunteered to participate in a 70 day 6deg head down tilt (HDT) study at UTMB hospital in Galveston. HDT are used to study microgravity for several reasons: 1. Allows subjects to experience atrophy of lower extremities from disuse. 2. Allows scientist to study the fluid shifts and the subject's cardiovascular and physiological effects. 3. Allows several studies to be measured and conducted simultaneously in a safe and monitored environment. Throughout those 10 weeks, subjects were either in an exercise or control group. Never before has cardiac strain been monitored at set time points throughout spaceflight or bed rest study. Once we clearly understand this technique, protocols can be formulated for astronauts to use on the ISS as both a diagnostic and monitoring tool. Echoes could have the possibility to predict & monitor heart health, cardiac strength, endurance, and overall rate of muscle degradation. Also, echoes can act as an additional factor in determining exercise prescriptions and effectiveness.

  1. Using strain rates to forecast seismic hazards

    Science.gov (United States)

    Evans, Eileen

    2017-01-01

    One essential component in forecasting seismic hazards is observing the gradual accumulation of tectonic strain accumulation along faults before this strain is suddenly released as earthquakes. Typically, seismic hazard models are based on geologic estimates of slip rates along faults and historical records of seismic activity, neither of which records actively accumulating strain. But this strain can be estimated by geodesy: the precise measurement of tiny position changes of Earth’s surface, obtained from GPS, interferometric synthetic aperture radar (InSAR), or a variety of other instruments.

  2. Differentiation of Listeria and Streptococcus strains.

    Science.gov (United States)

    Herendi, A; Ralovich, B

    1989-01-01

    Colonial morphology of non-beta haemolytic Listeria strains is frequently similar to that of non-haemolytic streptococci. Biochemical characteristics, motility, haemolysis on ox blood agar, growth on Clauberg, selective streptococcus (Si) and Mitis-Salivarius agar medium, CAMP test, serological behaviour of 16 Listeria strains were studied and the results were compared with the properties of Streptococcus strains. Microscopic morphology, motility and catalase activity are useful for distinguishing these strains. To avoid a false diagnosis, latex-agglutination should be supplemented with the above tests.

  3. [Antigenic relationships between Debaryomyces strains (author's transl)].

    Science.gov (United States)

    Aksoycan, N

    1980-01-01

    The results of the agglutinations between homologous and heterologous Debaryomyces strains and their agglutinating sera are shown in table I. According to these findings, D. hansenii and D. marama are antigenically different from other Debaryomyces strains in this genus. In a previous study Aksoycan et al. have shown a common antigenic factor between D. hansenii, D. marama strains and Salmonella 0:7 antigen. This factor was not present in other six strains of Debaryomyces. These results also show that D. tamarii does not have any antigenic relationship with the other seven species of Debaryomyces in this genus.

  4. Cytopathogenesis of Naegleria fowleri Thai strains for cultured human neuroblastoma cells.

    Science.gov (United States)

    Tiewcharoen, Supathra; Malainual, Nat; Junnu, Virach; Chetanachan, Pruksawan; Rabablert, Jundee

    2008-04-01

    The aim of this study is to evaluate cellular interaction between free-living amoebae Naegleria fowleri strains and mammalian target cells in vitro. Two Thai strains of N. fowleri; Khon Kaen strain from the environment and Siriraj strain from the patient's cerebrospinal fluid and the Center of Disease Control VO 3081 strain from Atlanta (US) were studied. Human neuroblastoma (SK-N-MC) and African Green monkey Kidney (Vero) cells were used as target cells. Each cell line was inoculated with each strain of N. fowleri at a ratio of 1:1 and observed for 7 days. The uninoculated target cells and each strain of N. fowleri were used as control. The numbers of the challenged and unchallenged cells as well as the free-living amoebae were counted three times by trypan blue exclusion method. The inoculation began when the amoebae attached to the cell membrane and ingested the target cells. In this study, extensive cytopathogenesis with many floating inoculated cells and abundant number of amoebae were observed. The destruction pattern of both inoculated SK-N-MC and Vero target cells were similar. Interestingly, SK-N-MC was more susceptible to N. fowleri strains than the Vero cell. In addition, N. fowleri Siriraj strain showed the highest destruction pattern for each target cell. Our findings suggest that the SK-N-MC should be used as a base model for studying the neuropathogenesis in primary amoebic meningoencephalitis patients.

