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Sample records for 17-4 ph ss

  1. 17-4 PH and 15-5 PH

    NASA Technical Reports Server (NTRS)

    Johnson, Howard T.

    1995-01-01

    17-4 PH and 15-5 PH are extremely useful and versatile precipitation-hardening stainless steels. Armco 17-4 PH is well suited for the magnetic particle inspection requirements of Aerospace Material Specification. Armco 15-5 PH and 17-4 PH are produced in billet, plate, bar, and wire. Also, 15-5 PH is able to meet the stringent mechanical properties required in the aerospace and nuclear industries. Both products are easy to heat treat and machine, making them very useful in many applications.

  2. Hot Ductility of the 17-4 PH Stainless Steels

    NASA Astrophysics Data System (ADS)

    Herrera Lara, V.; Guerra Fuentes, L.; Covarrubias Alvarado, O.; Salinas Rodriguez, A.; Garcia Sanchez, E.

    2016-03-01

    The mechanisms of loss of hot ductility and the mechanical behavior of 17-4 PH alloys were investigated using hot tensile testing at temperatures between 700 and 1100 °C and strain rates of 10-4, 10-2, and 10-1 s-1. Scanning electron microscopy was used in conjunction with the results of the tensile tests to find the temperature region of loss of ductility and correlate it with cracking observed during processing by hot upsetting prior to ring rolling. It is reported that 17-4 PH alloys lose ductility in a temperature range around 900 °C near to the duplex austenite + ferrite phase field. Furthermore, it is found that niobium carbides precipitated at austenite/ferrite interfaces and grain boundaries have a pronounced effect on the mechanical behavior of the alloy during high-temperature deformation.

  3. Two-Phase Master Sintering Curve for 17-4 PH Stainless Steel

    NASA Astrophysics Data System (ADS)

    Jung, Im Doo; Ha, Sangyul; Park, Seong Jin; Blaine, Deborah C.; Bollina, Ravi; German, Randall M.

    2016-11-01

    The sintering behavior of 17-4 PH stainless steel has been efficiently characterized by a two-phase master sintering curve model (MSC). The activation energy for the sintering of gas-atomized and water-atomized 17-4 PH powders is derived using the mean residual method, and the relative density of both powders is well predicted by the two-phase MSC model. The average error between dilatometry data and MSC model has been reduced by 68 pct for gas-atomized powder and by 45 pct for water-atomized powder through the consideration of phase transformation of 17-4 PH in MSC model. The effect of δ-ferrite is considered in the two-phase MSC model, leading to excellent explanation of the sintering behavior for 17-4 PH stainless steel. The suggested model is useful in predicting the densification and phase change phenomenon during sintering of 17-4 PH stainless steel.

  4. Two-Phase Master Sintering Curve for 17-4 PH Stainless Steel

    NASA Astrophysics Data System (ADS)

    Jung, Im Doo; Ha, Sangyul; Park, Seong Jin; Blaine, Deborah C.; Bollina, Ravi; German, Randall M.

    2016-08-01

    The sintering behavior of 17-4 PH stainless steel has been efficiently characterized by a two-phase master sintering curve model (MSC). The activation energy for the sintering of gas-atomized and water-atomized 17-4 PH powders is derived using the mean residual method, and the relative density of both powders is well predicted by the two-phase MSC model. The average error between dilatometry data and MSC model has been reduced by 68 pct for gas-atomized powder and by 45 pct for water-atomized powder through the consideration of phase transformation of 17-4 PH in MSC model. The effect of δ-ferrite is considered in the two-phase MSC model, leading to excellent explanation of the sintering behavior for 17-4 PH stainless steel. The suggested model is useful in predicting the densification and phase change phenomenon during sintering of 17-4 PH stainless steel.

  5. Data demonstrating the effects of build orientation and heat treatment on fatigue behavior of selective laser melted 17-4 PH stainless steel.

    PubMed

    Yadollahi, Aref; Simsiriwong, Jutima; Thompson, Scott M; Shamsaei, Nima

    2016-06-01

    Axial fully-reversed strain-controlled ([Formula: see text]) fatigue experiments were performed to obtain data demonstrating the effects of building orientation (i.e. vertical versus horizontal) and heat treatment on the fatigue behavior of 17-4 PH stainless steel (SS) fabricated via Selective Laser Melting (SLM) (Yadollahi et al., submitted for publication [1]). This data article provides detailed experimental data including cyclic stress-strain responses, variations of peak stresses during cyclic deformation, and fractography of post-mortem specimens for SLM 17-4 PH SS.

  6. Data demonstrating the effects of build orientation and heat treatment on fatigue behavior of selective laser melted 17-4 PH stainless steel.

    PubMed

    Yadollahi, Aref; Simsiriwong, Jutima; Thompson, Scott M; Shamsaei, Nima

    2016-06-01

    Axial fully-reversed strain-controlled ([Formula: see text]) fatigue experiments were performed to obtain data demonstrating the effects of building orientation (i.e. vertical versus horizontal) and heat treatment on the fatigue behavior of 17-4 PH stainless steel (SS) fabricated via Selective Laser Melting (SLM) (Yadollahi et al., submitted for publication [1]). This data article provides detailed experimental data including cyclic stress-strain responses, variations of peak stresses during cyclic deformation, and fractography of post-mortem specimens for SLM 17-4 PH SS. PMID:26955653

  7. Biocompatibility of 17-4 PH stainless steel foam for implant applications.

    PubMed

    Mutlu, Ilven; Oktay, Enver

    2011-01-01

    In this study, biocompatibility of 17-4 PH stainless steel foam for biomedical implant applications was investigated. 17-4 PH stainless steel foams having porosities in the range of 40-82% with an average pore size of around 600 μm were produced by space holder-sintering technique. Sintered foams were precipitation hardened for times of 1-6 h at temperatures between 450-570 °C. Compressive yield strength and Young's modulus of aged stainless steel foams were observed to vary between 80-130 MPa and 0.73-1.54 GPa, respectively. Pore morphology, pore size and the mechanical properties of the 17-4 PH stainless steel foams were close to cancellous bone. In vitro evaluations of cytotoxicity of the foams were investigated by XTT and MTT assays and showed sufficient biocompatibility. Surface roughness parameters of the stainless steel foams were also determined to characterize the foams.

  8. Hybrid Laser-arc Welding of 17-4 PH Martensitic Stainless Steel

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Ma, Junjie; Atabaki, Mehdi Mazar; Pillai, Raju; Kumar, Biju; Vasudevan, Unnikrishnan; Sreshta, Harold; Kovacevic, Radovan

    2015-06-01

    17-4 PH stainless steel has wide applications in severe working conditions due to its combination of good corrosion resistance and high strength. The weldability of 17-4 PH stainless steel is challenging. In this work, hybrid laser-arc welding was developed to weld 17-4 PH stainless steel. This method was chosen based on its advantages, such as deep weld penetration, less filler materials, and high welding speed. The 17-4 PH stainless steel plates with a thickness of 19 mm were successfully welded in a single pass. During the hybrid welding, the 17-4 PH stainless steel was immensely susceptible to porosity and solidification cracking. The porosity was avoided by using nitrogen as the shielding gas. The nitrogen stabilized the keyhole and inhibited the formation of bubbles during welding. Solidification cracking easily occurred along the weld centerline at the root of the hybrid laser-arc welds. The microstructural evolution and the cracking susceptibility of 17-4 PH stainless steel were investigated to remove these centerline cracks. The results showed that the solidification mode of the material changed due to high cooling rate at the root of the weld. The rapid cooling rate caused the transformation from ferrite to austenite during the solidification stage. The solidification cracking was likely formed as a result of this cracking-susceptible microstructure and a high depth/width ratio that led to a high tensile stress concentration. Furthermore, the solidification cracking was prevented by preheating the base metal. It was found that the preheating slowed the cooling rate at the root of the weld, and the ferrite-to-austenite transformation during the solidification stage was suppressed. Delta ferrite formation was observed in the weld bead as well no solidification cracking occurred by optimizing the preheating temperature.

  9. Failure Maps for Rectangular 17-4PH Stainless Steel Sandwiched Foam Panels

    NASA Technical Reports Server (NTRS)

    Raj, S. V.; Ghosn, L. J.

    2007-01-01

    A new and innovative concept is proposed for designing lightweight fan blades for aircraft engines using commercially available 17-4PH precipitation hardened stainless steel. Rotating fan blades in aircraft engines experience a complex loading state consisting of combinations of centrifugal, distributed pressure and torsional loads. Theoretical failure plastic collapse maps, showing plots of the foam relative density versus face sheet thickness, t, normalized by the fan blade span length, L, have been generated for rectangular 17-4PH sandwiched foam panels under these three loading modes assuming three failure plastic collapse modes. These maps show that the 17-4PH sandwiched foam panels can fail by either the yielding of the face sheets, yielding of the foam core or wrinkling of the face sheets depending on foam relative density, the magnitude of t/L and the loading mode. The design envelop of a generic fan blade is superimposed on the maps to provide valuable insights on the probable failure modes in a sandwiched foam fan blade.

  10. Laser-based welding of 17-4 PH martensitic stainless steel in a tubular butt joint configuration with a built-in backing bar

    NASA Astrophysics Data System (ADS)

    Ma, Junjie; Atabaki, Mehdi Mazar; Liu, Wei; Pillai, Raju; Kumar, Biju; Vasudevan, Unnikrishnan; Kovacevic, Radovan

    2016-08-01

    Laser-based welding of thick 17-4 precipitation hardening (PH) martensitic stainless steel (SS) plates in a tubular butt joint configuration with a built-in backing bar is very challenging because the porosity and cracks are easily generated in the welds. The backing bar blocked the keyhole opening at the bottom surface through which the entrapped gas could escape, and the keyhole was unstable and collapsed overtime in a deep partially penetrated welding conditions resulting in the formation of pores easily. Moreover, the fast cooling rate prompted the ferrite transform to austenite which induced cracking. Two-pass welding procedure was developed to join 17-4 PH martensitic SS. The laser welding assisted by a filler wire, as the first pass, was used to weld the groove shoulder. The added filler wire could absorb a part of the laser beam energy; resulting in the decreased weld depth-to-width ratio and relieved intensive restraint at the weld root. A hybrid laser-arc welding or a gas metal arc welding (GMAW) was used to fill the groove as the second pass. Nitrogen was introduced to stabilize the keyhole and mitigate the porosity. Preheating was used to decrease the cooling rate and mitigate the cracking during laser-based welding of 17-4 PH martensitic SS plates.

  11. Nonlinear ultrasonic characterization of precipitation in 17-4PH stainless steel

    SciTech Connect

    Matlack, Kathryn; Bradley, Harrison A.; Thiele, Sebastian; Kim, Jin-Yeon; Wall, James J.; Jung, Hee Joon; Qu, Jianmin; Jacobs, Laurence J.

    2015-04-01

    The extension of operational lifetime of most US nuclear reactors will cause reactor pressure vessel to be exposed to increased levels of neutron radiation damage. This research is part of a broader effort to develop a nondestructive evaluation technique to monitor radiation damage in reactor pressure vessel steels. The main contributor to radiation embrittlement in these steels is the formation of copper-rich precipitates. In this work, a precipitate hardenable martensitic alloy, 17-4PH stainless steel is exposed to thermal aging treatments, and used as a surrogate material to study the effects of copper precipitates on the measured acoustic nonlinearity parameter. Previous work has demonstrated the effectiveness of these nonlinear ultrasonic (NLU) measurements in the characterization of radiation-induced microstructural changes in neutron irradiated reactor pressure vessel steels. NLU measurements using Rayleigh surface waves are performed on 17-4PH samples subjected to isothermal aging. NLU measurements are interpreted with hardness, thermo-electric power, TEM, and atom probe tomography measurements. The Rayleigh wave measurements showed a decrease in the acoustic nonlinearity parameter with increasing aging time, consistent with evidence of increasing number density of nucleated precipitates.

  12. Alloy Shrinkage factors for the investment casting of 17-4PH stainless steel parts

    SciTech Connect

    Sabau, Adrian S; Porter, Wallace D

    2008-01-01

    In this study, the alloy shrinkage factors were obtained for the investment casting of 17-4PH stainless steel parts. For the investment casting process, unfilled wax and fused silica with a zircon prime coat were used for patterns and shell molds, respectively. Dimensions of the die tooling, wax pattern, and casting were measured using a Coordinate Measurement Machine. For all the properties, the experimental data available in the literature did not cover the entire temperature range necessary for process simulation. A comparison between the predicted material property data measured property data is made. It was found that most material properties were accurately predicted over the most of the temperature range of the process. Several assumptions were made in order to obtain a complete set of mechanical property data at high temperatures. Thermal expansion measurements for the 17-4PH alloy were conducted at heating and cooling. As a function of temperature, the thermal expansion for both the alloy and shell mold materials showed different evolution at heating and cooling. Thus, one generic simulation were performed with thermal expansion obtained at heating and another one with thermal expansion obtained at cooling. The alloy dimensions were obtained from numerical simulation results of solidification, heat transfer, and deformation phenomena. As compared with experimental results, the numerical simulation results for the shrinkage factors were slightly over-predicted.

  13. Characterization of 17-4 PH stainless steel foam for biomedical applications in simulated body fluid and artificial saliva environments.

    PubMed

    Mutlu, Ilven; Oktay, Enver

    2013-04-01

    Highly porous 17-4 PH stainless steel foam for biomedical applications was produced by space holder technique. Metal release and weight loss from 17-4 PH stainless steel foams was investigated in simulated body fluid and artificial saliva environments by static immersion tests. Inductively coupled plasma-mass spectrometer was employed to measure the concentrations of various metal ions released from the 17-4 PH stainless steel foams into simulated body fluids and artificial saliva. Effect of immersion time and pH value on metal release and weight loss in simulated body fluid and artificial saliva were determined. Pore morphology, pore size and mechanical properties of the 17-4 PH stainless steel foams were close to human cancellous bone.

  14. Shot Peening and Thermal Stress Relaxation in 17-4 PH Stainless Steel

    NASA Astrophysics Data System (ADS)

    Qin, Enwei; Chen, Guoxing; Tan, Ziming; Wu, Shuhui

    2015-11-01

    Shot peening is an effective process to enhance the fatigue performance of turbine blades. In this study, the effect of peening pressures was discussed in terms of the residual stress distribution and the surface morphology. Shot peening processes were designed at varying pressures on a 17-4 PH martensitic stainless steel. The profiles of hardness and residual stress were characterized in the cross section. The thermal stress relaxation was further carried out to evaluate the stability of the compressive residual stress under service temperatures of turbine blades. Results show that a maximum stress depth is obtained with peening pressure of 0.40 MPa, and the residual stress can be maintained up to 400 °C, which ensures the service in low-pressure turbine blades.

  15. Mechanical Properties of 17-4PH Stainless Steel Foam Panels

    NASA Technical Reports Server (NTRS)

    Raj, S. V.; Ghosn, L. J.; Lerch, B. a.; Hebsur, M.; Cosgriff, L. M.; Fedor, J.

    2007-01-01

    Rectangular 17-4PH stainless steel sandwiched foam panels were fabricated using a commercial manufacturing technique by brazing two sheets to a foam core. Microstructural observations and ultrasonic nondestructive evaluation of the panels revealed large variations in the quality of the brazed areas from one panel to the next as well as within the same panel. Shear tests conducted on specimens machined from the panels exhibited failures either in the brazed region or in the foam core for the poorly brazed and well-brazed samples, respectively. Compression tests were conducted on the foam cores to evaluate their elastic and plastic deformation behavior. These data were compared with published data on polymeric and metallic foams, and with theoretical deformation models proposed for open cell foams.

  16. Gating geometry studies of thin-walled 17-4PH investment castings

    SciTech Connect

    Maguire, M.C.; Zanner, F.J.

    1992-01-01

    The ability to design gating systems that reliably feed and support investment castings is often the result of cut-and-try'' methodology. Factors such as hot tearing, porosity, cold shuts, misruns, and shrink are defects often corrected by several empirical gating design iterations. Sandia National Laboratories is developing rules that aid in removing the uncertainty involved in the design of gating systems for investment castings. In this work, gating geometries used for filling of thin walled investment cast 17-4PH stainless steel flat plates were investigated. A full factorial experiment evaluating the influence of metal pour temperature, mold preheat temperature, and mold channel thickness were conducted for orientations that filled a horizontal flat plate from the edge. A single wedge gate geometry was used for the edge-gated configuration. Thermocouples placed along the top of the mold recorded metal front temperatures, and a real-time x-ray imaging system tracked the fluid flow behavior during filling of the casting. Data from these experiments were used to determine the terminal fill volumes and terminal fill times for each gate design.

  17. Gating geometry studies of thin-walled 17-4PH investment castings

    SciTech Connect

    Maguire, M.C.; Zanner, F.J.

    1992-11-01

    The ability to design gating systems that reliably feed and support investment castings is often the result of ``cut-and-try`` methodology. Factors such as hot tearing, porosity, cold shuts, misruns, and shrink are defects often corrected by several empirical gating design iterations. Sandia National Laboratories is developing rules that aid in removing the uncertainty involved in the design of gating systems for investment castings. In this work, gating geometries used for filling of thin walled investment cast 17-4PH stainless steel flat plates were investigated. A full factorial experiment evaluating the influence of metal pour temperature, mold preheat temperature, and mold channel thickness were conducted for orientations that filled a horizontal flat plate from the edge. A single wedge gate geometry was used for the edge-gated configuration. Thermocouples placed along the top of the mold recorded metal front temperatures, and a real-time x-ray imaging system tracked the fluid flow behavior during filling of the casting. Data from these experiments were used to determine the terminal fill volumes and terminal fill times for each gate design.

  18. Additive Manufacturing of 17-4 PH Stainless Steel: Post-processing Heat Treatment to Achieve Uniform Reproducible Microstructure

    NASA Astrophysics Data System (ADS)

    Cheruvathur, Sudha; Lass, Eric A.; Campbell, Carelyn E.

    2016-03-01

    17-4 precipitation hardenable (PH) stainless steel is a useful material when a combination of high strength and good corrosion resistance up to about 315°C is required. In the wrought form, this steel has a fully martensitic structure that can be strengthened by precipitation of fine Cu-rich face-centered cubic phase upon aging. When fabricated via additive manufacturing (AM), specifically laser powder-bed fusion, 17-4 PH steel exhibits a dendritic structure containing a substantial fraction of nearly 50% of retained austenite along with body centered cubic/martensite and fine niobium carbides preferentially aligned along interdendritic boundaries. The effect of post-build thermal processing on the material microstructure is studied in comparison to that of conventionally produced wrought 17-4 PH with the intention of creating a more uniform, fully martensitic microstructure. The recommended stress relief heat treatment currently employed in industry for post-processing of AM 17-4 PH steel is found to have little effect on the as-built dendritic microstructure. It is found that, by implementing the recommended homogenization heat treatment regimen of Aerospace Materials Specification 5355 for CB7Cu-1, a casting alloy analog to 17-4 PH, the dendritic solidification structure is eliminated, resulting in a microstructure containing about 90% martensite with 10% retained austenite.

  19. The Structure and Properties of Diffusion Assisted Bonded Joints in 17-4 PH, Type 347, 15-5 PH and Nitronic 40 Stainless Steels

    NASA Technical Reports Server (NTRS)

    Wigley, D. A.

    1981-01-01

    Diffusion assisted bonds are formed in 17-4 PH, 15-5 PH, type 347 and Nitronic 40 stainless steels using electrodeposited copper as the bonding agent. The bonds are analyzed by conventional metallographic, electron microprobe analysis, and scanning electron microscopic techniques as well as Charpy V-notch impact tests at temperatures of 77 and 300 K. Results are discussed in terms of a postulated model for the bonding process.

  20. Effects of Temperature on Microstructure and Wear of Salt Bath Nitrided 17-4PH Stainless Steel

    NASA Astrophysics Data System (ADS)

    Wang, Jun; Lin, Yuanhua; Fan, Hongyuan; Zeng, Dezhi; Peng, Qian; Shen, Baoluo

    2012-08-01

    Salt bath nitriding of 17-4 PH martensitic precipitation hardening stainless steels was conducted at 610, 630, and 650 °C for 2 h using a complex salt bath heat-treatment, and the properties of the nitrided surface were systematically evaluated. Experimental results revealed that the microstructure and phase constituents of the nitrided surface alloy are highly process condition dependent. When 17-4PH stainless steel was subjected to complex salt bathing nitriding, the main phase of the nitrided layer was expanded martensite (α'), expanded austenite (γN), CrN, Fe4N, and (Fe,Cr) x O y . In the sample nitrided above 610 °C, the expanded martensite transformed into expanded austenite. But in the sample nitrided at 650 °C, the expanded austenite decomposed into αN and CrN. The decomposed αN then disassembled into CrN and alpha again. The nitrided layer depth thickened intensively with the increasing nitriding temperature. The activation energy of nitriding in this salt bath was 125 ± 5 kJ/mol.

  1. Microstructural evolution in a 17-4 PH stainless steel after aging at 400 °C

    NASA Astrophysics Data System (ADS)

    Murayama, M.; Hono, K.; Katayama, Y.

    1999-02-01

    The microstructure of 17-4 PH stainless steel at various stages of heat treatment, i.e., after solution heat treatment, tempering at 580 °C, and long-term aging at 400 °C, have been studied by atom probe field ion microscopy (APFIM) and transmission electron microscopy (TEM). The solution-treated specimen consists largely of martensite with a small fraction of δ-ferrite. No precipitates are present in the martensite phase, while spherical fcc-Cu particles are present in the δ-ferrite. After tempering for 4 hours at 580 °C, coherent Cu particles precipitate in the martensite phase. At this stage, the Cr concentration in the martensite phase is still uniform. After 5000 hours aging at 400 °C, the martensite spinodaly decomposes into Fe-rich α and Cr-enriched α‧. In addition, fine particles of the G-phase (structure type D8 a , space group Fmbar 3m) enriched in Si, Ni, and Mn have been found in intimate contact with the Cu precipitates. Following spinodal decomposition of the martensite phase, G-phase precipitation occurs after long-term aging.

  2. The effect of 17-4PH stainless steel on the lifetime of a Pennzane lubricated Microwave Limb Sounder Antenna Actuator Assembly ball screw for the AURA spacecraft

    NASA Astrophysics Data System (ADS)

    Jones, William R., Jr.; Jansen, Mark J.; Chen, Gun-Shing; Lam, Jonathan; Balzer, Mark; Lo, John; Anderson, Mark; Schepis, Joseph P.

    2005-07-01

    During ground based life testing of a Microwave Limb Sounder (MLS) Antenna Actuator Assembly (AAA) ball-screw assembly, lubricant darkening and loss were noted when approximately 10% of required lifetime was completed. The MLS-AAA ball screw and nut are made from 17-4 PH steel, the nut has 440C stainless steel balls, and the assembly is lubricated with a Pennzane formulation containing a three weight percent lead naphthenate additive. Life tests were done in dry nitrogen at 50°C. To investigate the MLS-AAA life test anomaly, Spiral Orbit Tribometer (SOT) accelerated tests were performed. SOT results indicated greatly reduced relative lifetimes of Pennzane formulations in contact with 17-4 PH steel compared to 440C stainless steel. Also, dry nitrogen tests yielded longer relative lifetimes than comparable ultrahigh vacuum tests. Generally, oxidized Pennzane formulations yielded shorter lifetimes than non-oxidized lubricant. This study emphasizes surface chemistry effects on the lubricated lifetime of moving mechanical assemblies.

  3. Effects of Powder Attributes and Laser Powder Bed Fusion (L-PBF) Process Conditions on the Densification and Mechanical Properties of 17-4 PH Stainless Steel

    NASA Astrophysics Data System (ADS)

    Irrinki, Harish; Dexter, Michael; Barmore, Brenton; Enneti, Ravi; Pasebani, Somayeh; Badwe, Sunil; Stitzel, Jason; Malhotra, Rajiv; Atre, Sundar V.

    2016-03-01

    The effects of powders attributes (shape and size distribution) and critical processing conditions (energy density) on the densification and mechanical properties of laser powder bed fusion (L-PBF) 17-4 PH stainless steel were studied using four types of powders. The % theoretical density, ultimate tensile strength and hardness of both water- and gas-atomized powders increased with increased energy density. Gas-atomized powders showed superior densification and mechanical properties when processed at low energy densities. However, the % theoretical density and mechanical properties of water-atomized powders were comparable to gas-atomized powders when sintered at a high energy density of 104 J/mm3. An important result of this study was that, even at high % theoretical density (97% ± 1%), the properties of as-printed parts could vary over a relatively large range (UTS: 500-1100 MPa; hardness: 25-39 HRC; elongation: 10-25%) depending on powder characteristics and process conditions. The results also demonstrate the feasibility of using relatively inexpensive water-atomized powders as starting raw material instead of the typically used gas-atomized powders to fabricate parts using L-PBF techniques by sintering at high energy densities.

  4. Precipitation-Induced Changes in Microstrain and Its Relation with Hardness and Tempering Parameter in 17-4 PH Stainless Steel

    NASA Astrophysics Data System (ADS)

    Mahadevan, S.; Manojkumar, R.; Jayakumar, T.; Das, C. R.; Rao, B. P. C.

    2016-06-01

    17-4 PH (precipitation hardening) stainless steel is a soft martensitic stainless steel strengthened by aging at appropriate temperature for sufficient duration. Precipitation of copper particles in the martensitic matrix during aging causes coherency strains which improves the mechanical properties, namely hardness and strength of the matrix. The contributions to X-ray diffraction (XRD) profile broadening due to coherency strains caused by precipitation and crystallite size changes due to aging are separated and quantified using the modified Williamson-Hall approach. The estimated normalized mean square strain and crystallite size are used to explain the observed changes in hardness. Microstructural changes observed in secondary electron images are in qualitative agreement with crystallite size changes estimated from XRD profile analysis. The precipitation kinetics in the age-hardening regime and overaged regime are studied from hardness changes and they follow the Avrami kinetics and Wilson's model, respectively. In overaged condition, the hardness changes are linearly correlated to the tempering parameter (also known as Larson-Miller parameter). Similar linear variation is observed between the normalized mean square strain (determined from XRD line profile analysis) and the tempering parameter, in the incoherent regime which is beyond peak microstrain conditions.

  5. The Effect of 17-4 PH Stainless Steel on the Lifetime of a Pennzane(Trademark) Lubricated Microwave Limb Sounder Antenna Actuator Assembly Ball Screw for the AURA Spacecraft

    NASA Technical Reports Server (NTRS)

    Jones, William R., Jr.; Jansen, Mark J.; Chen, Gun-Shing; Lam, Jonathan; Balzer, Mark; Anderson, Mark; Lo, John; Schepis, Joseph P.

    2005-01-01

    During ground based life testing of a Microwave Limb Sounder (MLS) Antenna Actuator Assembly (AAA) ball-screw assembly, lubricant darkening and loss were noted when approximately 10 percent of required lifetime was completed. The MLS-AAA ball screw and nut are made from 17-4 PH steel, the nut has 440C stainless steel balls, and the assembly is lubricated with a Pennzane formulation containing a three weight percent lead naphthenate additive. Life tests were done in dry nitrogen at 50 C. To investigate the MLS-AAA life test anomaly, Spiral Orbit Tribometer (SOT) accelerated tests were performed. SOT results indicated greatly reduced relative lifetimes of Pennzane formulations in contact with 17-4 PH steel compared to 440C stainless steel. Also, dry nitrogen tests yielded longer relative lifetimes than comparable ultrahigh vacuum tests. Generally, oxidized Pennzane formulations yielded shorter lifetimes than non-oxidized lubricant. This study emphasizes surface chemistry effects on the lubricated lifetime of moving mechanical assemblies.

  6. 43 CFR 17.4 - Assurances required.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Assurances required. 17.4 Section 17.4 Public Lands: Interior Office of the Secretary of the Interior NONDISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS OF THE DEPARTMENT OF THE INTERIOR Nondiscrimination on the Basis of Race, Color, or...

  7. 43 CFR 17.4 - Assurances required.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... PROGRAMS OF THE DEPARTMENT OF THE INTERIOR Nondiscrimination on the Basis of Race, Color, or National Origin § 17.4 Assurances required. (a) General. (1) Every application for Federal financial assistance to which this part applies, except an application to which paragraph (b) of this section applies, and...

  8. 43 CFR 17.4 - Assurances required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... PROGRAMS OF THE DEPARTMENT OF THE INTERIOR Nondiscrimination on the Basis of Race, Color, or National Origin § 17.4 Assurances required. (a) General. (1) Every application for Federal financial assistance to which this part applies, except an application to which paragraph (b) of this section applies, and...

  9. 22 CFR 17.4 - Equity and good conscience.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Equity and good conscience. 17.4 Section 17.4 Foreign Relations DEPARTMENT OF STATE PERSONNEL OVERPAYMENTS FROM THE FOREIGN SERVICE RETIREMENT AND... PENSION SYSTEM (FSPS) § 17.4 Equity and good conscience. (a) Defined. Recovery is against equity and...

  10. 40 CFR 17.4 - Applicability to EPA proceedings.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Applicability to EPA proceedings. 17.4 Section 17.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS General Provisions § 17.4 Applicability to...

  11. 40 CFR 17.4 - Applicability to EPA proceedings.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Applicability to EPA proceedings. 17.4 Section 17.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS General Provisions § 17.4 Applicability to...

  12. 40 CFR 17.4 - Applicability to EPA proceedings.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Applicability to EPA proceedings. 17.4 Section 17.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS General Provisions § 17.4 Applicability to...

  13. 40 CFR 17.4 - Applicability to EPA proceedings.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Applicability to EPA proceedings. 17.4 Section 17.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS General Provisions § 17.4 Applicability to...

  14. 40 CFR 17.4 - Applicability to EPA proceedings.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Applicability to EPA proceedings. 17.4 Section 17.4 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS General Provisions § 17.4 Applicability to...

  15. 47 CFR 17.4 - Antenna structure registration.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Antenna structure registration. 17.4 Section 17... ANTENNA STRUCTURES General Information § 17.4 Antenna structure registration. (a) Effective July 1, 1996, the owner of any proposed or existing antenna structure that requires notice of proposed...

  16. 47 CFR 17.4 - Antenna structure registration.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Antenna structure registration. 17.4 Section 17... ANTENNA STRUCTURES General Information § 17.4 Antenna structure registration. (a) Effective July 1, 1996, the owner of any proposed or existing antenna structure that requires notice of proposed...

  17. 47 CFR 17.4 - Antenna structure registration.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Bureau shall resolve all environmental issues, in accordance with the environmental regulations (47 CFR 1... 47 Telecommunication 1 2013-10-01 2013-10-01 false Antenna structure registration. 17.4 Section 17... ANTENNA STRUCTURES General Information § 17.4 Antenna structure registration. (a) Effective July 1,...

  18. 47 CFR 17.4 - Antenna structure registration.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... issues, in accordance with the environmental regulations (47 CFR 1.1301 through 1.1319) specified in part... 47 Telecommunication 1 2014-10-01 2014-10-01 false Antenna structure registration. 17.4 Section 17... ANTENNA STRUCTURES General Information § 17.4 Antenna structure registration. Link to an...

  19. Microstructure and Mechanical Behavior of 17-4 Precipitation Hardenable Steel Processed by Selective Laser Melting

    NASA Astrophysics Data System (ADS)

    Rafi, H. Khalid; Pal, Deepankar; Patil, Nachiket; Starr, Thomas L.; Stucker, Brent E.

    2014-12-01

    The mechanical behavior and the microstructural evolution of 17-4 precipitation hardenable (PH) stainless steel processed using selective laser melting have been studied. Test coupons were produced from 17-4 PH stainless steel powder in argon and nitrogen atmospheres. Characterization studies were carried out using mechanical testing, optical microscopy, scanning electron microscopy, and x-ray diffraction. The results show that post-process heat treatment is required to obtain typically desired tensile properties. Columnar grains of smaller diameters (<2 µm) emerged within the melt pool with a mixture of martensite and retained austenite phases. It was found that the phase content of the samples is greatly influenced by the powder chemistry, processing environment, and grain diameter.

  20. 22 CFR 17.4 - Equity and good conscience.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... DISABILITY FUND UNDER THE FOREIGN SERVICE RETIREMENT AND DISABILITY SYSTEM (FSRDS) AND THE FOREIGN SERVICE PENSION SYSTEM (FSPS) § 17.4 Equity and good conscience. (a) Defined. Recovery is against equity and...

  1. SS Lac Revisited

    NASA Astrophysics Data System (ADS)

    Milone, E. F.; Schiller, S. J.; Munari, U.; Kallrath, J.

    1999-05-01

    We have evidence confirming changes in light curve amplitude of the former eclipsing and current SB2 system SS Lac in the open cluster NGC 7209. Remeasured Harvard plate data and published and compiled data sets reveal that the depth of the primary minimum increased between the 1890s and early 1900s and decreased in the 1920s and 1930s. Peak fittings of the amplitude with phase suggests a peak amplitude centered ca. 1911.5, with eclipse onset at about 1885 and effective eclipse cessation late in 1937. We thus concur with the findings of Lehmann (IBVS 3610, 1991), that the apparent inclination varies with time and that a central eclipse occurred about 1911, and of Mossakovskaya (Astron. Lett., 19, 35, 1993), that eclipses ceased prior to 1940. Estimates of SS Lac from plates taken at Tashkent between 1937 and 1940 serve to confirm these results. We have completed now an exhaustive study of the radial velocity curves of Tomasella & Munari (1998, A&A, 335, 561) and all three potentially useful archival light curves available to us, and will discuss the implications of the solutions for models of the system and the cluster to which it belongs. This work was supported in part by grants to Milone from NSERC of Canada, and the URGC of the University of Calgary.

  2. 24 CFR 17.4 - Administrative claim; evidence and information to be submitted.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Administrative claim; evidence and information to be submitted. 17.4 Section 17.4 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development ADMINISTRATIVE CLAIMS Claims Against Government Under Federal Tort Claims Act Procedures §...

  3. 17. 4th floor roof, view south, 4th and 5th floor ...

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

    17. 4th floor roof, view south, 4th and 5th floor setback to left and atrium structure to right - Sheffield Farms Milk Plant, 1075 Webster Avenue (southwest corner of 166th Street), Bronx, Bronx County, NY

  4. 76 FR 17988 - Proposed Collection; Comment Request for Form SS-4 and SS-4PR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-31

    ... Internal Revenue Service Proposed Collection; Comment Request for Form SS-4 and SS-4PR AGENCY: Internal...(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form SS-4, Application for Employer Identification Number, and Form SS- 4PR, Solicitud de Numero de Indentification Patronal (EIN). DATES:...

  5. Relativistic Jets in SS 433.

    PubMed

    Margon, B

    1982-01-15

    A variety of recent optical, radio, and x-ray observation have confirmed the hypothesis that the peculiar star SS 433 is ejecting two narrow, opposed, highly collimated jets of matter at one-quarter the speed of light. This unique behavior is probably driven by mass exchange between a relatively normal star and a compact companion, either a neutron star or a black hole. However, numerous details regarding the energetics, radiation, acceleration, and collimation of the jets remain to be understood. This phenomenon may well be a miniature example of similar collimated ejection of gas by active extragalactic objects such as quasars and radio galaxies.

  6. Optical flares in SS433

    NASA Astrophysics Data System (ADS)

    Irsmambetova, T. R.

    2014-03-01

    An analysis of the precessional and orbital variability separately in active and quiescent states was carried out by using the photometric database in V-band of the SAI. The main orbital light curves in the active and quiet states in different precessional phases are approximately the same - primary and secondary eclipses are also observed. There are 30 most bright flares that have been studied on phase diagrams. The phase diagrams show the dependence of the flares' appearance on combination between the nodding phases and the precession phases. An analysis of the above results suggests that the flares originate in jets. Perhaps variations in jet speed cause flares activity in SS433.

  7. 27 CFR 17.4 - OMB control numbers assigned under the Paperwork Reduction Act.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false OMB control numbers... ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS DRAWBACK ON TAXPAID DISTILLED SPIRITS USED IN MANUFACTURING NONBEVERAGE PRODUCTS General Provisions § 17.4 OMB control numbers...

  8. 45 CFR 17.4 - Regulatory investigations and trial-type proceedings.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... RELEASE OF ADVERSE INFORMATION TO NEWS MEDIA § 17.4 Regulatory investigations and trial-type proceedings... 45 Public Welfare 1 2012-10-01 2012-10-01 false Regulatory investigations and trial-type... organizations or to pending agency trial-type proceedings shall be released only in limited circumstances...

  9. 45 CFR 17.4 - Regulatory investigations and trial-type proceedings.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... RELEASE OF ADVERSE INFORMATION TO NEWS MEDIA § 17.4 Regulatory investigations and trial-type proceedings... 45 Public Welfare 1 2010-10-01 2010-10-01 false Regulatory investigations and trial-type... organizations or to pending agency trial-type proceedings shall be released only in limited circumstances...

  10. 45 CFR 17.4 - Regulatory investigations and trial-type proceedings.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... RELEASE OF ADVERSE INFORMATION TO NEWS MEDIA § 17.4 Regulatory investigations and trial-type proceedings... 45 Public Welfare 1 2013-10-01 2013-10-01 false Regulatory investigations and trial-type... organizations or to pending agency trial-type proceedings shall be released only in limited circumstances...

  11. 45 CFR 17.4 - Regulatory investigations and trial-type proceedings.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... RELEASE OF ADVERSE INFORMATION TO NEWS MEDIA § 17.4 Regulatory investigations and trial-type proceedings... economic harm may occur unless the public is notified immediately, it may release information to news media... operating component shall rely on the news media to the extent necessary to provide such notice even...

  12. Infrared variability of SS 433

    SciTech Connect

    Kodaira, K.; Nakada, Y.; Backman, D.E.

    1985-09-01

    New JHKLM photometry of SS 433 showing short time scale variabilities is reported for the period of 1983 July 16-22 UT. The entire body of infrared data included in this paper, Giles et al. (1980), and Catchpole et al. (1981), is examined with reference to periods of 164 days and 13.08 days. Comparison of the infrared light curves with the optical light curves of Leibowitz et al. (1984) makes it possible to conclude, within the context of an accretion disk model, that the majority of the infrared flux in the SS 433 system comes from the disk, and that the hot spot responsible for the hump in the visual and infrared light curves has a color similar to the average of the disk. A two-dimensional Fourier analysis of the infrared data suggests that the brightness maximum occurs when, seen from the compact star, the noncompact companion passes through a fixed elongation relative to the disk line of nodes with the orbital plane, if the precession is prograde. 15 references.

  13. A study of the efficiency of edible oils degraded in alkaline conditions by Pseudomonas aeruginosa SS-219 and Acinetobacter sp. SS-192 bacteria isolated from Japanese soil.

    PubMed

    Sugimori, Daisuke; Utsue, Tomohiro

    2012-03-01

    High lipid concentration contained in wastewater inhibits the activity of microorganisms in biological wastewater treatment systems such as activated sludge and methane fermentation. To reduce the inhibitory effects, microorganisms capable of efficiently degrading edible oils were screened from various environmental sources. From Japanese soil, we isolated 2 bacteria strains with high degradation abilities at an alkaline pH without consumption of biological oxygen demand (BOD) constituents. Acinetobacter sp. strain SS-192 and Pseudomonas aeruginosa strain SS-219 degraded 77.5 ± 0.6% and 89.5 ± 1.5%, respectively, of 3,000 ppm of mixed oil consisting of salad oil/lard/beef tallow (1/1/1, w/w/w) at 37°C and pH 9.0 in 24 h. Efficient degradation by the two strains occurred at pH 8-9 and 25-40°C. Strain SS-219 degraded lipids even at pH 3. The degradation rate of 3,000 ppm of salad oil, lard, and beef tallow by strain SS-192 was 79.9 ± 2.6%, 63.6 ± 1.9%, and 70.1 ± 1.2%, respectively, during a 24-h cultivation. The degradation rate of 3,000 ppm of salad oil, lard, and beef tallow by strain SS-219 was 82.3 ± 2.1%, 71.9 ± 2.2%, and 71.0 ± 1.1%, respectively, during a 24-h cultivation. After mixed oil degradation by both strains, the BOD value of the cell culture increased from 2,100 ppm to 3,200-4,000 ppm. The fact that neither strain utilizes BOD ingredients will be beneficial to pretreatment of methane fermentation systems such as upflow anaerobic sludge blanket reactors. In addition, the growth of usual heterotrophic microorganisms utilizing soluble BOD can be suppressed under alkaline pH. PMID:22805803

  14. Prediction of V(ss) from in vitro tissue-binding studies.

    PubMed

    Berry, Loren M; Roberts, Jonathan; Be, Xuhai; Zhao, Zhiyang; Lin, Min-Hwa Jasmine

    2010-01-01

    To predict volume of distribution at steady-state (V(ss)), empirical (e.g., allometry) and mechanistic (using physicochemical property data and plasma protein binding) methods have been used. None of these approaches has been able to predict V(ss) accurately for the total compliment of a wide range of drugs. Therefore, alternative approaches would be of value. This study evaluates the utility of in vitro nonspecific tissue-binding measurements in predicting V(ss) for a wide range of drugs in rats. Literature as well as proprietary compounds were studied. It was found that in vitro tissue-binding measurements combined with calculated effects of the pH partition hypothesis often predict V(ss) more accurately than other available mechanistic methods and that this approach can compliment existing methods. The V(ss) values for some compounds were not accurately predicted using either nonspecific tissue-binding experiments or other available mechanistic methods. The V(ss) for these drugs may not be describable by nonspecific tissue binding alone; there may be significant specific components to the mechanism of distribution for these drugs, such as pH-dependent uptake into lysosomes (primarily strongly basic drugs), active transport, and/or enterohepatic recirculation. A lack of prediction for certain drugs warrants further investigation into these mechanisms and their application to more accurate prediction of V(ss) by mechanistic means.

  15. Steel slag raises pH of greenhouse substrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dolomitic lime (DL) is the primary liming agent used for increasing pH in peatmoss-based substrates. Steel slag (SS) is a byproduct of the steel manufacturing industry that has been used to elevate field soil pH. The objective of this research was to determine the pH response of a peatmoss-based g...

  16. SS433 Trek 2: light curve analysis.

    NASA Astrophysics Data System (ADS)

    Fukue, J.; Obana, Y.; Okugami, M.

    The authors have calculated theoretical light curves of SS433 during eclipse and precession, using a model in which SS433 consists of a geometrically thick torus around a compact star and a companion star filling the Roche lobe. The favorite combination is that the mass ratio is about 2 (a compact star is a black hole) and the surface temperature of the companion is around 17000K.

  17. Gluconeotrehalose is the principal organic solute in the psychrotolerant bacterium Carnobacterium strain 17-4.

    PubMed

    Lamosa, Pedro; Mingote, Ana I; Groudieva, Tatiana; Klippel, Barbara; Egorova, Ksenia; Jabbour, Dina; Santos, Helena; Antranikian, Garabed

    2011-07-01

    A high proportion of microorganisms that colonise cold environments originate from marine sites; hence, they must combine adaptation to low temperature with osmoregulation. However, little or nothing is known about the nature of compatible solutes used by cold-adapted organisms to balance the osmotic pressure of the external medium. We studied the intracellular accumulation of small organic solutes in the Arctic isolate Carnobacterium strain 17-4 as a function of the growth temperature and the NaCl concentration in the medium. Data on 16S rDNA sequence and DNA-DNA hybridisation tests corroborate the assignment of this isolate as a new species of the bacterial genus Carnobacterium. The growth profiles displayed maximal specific growth rate at 30°C in medium without NaCl, and maximal values of final biomass at growth temperatures between 10 and 20°C. Therefore, Carnobacterium strain 17-4 exhibits halotolerant and psychrotolerant behaviours. The solute pool contained glycine-betaine, the main solute used for osmoregulation, and an unknown compound whose structure was identified as α-glucopyranosyl-(1-3)-β-glucopyranosyl-(1-1)-α-glucopyranose (abbreviated as gluconeotrehalose), using nuclear magnetic resonance and mass spectrometry. This unusual solute consistently accumulated to high levels (0.35 ± 0.05 mg/mg cell protein) regardless of the growth temperature or salinity. The efficiency of gluconeotrehalose in the stabilisation of four model enzymes against heat damage was also assessed, and the effects were highly protein dependent. The lack of variation in the gluconeotrehalose content observed under heat stress, osmotic stress, and starvation provides no clue for the physiological role of this rare solute.

  18. Early Careers of Recent U.S. Social Science PhDs

    ERIC Educational Resources Information Center

    Morrison, Emory; Rudd, Elizabeth; Nerad, Maresi

    2011-01-01

    In this article, we analyse findings of the largest, most comprehensive survey of the career paths of social science PhD graduates to date, "Social Science PhDs--Five+Years Out (SS5)". "SS5" surveyed more than 3,000 graduates of U.S. PhD programmes in six social science fields six to ten years after earning their PhD. The survey collected data on…

  19. Study of a synthetic human olfactory receptor 17-4: expression and purification from an inducible mammalian cell line.

    PubMed

    Cook, Brian L; Ernberg, Karin E; Chung, Hyeyoun; Zhang, Shuguang

    2008-01-01

    In order to begin to study the structural and functional mechanisms of olfactory receptors, methods for milligram-scale purification are required. Here we demonstrate the production and expression of a synthetically engineered human olfactory receptor hOR17-4 gene in a stable tetracycline-inducible mammalian cell line (HEK293S). The olfactory receptor gene was fabricated from scratch using PCR-based gene-assembly, which facilitated codon optimization and attachment of a 9-residue bovine rhodopsin affinity tag for detection and purification. Induction of adherent cultures with tetracycline together with sodium butyrate led to hOR17-4 expression levels of approximately 30 microg per 150 mm tissue culture plate. Fos-choline-based detergents proved highly capable of extracting the receptors, and fos-choline-14 (N-tetradecylphosphocholine) was selected for optimal solubilization and subsequent purification. Analysis by SDS-PAGE revealed both monomeric and dimeric receptor forms, as well as higher MW oligomeric species. A two-step purification method of immunoaffinity and size exclusion chromatography was optimized which enabled 0.13 milligrams of hOR17-4 monomer to be obtained at >90% purity. This high purity of hOR17-4 is not only suitable for secondary structural and functional analyses but also for subsequent crystallization trials. Thus, this system demonstrates the feasibility of purifying milligram quantities of the GPCR membrane protein hOR17-4 for fabrication of olfactory receptor-based bionic sensing device.