  5. Effects of cyanogenic plants on fitness in two host strains of the fall armyworm (Spodoptera frugiperda).

    Science.gov (United States)

    Hay-Roe, Mirian M; Meagher, Robert L; Nagoshi, Rodney N

    2011-12-01

    The generalist moth, Spodoptera frugiperda (J. E. Smith) consists of two genetic subgroups (host strains) that differ in their distribution among host plant species. The corn strain prefers crop plants such as corn, sorghum, and cotton, while the rice strain is found in small grasses such as Cynodon spp. and rice. Little is known about the physiological factors that drive this host preference. Here, we report a feeding study with natural host plants and an artificial diet containing cyanide. We found that corn, two Cynodon spp. (bermudagrass C. dactylon (L.) Persoon, 'NuMex Sahara', and stargrass C. nlemfuensis var. nlemfuensis Vanderyst, 'Florona'), and a hybrid between bermudagrass and stargrass, 'Tifton 85', exhibited differences in the concentration of the cyanogenic precursors or cyanogenic potential (HCNp) and the release of hydrogen cyanide per unit time or cyanogenic capacity (HCNc). Corn plants released low levels of hydrogen cyanide, while stargrass had greater HCNp/HCNc than bermudagrass and 'Tifton 85'. Feeding studies showed that corn strain larvae experienced higher mortality than the rice strain when fed stargrass or artificial diet supplemented with cyanide. Also, corn strain larvae excreted higher levels of cyanogenic compounds than the rice strain when fed Cynodon spp. These differences in excretion suggest potential disparities in cyanide metabolism between the two strains. We hypothesize that differences in the susceptibility to cyanide levels in various host plants could play a role in driving strain divergence and what appears to be the incipient speciation of this moth.

  6. Evaluation of the human transmission risk of an atypical bovine spongiform encephalopathy prion strain.

    Science.gov (United States)

    Kong, Qingzhong; Zheng, Mengjie; Casalone, Cristina; Qing, Liuting; Huang, Shenghai; Chakraborty, Bikram; Wang, Ping; Chen, Fusong; Cali, Ignazio; Corona, Cristiano; Martucci, Francesca; Iulini, Barbara; Acutis, Pierluigi; Wang, Lan; Liang, Jingjing; Wang, Meiling; Li, Xinyi; Monaco, Salvatore; Zanusso, Gianluigi; Zou, Wen-Quan; Caramelli, Maria; Gambetti, Pierluigi

    2008-04-01

    Bovine spongiform encephalopathy (BSE), the prion disease in cattle, was widely believed to be caused by only one strain, BSE-C. BSE-C causes the fatal prion disease named new variant Creutzfeldt-Jacob disease in humans. Two atypical BSE strains, bovine amyloidotic spongiform encephalopathy (BASE, also named BSE-L) and BSE-H, have been discovered in several countries since 2004; their transmissibility and phenotypes in humans are unknown. We investigated the infectivity and human phenotype of BASE strains by inoculating transgenic (Tg) mice expressing the human prion protein with brain homogenates from two BASE strain-infected cattle. Sixty percent of the inoculated Tg mice became infected after 20 to 22 months of incubation, a transmission rate higher than those reported for BSE-C. A quarter of BASE strain-infected Tg mice, but none of the Tg mice infected with prions causing a sporadic human prion disease, showed the presence of pathogenic prion protein isoforms in the spleen, indicating that the BASE prion is intrinsically lymphotropic. The pathological prion protein isoforms in BASE strain-infected humanized Tg mouse brains are different from those from the original cattle BASE or sporadic human prion disease. Minimal brain spongiosis and long incubation times are observed for the BASE strain-infected Tg mice. These results suggest that in humans, the BASE strain is a more virulent BSE strain and likely lymphotropic.