  20. NARSTO EPA SS PITTSBURGH RAPID SPMS DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS PITTSBURGH RAPID SPMS DATA Project Title:  NARSTO Discipline:  ... Parameters:  Particulates Order Data:  ASDC Order Tool:   Order Data Guide Documents:  ... Earth Related Data:  Environmental Protection Agency Supersites Pittsburgh, Pennsylvania SCAR-B ...

  1. NARSTO EPA SS HOUSTON DMA DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON DMA DATA Project Title:  NARSTO Discipline:  ... Particulates Cloud Condensation Nuclei Order Data:  ASDC Order Tool:   Order Data Guide Documents:  ... Earth Related Data:  Environmental Protection Agency Supersites Houston, Texas SCAR-B Block:  ...

  2. NARSTO EPA SS LOS ANGELES SMPS DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS LOS ANGELES SMPS DATA Project Title:  NARSTO Discipline:  ... Particle Properties Particulate Matter Order Data:  ASDC Order Tool:   Order Data Guide Documents:  ... Earth Related Data:  Environmental Protection Agency Supersites Los Angeles, California SCAR-B ...

  3. NARSTO EPA SS LOS ANGELES PARTISOL DATA

    Atmospheric Science Data Center

    2014-05-07

    NARSTO EPA SS LOS ANGELES PARTISOL DATA Project Title:  NARSTO Discipline:  ... Properties Trace Elements Trace Metals Order Data:  Reverb:  Order Data Guide Documents:  ... Earth Related Data:  Environmental Protection Agency Supersites Los Angeles, California SCAR-B ...

  4. NARSTO EPA SS ATLANTA RAPID SPMS DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS ATLANTA RAPID SPMS DATA Project Title:  NARSTO ...   Order Data Guide Documents:  Atlanta SPMS Guide EPA Sites Get Google Earth ... Data:  Environmental Protection Agency Supersites Atlanta, Georgia SCAR-B Block:  ...

  5. Middle Level SS&C Energy Series.

    ERIC Educational Resources Information Center

    Crow, Linda W.; Aldridge, Bill G.

    The project on Scope Sequence and Coordination of Secondary School Science (SS&C) was initiated by the National Science Teachers Association (NSTA) and recommends that all students study science every year and advocates carefully sequenced, well-coordinated instruction in biology, chemistry, earth/space science, and physics. This document…

  6. NARSTO EPA SS LOS ANGELES APS DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS LOS ANGELES APS DATA Project Title:  NARSTO Discipline:  ... Platform:  Ground Station Instrument:  APS - Aerodynamic Particle Sizer Location:  Los Angeles, ... Data Guide Documents:  Los Angeles APS Guide Los Angeles Project Plan  (PDF) Los Angeles ...

  7. Structure and Long-Term Stability of Alkylphosphonic Acid Monolayers on SS316L Stainless Steel.

    PubMed

    Kosian, Medea; Smulders, Maarten M J; Zuilhof, Han

    2016-02-01

    Surface modification of stainless steel (SS316L) to improve surface properties or durability is an important avenue of research, as SS316L is widely used in industry and science. We studied, therefore, the formation and stability of a series of organic monolayers on SS316L under industrially relevant conditions. These included acidic (pH 3), basic (pH 11), neutral (Milli-Q water), and physiological conditions [10 mM phosphate-buffered saline (PBS)], as well as dry heating (120 °C). SS316L was modified with alkylphosphonic acids of chain length (CH2)n with n varying between 3 and 18. While alkylphosphonic acids of all chain lengths formed self-assembled monolayers with hydrophobic properties, only monolayers of chain lengths 12-18 formed ordered monolayers, as evidenced by static water contact angle (SCA), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and infrared reflection absorption spectroscopy (IRRAS). A long-term stability study revealed the excellent stability of monolayers with chain lengths 12-18 for up to 30 days in acid, neutral, and physiological solutions, and for up to 7 days under dry heating. Under strong basic conditions a partial breakdown of the monolayer was observed, especially for the shorter chain lengths. Finally, the effect of multivalent surface attachment on monolayer stability was explored by means of a series of divalent bisphosphonic acids. PMID:26771302

  8. An Ss Model with Adverse Selection.

    ERIC Educational Resources Information Center

    House, Christopher L.; Leahy, John V.

    2004-01-01

    We present a model of the market for a used durable in which agents face fixed costs of adjustment, the magnitude of which depends on the degree of adverse selection in the secondary market. We find that, unlike typical models, the sS bands in our model contract as the variance of the shock increases. We also analyze a dynamic version of the model…

  9. NARSTO EPA SS ATLANTA 1999 CHEM PM MET DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS ATLANTA 1999 CHEM PM MET DATA Note: The negative sign is ... the longitude in the following data files: NARSTO_EPA_SS_ATLANTA_GAS_GAS_DATA_1_KB_V1.csv and NARSTO_EPA_SS_ATLANTA_MET_MET_DATA_1_KB_V1.csv Project Title:  NARSTO ...

  10. Enhanced undecylprodigiosin production from Serratia marcescens SS-1 by medium formulation and amino-acid supplementation.

    PubMed

    Wei, Yu-Hong; Yu, Wan-Ju; Chen, Wei-Chuan

    2005-10-01

    Serratia marcescens Simon Swift-1 (SS-1) was used to produce a prodigiosin-like pigment, undecylprodigiosin (UP), known to have antitumor activities and potential as an anticancer drug. Modified media containing components of Luria-Bertani (LB) broth and selected amino acids were used to improve UP production from S. marcescens SS-1. Optimal culture conditions (e.g., temperature, pH, agitation rate) for UP production were also identified. It was found that S. marcescens SS-1 was able to produce 690 mg l-1 of UP when it was grown with 5 g l-1 yeast extract alone (YE medium) under the optimal culture conditions of 30 degrees C, 200 rpm, and pH 8. The UP production of 690 mg l-1 is nearly 23-fold of that obtained from original LB medium. Addition of amino acids containing pyrrole-like structures further enhanced UP production. Nearly 2 and 1.4 g l-1 of UP was produced when the SS-1 strain was cultivated with YE medium supplemented with proline and histidine (5 g l-1), respectively. Moreover, the addition of aspartic acid (5 g l-1) also resulted in a high UP production of 1.4 g l-1. Optimal dosages of the three amino acids were subsequently determined and the highest UP production (2.5 g l-1) was achieved with the addition of 10 g l-1 of proline. This suggests that the supplementation of amino acids related to the formation of a UP precursor (e.g., pyrrolylpyrromethene) could enhance UP production by the SS-1 strain.

  11. [Solidification/Stabilization (S/S) of sludge using calcium-bentonite as additive].

    PubMed

    Zhu, Wei; Lin, Cheng; Li, Lei; Ohki, T

    2007-05-01

    Cement-based S/S of sludge confronted the problems of consuming the large amount of cement and high pH leaching from solidified sludge. This research utilized calcium-bentonite as additive to assist cement-based S/S of sludge. Unconfined compressive strength (UCS) test and leach test were conducted to assess its effect by measuring UCS of the solidified sludge, leaching ratio of heavy metal, COD and pH of leachate from the solidified sludge. The results show that compressive strength of the solidified sludge increases remarkably after adding calcium-bentonite, and when half of cement content of 0.4 (to sludge by weight) is replaced by bentonite, strength of the solidified sludge increases nearly 6 times. Furthermore, volume of the solidified sludge after adding bentonite changes small. With calcium-bentonite adding, leaching Zn, Pb and pH from the solidified sludge appears in a declining trend, zinc and lead leaching ratios decrease from 6.9% to 0.25%, 9.6% to 5% respectively and pH decreases from 12.3 to 12.1. Copper would be leached out as organics dissolve at high pH or natural drying conditions, which increases leaching ratio of copper from sludge. However, bentonite can reduce these bad influences and improve stability of copper stable in the solidified sludge. PMID:17633173

  12. The Power of SS 433's Jets

    NASA Technical Reports Server (NTRS)

    Band, David F.

    1999-01-01

    We observed SS 433 for the third time with RXTE, this time simultaneously with a Nobeyama millimeter band monitoring campaign. These observations extended the RXTE coverage of SS 433's precession phases. and once again monitored the source during a binary eclipse. Our AO-2 campaign of a joint RXTE-VLBA-VLA-MERLIN observation was delayed to little more than a month before the AO-3 observations. We also had an AO-1 observation of SS 433. In each case we observed an eclipse of the compact ob'ect by the companion star, and had contemporaneous optical observations. We are analyzing all three sets of observations together. A publication is in preparation; Its completion will be supported by the remaining AO-2 funds. Here I will summarize the general results and point out the relevant features of the AO-3 observations. The spectrum is detected to approx. 50 keV, which is entirely within the PCA energy band. We find that the HEXTE data do not add significantly to the spectrum, and most of our fits are without HEXTE. We find that the continuum can be fit with a power law with an exponential cutoff; the photon index is usually approx. 1.4. A line at approx. 6.4 keV is definitely required, and the fits improve significant, if we add a second line, also with an energy in the iron K(alpha) complex, and an absorption edge. The edge usually has an energy of approx. 5.8 keV, which does not correspond to any known physical feature. and may be an instrumental artifact. This is under further investigation.

  13. Kinetic and thermodynamic analysis of the conformational folding process of SS-reduced bovine pancreatic ribonuclease A using a selenoxide reagent with high oxidizing ability.

    PubMed

    Arai, Kenta; Kumakura, Fumio; Iwaoka, Michio

    2012-01-01

    Redox-coupled folding pathways of bovine pancreatic ribonuclease A (RNase A) with four intramolecular disulfide (SS) bonds comprise three phases: (I) SS formation to generate partially oxidized intermediate ensembles with no rigid folded structure; (II) SS rearrangement from the three SS intermediate ensemble (3S) to the des intermediates having three native SS linkages; (III) final oxidation of the last native SS linkage to generate native RNase A. We previously demonstrated that DHS(ox), a water-soluble selenoxide reagent for rapid and quantitative SS formation, allows clear separation of the three folding phases. In this study, the main conformational folding phase (phase II) has been extensively analyzed at pH 8.0 under a wide range of temperatures (5-45 °C), and thermodynamic and kinetic parameters for the four des intermediates were determined. The free-energy differences (ΔG) as a function of temperature suggested that the each SS linkage has different thermodynamic and kinetic roles in stability of the native structure. On the other hand, comparison of the rate constants and the activation energies for 3S → des with those reported for the conformational folding of SS-intact RNase A suggested that unfolded des species (desU) having three native SS linkages but not yet being folded are involved in very small amounts (<1%) in the 3S intermediate ensemble and the desU species would gain the native-like structures via X-Pro isomerization like SS-intact RNase A. It was revealed that DHS(ox) is useful for kinetic and thermodynamic analysis of the conformational folding process on the oxidative folding pathways of SS-reduced proteins.

  14. Kinetics of Mn(II) oxidation by Leptothrix discophora SS1

    NASA Astrophysics Data System (ADS)

    Zhang, Jinghao; Lion, Leonard W.; Nelson, Yarrow M.; Shuler, Michael L.; Ghiorse, William C.

    2002-03-01

    The kinetics of Mn(II) oxidation by the bacterium Leptothrix discophora SS1 was investigated in this research. Cells were grown in a minimal mineral salts medium in which chemical speciation was well defined. Mn(II) oxidation was observed in a bioreactor under controlled conditions with pH, O 2, and temperature regulation. Mn(II) oxidation experiments were performed at cell concentrations between 24 mg/L and 35 mg/L, over a pH range from 6 to 8.5, between temperatures of 10°C and 40°C, over a dissolved oxygen range of 0 to 8.05 mg/L, and with L. discophora SS1 cells that were grown in the presence of Cu concentrations ranging from zero to 0.1 μM. Mn(II) oxidation rates were determined when the cultures grew to stationary phase and were found to be directly proportional to O 2 and cell concentrations over the ranges investigated. The optimum pH for Mn(II) oxidation was approximately 7.5, and the optimum temperature was 30°C. A Cu level as low as 0.02 μM was found to inhibit the growth rate and yield of L. discophora SS1 observed in shake flasks, while Cu levels between 0.02 and 0.1 μM stimulated the Mn(II) oxidation rate observed in bioreactors. An overall rate law for Mn(II) oxidation by L. discophora as a function of pH, temperature, dissolved oxygen concentration (D.O.), and Cu concentration is proposed. At circumneutral pH, the rate of biologically mediated Mn(II) oxidation is likely to exceed homogeneous abiotic Mn(II) oxidation at relatively low (≈μg/L) concentrations of Mn oxidizing bacteria.

  15. Multiwavelength Observations of the SS 433 Jets

    NASA Astrophysics Data System (ADS)

    Marshall, Herman L.; Canizares, Claude R.; Hillwig, Todd; Mioduszewski, Amy; Rupen, Michael; Schulz, Norbert S.; Nowak, Michael; Heinz, Sebastian

    2013-09-01

    We present observations of the SS 433 jets using the Chandra High Energy Transmission Grating Spectrometer with contemporaneous optical and Very Long Baseline Array observations. The X-ray and optical emission line regions are found to be related but not coincident as the optical line emission persists for days while the X-ray emission lines fade in less than 5000 s. The line Doppler shifts from the optical and X-ray lines match well, indicating that they are less than 3 × 1014 cm apart. The jet Doppler shifts show aperiodic variations that could result from shocks in interactions with the local environment. These perturbations are consistent with a change in jet direction but not jet speed. The proper motions of the radio knots match the kinematic model only if the distance to SS 433 is 4.5 ± 0.2 kpc. Observations during eclipse show that the occulted emission is very hard, seen only above 2 keV and rising to comprise >50% of the flux at 8 keV. The soft X-ray emission lines from the jet are not blocked, constraining the jet length to >~ 2 × 1012 cm. The base jet density is in the range 1010-13 cm-3, in contrast to our previous estimate based on the Si XIII triplet, which is likely to have been affected by UV de-excitation. There is a clear overabundance of Ni by a factor of about 15 relative to the solar value, which may have resulted from an unusual supernova that formed the compact object.

  16. Synthesis of amphiphilic copolymers containing zwitterionic sulfobetaine as pH and redox responsive drug carriers.

    PubMed

    Cai, Mengtan; Leng, Mengtian; Lu, Aijing; He, Liu; Xie, Xiaoxiong; Huang, Lei; Ma, Yuhao; Cao, Jun; Chen, Yuanwei; Luo, Xianglin

    2015-02-01

    Amphiphilic poly(ɛ-caprolactone)-SS-poly(N,N-diethylaminoethyl methacrylate)-r-poly(N-(3-sulfopropyl)-N-methacrylate-N,N-diethylammonium-betaine) (PCL-SS-PDEASB) was designed and synthesized successfully. pH and redox dually responsive micelles were prepared based on the obtained copolymers, with zwitterionic sulfobetaines as hydrophilic shell, DEA as pH sensitive content and disulfide as redox responsive linkage. The micelle diameters were all less than 200 nm and the micelle diameter distributions were narrow. These micelles could be triggered by pH and redox condition. The drug release from the drug-loaded micelles displayed fastest under simultaneously acidic and reductive conditions. Results of in vitro cell toxicity evaluation showed that introduction of sulfobetaines could greatly decrease the toxicity of poly(ɛ-caprolactone)-SS-poly(N,N-diethylaminoethyl methacrylate) (PCL-SS-PDEA) micelles. DOX-loaded PCL-SS-PDEASB micelles showed higher efficiency to kill HeLa cells than DOX-loaded PCL-PDEASB micelles. Half inhibitory concentration (IC50) of DOX-loaded PCL-SS-PDEASB micelles decreased with the content of sulfobetaines increasing and was even closer to that of DOX·HCl. Thus, the pH and redox dually responsive biodegradable micelles generated by PCL-SS-PDEASB may be potential smart drug carriers for tumor targeted delivery. PMID:25531063

  17. The reproducible radio outbursts of SS Cygni

    NASA Astrophysics Data System (ADS)

    Russell, T. D.; Miller-Jones, J. C. A.; Sivakoff, G. R.; Altamirano, D.; O'Brien, T. J.; Page, K. L.; Templeton, M. R.; Körding, E. G.; Knigge, C.; Rupen, M. P.; Fender, R. P.; Heinz, S.; Maitra, D.; Markoff, S.; Migliari, S.; Remillard, R. A.; Russell, D. M.; Sarazin, C. L.; Waagen, E. O.

    2016-08-01

    We present the results of our intensive radio observing campaign of the dwarf nova SS Cyg during its 2010 April outburst. We argue that the observed radio emission was produced by synchrotron emission from a transient radio jet. Comparing the radio light curves from previous and subsequent outbursts of this system (including high-resolution observations from outbursts in 2011 and 2012) shows that the typical long and short outbursts of this system exhibit reproducible radio outbursts that do not vary significantly between outbursts, which is consistent with the similarity of the observed optical, ultraviolet and X-ray light curves. Contemporaneous optical and X-ray observations show that the radio emission appears to have been triggered at the same time as the initial X-ray flare, which occurs as disc material first reaches the boundary layer. This raises the possibility that the boundary region may be involved in jet production in accreting white dwarf systems. Our high spatial resolution monitoring shows that the compact jet remained active throughout the outburst with no radio quenching.

  18. Mechanochemical regulations of RPA's binding to ssDNA.

    PubMed

    Chen, Jin; Le, Shimin; Basu, Anindita; Chazin, Walter J; Yan, Jie

    2015-01-01

    Replication protein A (RPA) is a ubiquitous eukaryotic single-stranded DNA (ssDNA) binding protein that serves to protect ssDNA from degradation and annealing, and as a template for recruitment of many downstream factors in virtually all DNA transactions in cell. During many of these transactions, DNA is tethered and is likely subject to force. Previous studies of RPA's binding behavior on ssDNA were conducted in the absence of force; therefore the RPA-ssDNA conformations regulated by force remain unclear. Here, using a combination of atomic force microscopy imaging and mechanical manipulation of single ssDNA tethers, we show that force mediates a switch of the RPA bound ssDNA from amorphous aggregation to a much more regular extended conformation. Further, we found an interesting non-monotonic dependence of the binding affinity on monovalent salt concentration in the presence of force. In addition, we discovered that zinc in micromolar concentrations drives ssDNA to a unique, highly stiff and more compact state. These results provide new mechanochemical insights into the influences and the mechanisms of action of RPA on large single ssDNA. PMID:25787788

  19. Human bulbar conjunctival hemodynamics in hemoglobin SS and SC disease.

    PubMed

    Wanek, Justin; Gaynes, Bruce; Lim, Jennifer I; Molokie, Robert; Shahidi, Mahnaz

    2013-08-01

    The known biophysical variations of hemoglobin (Hb) S and Hb C may result in hemodynamic differences between subjects with SS and SC disease. The purpose of this study was to measure and compare conjunctival hemodynamics between subjects with Hb SS and SC hemoglobinopathies. Image sequences of the conjunctival microcirculation were acquired in 9 healthy control subjects (Hb AA), 24 subjects with SC disease, and 18 subjects with SS disease, using a prototype imaging system. Diameter (D) and blood velocity (V) measurements were obtained in multiple venules of each subject. Data were categorized according to venule caliber by averaging V and D for venules with diameters less than (vessel size 1) or greater than (vessel size 2) 15 µm. V in vessel size 2 was significantly greater than V in vessel size 1 in the AA and SS groups (P ≥ 0.009), but not in the SC group (P = 0.1). V was significantly lower in the SC group as compared to the SS group (P = 0.03). In AA and SS groups, V correlated with D (P ≤ 0.005), but the correlation was not statistically significant in the SC group (P = 0.08). V was inversely correlated with hematocrit in the SS group for large vessels (P = 0.03); however, no significant correlation was found in the SC group (P ≥ 0.2). Quantitative assessment of conjunctival microvascular hemodynamics in SS and SC disease may advance understanding of sickle cell disease pathophysiology and thereby improve therapeutic interventions.

  20. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  1. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  2. 47 CFR 97.311 - SS emission types.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AMATEUR RADIO SERVICE Technical Standards § 97.311 SS emission types. (a) SS emission transmissions by an amateur station are authorized only for communications between points within areas where the amateur service...

  3. Mechanochemical regulations of RPA's binding to ssDNA

    NASA Astrophysics Data System (ADS)

    Chen, Jin; Le, Shimin; Basu, Anindita; Chazin, Walter J.; Yan, Jie

    2015-03-01

    Replication protein A (RPA) is a ubiquitous eukaryotic single-stranded DNA (ssDNA) binding protein that serves to protect ssDNA from degradation and annealing, and as a template for recruitment of many downstream factors in virtually all DNA transactions in cell. During many of these transactions, DNA is tethered and is likely subject to force. Previous studies of RPA's binding behavior on ssDNA were conducted in the absence of force; therefore the RPA-ssDNA conformations regulated by force remain unclear. Here, using a combination of atomic force microscopy imaging and mechanical manipulation of single ssDNA tethers, we show that force mediates a switch of the RPA bound ssDNA from amorphous aggregation to a much more regular extended conformation. Further, we found an interesting non-monotonic dependence of the binding affinity on monovalent salt concentration in the presence of force. In addition, we discovered that zinc in micromolar concentrations drives ssDNA to a unique, highly stiff and more compact state. These results provide new mechanochemical insights into the influences and the mechanisms of action of RPA on large single ssDNA.

  4. SS1 (NAL1)- and SS2-Mediated Genetic Networks Underlying Source-Sink and Yield Traits in Rice (Oryza sativa L.).

    PubMed

    Xu, Jian-Long; Wang, Yun; Zhang, Fan; Wu, Yuan; Zheng, Tian-Qing; Wang, Yong-Hong; Zhao, Xiu-Qin; Cui, Yan-Ru; Chen, Kai; Zhang, Qiang; Lin, Hong-Xuan; Li, Jia-Yang; Li, Zhi-Kang

    2015-01-01

    Source leaf/sink capacity (SS) traits are important determinants of grain yield (GY) of rice. To understand the genetic basis of the SS relationship in rice, five SS and GY traits of rice were genetically dissected using two reciprocal introgression populations. Seventy-three QTL affecting the SS and GY traits were identified, most of which were detected in one of the parental genetic backgrounds (GBs). Two major QTL at bins 4.7 (SS1) and 3.12 (SS2) were associated consistently with all measured SS and yield traits in both GBs across two contrasting environments. Strong interactions between SS1/SS2 and the detected QTL led us to the discovery of genetic networks affecting the SS and GY traits. The SS1 acted as a regulator controlling two groups of downstream QTL affecting the source leaf width and grain number per panicle (GNP). SS2 functioned as a regulator positively regulating different groups of downstream QTL affecting the source leaf length, GNP, grain weight, and GY. Map-based cloning of SS1 indicates that SS1 is NAL1 involved in polar auxin/IAA transport. Different alleles at NAL1 were apparently able to qualitatively and/or quantitatively control the IAA transport from the apical meristem to different plant tissues and thus regulate those downstream loci/pathways controlling different SS traits of rice. There was a functional allele and a non-functional mutation in the parents at each of the QTL downstream of SS1 or SS2, which were detectable only in the presence of the functional allele of SS1 or SS2. Our results provided direct evidence that SS and yield traits in rice are controlled by complex signaling pathways and suggest further improvement of rice yield potential with enhanced and balanced SS relationships can be achieved by accurately manipulating allelic combinations at loci in the SS1 and SS2 mediated pathways.

  5. New rhodomycin analogs, SS-288A and SS-288B, produced by a Streptomyces violaceus A262 mutant.

    PubMed

    Saito, S; Katsuda, Y; Johdo, O; Yoshimoto, A

    1995-01-01

    Two new rhodomycin metabolites, SS-288A and SS-288B, were specifically produced by a blocked mutant obtained from Streptomyces violaceus A262 and were respectively identified as 7,10-di(O-rhodosaminyl-deoxyfucosyl-deoxyfucosyl)-beta -rhodomycinone and -beta-isorhodomycinone. PMID:7765964

  6. 1. HISTORIC AMERICAN BUILDINGS SURVEY. S. Lucas, Photographer, 1934 SS. ...

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

    1. HISTORIC AMERICAN BUILDINGS SURVEY. S. Lucas, Photographer, 1934 SS. PETER & PAUL'S JESUIT CHURCH, DETROIT MICHIGAN - Sts. Peter & Paul's Jesuit Church, East Jefferson Avenue & Saint Antoine Street, Detroit, MI

  7. NARSTO EPA SS NEW YORK AIR CHEM PM MET DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS NEW YORK AIR CHEM PM MET DATA Project Title:  NARSTO ... Nitrogen Oxides Ozone Surface Winds Air Temperature Humidity Solar Irradiance Particulate Matter Ultraviolet Radiation Surface Pressure Nitric Acid Aerosol Extinction Aerosol Backscatter ...

  8. Proceedings of GLaSS: Global Lakes Sentinel Services

    NASA Astrophysics Data System (ADS)

    Peters, Steef; Hommersom, Annelies; Alikas, Krista; Heege, Thomas; Schenk, Karin; Ruescas, Ana; Eleveld, Marieke; Giardino, Claudia; Koponen, Sampsa; Kallio, Kari; Philipson, Petra

    2015-12-01

    Global Lakes Sentinel Services (GLaSS) is developing a prototype Sentinel service infrastructure to ingest and process Sentinel-2 and Sentinel-3 data into validated ecological water quality parameters for lakes, plus training material. GLaSS is an EU-funded R&D project within the Copernicus framework. The project is well on its way to reach its goals. Some results on comparisons on atmospheric correction methods for inland waters are presented here.

  9. Human bulbar conjunctival hemodynamics in hemoglobin SS and SC disease

    PubMed Central

    Wanek, Justin; Gaynes, Bruce; Lim, Jennifer I.; Molokie, Robert; Shahidi, Mahnaz

    2014-01-01

    The known biophysical variations of hemoglobin (Hb) S and Hb C may result in hemodynamic differences between subjects with SS and SC disease. The purpose of this study was to measure and compare conjunctival hemodynamics between subjects with Hb SS and SC hemoglobinopathies. Image sequences of the conjunctival microcirculation were acquired in 9 healthy control subjects (Hb AA), 24 subjects with SC disease, and 18 subjects with SS disease, using a prototype imaging system. Diameter (D) and blood velocity (V) measurements were obtained in multiple venules of each subject. Data were categorized according to venule caliber by averaging V and D for venules with diameters less than (vessel size 1) or greater than (vessel size 2) 15 µm. V in vessel size 2 was significantly greater than V in vessel size 1 in the AA and SS groups (P ≥ 0.009), but not in the SC group (P = 0.1). V was significantly lower in the SC group as compared to the SS group (P = 0.03). In AA and SS groups, V correlated with D (P ≥ 0.005), but the correlation was not statistically significant in the SC group (P = 0.08). V was inversely correlated with hematocrit in the SS group for large vessels (P = 0.03); however, no significant correlation was found in the SC group (P ≥ 0.2). Quantitative assessment of conjunctival microvascular hemodynamics in SS and SC disease may advance understanding of sickle cell disease pathophysiology and thereby improve therapeutic interventions. PMID:23657867

  10. Analyses of the Currently Noneclipsing Binary SS Lacertae or SS Lacertae's Eclipses

    NASA Astrophysics Data System (ADS)

    Milone, E. F.; Schiller, S. J.; Munari, U.; Kallrath, J.

    2000-03-01

    Confirmatory evidence for changing light-curve amplitude of the former eclipsing and current SB2 system SS Lac in the Open Cluster NGC 7209 has been uncovered. Remeasured Harvard plate data and published and compiled data sets reveal that the depth of the primary minimum increased between the 1890s and 1902 and decreased in the 1920s and 1930s. A parabolic fitting of the amplitude with phase predicts a maximum at 1911.5, with an eclipse onset at 1885.3 and eclipse cessation at 1937.8. We confirm the finding of Lehmann, that the system's inclination varies with time and that a central eclipse occurred ~1912, and we concur with Mossakovskaya that eclipses effectively ceased ~1940. Estimates of SS Lac on plates taken at Tashkent between 1937 and 1940 further serve to confirm the result. Thus, SS Lac belongs to a small but elite class of triple systems in which changes due to dynamical effects can be seen over a single human lifetime. In order to explore the properties of the SS Lac system, recent radial velocity curves and archival photographic and visual light curves have been analyzed with versions of the Wilson-Devinney code, augmented with a simplex routine to test solution uniqueness. The modeling solutions for the Dugan-Wright light curves ostensibly indicate that the former eclipsing system is composed of two early A stars of only slightly differing masses (2.57+/-0.16 and 2.59+/-0.19 Msolar) and effective surface temperatures (8750+/-300 [assumed for component 1] and 8542+/-309 K), but significantly different radii (2.38+/-0.02 and 3.63+/-0.07 Rsolar) and luminosities (30+/-4 and 63+/-9 Lsolar) for the hotter and cooler components, respectively. The light-curve solutions are compromised somewhat by variable eclipse depths over the ranges of dates of the data sets. This is especially true of the most complete light curve, that of Dugan & Wright; the others also suffer from incompleteness (that of Wachmann) and high scatter (that of Kordylewski, Pagaczewski

  11. Using Surface-Assisted Laser Desorption/Ionization Mass Spectrometry to Detect ss- and ds-Oligodeoxynucleotides

    NASA Astrophysics Data System (ADS)

    Chen, Wen-Tsen; Huang, Ming-Feng; Chang, Huan-Tsung

    2013-06-01

    We applied surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) with HgTe nanostructures as the matrix for the detection of single- and double-stranded oligodeoxynucleotides (ss-ODNs and ds-ODNs). The concentrations of surfactant and additives (metal ions, an amine) and the pH and ionic strength of the sample matrix played significantly different roles in the detection of ss- and ds-ODNs with various sequences. In the presence of Brij 76 (1.5 %), Hg2+ (7.5 μM), and cadaverine (10 μM) at pH 5.0, this SALDI-MS approach allowed the simultaneous detection of T15, T20, T33, and T40, with limits of detection at the femtomole-to-picomole level and sample-to-sample intensity variation <23 %. In the presence of Ag+ (1 μM) and cadaverine (10 μM) at pH 7.0, this technique allowed the detection of randomly sequenced ss- and ds-ODNs at concentrations down to the femtomole level. To the best of our knowledge, this paper is the first to report the detection of ss-ODNs (up to 50-mer) and ds-ODNs (up to 30 base pairs) through the combination of SALDI-MS with HgTe nanostructures as matrices. We demonstrated the practicality of this approach through analysis of a single nucleotide polymorphism that determines the fate of the valine residue in the β-globin of sickle cell megaloblasts.

  12. SS-mPMG and SS-GA: tools for finding pathways and dynamic simulation of metabolic networks.

    PubMed

    Katsuragi, Tetsuo; Ono, Naoaki; Yasumoto, Keiichi; Altaf-Ul-Amin, Md; Hirai, Masami Y; Sriyudthsak, Kansuporn; Sawada, Yuji; Yamashita, Yui; Chiba, Yukako; Onouchi, Hitoshi; Fujiwara, Toru; Naito, Satoshi; Shiraishi, Fumihide; Kanaya, Shigehiko

    2013-05-01

    Metabolomics analysis tools can provide quantitative information on the concentration of metabolites in an organism. In this paper, we propose the minimum pathway model generator tool for simulating the dynamics of metabolite concentrations (SS-mPMG) and a tool for parameter estimation by genetic algorithm (SS-GA). SS-mPMG can extract a subsystem of the metabolic network from the genome-scale pathway maps to reduce the complexity of the simulation model and automatically construct a dynamic simulator to evaluate the experimentally observed behavior of metabolites. Using this tool, we show that stochastic simulation can reproduce experimentally observed dynamics of amino acid biosynthesis in Arabidopsis thaliana. In this simulation, SS-mPMG extracts the metabolic network subsystem from published databases. The parameters needed for the simulation are determined using a genetic algorithm to fit the simulation results to the experimental data. We expect that SS-mPMG and SS-GA will help researchers to create relevant metabolic networks and carry out simulations of metabolic reactions derived from metabolomics data.

  13. O-Demethylation and successive oxidative dechlorination of methoxychlor by Bradyrhizobium sp. strain 17-4, isolated from river sediment.

    PubMed

    Satsuma, Koji; Masuda, Minoru; Sato, Kiyoshi

    2012-08-01

    O-Demethylation of insecticide methoxychlor is well known as a phase I metabolic reaction in various eukaryotic organisms. Regarding prokaryotic organisms, however, no individual species involved in such reaction have been specified and characterized so far. Here we successfully isolated a bacterium that mediates oxidative transformation of methoxychlor, including O-demethylation and dechlorination, from river sediment. The isolate was found to be closely related to Bradyrhizobium elkanii at the 16S rRNA gene sequence level (100% identical). However, based on some differences in the physiological properties of this bacterium, we determined that it was actually a different species, Bradyrhizobium sp. strain 17-4. The isolate mediated O-demethylation of methoxychlor to yield a monophenolic derivative [Mono-OH; 1,1,1-trichloro-2-(4-hydroxyphenyl)-2-(4-methoxyphenyl)ethane] as the primary degradation product. The chiral high-performance liquid chromatography (HPLC) analysis revealed that the isolate possesses high enantioselectivity favoring the formation of (S)-Mono-OH (nearly 100%). Accompanied by the sequential O-demethylation to form the bis-phenolic derivative Bis-OH [1,1,1-trichloro-2,2-bis(4-hydroxyphenyl)ethane], oxidative dechlorination of the side chain proceeded, and monophenolic carboxylic acid accumulated, followed by the formation of multiple unidentified polar degradation products. The breakdown proceeded more rapidly when reductively dechlorinated (dichloro-form) methoxychlor was applied as the initial substrate. The resultant carboxylic acids and polar degradation products are likely further biodegraded by ubiquitous bacteria. The isolate possibly plays an important role for complete degradation (mineralization) of methoxychlor by providing the readily biodegradable substrates.

  14. A smart tumor targeting peptide-drug conjugate, pHLIP-SS-DOX: synthesis and cellular uptake on MCF-7 and MCF-7/Adr cells.

    PubMed

    Song, Qin; Chuan, Xingxing; Chen, Binlong; He, Bing; Zhang, Hua; Dai, Wenbing; Wang, Xueqing; Zhang, Qiang

    2016-06-01

    Doxorubicin (DOX) is a potent anticancer drug for the treatment of tumors, but the poor specificity and multi-drug resistance (MDR) on tumor cells have restricted its application. Here, a pH and reduction-responsive peptide-drug conjugate (PDC), pHLIP-SS-DOX, was synthesized to overcome these drawbacks. pH low insertion peptide (pHLIP) is a cell penetrating peptide (CPP) with pH-dependent transmembrane ability. And because of the unique cell membrane insertion pattern, it might reverse the MDR. The cellular uptake study showed that on both drug-sensitive MCF-7 and drug-resistant MCF-7/Adr cells, pHLIP-SS-DOX obviously facilitated the uptake of DOX at pH 6.0 and the uptake level on MCF-7/Adr cells was similar with that on MCF-7 cells, indicating that pHLIP-SS-DOX had the ability to target acidic tumor cells and reverse MDR. In vitro cytotoxicity study mediated by GSH-OEt demonstrated that the cytotoxic effect of pHLIP-SS-DOX was reduction responsive, with obvious cytotoxicity at pH 6.0; while it had poor cytotoxicity at pH 7.4, no matter with or without GSH-OEt pretreatment. This illustrated that pHLIP could deliver DOX into tumor cells with acidic microenvironment specifically and could not deliver drugs into normal cells with neutral microenvironment. In summary, pHLIP-SS-DOX is a promising strategy to target drugs to tumors and provides a possibility to overcome MDR.

  15. Performance of DMFC with SS 316 bipolar/end plates

    NASA Astrophysics Data System (ADS)

    Padhy, Biswa R.; Reddy, Ramana G.

    This work mainly emphasizes the development of new materials and design for a bipolar/end plate in a direct methanol fuel cell (DMFC). According to the DOE requirements, preliminary studies show that SS 316 (Stainless Steel 316) is a suitable candidate. Several flow field designs were studied and a modified serpentine design was proposed. SS 316 end plates were fabricated with an intricate modified serpentine flow field design on it. The performance of a single stack DMFC with SS 316 end plates were studied with different operational parameters. A long-term test was carried out for 100 h with recycling the methanol and the contaminants in the MEA were characterized. The stack efficiency is found to be 51% and polarization losses are discussed. SS 316 with low permeability resulted in an increased pressure drop across the flow field, which increased the fuel cell performance. The use of SS 316 as bipolar plate material will reduce the machining cost as well as volume of the fuel cell stack.

  16. On the Nature of Compact Object in SS~433. An Observational Evidence of Black Hole Mass in SS 433

    NASA Astrophysics Data System (ADS)

    Titarchuk, Lev

    We present an analysis of X-ray spectral properties observed from black hole candidate (BHC) binary SS 433. We analyze RXTE data from this source, coordinated with Green Bank Interferometer/RATAN-600. We show that SS 433 demonstrates a X-ray spectral transition from low hard state to intermediate state (IS). We show that the X-ray broad-band energy spectra during all spectral states are well fit by a sum of so called "Bulk Motion Comptoniza-tion (BMC)" component and by two (broad and narrow) Gaussians for the continuum and line emissions respectively. In addition to these spectral model components we also find a strong feature of "blackbody-like (BB)" bump which color temperature is in the range of 4-5 keV in 24 IS spectra during radio outburst decay in SS 433. Our observational results on the "high temperature BB" bump leads us to support the presence of gravitationally redshifted annihila-tion lines in this source. We also established the photon index saturation at about 2.3 in index vs mass accretion correlation. This index-mass accretion correlation allows us to evaluate the low limit of black hole (BH) mass of compact object in SS 433, greater than 2 solar masses, using the scaling method using BHC GX 339-4 as a reference source. Our estimate of BH mass in SS 433 is consistent with the recent BH mass measurement by Hillwig Gies who find that BH mass about 4.3 solar masses. It is the smallest BH mass up to now found among all BHC sources where BH masses have been estimated so far. Moreover, the index saturation effect versus mass accretion rate revealed in SS 433, like in a number of other BHCs, is the strongest observational evidence of the presence of BH in SS 433.

  17. Search for gamma ray lines from SS433

    NASA Technical Reports Server (NTRS)

    Geldzahler, B. J.; Share, G. H.; Kinzer, R. L.; Forrest, D. J.; Chupp, E. L.; Rieger, E.

    1985-01-01

    Data obtained with the Gamma Ray Spectrometer (0.3 to 9 MeV) aboard the Solar Maximum Mission satellite from 1980 to 1985 for evidence of the reported Doppler shifted lines from SS433 were examined. The data base covers a total of 468 days when SS433 was in the field of view and includes times of quiescent and flaring radio activity. In 9 day integrations of the SMM data no evidence is found for gamma ray line emission from SS433. The 99% confidence upper limits for 9 day integrations of the shifted 1.37 and 6.1 MeV lines are 0.0013 gamma/sq cm-s and 0.0007 gamma/sq cm-s, respectively. The 360 day time averaged upper limits are 0.0002 gamma/sq cm-s x 0.0001 gamma/sq cm-s for both lines.

  18. 78 FR 23981 - Proposed Collection; Comment Request for Form SS-8

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-23

    ... Internal Revenue Service Proposed Collection; Comment Request for Form SS-8 AGENCY: Internal Revenue...(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form SS-8, Determination of Worker... Employment Taxes and Income Tax Withholding. OMB Number: 1545-0004. Form Number: SS-8. Abstract: Form SS-8...

  19. 75 FR 10017 - Proposed Collection; Comment Request for Form SS-8

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-04

    ... Internal Revenue Service Proposed Collection; Comment Request for Form SS-8 AGENCY: Internal Revenue...(c)(2)(A)). Currently, the IRS is soliciting comments concerning Form SS-8, Determination of Worker... Employment Taxes and Income Tax Withholding. OMB Number: 1545-0004. Form Number: SS-8. Abstract: Form SS-8...

  20. e-VLBI observations of SS 433 in outburst

    NASA Astrophysics Data System (ADS)

    Tudose, V.; Paragi, Z.; Trushkin, S.; Soleri, P.; Fender, R.; Garrett, M.; Spencer, R.; Rushton, A.; Burgess, P.; Kunert-Bajraszewska, M.; Pazderski, E.; Borkowski, K.; Hammargren, R.; Lindqvist, M.; Maccaferri, G.

    2008-11-01

    We have observed the X-ray binary SS 433 on November 6, 2008 between 13:48-18:35 UT at 5 GHz with the European VLBI Network (EVN) using the e-VLBI technique. The radio telescopes participating in the experiment were: Medicina, Onsala 25m, Torun, Jodrell Bank MkII and Cambridge. The X-ray binary SS 433 is in outburst. Trushkin & Nizhelskij (ATel #1819) reported a major flare already active during the RATAN-600 observations in the 1-22 GHz band on 2008 October 28.

  1. The development of a quantitative assay for the detection of anti-Ro/SS-A and anti-LA/SS-B autoantibodies using purified recombinant proteins.

    PubMed

    Veldhoven, C H; Meilof, J F; Huisman, J G; Smeenk, R J

    1992-07-01

    A characteristic of patients with autoimmune diseases such as Sjögren's syndrome and systemic lupus erythematosus is the presence of anti-Ro/SS-A and anti-La/SS-B autoantibodies in their circulation. In order to investigate specific autoantibody levels in the sera of these patients quantitative assays for the detection of both anti-Ro/SS-A and anti-La/SS-B reactivity were developed. Ro/SS-A (60 kDa) and La-SS-B (50 kDa) cDNAs were cloned and expressed in E. coli as non-fusion proteins. These were purified to homogeneity using two different purification protocols. With these recombinant antigens, specific enzyme-linked immunosorbent assays (ELISAs) were developed. 40 sera positive for anti-Ro/SS-A autoantibodies in counterimmunoelectrophoresis (CIE) were tested in both the Ro/SS-A and La/SS-B ELISA. Activity values reproducibly ranged from 1536 to 120,000 U in the Ro/SS-A ELISA and from 763 to 2,500,000 U in the La/SS-B ELISA. The suitability of these ELISAs as screening assays was further investigated by testing 200 sera sent to our laboratory for routine detection of autoantibodies to extractable nuclear antigen (ENA: anti-Sm, anti-RNP, anti-Ro/SS-A and anti-La/SS-B). Both ELISAs showed a high sensitivity and specificity (Ro/SS-A ELISA 85% and 94%, La/SS-B ELISA 100% and 98% respectively), when compared to the standard assays, the RNA-precipitation assay and the HeLa immunoblotting test. From these data we conclude that a quantitative analysis of both anti-Ro/SS-A and anti-La/SS-B autoantibodies is now possible using purified recombinant non-fusion proteins. For screening purposes the La/SS-B ELISA showed a great improvement in sensitivity for the detection of anti-La/SS-B activity in comparison to the La/SS-B CIE, while the Ro/SS-A ELISA almost equalled the performance of the Ro/SS-A CIE.

  2. A third bright radio flare of SS433 during 2016

    NASA Astrophysics Data System (ADS)

    Trushkin, S. A.; Nizhelskij, N. A.; Tsybulev, P. G.; Zhekanis, G. V.

    2016-09-01

    During this year we have detected three powerful radio flares from SS433 with the RATAN-600 radio telescope. The last one began on 05 September (MJD57636.72) and reached 1 Jy at 4.8 GHz and 0.6 Jy at 11.2 GHz on 9 September (MJD57640.72).

  3. NARSTO EPA SS LOS ANGELES AETHALOMETER EC DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS LOS ANGELES AETHALOMETER EC DATA Project Title:  NARSTO Discipline:  ... Carbonaceous Aerosols Particulate Matter Order Data:  ASDC Order Tool:   Order Data Guide Documents:  ... Earth Related Data:  Environmental Protection Agency Supersites Los Angeles, California SCAR-B ...

  4. NARSTO EPA SS LOS ANGELES TEOM PM25 DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS LOS ANGELES TEOM PM25 DATA Project Title:  NARSTO Discipline:  ... Particulate Matter Mass Concentration Order Data:  ASDC Order Tool:   Order Data Guide Documents:  ... Earth Related Data:  Environmental Protection Agency Supersites Los Angeles, California SCAR-B ...

  5. NARSTO EPA SS HOUSTON NH3 HNO3 DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON NH3 HNO3 DATA Project Title:  NARSTO Discipline:  ... Parameters:  Ammonia Nitric Acid Order Data:  ASDC Order Tool:   Order Data Guide Documents:  ... Earth Related Data:  Environmental Protection Agency Supersites Houston, Texas SCAR-B Block:  ...

  6. Liquid-phase ozonation of fusainized components of SS coal

    SciTech Connect

    Semenova, S.A.; Patrakov, Y.F.

    2007-11-15

    Stepwise ozonation of leaning fusainized components of fossil coal of SS grade in acetic acid was studied. The dynamics of accumulation of oxygen-containing groups in the course of ozonation was examined, and the main pathways of the reaction of ozone with structural fragments of the coal substance were revealed.

  7. NARSTO EPA SS ATLANTA 1999 UAH MIPS DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS ATLANTA 1999 UAH MIPS DATA Project Title:  NARSTO ... - Radio Acoustic Sounding System Location:  Atlanta, Georgia Spatial Resolution:  Point Measurements ...   Order Data Guide Documents:  Atlanta UAH MIPS Guide Readme Files:  EPA Sites ...

  8. RPA homologs and ssDNA processing during meiotic recombination.

    PubMed

    Ribeiro, Jonathan; Abby, Emilie; Livera, Gabriel; Martini, Emmanuelle

    2016-06-01

    Meiotic homologous recombination is a specialized process that involves homologous chromosome pairing and strand exchange to guarantee proper chromosome segregation and genetic diversity. The formation and repair of DNA double-strand breaks (DSBs) during meiotic recombination differs from those during mitotic recombination in that the homologous chromosome rather than the sister chromatid is the preferred repair template. The processing of single-stranded DNA (ssDNA) formed on intermediate recombination structures is central to driving the specific outcomes of DSB repair during meiosis. Replication protein A (RPA) is the main ssDNA-binding protein complex involved in DNA metabolism. However, the existence of RPA orthologs in plants and the recent discovery of meiosis specific with OB domains (MEIOB), a widely conserved meiosis-specific RPA1 paralog, strongly suggest that multiple RPA complexes evolved and specialized to subdivide their roles during DNA metabolism. Here we review ssDNA formation and maturation during mitotic and meiotic recombination underlying the meiotic specific features. We describe and discuss the existence and properties of MEIOB and multiple RPA subunits in plants and highlight how they can provide meiosis-specific fates to ssDNA processing during homologous recombination. Understanding the functions of these RPA homologs and how they interact with the canonical RPA subunits is of major interest in the fields of meiosis and DNA repair.