  7. Complete genomic sequence analysis of infectious bronchitis virus Ark DPI strain and its evolution by recombination.

    Science.gov (United States)

    Ammayappan, Arun; Upadhyay, Chitra; Gelb, Jack; Vakharia, Vikram N

    2008-12-22

    An infectious bronchitis virus Arkansas DPI (Ark DPI) virulent strain was sequenced, analyzed and compared with many different IBV strains and coronaviruses. The genome of Ark DPI consists of 27,620 nucleotides, excluding poly (A) tail, and comprises ten open reading frames. Comparative sequence analysis of Ark DPI with other IBV strains shows striking similarity to the Conn, Gray, JMK, and Ark 99, which were circulating during that time period. Furthermore, comparison of the Ark genome with other coronaviruses demonstrates a close relationship to turkey coronavirus. Among non-structural genes, the 5'untranslated region (UTR), 3C-like proteinase (3CLpro) and the polymerase (RdRp) sequences are 100% identical to the Gray strain. Among structural genes, S1 has 97% identity with Ark 99; S2 has 100% identity with JMK and 96% to Conn; 3b 99%, and 3C to N is 100% identical to Conn strain. Possible recombination sites were found at the intergenic region of spike gene, 3'end of S1 and 3a gene. Independent recombination events may have occurred in the entire genome of Ark DPI, involving four different IBV strains, suggesting that genomic RNA recombination may occur in any part of the genome at number of sites. Hence, we speculate that the Ark DPI strain originated from the Conn strain, but diverged and evolved independently by point mutations and recombination between field strains.

  8. Complete genomic sequence analysis of infectious bronchitis virus Ark DPI strain and its evolution by recombination

    Directory of Open Access Journals (Sweden)

    Gelb Jack

    2008-12-01

    Full Text Available Abstract An infectious bronchitis virus Arkansas DPI (Ark DPI virulent strain was sequenced, analyzed and compared with many different IBV strains and coronaviruses. The genome of Ark DPI consists of 27,620 nucleotides, excluding poly (A tail, and comprises ten open reading frames. Comparative sequence analysis of Ark DPI with other IBV strains shows striking similarity to the Conn, Gray, JMK, and Ark 99, which were circulating during that time period. Furthermore, comparison of the Ark genome with other coronaviruses demonstrates a close relationship to turkey coronavirus. Among non-structural genes, the 5'untranslated region (UTR, 3C-like proteinase (3CLpro and the polymerase (RdRp sequences are 100% identical to the Gray strain. Among structural genes, S1 has 97% identity with Ark 99; S2 has 100% identity with JMK and 96% to Conn; 3b 99%, and 3C to N is 100% identical to Conn strain. Possible recombination sites were found at the intergenic region of spike gene, 3'end of S1 and 3a gene. Independent recombination events may have occurred in the entire genome of Ark DPI, involving four different IBV strains, suggesting that genomic RNA recombination may occur in any part of the genome at number of sites. Hence, we speculate that the Ark DPI strain originated from the Conn strain, but diverged and evolved independently by point mutations and recombination between field strains.

  9. Effect of microstructure on anomalous strain-rate-dependent behaviour of bacterial cellulose hydrogel.

    Science.gov (United States)

    Gao, Xing; Shi, Zhijun; Lau, Andrew; Liu, Changqin; Yang, Guang; Silberschmidt, Vadim V

    2016-05-01

    This study is focused on anomalous strain-rate-dependent behaviour of bacterial cellulose (BC) hydrogel that can be strain-rate insensitive, hardening, softening, or strain-rate insensitive in various ranges of strain rate. BC hydrogel consists of randomly distributed nanofibres and a large content of free water; thanks to its ideal biocompatibility, it is suitable for biomedical applications. Motivated by its potential applications in complex loading conditions of body environment, its time-dependent behaviour was studied by means of in-aqua uniaxial tension tests at constant temperature of 37 °C at various strain rates ranging from 0.000 1s(-1) to 0.3s(-1). Experimental results reflect anomalous strain-rate-dependent behaviour that was not documented before. Micro-morphological observations allowed identification of deformation mechanisms at low and high strain rates in relation to microstructural changes. Unlike strain-rate softening behaviours in other materials, reorientation of nanofibres and kinematics of free-water flow dominate the softening behaviour of BC hydrogel at high strain rates.