  9. KInNeSS: a modular framework for computational neuroscience.

    PubMed

    Versace, Massimiliano; Ames, Heather; Léveillé, Jasmin; Fortenberry, Bret; Gorchetchnikov, Anatoli

    2008-01-01

    Making use of very detailed neurophysiological, anatomical, and behavioral data to build biologically-realistic computational models of animal behavior is often a difficult task. Until recently, many software packages have tried to resolve this mismatched granularity with different approaches. This paper presents KInNeSS, the KDE Integrated NeuroSimulation Software environment, as an alternative solution to bridge the gap between data and model behavior. This open source neural simulation software package provides an expandable framework incorporating features such as ease of use, scalability, an XML based schema, and multiple levels of granularity within a modern object oriented programming design. KInNeSS is best suited to simulate networks of hundreds to thousands of branched multi-compartmental neurons with biophysical properties such as membrane potential, voltage-gated and ligand-gated channels, the presence of gap junctions or ionic diffusion, neuromodulation channel gating, the mechanism for habituative or depressive synapses, axonal delays, and synaptic plasticity. KInNeSS outputs include compartment membrane voltage, spikes, local-field potentials, and current source densities, as well as visualization of the behavior of a simulated agent. An explanation of the modeling philosophy and plug-in development is also presented. Further development of KInNeSS is ongoing with the ultimate goal of creating a modular framework that will help researchers across different disciplines to effectively collaborate using a modern neural simulation platform. PMID:18695948

  10. The Symbiotic System SS73 17 seen with Suzaku

    NASA Technical Reports Server (NTRS)

    Smith, Randall K.; Mushotzky, Richard; Kallman, Tim; Tueller, Jack; Mukai, Koji; Markwardt, Craig

    2007-01-01

    We observed with Suzaku the symbiotic star SS73 17, motivated by the discovery by the INTEGRAL satellite and the Swift BAT survey that it emits hard X-rays. Our observations showed a highly-absorbed X-ray spectrum with NH > loz3 emp2, equivalent to Av > 26, although the source has B magnitude 11.3 and is also bright in UV. The source also shows strong, narrow iron lines including fluorescent Fe K as well as Fe xxv and Fe XXVI. The X-ray spectrum can be fit with a thermal model including an absorption component that partially covers the source. Most of the equivalent width of the iron fluorescent line in this model can be explained as a combination of reprocessing in a dense absorber plus reflection off a white dwarf surface, but it is likely that the continuum is partially seen in reflection as well. Unlike other symbiotic systems that show hard X-ray emission (CH Cyg, RT Cru, T CrB, GX1+4), SS73 17 is not known to have shown nova-like optical variability, X-ray flashes, or pulsations, and has always shown faint soft X-ray emission. As a result, although it is likely a white dwarf, the nature of the compact object in SS73 17 is still uncertain. SS73 17 is probably an extreme example of the recently discovered and relatively small class of hard X-ray emitting symbiotic systems.

  11. NARSTO EPA SS HOUSTON TEXAQS2000 CAMS DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON TEXAQS2000 CAMS DATA Project Title:  NARSTO ... TEOM Fluorescence Spectroscopy Location:  Houston, Texas Spatial Resolution:  Point Measurements ... Monoxide Nitrogen Oxides Ozone Surface Winds Air Temperature Humidity Solar Irradiance Particulate Matter Sulfur ...

  12. NARSTO EPA SS HOUSTON TEXAQS2000 DOE G-1 DATA

    Atmospheric Science Data Center

    2014-04-25

    NARSTO EPA SS HOUSTON TEXAQS2000 DOE G-1 DATA Project Title:  NARSTO ... Fluorometer Ion Chromatograph Location:  Houston, Texas Spatial Resolution:  Point Measurements ... Parameters:  Atmospheric Pressure Air Temperature Dew Point Flight Level Winds Nitrogen Oxides Ozone ...

  13. KInNeSS: a modular framework for computational neuroscience.

    PubMed

    Versace, Massimiliano; Ames, Heather; Léveillé, Jasmin; Fortenberry, Bret; Gorchetchnikov, Anatoli

    2008-01-01

    Making use of very detailed neurophysiological, anatomical, and behavioral data to build biologically-realistic computational models of animal behavior is often a difficult task. Until recently, many software packages have tried to resolve this mismatched granularity with different approaches. This paper presents KInNeSS, the KDE Integrated NeuroSimulation Software environment, as an alternative solution to bridge the gap between data and model behavior. This open source neural simulation software package provides an expandable framework incorporating features such as ease of use, scalability, an XML based schema, and multiple levels of granularity within a modern object oriented programming design. KInNeSS is best suited to simulate networks of hundreds to thousands of branched multi-compartmental neurons with biophysical properties such as membrane potential, voltage-gated and ligand-gated channels, the presence of gap junctions or ionic diffusion, neuromodulation channel gating, the mechanism for habituative or depressive synapses, axonal delays, and synaptic plasticity. KInNeSS outputs include compartment membrane voltage, spikes, local-field potentials, and current source densities, as well as visualization of the behavior of a simulated agent. An explanation of the modeling philosophy and plug-in development is also presented. Further development of KInNeSS is ongoing with the ultimate goal of creating a modular framework that will help researchers across different disciplines to effectively collaborate using a modern neural simulation platform.

  14. NARSTO EPA SS ST LOUIS AIR CHEM PM MET DATA

    Atmospheric Science Data Center

    2014-05-07

    NARSTO EPA SS ST LOUIS AIR CHEM PM MET DATA Project Title:  NARSTO ... Aethaelometer Anemometer Rain Gauge Pressure Sensor Radiometers Temperature Sensor Weighing Balance AA ... Amount Surface Pressure Solar Radiation Surface Air Temperature Particulates Trace Metals Order Data:  ...

  15. Outburst from SS 433 observed with BOOTES-2/COLORES

    NASA Astrophysics Data System (ADS)

    Caballero-Garcia, M. D.; Castro-Tirado, A.; Jelinek, M.; et al.

    2014-08-01

    In light of the recent extreme outburst of SS 433 (ATELs #6347, #6355) and follow-up by SWIFT (ATEL #6364) the 0.6m TELMA robotic telescope at the BOOTES-2 (+COLORES) astronomical station in Malaga (Spain), obtained optical 4000-9000 A spectra starting at 2014-08-01 and ending at 2014-08-07.

  16. Sites of pH regulation of the urea channel of Helicobacter pylori.

    PubMed

    Weeks, D L; Sachs, G

    2001-06-01

    Helicobacter pylori (Hp) and Streptococcus salivarius (Ss) require intrabacterial urease for acid resistance and express a urea channel, UreI. The presence of UreI was shown to increase urea permeability approximately 300-fold over that of a non-polar ureI deletion mutant. Expression of SsUreI in Xenopus oocytes increased urea uptake pH independently, whereas HpUreI shows an acidic pH dependence, half-maximal at pH 6.0. Mutagenesis of all histidines, aspartates, glutamates and the lysine in the periplasmic domain of HpUreI showed that His-123, His-131, Asp-129, Asp-140, Glu-138 and Lys-132 in the second periplasmic loop (PL2) and His-193 in the C-terminus (Ct) were important for activation of transport. With the exception of a lysine that was shown to substitute for His-193 in HpUreI, these charged amino acids are absent in SsUreI. A chimera in which PL1 of HpUreI was replaced by PL1 of SsUreI retained activity at acidic pH and gained partial activity at neutral pH. Exchange of PL2 inactivated transport, whereas exchange of Ct had no effect. Chimeras, in which either PL1 or PL2 of HpUreI replaced those of SsUreI, retained wild-type transport, but replacement of the Ct or both loops inactivated transport. PL1 appears to be important for restricting transport through HpUreI at neutral pH, whereas protonation of three histidines in PL2 and Ct and the presence of three dicarboxylic amino acids in PL2 appears to be necessary to activate HpUreI at acidic pH.

  17. Experimental atomic scale investigation of irradiation effects in CW 316SS and UFG-CW 316SS

    NASA Astrophysics Data System (ADS)

    Pareige, P.; Etienne, A.; Radiguet, B.

    2009-06-01

    Materials of the core internals of pressurized water reactor (austenitic stainless steels) are subject to neutron irradiation. To understand the ageing mechanisms associated with irradiation and propose life predictions of components or develop new materials, irradiation damage needs to be experimentally investigated. Atomic scale investigation of a neutron-irradiated CW316 SS with the laser pulsed atom probe gives a detailed description of the solute segregation in the austenitic grains. In order to understand the mechanism of solute segregation detected in the neutron-irradiated materials, ion irradiations were performed. These latest irradiations were realized on a CW 316SS as well as on a nanostructured CW 316SS. The study of irradiation effects in a nanograin material allows first, to easily analyse grain boundary segregation and second, to test the behaviour under irradiation of a new nanostructured material. The three aspects of this atomic scale investigation (neutron irradiation effect, model ion irradiation, new nanostructured CW 316 SS) are tackled in this paper.

  18. Imaging Transition Zone Thickness Beneath South America from SS Precursors

    NASA Astrophysics Data System (ADS)

    Schmerr, N.; Garnero, E.

    2006-12-01

    We image detailed upper mantle discontinuity structure beneath a number of geologically active regions, including the South American subduction zone, the Scotia plate subduction zone, and several volcanic hotspots (e.g., the Galapagos Islands), in a region ~10,000 km by 10,000 km wide, spanning 70° S to 20° N and 20° W to 110° W. Precursors to the seismic phase SS are analyzed, which form as a result of underside reflections off seismic discontinuities beneath the midpoint of the SS path and are highly sensitive to discontinuity depth and sharpness. Our SS dataset consists of over 15,000 high-quality transverse component broadband displacement seismograms collected from the Incorporated Research Institutions for Seismology (IRIS), the Canadian National Seismic Network (CNSN), as well as data from EarthScope seismic stations, and from the Canadian Northwest Experiment (CANOE) temporary broadband array deployment. This dataset densely samples several regions in our study area and significantly improves the sampling for this area compared to previous precursor studies. Data with common central SS bouncepoints are stacked to enhance precursory phases. Solution discontinuity structure depends on a number of factors, including dominant seismic period, crustal correction, signal-to-noise ratio threshold, and tomography model used for mantle heterogeneity correction. We exclude precursor data predicted to interfere with other seismic phases, such as topside reflections (e.g., s670sS), which have been demonstrated to contaminate final stacks. Solution transition zone thickness is at least 20 km thicker than global average estimates of 242 km along the northwestern portion of the South American subduction complex (Peru, Ecuador, and Columbia); this thickening extends 1000-1500 km to the east beneath the continent, but does not appear to continue south of -20° latitude along the convergent margin. A minimum of 10 km of thickening is imaged to the west of the Scotia

  19. Inoculating plants with the endophytic bacterium Pseudomonas sp. Ph6-gfp to reduce phenanthrene contamination.

    PubMed

    Sun, Kai; Liu, Juan; Gao, Yanzheng; Sheng, Yuehui; Kang, Fuxing; Waigi, Michael Gatheru

    2015-12-01

    Plant organic contamination poses a serious threat to the safety of agricultural products and human health worldwide, and the association of endophytic bacteria with host plants may decrease organic pollutants in planta. In this study, we firstly determined the growth response and biofilm formation of endophytic Pseudomonas sp. Ph6-gfp, and then systematically evaluated the performance of different plant colonization methods (seed soaking (SS), root soaking (RS), leaf painting (LP)) for circumventing the risk of plant phenanthrene (PHE) contamination. After inoculation for 48 h, strain Ph6-gfp grew efficiently with PHE, oxalic acid, or malic acid as the sole sources of carbon and energy. Moreover, strain Ph6-gfp could form robust biofilms in LB medium. In greenhouse hydroponic experiments, strain Ph6-gfp could actively colonize inoculated plants internally, and plants colonized with Ph6-gfp showed a higher capacity for PHE removal. Compared with the Ph6-gfp-free treatment, the accumulations of PHE in Ph6-gfp-colonized plants via SS, RS, and LP were 20.1, 33.1, and 7.1 %, respectively, lower. Our results indicate that inoculating plants with Ph6-gfp could lower the risk of plant PHE contamination. RS was most efficient for improving PHE removal in whole plant bodies by increasing the cell numbers of Ph6-gfp in plant roots. The findings in this study provide an optimized method to strain Ph6-gfp reduce plant PAH residues, which may be applied to agricultural production in PAH-contaminated soil.

  20. Nuclear processes in the jets of SS 433

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Kozlovsky, B.; Lingenfelter, R. E.

    1984-01-01

    The very narrow gamma-ray lines observed at 1.495 and 6.695 MeV from SS 433 which are blueshifted 1.369 and 6.129 emissions from deexcitations of (24)Mg-asterisk and (16)O-asterisk in grains moving with the jets and inelastically excited by interactions with the ambient medium are discussed. Energetic particle interactions in grains produce very narrow gamma ray lines from deexcitation of nuclear levels whose lifetimes are long enough that the excited nuclei stop before deexcitation. The presence of grains in the jets resolves hitherto discussed difficulties of inelastic excitation models for gamma ray production in SS 433, the very narrow widths of the observed lines and the absence of other strong lines, expected from abundant elements. A model is proposed which could be distinguished from a previously proposed fusion model by gamma ray line observations.

  1. Nuclear processes in the jets of SS433

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Kozlovsky, B.; Lingenfelter, R. E.

    1984-01-01

    The very narrow gamma-ray lines observed at 1.495 and 6.695 MeV from SS433 which are blueshifted 1.369 and 6.129 emissions from deexcitations of (24)Mg* and (16)O* in grains moving with the jets and inelastically excited by interactions with the ambient medium are discussed. Energetic particle interactions in grains produce very narrow gamma ray lines from deexcitation of nuclear levels whose lifetimes are long enough that the excited nuclei stop before deexcitation. The presence of grains in the jets resolves hitherto discussed difficulties of inelastic excitation models for gamma ray production in SS433, the very narrow widths of the observed lines and the absence of other strong lines, expected from abundant elements. A model is proposed which could be distinguished from a previously proposed fusion model by gamma ray line observations.

  2. Fluence dependence of deuterium retention in oxidized SS-316

    NASA Astrophysics Data System (ADS)

    Oya, Yasuhisa; Suzuki, Sachiko; Matsuyama, Masao; Hayashi, Takumi; Yamanishi, Toshihiko; Asakura, Yamato; Okuno, Kenji

    2011-10-01

    The ion fluence dependence of deuterium retention in SS-316 during oxidation at a temperature of 673 K was studied to evaluate the dynamics of deuterium retention in the oxide layer of SS-316. The correlation between the chemical state of stainless steel and deuterium retention was evaluated using XPS and TDS. It was found that the major deuterium desorption temperatures were located at around 660 K and 935 K, which correspond to the desorption of deuterium trapped as hydroxide. The deuterium retention increased with increasing deuterium ion fluence, since the deuterium retention as hydroxide increased significantly. However, retention saturated at an ion fluence of ˜2.5 × 10 21 D + m -2. The XPS result showed that FeOOD was formed on the surface, although pure Fe also remained in the oxide layer. These facts indicate the nature of the oxide layer have a key role in deuterium trapping behavior.

  3. Elastic-plastic analysis of the SS-3 tensile specimen

    SciTech Connect

    Majumdar, S.

    1998-09-01

    Tensile tests of most irradiated specimens of vanadium alloys are conducted using the miniature SS-3 specimen which is not ASTM approved. Detailed elastic-plastic finite element analysis of the specimen was conducted to show that, as long as the ultimate to yield strength ratio is less than or equal to 1.25 (which is satisfied by many irradiated materials), the stress-plastic strain curve obtained by using such a specimen is representative of the true material behavior.

  4. Social class and survival on the S.S. Titanic.

    PubMed

    Hall, W

    1986-01-01

    Passengers' chances of surviving the sinking of the S.S. Titanic were related to their sex and their social class: females were more likely to survive than males, and the chances of survival declined with social class as measured by the class in which the passenger travelled. The probable reasons for these differences in rates of survival are discussed as are the reasons accepted by the Mersey Committee of Inquiry into the sinking.

  5. Revisiting the HST Fine Guidance Sensor Parallax of SS Cygni

    NASA Astrophysics Data System (ADS)

    Harrison, Thomas E.; McArthur, Barbara

    2016-01-01

    Recently, our results for the HST FGS parallax of SS Cyg (Harrison et al. 2000) have been called into question due to a recent radio parallax for this object (Miller-Jones et al. 2013). We have re-analyzed the data for our FGS program on SS Cyg and derive a revised parallax of 7.3 +/- 0.2 mas (137 pc). This parallax is 17% larger than that originally published. We discuss the new analysis effort, and the reasons for the change in our result. We believe we have identified why the radio parallax (8.77 mas) disagrees with the FGS results: We find that if we allow for a roll of two degrees in the HST coordinate system, we obtain the discrepant VLBA radio parallax. It is impossible, however, for the error in the roll of HST to be more than a few tenths of a degree, or else the FGS would not lock-on to the program targets. This roll leads to the large, and erroneous VLBA parallax for SS Cyg. We note that the radio parallax for the black hole system V404 Cyg (Miller-Jones et al. 2009) is also much larger than the spectroscopic parallax of its secondary star. In addition, we closely examine the attempt by Nelan & Bond (2013) to reconcile the FGS data set with the radio result. We identify what we believe to be significant issues with their analysis. Finally, we present a quantitative abundance analysis for SS Cyg, RU Peg, and GK Per derived from moderate resolution K-band spectroscopy. We find severe carbon deficiencies (10 to 20% of the solar value) in the secondary stars of all three objects. We describe the Python program "kmoog" which generates synthetic spectra, and autonomously compares them to observational data.

  6. Hollow conical jet models for SS 433 - A paradigm lost?

    NASA Technical Reports Server (NTRS)

    Kochanek, Christopher S.; Hawley, John F.

    1990-01-01

    A precessing jet such as that in SS 433 may be approximated as an axisymmetric flow, if the precession time is short by comparison to the propagation time. A series of simulations has been conducted for precessing jets using an axisymmetric finite-difference hydrodynamics code. Examinations are made of hollow cylindrical jets, which lack the complication of a growing interior volume, and conical jets, which model the behavior of a precessing jet propagating on the surface of its precession cone.

  7. Tritium uptake by SS316 and its decontamination

    NASA Astrophysics Data System (ADS)

    Torikai, Y.; Penzhorn, R.-D.; Matsuyama, M.; Watanabe, K.

    2004-08-01

    As-received and highly polished SS316 specimens were loaded with HT at 473-573 K. The uptake by polished samples was found to be up to five times that of as-received ones, when loading was performed immediately after polishing. This disparity vanished when polished specimens were subjected to a prolonged exposure to air prior to loading. The tritium loss from tritium-loaded SS316 specimens was examined by chemical etching and by thermal release in a flow system using various carrier gases at several temperatures. While at moderate temperatures the type of carrier has an impact on the tritium release rate, at higher ones this effect disappears. Moisture in the carrier gas has little influence on the loss rate of bulk tritium. Etching depth profiles of specimens previously heat-treated in the presence of air or Ar + H 2 and of untreated specimens are given. Evidence for chronic tritium liberation from SS316 at 298 K is provided.

  8. Global Observations of Mantle Discontinuities Using SS and PP Precursors

    NASA Astrophysics Data System (ADS)

    Deuss, Arwen

    2009-10-01

    SS and PP precursors are currently the only body wave data types that have significant coverage in both oceanic and continental regions to study the existence and characteristics of mantle discontinuities on a global scale. Here, the techniques used by global seismologists to observe SS and PP precursors are reviewed. Seismograms, aligned on SS or PP, are stacked using normal move out (NMO) techniques to obtain common depth point gathers. Bootstrap methods are employed to determine 95% confidence levels of the stacks and robustness of the observations. With these relatively simple techniques, a range of discontinuities has been found in the mantle up to 1,200 km depth. The stacks are dominated by the transition zone discontinuities at 410, 520 and 660 km depth, but additional discontinuities at 220, 300-350, 800-900 and 1,100-1,200 km depth are also seen in certain regions. An overview is given of the most recent observational results with a discussion of their mineral physical interpretation and geodynamical significance. Both seismology and mineral physics agree on the level of complexity at the transition discontinuities: a simple 410, a more complicated 520 and a highly complicated 660-km discontinuity are consistently found in both disciplines.

  9. THE Be STAR SPECTRA (BeSS) DATABASE

    SciTech Connect

    Neiner, C.; De Batz, B.; Cochard, F.; Floquet, M.; Mekkas, A.; Desnoux, V.

    2011-11-15

    Be stars vary on many timescales, from hours to decades. A long time base of observations to analyze certain phenomena in these stars is therefore necessary. Collecting all existing and future Be star spectra into one database has thus emerged as an important tool for the Be star community. Moreover, for statistical studies, it is useful to have centralized information on all known Be stars via an up-to-date catalog. These two goals are what the Be Star Spectra (BeSS, http://basebe.obspm.fr) database proposes to achieve. The database contains an as-complete-as-possible catalog of known Be stars with stellar parameters, as well as spectra of Be stars from all origins (any wavelength, any epoch, any resolution, etc.). It currently contains over 54,000 spectra of more than 600 different Be stars among the {approx}2000 Be stars in the catalog. A user can access and query this database to retrieve information on Be stars or spectra. Registered members can also upload spectra to enrich the database. Spectra obtained by professional as well as amateur astronomers are individually validated in terms of format and science before being included in BeSS. In this paper, we present the database itself as well as examples of the use of BeSS data in terms of statistics and the study of individual stars.

  10. SS 383: A NEW S-TYPE YELLOW SYMBIOTIC STAR?

    SciTech Connect

    Baella, N. O.; Pereira, C. B.; Miranda, L. F.

    2013-11-01

    Symbiotic stars are key objects in understanding the formation and evolution of interacting binary systems, and are probably the progenitors of Type Ia supernovae. However, the number of known symbiotic stars is much lower than predicted. We aim to search for new symbiotic stars, with particular emphasis on the S-type yellow symbiotic stars, in order to determine their total population, evolutionary timescales, and physical properties. The Two Micron All Sky Survey (2MASS) (J – H) versus (H – K {sub s}) color-color diagram has been previously used to identify new symbiotic star candidates and show that yellow symbiotics are located in a particular region of that diagram. Candidate symbiotic stars are selected on the basis of their locus in the 2MASS (J – H) versus (H – K {sub s}) diagram and the presence of Hα line emission in the Stephenson and Sanduleak Hα survey. This diagram separates S-type yellow symbiotic stars from the rest of the S-type symbiotic stars, allowing us to select candidate yellow symbiotics. To establish the true nature of the candidates, intermediate-resolution spectroscopy is obtained. We have identified the Hα emission line source SS 383 as an S-type yellow symbiotic candidate by its position in the 2MASS color-color diagram. The optical spectrum of SS 383 shows Balmer, He I, He II, and [O III] emission lines, in combination with TiO absorption bands that confirm its symbiotic nature. The derived electron density (≅10{sup 8-9} cm{sup –3}), He I emission line intensity ratios, and position in the [O III] λ5007/Hβ versus [O III] λ4363/Hγ diagram indicate that SS 383 is an S-type symbiotic star, with a probable spectral type of K7-M0 deduced for its cool component based on TiO indices. The spectral type and the position of SS 383 (corrected for reddening) in the 2MASS color-color diagram strongly suggest that SS 383 is an S-type yellow symbiotic. Our result points out that the 2MASS color-color diagram is a powerful tool in

  11. Oxidation of elemental sulfur, tetrathionate and ferrous iron by the psychrotolerant Acidithiobacillus strain SS3.

    PubMed

    Kupka, Daniel; Liljeqvist, Maria; Nurmi, Pauliina; Puhakka, Jaakko A; Tuovinen, Olli H; Dopson, Mark

    2009-12-01

    Mesophilic iron and sulfur-oxidizing acidophiles are readily found in acid mine drainage sites and bioleaching operations, but relatively little is known about their activities at suboptimal temperatures and in cold environments. The purpose of this work was to characterize the oxidation of elemental sulfur (S(0)), tetrathionate (S4O6(2-)) and ferrous iron (Fe2+) by the psychrotolerant Acidithiobacillus strain SS3. The rates of elemental sulfur and tetrathionate oxidation had temperature optima of 20 degrees and 25 degrees C, respectively, determined using a temperature gradient incubator that involved narrow (1.1 degrees C) incremental increases from 5 degrees to 30 degrees C. Activation energies calculated from the Arrhenius plots were 61 and 89 kJ mol(-1) for tetrathionate and 110 kJ mol(-1) for S(0) oxidation. The oxidation of elemental sulfur produced sulfuric acid at 5 degrees C and decreased the pH to approximately 1. The low pH inhibited further oxidation of the substrate. In media with both S(0) and Fe2+, oxidation of elemental sulfur did not commence until all available ferrous iron was oxidized. These data on sequential oxidation of the two substrates are in keeping with upregulation and downregulation of several proteins previously noted in the literature. Ferric iron was reduced to Fe2+ in parallel with elemental sulfur oxidation, indicating the presence of a sulfur:ferric iron reductase system in this bacterium. PMID:19782750

  12. pH and reduction dual-bioresponsive polymersomes for efficient intracellular protein delivery.

    PubMed

    Zhang, Jinchao; Wu, Liangliang; Meng, Fenghua; Wang, Zhongjuan; Deng, Chao; Liu, Haiyan; Zhong, Zhiyuan

    2012-01-31

    pH and reduction dual-bioresponsive nanosized polymersomes based on poly(ethylene glycol)-SS-poly(2-(diethyl amino)ethyl methacrylate) (PEG-SS-PDEA) diblock copolymers were developed for efficient encapsulation and triggered intracellular release of proteins. PEG-SS-PDEA copolymers with PDEA-block molecular weights ranging from 4.7, 6.8, to 9.2 kg/mol were synthesized in a controlled manner via reversible addition-fragmentation chain transfer (RAFT) polymerization of 2-(diethyl amino)ethyl methacrylate (DEAEMA) using PEG-SS-CPADN (CPADN = 4-cyanopentanoic acid dithionaphthalenoate; M(n) PEG = 1.9 kg/mol) as a macro-RAFT agent. These copolymers existed as unimers in water at mildly acidic pH (<7.2) conditions, but readily formed monodisperse nanosized polymersomes (54.5-66.8 nm) when adjusting solution pH to 7.4. These polymersomes were highly sensitive to intracellular pH and reductive environments, which resulted in fast dissociation and aggregation of polymersomes, respectively. Notably, both fluorescein isothiocyanate (FITC)-labeled bovine serum albumin (FITC-BSA) and cytochrome C (FITC-CC) proteins could facilely be encapsulated into polymersomes with excellent protein-loading efficiencies, likely as a result of electrostatic interactions between proteins and PDEA. The in vitro release studies showed that protein release was minimal (<20% in 8 h) at pH 7.4 and 37 °C. The release of proteins was significantly enhanced at pH 6.0 due to collapse of polymersomes. Notably, the fastest protein release was observed under intracellular-mimicking reductive environments (10 mM dithiothreitol, pH 7.4). MTT assays in RAW 264.7 and MCF-7 cells indicated that PEG-SS-PDEA (9.2 k) polymersomes had low cytotoxicity up to a polymer concentration of 300 μg/mL. Confocal laser scanning microscope (CLSM) observations revealed that FITC-CC-loaded PEG-SS-PDEA (9.2 k) polymersomes efficiently delivered and released proteins into MCF-7 cells following 6 h of incubation. Importantly

  13. 27 CFR 40.361 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... such district as provided for in 26 CFR § 301.6091-1. The application shall be signed by: (a) The... Form SS-4. 40.361 Section 40.361 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Execution and filing of Form SS-4. The application on IRS form SS-4, together with any...

  14. 20 CFR 225.24 - SS Earnings PIA used in survivor annuities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false SS Earnings PIA used in survivor annuities... Amount of the Residual Lump-Sum Payable § 225.24 SS Earnings PIA used in survivor annuities. The Social Security Earnings PIA (SS Earnings PIA) used in survivor annuities may be used in computing the tier...

  15. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of directors shall monitor planning and execution of the S&S business activities. 2. The S&S board of...-year business strategic and corporate plan that shall be forwarded to the S&S board of directors. The Unified Commands shall forward the on-going strategic and corporate plan to the Director of the AFIS...

  16. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 2 2012-07-01 2012-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  17. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 2 2014-07-01 2014-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  18. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 2 2013-07-01 2013-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  19. 32 CFR Appendix E to Part 246 - Stars and Stripes (S&S) Board of Directors

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 2 2011-07-01 2011-07-01 false Stars and Stripes (S&S) Board of Directors E... DEFENSE (CONTINUED) MISCELLANEOUS STARS AND STRIPES (S&S) NEWSPAPER AND BUSINESS OPERATIONS Pt. 246, App. E Appendix E to Part 246—Stars and Stripes (S&S) Board of Directors A. Organization and...

  20. Mid-Tertiary Isopach and Lithofacies Maps for the Los Angeles Region, California: Templates for Palinspastic Reconstruction to 17.4 Ma

    USGS Publications Warehouse

    McCulloh, Thane H.; Beyer, Larry A.

    2004-01-01

    Opening of the Neogene Los Angeles Basin began abruptly about 17.4 Ma. Extensional rifting, with local basaltic volcanism, began the process and accompanied its early stages. Crustal detachment, followed by clockwise tectonic rotation and translation of large crustal blocks has been shown by previous paleomagnetic declination measurements in the western Transverse Ranges Province northwest of the basin and by large strike-slip and dip-slip separations on several major faults transecting it. Successful palinspastic reconstruction of the region to its arrangement before 17.4 Ma depends on understanding and integration of many stratigraphic and structural components. Before 17.4 Ma, fluviatile, alluvial and floodplain deposits, interstratified in the younger part with shallow marine to deeper shelf transgressive equivalents, accumulated to thicknesses as great as several kilometers. This report maps the surface and subsurface extents, thickness variations, and facies patterns of these strata, the Sespe plus Vaqueros and Trancas Formations or equivalents. Separate southeast and northwest sectors are revealed, each with distinctive internal thickness and facies patterns, which must have been related before rifting and transrotation. Terrestrial vertebrate and marine molluscan and foraminiferal fossils, plus magnetostratigraphic profiles of other workers and a few dates of igneous rocks, provide timing for key depositional and structural events. Our preliminary reconstruction of the region brings the internal patterns of the northwest and southeast sectors toward congruity but leaves unsatisfied discrepancies that suggest important information is missing. The reconstruction focuses attention on critical elements, specific uncertainties, and deficiencies of prior reconstructions. It also provides a new foundation for further work

  1. VirE2: a unique ssDNA-compacting molecular machine.

    PubMed

    Grange, Wilfried; Duckely, Myriam; Husale, Sudhir; Jacob, Susan; Engel, Andreas; Hegner, Martin

    2008-02-01

    The translocation of single-stranded DNA (ssDNA) across membranes of two cells is a fundamental biological process occurring in both bacterial conjugation and Agrobacterium pathogenesis. Whereas bacterial conjugation spreads antibiotic resistance, Agrobacterium facilitates efficient interkingdom transfer of ssDNA from its cytoplasm to the host plant cell nucleus. These processes rely on the Type IV secretion system (T4SS), an active multiprotein channel spanning the bacterial inner and outer membranes. T4SSs export specific proteins, among them relaxases, which covalently bind to the 5' end of the translocated ssDNA and mediate ssDNA export. In Agrobacterium tumefaciens, another exported protein-VirE2-enhances ssDNA transfer efficiency 2000-fold. VirE2 binds cooperatively to the transferred ssDNA (T-DNA) and forms a compact helical structure, mediating T-DNA import into the host cell nucleus. We demonstrated-using single-molecule techniques-that by cooperatively binding to ssDNA, VirE2 proteins act as a powerful molecular machine. VirE2 actively pulls ssDNA and is capable of working against 50-pN loads without the need for external energy sources. Combining biochemical and cell biology data, we suggest that, in vivo, VirE2 binding to ssDNA allows an efficient import and pulling of ssDNA into the host. These findings provide a new insight into the ssDNA translocation mechanism from the recipient cell perspective. Efficient translocation only relies on the presence of ssDNA binding proteins in the recipient cell that compacts ssDNA upon binding. This facilitated transfer could hence be a more general ssDNA import mechanism also occurring in bacterial conjugation and DNA uptake processes. PMID:18303950

  2. VirE2: A Unique ssDNA-Compacting Molecular Machine

    PubMed Central

    Jacob, Susan; Engel, Andreas; Hegner, Martin

    2008-01-01

    The translocation of single-stranded DNA (ssDNA) across membranes of two cells is a fundamental biological process occurring in both bacterial conjugation and Agrobacterium pathogenesis. Whereas bacterial conjugation spreads antibiotic resistance, Agrobacterium facilitates efficient interkingdom transfer of ssDNA from its cytoplasm to the host plant cell nucleus. These processes rely on the Type IV secretion system (T4SS), an active multiprotein channel spanning the bacterial inner and outer membranes. T4SSs export specific proteins, among them relaxases, which covalently bind to the 5' end of the translocated ssDNA and mediate ssDNA export. In Agrobacterium tumefaciens, another exported protein—VirE2—enhances ssDNA transfer efficiency 2000-fold. VirE2 binds cooperatively to the transferred ssDNA (T-DNA) and forms a compact helical structure, mediating T-DNA import into the host cell nucleus. We demonstrated—using single-molecule techniques—that by cooperatively binding to ssDNA, VirE2 proteins act as a powerful molecular machine. VirE2 actively pulls ssDNA and is capable of working against 50-pN loads without the need for external energy sources. Combining biochemical and cell biology data, we suggest that, in vivo, VirE2 binding to ssDNA allows an efficient import and pulling of ssDNA into the host. These findings provide a new insight into the ssDNA translocation mechanism from the recipient cell perspective. Efficient translocation only relies on the presence of ssDNA binding proteins in the recipient cell that compacts ssDNA upon binding. This facilitated transfer could hence be a more general ssDNA import mechanism also occurring in bacterial conjugation and DNA uptake processes. PMID:18303950

  3. Sequence and expression of a xylanase gene from the hyperthermophile Thermotoga sp. strain FjSS3-B.1 and characterization of the recombinant enzyme and its activity on kraft pulp.

    PubMed Central

    Saul, D J; Williams, L C; Reeves, R A; Gibbs, M D; Bergquist, P L

    1995-01-01

    A gene expressing xylanase activity was isolated from a genomic library of Thermotoga sp. strain FjSS3-B.1. The sequence of the gene shows that it encodes a single domain, family 10 xylanase. The recombinant enzyme has extremely high thermal stability, activity over a relatively broad pH range, and activity on Pinus radiata kraft pulp. PMID:8526526

  4. The quasi-coherent oscillations of SS Cygni

    SciTech Connect

    Mauche, C.W.

    1996-08-01

    Properties of the quasi-coherent oscillations in the extreme ultraviolet flux of the dwarf nova SS Cygni are described. Rapid periodic oscillations are observed in the optical and soft X-ray flux of high accretion rate cataclysmic variables (CVs; nova-like variables and dwarf novae in outburst). These so-called `dwarf nova oscillations` (DNOS) have high coherence (Q {approx} 10{sup 4}-10{sup 6}), periods of {approx} 10-30 s, and amplitudes of @ 10-30% in soft X-rays and @ 0.5% in the optical. DNOs have never been detected in dwarf novae in quiescence, despite extensive searches; they appear on the rising branch of the dwarf nova, outburst, typically persist through maximum, and disappear on the declining branch of the outburst. The period of the oscillation also correlates with outburst state, decreasing on the rising branch and increasing on the declining branch. 2048 The dwarf nova SS Cygni routinely exhibits DNOs during outburst. Optical oscillations have been detected at various times with periods ranging from 7.3 s to 10.9 s. At soft X-ray energies, oscillations have been detected in {ital HEAO 1} LED 1 data at periods of @ 9 s and 11 s and in EXOSAT LE data at periods between 7.4 s and 10.4 s. Here, we describe the properties of the oscillations in the extreme ultraviolet (EUV) flux detected with the {ital Extreme Ultraviolet Explorer} (EUVE) Deep Survey (DS) photometer and Short Wavelength (SW) spectrometer during target-of-opportunity observations of SS Cyg in out- burst in 1993 August and 1994 June/July.

  5. EUVE photometry of SS Cygni: Dwarf nova outbursts and oscillations

    SciTech Connect

    Mauche, C.W.

    1995-05-15

    The authors present EUVE Deep Survey photometry and AAVSO optical measurements of the 1993 August and 1994 June/July outbursts of the dwarf nova SS Cygni. The EUV and optical light curves are used to illustrate the different response of the accretion disk to outbursts which begin at the inner edge and propagate outward, and those which begin at the outer edge and propagate inward. Furthermore, the authors describe the properties of the quasi-coherent 7--9 s sinusoidal oscillations in the EUV flux detected during the rise and plateau stages of these outbursts.

  6. Osler usque ad mare: the SS William Osler

    PubMed Central

    Bryan, C S; Fransiszyn, M

    1999-01-01

    William Osler's connections with the sea included a strong family history of seafaring, his own transatlantic crossings (of which there were at least 32) and the occasional use of nautical imagery in his inspirational writings. An unusual Oslerian connection with the sea emerged after his death in the form of a World War II Liberty ship. Through the SS William Osler and its sister ships, Osler was symbolically reunited with colleagues associated with the early days of the Johns Hopkins Hospital. The William Osler circumnavigated the globe in 1943 without engaging the enemy. She was then converted into an army hospital ship and renamed the USHS Wisteria. PMID:10530306

  7. ss3sim: An R Package for Fisheries Stock Assessment Simulation with Stock Synthesis

    PubMed Central

    Anderson, Sean C.; Monnahan, Cole C.; Johnson, Kelli F.; Ono, Kotaro; Valero, Juan L.

    2014-01-01

    Simulation testing is an important approach to evaluating fishery stock assessment methods. In the last decade, the fisheries stock assessment modeling framework Stock Synthesis (SS3) has become widely used around the world. However, there lacks a generalized and scriptable framework for SS3 simulation testing. Here, we introduce ss3sim, an R package that facilitates reproducible, flexible, and rapid end-to-end simulation testing with SS3. ss3sim requires an existing SS3 model configuration along with plain-text control files describing alternative population dynamics, fishery properties, sampling scenarios, and assessment approaches. ss3sim then generates an underlying ‘truth’ from a specified operating model, samples from that truth, modifies and runs an estimation model, and synthesizes the results. The simulations can be run in parallel, reducing runtime, and the source code is free to be modified under an open-source MIT license. ss3sim is designed to explore structural differences between the underlying truth and assumptions of an estimation model, or between multiple estimation model configurations. For example, ss3sim can be used to answer questions about model misspecification, retrospective patterns, and the relative importance of different types of fisheries data. We demonstrate the software with an example, discuss how ss3sim complements other simulation software, and outline specific research questions that ss3sim could address. PMID:24699270

  8. ss3sim: an R package for fisheries Stock Assessment simulation with stock synthesis.

    PubMed

    Anderson, Sean C; Monnahan, Cole C; Johnson, Kelli F; Ono, Kotaro; Valero, Juan L

    2014-01-01

    Simulation testing is an important approach to evaluating fishery stock assessment methods. In the last decade, the fisheries stock assessment modeling framework Stock Synthesis (SS3) has become widely used around the world. However, there lacks a generalized and scriptable framework for SS3 simulation testing. Here, we introduce ss3sim, an R package that facilitates reproducible, flexible, and rapid end-to-end simulation testing with SS3. ss3sim requires an existing SS3 model configuration along with plain-text control files describing alternative population dynamics, fishery properties, sampling scenarios, and assessment approaches. ss3sim then generates an underlying 'truth' from a specified operating model, samples from that truth, modifies and runs an estimation model, and synthesizes the results. The simulations can be run in parallel, reducing runtime, and the source code is free to be modified under an open-source MIT license. ss3sim is designed to explore structural differences between the underlying truth and assumptions of an estimation model, or between multiple estimation model configurations. For example, ss3sim can be used to answer questions about model misspecification, retrospective patterns, and the relative importance of different types of fisheries data. We demonstrate the software with an example, discuss how ss3sim complements other simulation software, and outline specific research questions that ss3sim could address.

  9. Molecular determinants of the interactions between proteins and ssDNA

    PubMed Central

    Mishra, Garima; Levy, Yaakov

    2015-01-01

    ssDNA binding proteins (SSBs) protect ssDNA from chemical and enzymatic assault that can derail DNA processing machinery. Complexes between SSBs and ssDNA are often highly stable, but predicting their structures is challenging, mostly because of the inherent flexibility of ssDNA and the geometric and energetic complexity of the interfaces that it forms. Here, we report a newly developed coarse-grained model to predict the structure of SSB–ssDNA complexes. The model is successfully applied to predict the binding modes of six SSBs with ssDNA strands of lengths of 6–65 nt. In addition to charge–charge interactions (which are often central to governing protein interactions with nucleic acids by means of electrostatic complementarity), an essential energetic term to predict SSB–ssDNA complexes is the interactions between aromatic residues and DNA bases. For some systems, flexibility is required from not only the ssDNA but also, the SSB to allow it to undergo conformational changes and the penetration of the ssDNA into its binding pocket. The association mechanisms can be quite varied, and in several cases, they involve the ssDNA sliding along the protein surface. The binding mechanism suggests that coarse-grained models are appropriate to study the motion of SSBs along ssDNA, which is expected to be central to the function carried out by the SSBs. PMID:25855635

  10. Plant Habitat (PH)

    NASA Technical Reports Server (NTRS)

    Onate, Bryan

    2016-01-01

    The International Space Station (ISS) will soon have a platform for conducting fundamental research of Large Plants. Plant Habitat (PH) is designed to be a fully controllable environment for high-quality plant physiological research. PH will control light quality, level, and timing, temperature, CO2, relative humidity, and irrigation, while scrubbing ethylene. Additional capabilities include leaf temperature and root zone moisture and oxygen sensing. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs. There will be several internal cameras (visible and IR) to monitor and record plant growth and operations.

  11. Acousto-microfluidics for screening of ssDNA aptamer.

    PubMed

    Park, Jee-Woong; Lee, Su Jin; Ren, Shuo; Lee, Sangwook; Kim, Soyoun; Laurell, Thomas

    2016-01-01

    We demonstrate a new screening method for obtaining a prostate-specific antigen (PSA) binding aptamer based on an acoustofluidic separation (acoustophoreis) technique. Since acoustophoresis provides simultaneous washing and separation in a continuous flow mode, we efficiently obtained a PSA binding aptamer that shows high affinity without any additional washing step, which is necessary in other screening methods. In addition, next-generation sequencing (NGS) was applied to accelerate the identification of the screened ssDNA pool, improving the selecting process of the aptamer candidate based on the frequency ranking of the sequences. After the 8(th) round of the acoustophoretic systematic evolution of ligands by exponential enrichment (SELEX) and following sequence analysis with NGS, 7 PSA binding ssDNA aptamer-candidates were obtained and characterized with surface plasmon resonance (SPR) for affinity and specificity. As a result of the new SELEX method with PSA as the model target protein, the best PSA binding aptamer showed specific binding to PSA with a dissociation constant (Kd) of 0.7 nM. PMID:27272884

  12. Acousto-microfluidics for screening of ssDNA aptamer

    PubMed Central

    Park, Jee-Woong; Lee, Su Jin; Ren, Shuo; Lee, Sangwook; Kim, Soyoun; Laurell, Thomas

    2016-01-01

    We demonstrate a new screening method for obtaining a prostate-specific antigen (PSA) binding aptamer based on an acoustofluidic separation (acoustophoreis) technique. Since acoustophoresis provides simultaneous washing and separation in a continuous flow mode, we efficiently obtained a PSA binding aptamer that shows high affinity without any additional washing step, which is necessary in other screening methods. In addition, next-generation sequencing (NGS) was applied to accelerate the identification of the screened ssDNA pool, improving the selecting process of the aptamer candidate based on the frequency ranking of the sequences. After the 8th round of the acoustophoretic systematic evolution of ligands by exponential enrichment (SELEX) and following sequence analysis with NGS, 7 PSA binding ssDNA aptamer-candidates were obtained and characterized with surface plasmon resonance (SPR) for affinity and specificity. As a result of the new SELEX method with PSA as the model target protein, the best PSA binding aptamer showed specific binding to PSA with a dissociation constant (Kd) of 0.7 nM. PMID:27272884

  13. XTE Proposal #20102--"SS 433's High Energy Spectrum"

    NASA Technical Reports Server (NTRS)

    Band, David L.; Blanco, P.; Rothschild, R.; Kawai, N.; Kotani, T.; Oka, T.; Wagner, R. M.; Hjellming, R.; Rupen, M.; Brinkmann, W.

    1999-01-01

    We observed the jet-producing compact binary system SS 433 with RXTE during three multiwavelength campaigns, the first in conjunction with ASCA observations, the second simultaneous with a VLA-VLBA-MERLIN campaign, and the third associated with a Nobeyama millimeter-band campaign. All these campaigns included optical observations. Occurring at different jet precession and binary phases, the observations also monitored the system during a radio flare. The data provide SS 433's X-ray spectrum over more than an energy decade, and track the spectral variations as the X-ray source was partially eclipsed. The continuum can be modeled as a power law with an exponential cutoff, which can be detected to approximately 50 keV. Strong line emission is evident in the 5-10 keV range which can be modeled as a broad line whose energy is precession independent and a narrow line whose energy does vary with jet precession phase; this line model is clearly an over simplification since the PCA does not have sufficient energy resolution to detect the lines ASCA observed. The eclipses are deeper at high energy and at jet precession phases when the jets are more inclined towards and away from us. A large radio flare occurred between two sets of X-ray monitoring observations; an X-ray observation at the peak of the flare found a softer spectrum with a flux approximately 1/3 that of the quiescent level.

  14. Reversibly shielded DNA polyplexes based on bioreducible PDMAEMA-SS-PEG-SS-PDMAEMA triblock copolymers mediate markedly enhanced nonviral gene transfection.