  10. Cyclic lipopeptide profile of three Bacillus subtilis strains; antagonists of Fusarium head blight.

    Science.gov (United States)

    Dunlap, Christopher A; Schisler, David A; Price, Neil P; Vaughn, Steven F

    2011-08-01

    The objective of the study was to identify the lipopetides associated with three Bacillus subtilis strains. The strains are antagonists of Gibberella zeae, and have been shown to be effective in reducing Fusarium head blight in wheat. The lipopeptide profile of three B. subtilis strains (AS43.3, AS43.4, and OH131.1) was determined using mass spectroscopy. Strains AS43.3 and AS43.4 produced the anti-fungal lipopeptides from the iturin and fengycin family during the stationary growth phase. All three strains produced the lipopeptide surfactin at different growth times. Strain OH131.1 only produced surfactin under these conditions. The antifungal activity of the culture supernatant and individual lipopeptides was determined by the inhibition of G. zeae. Cell-free supernatant from strains AS43.3 and AS43.4 demonstrated strong antibiosis of G. zeae, while strain OH131.1 had no antibiosis activity. These results suggest a different mechanism of antagonism for strain OH131.1, relative to AS43.3 and AS43.4.

  11. Antifungal activity and gene expression of lipopeptide antibiotics in strains of genus Bacillus

    Directory of Open Access Journals (Sweden)

    Grabova A. Yu.

    2016-02-01

    Full Text Available Aim. To research the antifungal activity and gene expression of lipopeptide antibiotics in strains of genus Bacillus. Methods. Deferred antagonism method, PCR, qRT-PCR, MALDI-TOF mass spectrometry. Results. It was revealed that Bacillus sp. strains C6 and Lg37s out of five tested strains had the highest antifungal activity. Based on the molecular genetic methods, it was shown that the expression of genes of lipopeptide antibiotics, related to the fengycin family, occurred in all these strains. At the same time, the gene expression of cyclolipopeptide iturin was found in the Bacillus sp. strains C6 and Lg37s. It was determined that Bacillus sp. C6 strain had the highest level of expression of the fengycin operon`s genes, whereas the lowest level was observed in Bacillus sp. C10 strain. By means of MALDI-TOF mass spectrometry, the presence of fengycins in the cell-free cultural fluid of Bacillus sp. C6 strain was detected. Conclusion. The direct correlation between the level of antifungal activity and the fengycin synthetases expression has not been disclosed. A higher level of antagonism detected for two Bacillus strains is more likely associated with the expression and subsequent synthesis of fengycin and iturin.

  12. A Numerical Investigation of the Strain Effect on Saturation Optical Intensity in Electroabsorption Modulators Based on Asymmetric Intra-step-barrier Coupled Double Strained Quantum Wells

    Science.gov (United States)

    Abedi, Kambiz

    2011-12-01

    In this paper, the strain effect on saturation optical intensity in electroabsorption modulators (EAMs) based on asymmetric intra-step-barrier coupled double strained quantum well (AICD-SQWs) active region is theoretically investigated and compared with intra-step quantum well (IQW) structure. For this purpose, the thermionic emission and tunneling escape processes are taken into account and the escape times of photogenerated carriers are calculated. Then, the electroabsorption coefficient is calculated for different well strains for TE input light polarization. Finally, the saturation optical intensity of electroabsorption modulators with AICD-SQW structures in comparison with IQW structure is evaluated. Numerical results show that the tensile strain of well has the most significant effect on the saturation optical intensity of electroabsorption modulators with AICD-SQW structures due to reduction in escape times.

  13. [Dynamic accumulation regulation of curcumin, demethoxycurcumin and bisdemethoxyeurcumin in three strains of curcuma longae rhizome].

    Science.gov (United States)

    Li, Qing-Miao; Yang, Wen-Yu; Tang, Xue-Mei; Zhang, Mei; Zhou, Xian-Jian; Shu, Guang-Ming; Zhao, Jun-Ning; Fang, Qing-Mao

    2014-06-01

    The paper is aimed to study the dynamic accumulation regulation of curcumin (Cur), demethoxycurcumin (DMC) and bisdemethoxyeurcumin (BDMC) in three strains of Curcuma longa, and provide scientific references for formalized cultivation, timely harvesting, quality control and breeding cultivation of C. longa. The accumulation regulation of the three curcumin derivatives was basically the same in rhizome of three strains. The relative contents decreased along with plant development growing, while the accumulation per hectare increased with plant development growing. The accumulation of curcuminoids per hectare could be taken as the assessment standard for the best harvest time of C. longa. A3 was the best strain in terms of Cur and BDMC content.