    PubMed

    Zhu, Caihong; Zheng, Meng; Meng, Fenghua; Mickler, Frauke Martina; Ruthardt, Nadia; Zhu, Xiulin; Zhong, Zhiyuan

    2012-03-12

    Reversibly shielded DNA polyplexes based on bioreducible poly(dimethylaminoethyl methacrylate)-SS-poly(ethylene glycol)-SS-poly(dimethylaminoethyl methacrylate) (PDMAEMA-SS-PEG-SS-PDMAEMA) triblock copolymers were designed, prepared and investigated for in vitro gene transfection. Two PDMAEMA-SS-PEG-SS-PDMAEMA copolymers with controlled compositions, 6.6-6-6.6 and 13-6-13 kDa, were obtained by reversible addition-fragmentation chain transfer (RAFT) polymerization of dimethylaminoethyl methacrylate (DMAEMA) using CPADN-SS-PEG-SS-CPADN (CPADN: 4-cyanopentanoic acid dithionaphthalenoate; PEG: 6 kDa) as a macro-RAFT agent. Like their nonreducible PDMAEMA-PEG-PDMAEMA analogues, PDMAEMA-SS-PEG-SS-PDMAEMA triblock copolymers could effectively condense DNA into small particles with average diameters less than 120 nm and close to neutral zeta potentials (0 ∼ +6 mV) at and above an N/P ratio of 3/1. The resulting polyplexes showed excellent colloidal stability against 150 mM NaCl, which contrasts with polyplexes of 20 kDa PDMAEMA homopolymer. In the presence of 10 mM dithiothreitol (DTT), however, polyplexes of PDMAEMA-SS-PEG-SS-PDMAEMA were rapidly deshielded and unpacked, as revealed by significant increase of positive surface charges as well as increase of particle sizes to over 1000 nm. Release of DNA in response to 10 mM DTT was further confirmed by gel retardation assays. These polyplexes, either stably or reversibly shielded, revealed a low cytotoxicity (over 80% cell viability) at and below an N/P ratio of 12/1. Notably, in vitro transfection studies showed that reversibly shielded polyplexes afforded up to 28 times higher transfection efficacy as compared to stably shielded control under otherwise the same conditions. Confocal laser scanning microscope (CLSM) studies revealed that reversibly shielded polyplexes efficiently delivered and released pDNA into the perinuclei region as well as nuclei of COS-7 cells. Hence, reduction-sensitive reversibly shielded DNA

  15. pH Basics

    ERIC Educational Resources Information Center

    Lunelli, Bruno; Scagnolari, Francesco

    2009-01-01

    The exposition of the pervasive concept of pH, of its foundations and implementation as a meaningful quantitative measurement, in nonspecialist university texts is often not easy to follow because too many of its theoretical and operative underpinnings are neglected. To help the inquiring student we provide a concise introduction to the depth just…

  16. pH optrode

    DOEpatents

    Northrup, M. Allen; Langry, Kevin C.

    1993-01-01

    A process is provided for forming a long-lasting, stable, pH-sensitive dye-acrylamide copolymer useful as a pH-sensitive material for use in an optrode or other device sensitive to pH. An optrode may be made by mechanically attaching the copolymer to a sensing device such as an optical fiber.

  17. Measurement of outgassing rate for GTAW welded SS304 materials

    NASA Astrophysics Data System (ADS)

    Bukhari, Mohsin; Mukherjee, Samiran; Panchal, Paresh; Gangradey, Ranjana; Shukla, Ajit Kumar

    2016-09-01

    Outgassing plays an important role to achieve Ultra High Vacuum (UHV) and to maintaining the required vacuum level of the vessel. For a large size machines like Tokamak, accelerators, space simulation chambers, outgassing from the structural materials and their welding sections need to be checked during the design. Hence studies were carried out for the measurement of outgassing rate for the Gas Tungsten Arc Welding (GTAW) welded SS304 materials at OutGassing Measurement System (OGMS) at IPR Extension Lab. The system consists of two chambers, pumping chamber and sample chamber, made up of 304 grades Stainless Steel pre-air baked at 400 °C. The pumping chamber connected to a turbo molecular pump having pumping speed 240 l/s, backed by a rotary vacuum pump having pumping speed 5m3/hour. Pumping chamber and sample chamber connected through a 100 CF flange having a circular aperture of 5.2 mm diameter. The conductance of aperture is 2.47 l/s. Bare SS304 sample & GTAW welded SS304 samples are prepared with 100mmX50mmX5mm and 95mmX55mmX5mm dimensions respectively. The base outgassing rate of the blank system is 2.34×10-11 mbar l/s-cm2. The calculated outgassing rate is 3.66×10-10 & 4.37×10-10 mbar l/s-cm2 for bare sample & welded sample. From the partial pressure analysis it has been found that hydrogen and nitrogen are in the partial level of 3.35×10-9 & 2.36×10-9 for bare sample and 3.14×10-9 mbar & 2.33×10-9 mbar for welded sample. It has been observed that, the GTAW doesn't have major effect on outgassing rate and one can use welded joint for designing a large vessel welding sections.

  18. Discovery of Circularly Polarized Radio Emission from SS 433.

    PubMed

    Fender; Rayner; Norris; Sault; Pooley

    2000-02-10

    We report the discovery of circularly polarized radio emission from the radio-jet X-ray binary SS 433 with the Australia Telescope Compact Array. The flux density spectrum of the circular polarization, clearly detected at four frequencies between 1 and 9 GHz, is of the form V~nu-0.9+/-0.1. Multiple components in the source and a lack of very high spatial resolution do not allow a unique determination of the origin of the circular polarization or of the spectrum of fractional polarization. However, we argue that the emission is likely to arise in the inner regions of the binary, possibly via propagation-induced conversion of linear to circular polarization, and the fractional circular polarization of these regions may be as high as 10%. Observations such as these have the potential to help us investigate the composition, whether pairs or baryonic, of the ejecta from X-ray binaries.

  19. Optical, UV, and EUV Oscillations of SS Cygni in Outburst

    SciTech Connect

    Mauche, C W

    2003-12-19

    I provide a review of observations in the optical, UV (HST), and EUV (EUVE and Chandra LETG) of the rapid periodic oscillations of nonmagnetic, disk-accreting, high mass-accretion rate cataclysmic variables (CVs), with particular emphasis on the dwarf nova SS Cyg in outburst. In addition, I drawn attention to a correlation, valid over nearly six orders of magnitude in frequency, between the frequencies of the quasi-periodic oscillations (QPOs) of white dwarf, neutron star, and black hole binaries. This correlation identifies the high frequency quasi-coherent oscillations (so-called ''dwarf nova oscillations'') of CVs with the kilohertz QPOs of low mass X-ray binaries (LMXBs), and the low frequency and low coherence QPOs of CVs with the horizontal branch oscillations (or the broad noise component identified as such) of LMXBs. Assuming that the same mechanisms produce the QPOs of white dwarf, neutron star, and black hole binaries, this correlation has important implications for QPO models.

  20. Distance/internet Astronomy Education (iau SS4)

    NASA Astrophysics Data System (ADS)

    McKinnon, David H.

    Over the past 10 years there has been a proliferation of Astronomy courses offered over the Internet. Accompanying the courses has been an increasing number of robotic and remote control telescopes such as the Bradford Robotic Telescope in the United Kingdom and the Telescopes in Education program in the United States of America. Since 1994 Charles Sturt University has offered a course on Cosmology for gifted and talented high school students and since 2000 a remote control telescope for use by elementary and high school teachers and their students. Both programs are accompanied by extensive resource materials and are offered by distance education to participants. This paper describes many of the outcomes of the research conducted on both projects and what has been learned with respect to the necessary conditions in order that elementary and high school teachers engage with exciting programs on offer. Professional development of teachers is a key issue if these programs are to be successful. For SS

  1. On the long-term behavior of SS Cygni

    NASA Technical Reports Server (NTRS)

    Cannizzo, John K.; Mattei, Janet A.

    1992-01-01

    The complete historical light curve of the dwarf nova SS Cygni taken by the American Association of Variable Star Observers from September 27, 1896 to April 7, 1992 is examined. The data consist of 29,387 daily means based on 180,233 individual observations. The statistical properties of the outburst durations, quiescence intervals, and cycle times associated with the 705 outbursts which occurred during this time are investigated. No significant difference is found between the correlations of the duration of a burst with the length of the following cycle time and the duration of a burst with the length of the preceding cycle time. On the basis of long-term moving averages, the inverse relation between cycle time and quiescent magnitude pointed out by Warner (1987, 1988) is confirmed.

  2. Mass transfer rate and outburst cycle of SS Cygni

    NASA Astrophysics Data System (ADS)

    Hempelmann, Alexander; Kurths, Juergen

    1993-07-01

    From an analysis of the SS Cygni light curve, we have recently shown (Hempelmann & Kurths, 1990) that the rate of mass transfer, M-dot(T), from the secondary star to the white dwarf primary is inversely correlated with the outburst cycle, t(c). This has been criticized as being of a trivial nature by Cannizzo & Mattei (1992). We demonstrate the nontrivial character of our finding by means of a gedankenexperiment which is based on the static outburst parameters observed. We show in this experiment that a positive M-dot(T)-t(c) correlation is possible. The negative correlation found by Hempelmann & Kurths (1990) is a consequence of the dynamics of small and strong outbursts.

  3. [Laboratory-based evaluation of "INOVA/QUANTA Lite" to determine antinuclear antibodies (ANA) and autoantibodies to double-stranded DNA, SS-A and SS-B].

    PubMed

    Yamauchi, Megumi S; Shingaki, Naohiko; Yamane, Nobuhisa

    2012-05-01

    We evaluated QUANTA Lite reagent series (INOVA Diagnostics, CA, USA) to determine antinuclear antibodies (ANA) and autoantibodies to double-stranded (ds) DNA, SS-A and SS-B, in parallel with MESACUP (Medical & Biological Laboratories, Nagoya). Overall agreements between two reagents for qualitative interpretation ranged from 77.5% (ANA) to 99.0%(anti-SS-B antibodies). When we compared to the results by indirect fluorescent antibody (IFA) test on HEp-2 cells, QUANTA Lite ANA demonstrated better sensitivity and specificity; 92.2% versus 76.5% in sensitivity and 92.1% versus 86.8% in specificity. Also, determining anti-chromatin antibodies and IFA test onto Chrithidia luciliae demonstrated greater interpretive correlation to detect anti-ds DNA by QUANTA Lite than by MESACUP. All the discrepant sera to which QUANTA Lite SS-A gave positive interpretations were confirmed to contain the antibodies specific to SS-A 52kDa antigen, which is supplemented to QUANTA Lite capture-probes. With these results, we can conclude that QUANTA Lite has superiorities over MESACUP; (1) to detect a variety of autoantibodies consisting of ANA, (2) to have a better correlation with confirmatory tests to detect anti-ds DNA antibodies, (3)to detect additional autoantibodies specific to SS-A 52kDa antigen, and (4) to have an enough compatibility in determining anti-SS-B antibodies.

  4. Cardiac involvement in patients with systemic lupus erythematosus and correlation of valvular lesions with anti-Ro/SS-A and anti-La/SS-B antibody levels.

    PubMed

    Shahin, Amira A; Shahin, Hesham A; Hamid, Magdy A; Amin, Mona A

    2004-01-01

    The aim of this study was to evaluate the incidence of morphologic and functional cardiac abnormalities in patients with systemic lupus erythematosus (SLE) and to correlate the findings with levels of anti-Ro/SS-A, anti-La/SS-B, and anti-cardiolipin antibody (aCL). Sixty-two patients with SLE were enrolled in this study. All patients underwent complete history taking, clinical assessment, and standard two-dimensional and Doppler echocardiography. Anti-Ro/SS-A, anti-La/SS-B, and aCL levels were measured using a standardized ELISA test. The patients were subdivided into two subgroups based on the presence or absence of valvular involvement. The two subgroups were then compared. Valvular involvement was present in 19 patients (30.6%), pericardial effusion in 12 patients (19.4%), impaired left ventricular relaxation abnormalities in 2 patients (3.2%), and pulmonary hypertension in 3 patients (4.8%). More patients in the valvular involvement group had positive anti-Ro/SS-A antibodies than in the valvular noninvolvement group (7/19 vs. 4/43). The difference was significant, with P < 0.01. Serum levels of anti-Ro/SS-A levels were significantly higher in the valvular involvement group (33.7 +/- 36.0 vs. 13.7 +/- 25.1; P < 0.01), as were the serum anti-La/SS-B levels (21.9 +/- 23.5 vs. 10.7 +/- 17.8; P < 0.05). The results suggest a causative correlation between anti-Ro/SS-A and anti-La/SS-B antibodies and the pathogenesis of the valvular lesions in SLE patients.

  5. Effectiveness of bomber deployed autonomous airborne vehicles in finding rail mobile SS-24s

    SciTech Connect

    Abey, A.E.; Erickson, S.A.; Norquist, P.D.

    1990-08-01

    Computer simulation predictions of the effectiveness of autonomous airborne vehicles in finding rail mobile SS-24s are presented. Effectiveness is discussed for several autonomous airborne vehicle endurances and survivabilities for the search area southwest of Moscow. The effect of where the Soviets place the SS-24s on the rail network was also investigated. The simulation predicts significant variations in the ability of a multi-autonomous airborne vehicle system to find SS-24s with these parameters. 12 figs., 1 tab.

  6. Tear and saliva ferning tests in Sjögren's syndrome (SS).

    PubMed

    Maragou, M; Vaikousis, E; Ntre, A; Koronis, N; Georgiou, P; Hatzidimitriou, E; Sotsiou, F; Dantis, P

    1996-03-01

    The purpose of this study was to evaluate the tear ferning test (TFT) and the saliva ferning test (SFT) as diagnostic tests for xerophthalmia and xerostomia respectively in patients with SS. Dried samples of freshly produced tears and saliva from: (A) 36 healthy controls without sicca symptoms, (B) 61 patients with primary SS, (C) 53 patients with secondary SS and (D) 22 patients with psychiatric disorders receiving antidepressants, were examined by polarizing light microscopy. All individuals included in the study were postmenopausal women. The crystallization was classified into 4 types according to the ferning phenomenon: uniformity, branching, spreading and integrity (type I normal and II, III, IV abnormal). Abnormal TFT was found in tear samples of: (A) 8/72 normal control eyes, (B) 110/122 prim SS eyes, (C) 86/106 sec SS eyes and (D) 30/44 psychiatric patients' eyes. Abnormal SFT was found in: (A) 6/36 of normal controls, (B) 59/61 of prim SS, (C) 51/53 of sec SS patients and (D) 16/22 of psychiatric patients. The differences of both TFT and SFT of patients with prim SS and sec SS versus controls were significant (p < 0.001). The sensitivity of TFT was found to be high both in prim SS (90%) and in sec SS (81%). In addition the specificities of TFT and SFT were high 89% and 83% respectively. On the other hand the differences of TFT and SFT in psychiatric patients receiving antidepressants versus normal controls were also significant (p < 0.05 and p < 0.025 respectively). According to our data TFT and SFT are simple, sensitive and specific tests to evaluate xerophthalmia and xerostomia in SS and probably in other conditions characterized by mucous membrane dryness.

  7. Synthesis and characterization of PEG-P(MAA-SS-VCL) nanoparticles

    NASA Astrophysics Data System (ADS)

    Yu, L. L.; Yang, K.; Mu, R. H.; Zhang, N.; Su, L.

    2016-07-01

    The PEG-P(MAA-SS-VCL) nanoparticles were obtained using disulfide containing dimethacrylate (SS) as cross-linking agent, using polyethylene glycol methyl acrylate (PEGMA), N-Vinyl-ε-caprolactam (VCL), and methacrylic acid (MAA) as monomers via homogeneous polymerization in aqueous. The PEG-P(MAA-SS-VCL) nanoparticles were characterized by FT-IR and TGA. The particle size and morphology variation in different environments were detected by dynamic light scattering (DLS) and scanning electron microscopy (SEM). It is the very method that PEG-P(MAA-SS-VCL) nanoparticles can be obtained in this study.

  8. APOBEC3G Interacts with ssDNA by Two Modes: AFM Studies

    NASA Astrophysics Data System (ADS)

    Shlyakhtenko, Luda S.; Dutta, Samrat; Banga, Jaspreet; Li, Ming; Harris, Reuben S.; Lyubchenko, Yuri L.

    2015-10-01

    APOBEC3G (A3G) protein has antiviral activity against HIV and other pathogenic retroviruses. A3G has two domains: a catalytic C-terminal domain (CTD) that deaminates cytidine, and a N-terminal domain (NTD) that binds to ssDNA. Although abundant information exists about the biological activities of A3G protein, the interplay between sequence specific deaminase activity and A3G binding to ssDNA remains controversial. We used the topographic imaging and force spectroscopy modalities of Atomic Force Spectroscopy (AFM) to characterize the interaction of A3G protein with deaminase specific and nonspecific ssDNA substrates. AFM imaging demonstrated that A3G has elevated affinity for deaminase specific ssDNA than for nonspecific ssDNA. AFM force spectroscopy revealed two distinct binding modes by which A3G interacts with ssDNA. One mode requires sequence specificity, as demonstrated by stronger and more stable complexes with deaminase specific ssDNA than with nonspecific ssDNA. Overall these observations enforce prior studies suggesting that both domains of A3G contribute to the sequence specific binding of ssDNA.

  9. Multimodal Pyrethroid Resistance in Malaria Vectors, Anopheles gambiae s.s., Anopheles arabiensis, and Anopheles funestus s.s. in Western Kenya

    PubMed Central

    Kawada, Hitoshi; Dida, Gabriel O.; Ohashi, Kazunori; Komagata, Osamu; Kasai, Shinji; Tomita, Takashi; Sonye, George; Maekawa, Yoshihide; Mwatele, Cassian; Njenga, Sammy M.; Mwandawiro, Charles; Minakawa, Noboru; Takagi, Masahiro

    2011-01-01

    Anopheles gambiae s.s., Anopheles arabiensis, and Anopheles funestus s.s. are the most important species for malaria transmission. Pyrethroid resistance of these vector mosquitoes is one of the main obstacles against effective vector control. The objective of the present study was to monitor the pyrethroid susceptibility in the 3 major malaria vectors in a highly malaria endemic area in western Kenya and to elucidate the mechanisms of pyrethroid resistance in these species. Gembe East and West, Mbita Division, and 4 main western islands in the Suba district of the Nyanza province in western Kenya were used as the study area. Larval and adult collection and bioassay were conducted, as well as the detection of point mutation in the voltage-gated sodium channel (1014L) by using direct DNA sequencing. A high level of pyrethroid resistance caused by the high frequency of point mutations (L1014S) was detected in An. gambiae s.s. In contrast, P450-related pyrethroid resistance seemed to be widespread in both An. arabiensis and An. funestus s.s. Not a single L1014S mutation was detected in these 2 species. A lack of cross-resistance between DDT and permethrin was also found in An. arabiensis and An. funestus s.s., while An. gambiae s.s. was resistant to both insecticides. It is noteworthy that the above species in the same area are found to be resistant to pyrethroids by their unique resistance mechanisms. Furthermore, it is interesting that 2 different resistance mechanisms have developed in the 2 sibling species in the same area individually. The cross resistance between permethrin and DDT in An. gambiae s.s. may be attributed to the high frequency of kdr mutation, which might be selected by the frequent exposure to ITNs. Similarly, the metabolic pyrethroid resistance in An. arabiensis and An. funestus s.s. is thought to develop without strong selection by DDT. PMID:21853038

  10. Interfacial Shear Strength of Oxide Scale and SS 441 Substrate

    SciTech Connect

    Liu, Wenning N.; Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2011-05-01

    Recent developments on decreasing the operating temperature for Solid Oxide Fuel Cells (SOFCs) have enabled the use of high temperature ferritic alloys as interconnect materials. Oxide scale will inevitably grow on the ferritic interconnects in a high temperature oxidation environment of SOFCs. The growth of the oxide scale induces growth stresses in the scale layer and on the scale/substrate interface. These growth stresses combined with the thermal stresses induced upon stacking cooling by the thermal expansion coefficient mismatch between the oxide scale and the substrate may lead to scale delamination/buckling and eventual spallation, which may lead to serious cell performance degradation. Hence the interfacial adhesion strength between the oxide scale and the substrate is crucial to the reliability and durability of the metallic interconnect in SOFC operating environments. In this paper, we applied an integrated experimental/modeling methodology to quantify the interfacial adhesion strength between the oxide scale and the SS 441 metallic interconnect. The predicted interfacial strength is discussed in details.

  11. S-S bond reactivity in metal-perthiocarboxylato compounds.

    PubMed

    Mas-Ballesté, Rubén; Guijarro, Alejandro; González-Prieto, Rodrigo; Castillo, Oscar; Sanz Miguel, Pablo J; Zamora, Félix

    2010-02-14

    While M-percarboxylato species are elusive intermediates, their sulfur containing analogues are known in some cases. The feasibility of isolation of M-perthioacetato compounds allowed, in this work, to obtain new insights into the pathways that follow the reactivity of M-E-ER (E = O, S) fragments. Herein we report on the isolation of two new M-perthioacetato compounds: trans-[Pt(CH(3)CS(2)S)(2)] () and [Ni(CH(3)CSS)(CH(3)CS(2)S)] (), which have been fully characterized, including X-ray structures. Reactivity of these compounds towards PPh(3) has been studied combining UV-vis monitorization and NMR measurements. Overall the accumulated data suggest that the evolution of the perthioacetato ligand in complexes and by reaction with PPh(3) consists of a complex multistep pathway in which the sulfur transfer is preceded by electron transfer. Cyclic voltammetry measurements indicate that the transference of two electrons from the phosphorus to the sulfur atom is not concerted, suggesting that the first step of the reaction with PPh(3) is the monoelectronic electron transfer followed by P-S bond formation. The results presented here show a novel pathway in the field of S-S bond reactivity processes relevant in biological, synthetic systems and in hydrocarbon desulfurization processes.

  12. Tritium release from SS316 under vacuum condition

    SciTech Connect

    Torikai, Y.; Penzhorn, R.D.

    2015-03-15

    The plasma facing surface of the ITER vacuum vessel, partly made of low carbon austenitic stainless steel type 316L, will incorporate tritium during machine operation. In this paper the kinetics of tritium release from stainless steel type 316 into vacuum and into a noble gas stream are compared and modelled. Type 316 stainless steel specimens loaded with tritium either by exposure to 1.2 kPa HT at 573 K or submersion into liquid HTO at 298 K showed characteristic thin surface layers trapping tritium in concentrations far higher than those determined in the bulk. The evolution of the tritium depth profile in the bulk during heating under vacuum was non-discernible from that of tritium liberated into a stream of argon. Only the relative amount of the two released tritium-species, i.e. HT or HTO, was different. Temperature-dependent depth profiles could be predicted with a one-dimensional diffusion model. Diffusion coefficients derived from fitting of the tritium release into an evacuated vessel or a stream of argon were found to be (1.4 ± 1.0)*10{sup -7} and (1.3 ± 0.9)*10{sup -9} cm{sup 2}/s at 573 and 423 K, respectively. Polished surfaces on type SS316 stainless steel inhibit considerably the thermal release rate of tritium.

  13. Corrosion erosion test of SS316 in flowing Pb Bi

    NASA Astrophysics Data System (ADS)

    Kikuchi, K.; Kurata, Y.; Saito, S.; Futakawa, M.; Sasa, T.; Oigawa, H.; Wakai, E.; Miura, K.

    2003-05-01

    Corrosion tests of austenitic stainless tube were done under flowing Pb-Bi conditions for 3000 h at 450 °C. Specimens were 316SS produced as a tubing form with 13.8 mm outer diameter, 2 mm thickness and 40 cm length. During operation, maximum temperature, temperature difference and flow velocity of Pb-Bi at the specimen were kept at 450, 50 °C, and 1 m/s, respectively. After the test, specimen and components of the loop were cut and examined by optical microscope, SEM, EDX, WDX and X-ray diffraction. Pb-Bi adhered on the surface of the specimen even after Pb-Bi was drained out to the storage tank from the circulating loop. Results differed from a stagnant corrosion test in that the specimen surface became rough and the corrosion rate was maximally 0.1 mm/3000 h. Mass transfer from the high temperature to the lower temperature area was observed: crystals of Fe-Cr were found on the tube surface in the low-temperature region. The sizes of crystals varied from 0.1 to 0.2 mm. The depositing crystals were ferrite grains and the chemical composition ratio (mass%) of Fe to Cr was 9:1.