  14. True stress-strain curves of cold worked stainless steel over a large range of strains

    Science.gov (United States)

    Kamaya, Masayuki; Kawakubo, Masahiro

    2014-08-01

    True stress-strain curves for cold worked stainless steel were obtained over a range of strains that included a large strain exceeding the strain for the tensile strength (post-necking strain). A specified testing method was used to obtain the stress-strain curves in air at room temperature. The testing method employed the digital image correlation (DIC) technique and iterative finite element analyses (FEA) and was referred to as IFD (Iteration FEA procedure based on DIC measurement) method. Although hourglass type specimens have been previously used for the IFD method, in this study, plate specimens with a parallel gage section were used to obtain accurate yield and tensile strengths together with the stress-strain curves. The stress-strain curves including the post-necking strain were successfully obtained by the IFD method, and it was shown that the stress-strain curves for different degrees of cold work collapsed onto a single curve when the offset strain was considered. It was also shown that the Swift type constitutive equation gave good regression for the true stress-strain curves including the post-necking strain regardless of the degree of cold work, although the Ramberg-Osgood type constitutive equation showed poor fit. In the regression for the Swift type constitutive equation, the constant for power law could be assumed to be nS = 0.5.

  15. Comparison of ruminant and human attaching and effacing Escherichia coli (AEEC) strains.

    Science.gov (United States)

    Horcajo, Pilar; Domínguez-Bernal, Gustavo; de la Fuente, Ricardo; Ruiz-Santa-Quiteria, José A; Blanco, Jesús E; Blanco, Miguel; Mora, Azucena; Dahbi, Ghizlane; López, Cecilia; Puentes, Beatriz; Alonso, María Pilar; Blanco, Jorge; Orden, José A

    2012-03-23

    The presence of 12 genes associated with virulence in human attaching and effacing Escherichia coli (AEEC) was studied within a collection of 20 enterohemorrhagic E. coli (EHEC) and 206 atypical enteropathogenic E. coli (EPEC) isolated from ruminants. In addition, virulence genes and the clonal relationship of 49 atypical EPEC O26 strains isolated from humans and ruminants were compared to clarify whether ruminants serve as a reservoir of atypical EPEC for humans. A great diversity in the content of virulence gene was found. Thus, the espH, espG and map genes were detected in more than 85% of ruminant AEEC strains; the tccP2, espI, efa1/lifA, ehxA and paa genes were present in 50-70% of strains; and other genes such as tccP, espP, katP and toxB were detected in <25% of strains. EHEC strains contained more virulence genes than atypical EPEC strains. Our results suggest for the first time that the efa1/lifA gene is associated with diarrhea in newborn ruminants and that the AEEC strains with the H11 flagellar antigen are potentially more virulent than the non-H11 AEEC strains. Importantly, we identified a new intimin variant gene, eaeρ, in three ruminant atypical EPEC strains. The comparison of ruminant and human EPEC O26 strains showed that some ruminant strains possess virulence gene profiles and pulse-field gel electrophoresis pulsotypes similar to those of human strains. In conclusion, our data suggest that atypical EPEC is a heterogeneous group with different pathogenic potential and that ruminants could serve as a reservoir of atypical EPEC for humans.

  16. Ability of vaccine strain induced antibodies to neutralize field isolates of caliciviruses from Swedish cats.

    Science.gov (United States)

    Wensman, Jonas Johansson; Samman, Ayman; Lindhe, Anna; Thibault, Jean-Christophe; Berndtsson, Louise Treiberg; Hosie, Margaret J

    2015-12-12

    Feline calicivirus (FCV) is a common cause of upper respiratory tract disease in cats worldwide. Its characteristically high mutation rate leads to escape from the humoral immune response induced by natural infection and/or vaccination and consequently vaccines are not always effective against field isolates. Thus, there is a need to continuously investigate the ability of FCV vaccine strain-induced antibodies to neutralize field isolates. Seventy-eight field isolates of FCV isolated during the years 2008-2012 from Swedish cats displaying clinical signs of upper respiratory tract disease were examined in this study. The field isolates were tested for cross-neutralization using a panel of eight anti-sera raised in four pairs of cats following infection with four vaccine strains (F9, 255, G1 and 431). The anti-sera raised against F9 and 255 neutralised 20.5 and 11.5 %, and 47.4 and 64.1 % of field isolates tested, respectively. The anti-sera against the more recently introduced vaccine strains G1 and 431 neutralized 33.3 and 55.1 % (strain G1) or 69.2 and 89.7 % (strain 431) of the field isolates with titres ≥5. [corrected]. Dual vaccine strains displayed a higher cross-neutralization. This study confirms previous observations that more recently introduced vaccine strains induce antibodies with a higher neutralizing capacity compared to vaccine strains that have been used extensively over a long period of time. This study also suggests that dual FCV vaccine strains might neutralize more field isolates compared to single vaccine strains. Vaccine strains should ideally be selected based on updated knowledge on the antigenic properties of field isolates in the local setting, and there is thus a need for continuously studying the evolution of FCV together with the neutralizing capacity of vaccine strain induced antibodies against field isolates at a national and/or regional level.

  17. Origins of the E. coli Strain Causing an Outbreak of Hemolytic–Uremic Syndrome in Germany

    Science.gov (United States)

    Rasko, David A.; Webster, Dale R.; Sahl, Jason W.; Bashir, Ali; Boisen, Nadia; Scheutz, Flemming; Paxinos, Ellen E.; Sebra, Robert; Chin, Chen-Shan; Iliopoulos, Dimitris; Klammer, Aaron; Peluso, Paul; Lee, Lawrence; Kislyuk, Andrey O.; Bullard, James; Kasarskis, Andrew; Wang, Susanna; Eid, John; Rank, David; Redman, Julia C.; Steyert, Susan R.; Frimodt-Møller, Jakob; Struve, Carsten; Petersen, Andreas M.; Krogfelt, Karen A.; Nataro, James P.; Schadt, Eric E.; Waldor, Matthew K.

    2011-01-01

    BACKGROUND A large outbreak of diarrhea and the hemolytic–uremic syndrome caused by an unusual serotype of Shiga-toxin–producing Escherichia coli (O104:H4) began in Germany in May 2011. As of July 22, a large number of cases of diarrhea caused by Shiga-toxin–producing E. coli have been reported — 3167 without the hemolytic–uremic syndrome (16 deaths) and 908 with the hemolytic–uremic syndrome (34 deaths) — indicating that this strain is notably more virulent than most of the Shiga-toxin–producing E. coli strains. Preliminary genetic characterization of the outbreak strain suggested that, unlike most of these strains, it should be classified within the enteroaggregative pathotype of E. coli. METHODS We used third-generation, single-molecule, real-time DNA sequencing to determine the complete genome sequence of the German outbreak strain, as well as the genome sequences of seven diarrhea-associated enteroaggregative E. coli serotype O104:H4 strains from Africa and four enteroaggregative E. coli reference strains belonging to other serotypes. Genomewide comparisons were performed with the use of these enteroaggregative E. coli genomes, as well as those of 40 previously sequenced E. coli isolates. RESULTS The enteroaggregative E. coli O104:H4 strains are closely related and form a distinct clade among E. coli and enteroaggregative E. coli strains. However, the genome of the German outbreak strain can be distinguished from those of other O104:H4 strains because it contains a prophage encoding Shiga toxin 2 and a distinct set of additional virulence and antibiotic-resistance factors. CONCLUSIONS Our findings suggest that horizontal genetic exchange allowed for the emergence of the highly virulent Shiga-toxin–producing enteroaggregative E. coli O104:H4 strain that caused the German outbreak. More broadly, these findings highlight the way in which the plasticity of bacterial genomes facilitates the emergence of new pathogens. PMID:21793740

  18. [Homology analysis and historical tracing for inter-continental Burkholderia pseudomallei strains of sequence type 562].

    Science.gov (United States)

    Zheng, X; Wang, L X; Wu, H; Chen, H; Zhu, X; He, J R; Xia, L X; Li, W

    2017-05-10

    Objective: To understand the homology of sequence type 562 (ST562) strains of Burkholderia pseudomallei which circulated in two separate continents (Asia and Australia) at different times. Methods:SpeⅠrestriction fragments and 4-locus multiple locus variable number tandem repeat analysis (MLVA-4) profiles were extracted from MSHR5858 (ST562 Australia strain) and 350105 (ST562 historical strain of Hainan) genomes respectively by in silico analysis and then compared with the PFGE and MLVA-4 results of five ST562 clinical isolates from Hainan to test their homology. Synteny and homology between MSHR5858 and 350105 genomes were evaluated with bioinformatics methods. Results: Five ST562 clinical strains from Hainan shared same PFGE pattern (similarity>97%) and this pattern coincided to the map of SpeⅠrestriction fragments of Australian strain MSHR5858. The amounts of genomic restriction fragments (SpeⅠ) for MSHR5858 and 350105 were 31 and 34 respectively, with 31 of them matched by each other. Five ST562 clinical strains of Hainan were distinct by MLVA-4 profiles, among which HPPH43 (MLVA-4 profile: 10, 8, 10, 8) was close to Australia strain MSHR5858 (10, 8, 8, 6), containing identical repeat numbers at VNTR loci 2341k and 1788k; while HK003 (11, 8, 15, 7) and HK061 (11, 8, 17, 7) similar to Hainan historical strain 350105 (11, 8, 11, 8), with same repeat numbers at loci 2341k and 1788k also. High-degree synteny and consistency on genomic contents were observed between 350105 and MSHR5858, indicating a similar origin for the 2 strains. Conclusion: All inter-continental and historical ST562 strains of B. pseudomallei had similar genomic characteristics, supporting the assumption that they had a common origin. Also, it is possible that Hainan historical strain 350105 is the ancestor of all circulating ST562 strains.

  19. Solar time, legal time, time in use

    Science.gov (United States)

    Guinot, Bernard

    2011-08-01

    The International Conference held in 1884 at Washington defined a universal time as the mean solar time at the Greenwich meridian (GMT). Now, the Universal Time, version UT1, is strictly defined as proportional to the angle of rotation of the Earth in space. In this evolution, the departure of UT1 from GMT does not exceed one or two seconds. This is quite negligible when compared with the departure between the solar time and the legal time of citizens, which may exceed two hours without raising protests.

  20. High-frequency rugose exopolysaccharide production by Vibrio cholerae strains isolated in Haiti.

    Directory of Open Access Journals (Sweden)

    Mustafizur Rahman

    Full Text Available In October, 2010, epidemic cholera was reported for the first time in Haiti in over 100 years. Establishment of cholera endemicity in Haiti will be dependent in large part on the continued presence of toxigenic V. cholerae O1 in aquatic reservoirs. The rugose phenotype of V. cholerae, characterized by exopolysaccharide production that confers resistance to environmental stress, is a potential contributor to environmental persistence. Using a microbiologic medium promoting high-frequency conversion of smooth to rugose (S-R phenotype, 80 (46.5% of 172 V. cholerae strains isolated from clinical and environmental sources in Haiti were able to convert to a rugose phenotype. Toxigenic V. cholerae O1 strains isolated at the beginning of the epidemic (2010 were significantly less likely to shift to a rugose phenotype than clinical strains isolated in 2012/2013, or environmental strains. Frequency of rugose conversion was influenced by incubation temperature and time. Appearance of the biofilm produced by a Haitian clinical rugose strain (altered biotype El Tor HC16R differed from that of a typical El Tor rugose strain (N16961R by confocal microscopy. On whole-genome SNP analysis, there was no phylogenetic clustering of strains showing an ability to shift to a rugose phenotype. Our data confirm the ability of Haitian clinical (and environmental strains to shift to a protective rugose phenotype, and suggest that factors such as temperature influence the frequency of transition to this phenotype.