  14. On the bizarre gamma-ray spectrum of SS 433

    NASA Technical Reports Server (NTRS)

    Helfer, H. L.; Savedoff, M. P.

    1984-01-01

    Lamb et al. (1983) have announced the discovery of a pair of gamma-ray lines interpretable as emission of the 1.368 MeV line of Mg-24 in the two oppositely directed relativistic jets of SS 433. The mass loss rate related to the Mg-24 and the kinetic energy flux of the Mg-24 are considered. In the present investigation, it is shown that the mass loss flux must be well in excess of 0.00001 solar mass per yr, while the abundance of the gamma-emitting nucleus is extremely high. Attention is given to the calculation of the gamma-ray production efficiency factor, the size of the emitting region, reaction processes, and X-ray luminosity. It is concluded that for plasma beam models, there must be a substantial overabundance, by a factor of 100 to approximately 1000, of the gamma-line producing nucleus. The association of the gamma-ray lines with Mg-24 is reasonable but not secure.

  15. Interfacial Shear Strength of Oxide Scale and SS 441 Substrate

    NASA Astrophysics Data System (ADS)

    Liu, Wenning; Sun, Xin; Stephens, Elizabeth; Khaleel, Moe

    2011-05-01

    Recent developments on decreasing the operating temperature for solid oxide fuel cells (SOFCs) have enabled the use of high-temperature ferritic alloys as interconnect materials. Oxide scale will inevitably grow on the ferritic interconnects in a high-temperature oxidation environment of SOFCs. The growth of the oxide scale induces growth stresses in the scale layer and on the scale/substrate interface. These growth stresses combined with the thermal stresses induced after stacking cooling by the thermal expansion coefficient mismatch between the oxide scale and the substrate may lead to scale delamination/buckling and eventual spallation, which may lead to serious cell performance degradation. Hence, the interfacial adhesion strength between the oxide scale and the substrate is crucial to the reliability and durability of the metallic interconnect in SOFC operating environments. In this article, we applied an integrated experimental/modeling methodology to quantify the interfacial adhesion strength between the oxide scale and the SS 441 metallic interconnect. The predicted interfacial strength is discussed in detail.

  16. Inoculating plants with the endophytic bacterium Pseudomonas sp. Ph6-gfp to reduce phenanthrene contamination.

    PubMed

    Sun, Kai; Liu, Juan; Gao, Yanzheng; Sheng, Yuehui; Kang, Fuxing; Waigi, Michael Gatheru

    2015-12-01

    Plant organic contamination poses a serious threat to the safety of agricultural products and human health worldwide, and the association of endophytic bacteria with host plants may decrease organic pollutants in planta. In this study, we firstly determined the growth response and biofilm formation of endophytic Pseudomonas sp. Ph6-gfp, and then systematically evaluated the performance of different plant colonization methods (seed soaking (SS), root soaking (RS), leaf painting (LP)) for circumventing the risk of plant phenanthrene (PHE) contamination. After inoculation for 48 h, strain Ph6-gfp grew efficiently with PHE, oxalic acid, or malic acid as the sole sources of carbon and energy. Moreover, strain Ph6-gfp could form robust biofilms in LB medium. In greenhouse hydroponic experiments, strain Ph6-gfp could actively colonize inoculated plants internally, and plants colonized with Ph6-gfp showed a higher capacity for PHE removal. Compared with the Ph6-gfp-free treatment, the accumulations of PHE in Ph6-gfp-colonized plants via SS, RS, and LP were 20.1, 33.1, and 7.1 %, respectively, lower. Our results indicate that inoculating plants with Ph6-gfp could lower the risk of plant PHE contamination. RS was most efficient for improving PHE removal in whole plant bodies by increasing the cell numbers of Ph6-gfp in plant roots. The findings in this study provide an optimized method to strain Ph6-gfp reduce plant PAH residues, which may be applied to agricultural production in PAH-contaminated soil. PMID:26263885

  17. Urine pH test

    MedlinePlus

    A urine pH test measures the level of acid in urine. ... pH - urine ... meat products, or cheese can decrease your urine pH. ... to check for changes in your urine acid levels. It may be done to ... more effective when urine is acidic or non-acidic (alkaline).

  18. Psychometric Reevaluation of the Women in Science Scale (WiSS)

    ERIC Educational Resources Information Center

    Owen, Steven V.; Toepperwein, Mary Anne; Pruski, Linda A.; Blalock, Cheryl L.; Liu, Yan; Marshall, Carolyn E.; Lichtenstein, Michael J.

    2007-01-01

    The Women in Science Scale (WiSS) was first developed in 1984, and is still being used in contemporary studies, yet its psychometric properties have not been evaluated with current statistical methods. In this study, the WiSS was administered in its original 27-item form to 1,439 middle and high school students. Confirmatory factor analysis based…

  19. 27 CFR 40.171 - Execution and filing of Form SS-4.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... applications may be filed with the district director of any such district as provided for in 26 CFR 301.6091-1... Form SS-4. 40.171 Section 40.171 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Payment of Taxes on Tobacco Products § 40.171 Execution and filing of Form SS-4. The application on...

  20. Mitochondria-targeted peptide SS-31 attenuates renal injury via an antioxidant effect in diabetic nephropathy.

    PubMed

    Hou, Yanjuan; Li, Shuangcheng; Wu, Ming; Wei, Jinying; Ren, Yunzhuo; Du, Chunyang; Wu, Haijiang; Han, Caili; Duan, Huijun; Shi, Yonghong

    2016-03-15

    Oxidative stress is implicated in the pathogenesis of diabetic kidney injury. SS-31 is a mitochondria-targeted tetrapeptide that can scavenge reactive oxygen species (ROS). Here, we investigated the effect and molecular mechanism of mitochondria-targeted antioxidant peptide SS-31 on injuries in diabetic kidneys and mouse mesangial cells (MMCs) exposed to high-glucose (HG) ambience. CD-1 mice underwent uninephrectomy and streptozotocin treatment prior to receiving daily intraperitoneal injection of SS-31 for 8 wk. The diabetic mice treated with SS-31 had alleviated proteinuria, urinary 8-hydroxy-2-deoxyguanosine level, glomerular hypertrophy, and accumulation of renal fibronectin and collagen IV. SS-31 attenuated renal cell apoptosis and expression of Bax and reversed the expression of Bcl-2 in diabetic mice kidneys. Furthermore, SS-31 inhibited expression of transforming-growth factor (TGF)-β1, Nox4, and thioredoxin-interacting protein (TXNIP), as well as activation of p38 MAPK and CREB and NADPH oxidase activity in diabetic kidneys. In vitro experiments using MMCs revealed that SS-31 inhibited HG-mediated ROS generation, apoptosis, expression of cleaved caspase-3, Bax/Bcl-2 ratio, and cytochrome c (cyt c) release from mitochondria. SS-31 normalized mitochondrial potential (ΔΨm) and ATP alterations, and inhibited the expression of TGF-β1, Nox4, and TXNIP, as well as activation of p38 MAPK and CREB and NADPH oxidase activity in MMCs under HG conditions. SS-31 treatment also could reverse the reduction of thioredoxin (TRX) biologic activity and upregulate expression of thioredoxin 2 (TRX2) in MMCs under HG conditions. In conclusion, this study demonstrates a protective effect of SS-31 against HG-induced renal injury via an antioxidant mechanism in diabetic nephropathy.

  1. Escherichia coli RecO protein anneals ssDNA complexed with its cognate ssDNA-binding protein: A common step in genetic recombination.

    PubMed

    Kantake, Noriko; Madiraju, Murty V V M; Sugiyama, Tomohiko; Kowalczykowski, Stephen C

    2002-11-26

    We present biochemical evidence for the functional similarity of Escherichia coli RecO protein and bacteriophage T4 UvsY protein to eukaryotic Rad52 protein. Although Rad52 protein is conserved in eukaryotes, no sequence homologue has been found in prokaryotes or archeabacteria. Rad52 protein has two unique activities: facilitation of replication protein-A (RPA) displacement by Rad51 protein and annealing of RPA-single-stranded DNA (ssDNA) complexes. Both activities require species-specific interaction between Rad52 protein and RPA. Both RecO and UvsY proteins also possess the former property with regard to their cognate ssDNA-binding protein. Here, we report that RecO protein anneals ssDNA that is complexed with only its cognate ssDNA-binding protein, suggesting the involvement of species-specific interactions. Optimal activity for RecO protein occurs after formation of a 1:1 complex with SSB protein. RecR protein, which is known to stimulate RecO protein to facilitate SSB protein displacement by RecA protein, inhibits annealing by RecO protein, suggesting that RecR protein may regulate the choice between the DNA strand invasion versus annealing pathways. In addition, we show that UvsY protein anneals ssDNA; furthermore, ssDNA, which is complexed only with its cognate ssDNA-binding protein, is annealed in the presence of UvsY protein. These results indicate that RecO and possibly UvsY proteins are functional counterparts of Rad52 protein. Based on the conservation of these functions, we propose a modified double-strand break repair model that includes DNA annealing as an important intermediate step. PMID:12438681

  2. Data demonstrating the effects of build orientation and heat treatment on fatigue behavior of selective laser melted 17–4 PH stainless steel

    PubMed Central

    Yadollahi, Aref; Simsiriwong, Jutima; Thompson, Scott M.; Shamsaei, Nima

    2016-01-01

    Axial fully-reversed strain-controlled (R=−1) fatigue experiments were performed to obtain data demonstrating the effects of building orientation (i.e. vertical versus horizontal) and heat treatment on the fatigue behavior of 17–4 PH stainless steel (SS) fabricated via Selective Laser Melting (SLM) (Yadollahi et al., submitted for publication [1]). This data article provides detailed experimental data including cyclic stress-strain responses, variations of peak stresses during cyclic deformation, and fractography of post-mortem specimens for SLM 17–4 PH SS. PMID:26955653

  3. The Pittsburgh Lung Screening Study (PLuSS)

    PubMed Central

    Wilson, David O.; Weissfeld, Joel L.; Fuhrman, Carl R.; Fisher, Stephen N.; Balogh, Paula; Landreneau, Rodney J.; Luketich, James D.; Siegfried, Jill M.

    2008-01-01

    Rationale: The role of computed tomography (CT) screening for lung cancer is controversial, currently under study, and not yet fully elucidated. Objectives: To report findings from initial and 1-year repeat screening low-radiation-dose CT of the chest and 3-year outcomes for 50- to 79-year-old current and ex-smokers in the Pittsburgh Lung Screening Study (PLuSS). Methods: Notified of findings on screening CT, subjects received diagnostic advice from both study and personal physicians. Tracking subjects for up to three years since initial screening, we obtained medical records to document diagnostic procedures, lung cancer diagnoses, and deaths. Measurements and Main Results: 3,642 and 3,423 subjects had initial and repeat screening. A total of 1,477 (40.6% of 3,624) were told about noncalcified lung nodules on the initial screening and, before repeat screening, 821 (55.6% of 1,477, 22.5% of 3,642) obtained one or more subsequent diagnostic imaging studies (CT, positron emission tomography [PET], or PET-CT). Tracking identified 80 subjects with lung cancer, including 53 subjects with tumor seen at initial screening. In all, 36 subjects (1.0% of the 3,642 screened), referred for abnormalities on either the initial or repeat screening, had a major thoracic surgical procedure (thoracotomy, video-assisted thoracoscopic surgery [VATS], median sternotomy, or mediastinoscopy) leading to a noncancer final diagnosis. Out of 82 subjects with thoracotomy or VATS to exclude malignancy in a lung nodule, 28 (34.1%) received a noncancer final diagnosis. Forty of 69 (58%) subjects with non–small cell lung cancer had stage I disease at diagnosis. Conclusions: Though leading to the discovery of early stage lung cancer, CT screening also led to many diagnostic follow-up procedures, including major thoracic surgical procedures with noncancer outcomes. PMID:18635890

  4. Yet more on the circumbinary disk of SS 433

    NASA Astrophysics Data System (ADS)

    Bowler, M. G.

    2013-08-01

    Context. Certain lines in spectra of the Galactic microquasar SS 433, in particular the Hα line and He I, have been interpreted as emission from a circumbinary disk. In this interpretation the orbital speed of the glowing material is in excess of 200 km s-1 and the mass of the binary system in excess of 40 M⊙. The data show that He I emission fades much faster than Hα. This requirement has been incorporated into successful heuristic models yet has remained unexplained hitherto. Aims: We present a model in which the different characteristics of the Hα and He I lines are naturally explained by the different ionization potentials of the atoms. Methods: A model was constructed in which the emission of any given patch of putative circumbinary disk material is determined both by its illumination and the depth of the ionization zone. Results: The depth of the ionization zones depend on the illumination with photons above ionization thresholds, much higher for He than for H. Thus in the new model the emission distribution round the ring is more uniform for Hα recombination lines than for He I. The new model provides an excellent description of the observations, including Hα intensity. The variations of the Hα and He I spectra with orbital phase are described quantitatively. Conclusions: The new model makes no appeal to ad hoc decay parameters and locates the differences between Hα and He I spectra in the different ionization potentials. If the circumbinary disk scenario is essentially correct, as now seems even more likely, the mass of the binary system must exceed 40 M⊙ and the compact object must be a rather massive stellar black hole.

  5. AtlasT4SS: A curated database for type IV secretion systems

    PubMed Central

    2012-01-01

    Background The type IV secretion system (T4SS) can be classified as a large family of macromolecule transporter systems, divided into three recognized sub-families, according to the well-known functions. The major sub-family is the conjugation system, which allows transfer of genetic material, such as a nucleoprotein, via cell contact among bacteria. Also, the conjugation system can transfer genetic material from bacteria to eukaryotic cells; such is the case with the T-DNA transfer of Agrobacterium tumefaciens to host plant cells. The system of effector protein transport constitutes the second sub-family, and the third one corresponds to the DNA uptake/release system. Genome analyses have revealed numerous T4SS in Bacteria and Archaea. The purpose of this work was to organize, classify, and integrate the T4SS data into a single database, called AtlasT4SS - the first public database devoted exclusively to this prokaryotic secretion system. Description The AtlasT4SS is a manual curated database that describes a large number of proteins related to the type IV secretion system reported so far in Gram-negative and Gram-positive bacteria, as well as in Archaea. The database was created using the RDBMS MySQL and the Catalyst Framework based in the Perl programming language and using the Model-View-Controller (MVC) design pattern for Web. The current version holds a comprehensive collection of 1,617 T4SS proteins from 58 Bacteria (49 Gram-negative and 9 Gram-Positive), one Archaea and 11 plasmids. By applying the bi-directional best hit (BBH) relationship in pairwise genome comparison, it was possible to obtain a core set of 134 clusters of orthologous genes encoding T4SS proteins. Conclusions In our database we present one way of classifying orthologous groups of T4SSs in a hierarchical classification scheme with three levels. The first level comprises four classes that are based on the organization of genetic determinants, shared homologies, and evolutionary

  6. Genomic analysis of the biocontrol strain Pseudomonas fluorescens Pf29Arp with evidence of T3SS and T6SS gene expression on plant roots.

    PubMed

    Marchi, Muriel; Boutin, Morgane; Gazengel, Kévin; Rispe, Claude; Gauthier, Jean-Pierre; Guillerm-Erckelboudt, Anne-Yvonne; Lebreton, Lionel; Barret, Matthieu; Daval, Stéphanie; Sarniguet, Alain

    2013-06-01

    Several bacterial strains of the Pseudomonas genus provide plant growth stimulation, plant protection against pests or bioremediation. Among these bacteria, P. fluorescens Pf29Arp reduces the severity of take-all, a disease caused by the pathogenic fungus Gaeumannomyces graminis var. tritici (Ggt) on wheat roots. In this study, we obtained a draft genome of Pf29Arp and subsequent comparative genomic analyses have revealed that this bacterial strain is closely related to strains of the 'P. brassicacearum-like' subgroup including P. brassicacearum ssp. brassicacearum NFM421 and P. fluorescens F113. Despite an overall chromosomal organization similar to these strains, a number of features including antibiotic synthesis gene clusters from secondary metabolism are not found in the Pf29Arp genome. But Pf29Arp possesses different protein secretion systems including type III (T3SS) and type VI (T6SS) secretion systems. Pf29Arp is the first Pseudomonas sp. strain described with four T6SS clusters (cluster I, II, III and IV). In addition, some protein-coding genes involved in the assembly of these secretion systems are basally expressed during Pf29Arp colonization of healthy wheat roots and display different expression patterns on necrotized roots caused by Ggt. These data suggest a role of T3SS and T6SS in the Pf29Arp adaptation to different root environments.

  7. Graphene oxide modified light addressable potentiometric sensor and its application for ssDNA monitoring.

    PubMed

    Jia, Yunfang; Yin, Xue-Bo; Zhang, Jia; Zhou, Shuang; Song, Meng; Xing, Ke-Li

    2012-12-21

    A light addressable potentiometric sensor (LAPS) is a kind of silicon based semiconductor sensor, and surface modification is a fundamental problem for its application in biological fields. Graphene oxide (GO) based biochemically activated LAPS were proposed, called GO-LAPS. The GO-LAPS were applied to monitoring single strand DNA (ssDNA) probe immobilization and its hybridization with complementary ssDNA molecules of different chain lengths (30, 21 and 14 base pairs, respectively). It was discovered that the curves of LAPS' currents versus analyte concentrations for ssDNA probe binding and the target ssDNA hybridization were different. Explanations were proposed based on the semiconductor's surface-electric-field-effect and the electrical properties of ssDNA molecule. Moreover, comparisons between GO-LAPS and LAPS without GO modification were carried out. Enhanced response currents of GO-LAPS were reported experimentally and analyzed theoretically based on X-ray photoelectron spectroscopy (XPS) of GO-LAPS. The limitation of target ssDNA monitoring was 1 pM to 10 nM, which suggested that this LAPS based platform could be developed as a sensitive means for short chain ssDNA detection.

  8. A novel protein elicitor (SsCut) from Sclerotinia sclerotiorum induces multiple defense responses in plants.

    PubMed

    Zhang, Huajian; Wu, Qun; Cao, Shun; Zhao, Tongyao; Chen, Ling; Zhuang, Peitong; Zhou, Xiuhong; Gao, Zhimou

    2014-11-01

    In this study, we report the cloning of the SsCut gene encoding cutinase from Sclerotinia sclerotiorum. We isolated a 609-bp cDNA encoding a polypeptide of 202 amino acids with a molecular weight of 20.4 kDa. Heterologous expression of SsCut in Escherichia coli (His-SsCut) caused the formation of lesions in tobacco that closely resembled hypersensitive response lesions. Mutational analysis identified the C-terminal-half peptide and the same amino acids indispensable for both enzyme and elicitor activity. His-SsCut was caused cell death in Arabidopsis, soybean (Glycine max), oilseed rape (Brassica napus), rice (Oryza sativa), maize (Zea mays), and wheat (Triticum aestivum), indicating that both dicot and monocot species are responsive to the elicitor. Furthermore, the elicitation of tobacco was effective in the induction of the activities of hydrogen peroxide, phenylalanine ammonia-lyase, peroxides, and polyphenol oxidase. His-SsCut-treated plants exhibited enhanced resistance as indicated by a significant reduction in the number and size of S. sclerotiorum, Phytophthora sojae, and P. nicotianae lesions on leaves relative to controls. Real-time PCR results indicated that the expression of defense-related genes and genes involved in signal transduction were induced by His-SsCut. Our results demonstrate that SsCut is an elicitor that triggers defense responses in plants and will help to clarify its relationship to downstream signaling pathways that induce defense responses.

  9. Species differences in distribution and prediction of human V(ss) from preclinical data.

    PubMed

    Berry, Loren M; Li, Chao; Zhao, Zhiyang

    2011-11-01

    Prediction of human volume of distribution at steady state (V(ss)) before first administration of a new drug candidate to humans has become an important part of the drug development process. This study examines the assumptions behind interspecies scaling techniques used to predict human V(ss) from preclinical data, namely the equivalency of V(ss,u) and/or f(ut) across species. In addition, several interspecies scaling techniques are evaluated side by side using a set of 67 reference compounds where observed V(ss) from rats, dogs, monkeys, and humans were compiled from the literature and where plasma protein binding was determined across species using an ultracentrifugation technique. Species similarity in V(ss,u) or f(ut) does not appear to be the norm among rats, dogs, monkeys, or humans. Despite this, interspecies scaling from rats, dogs, and monkeys is useful and can provide reasonably accurate predictions of human V(ss), although some interspecies scaling approaches were better than others. For example, the performance of the common V(ss,u) or f(ut) equivalency approaches using average V(ss,u) or f(ut) across three preclinical species was superior to allometric scaling techniques. In addition, considering data from several preclinical species, using the equivalency approach, was superior to scaling from any single species. Although the mechanistic tissue composition equations available in the Simcyp population-based pharmacokinetic simulator did not necessarily provide the most accurate predictions, and the equations used likely need refinement, they still provide the best opportunity for a mechanistic understanding and prediction of human V(ss).

  10. Corrosion Resistance of 304L SS Spray Coated with Zirconia Nanoparticles

    NASA Astrophysics Data System (ADS)

    Maheswari, A. Uma; Sivakumar, M.; Indhumathi, N.; Mohan, Sreedevi R.

    2016-09-01

    Influence of substrate temperature on corrosion (in 3.5% NaCl) and wear resistance of nanostructured zirconia thin film coated 304L SS substrates are studied by electrochemical and nano-indentation methods. This analysis shows 304L SS substrate spray coated with nanostructured zirconia at substrate temperature closer to the boiling point of the spray solvent ethanol exhibited good corrosion and wear resistance behaviour. This is because of the compressive stress developed during film fabrication at lower substrate temperature (∼50 °C) and hence constrains the indentation plasticity, which leads to higher indentation load than the bare 304L SS.

  11. Redox and pH dual-responsive PEG and chitosan-conjugated hollow mesoporous silica for controlled drug release.

    PubMed

    Jiao, Jian; Li, Xian; Zhang, Sha; Liu, Jie; Di, Donghua; Zhang, Ying; Zhao, Qinfu; Wang, Siling

    2016-10-01

    In this paper, a hollow mesoporous silica nanoparticles (HMSN) was used as the drug vehicle to develop the redox and pH dual stimuli-responsive delivery system, in which the chitosan (CS), a biodegradable cationic polymer, was grafted on the surface of HMSN via the cleavable disulfide bonds. CS was chosen as the gatekeeper mainly due to its appropriate molecular weight as well as possessing abundant amino groups which could be protonated in the acidic condition to achieve pH-responsive drug release. In addition, the PEG was further grafted on the surface of CS to increase the stability and biocompatibility under physiological conditions. The DOX loaded DOX/HMSN-SS-CS@PEG had a relatively high drug loading efficiency up to 32.8%. In vitro release results indicated that DOX was dramatically blocked within the mesopores of HMSN-SS-CS@PEG in pH 7.4 PBS without addition of GSH. However, the release rate of DOX was markedly increased after the addition of 10mM GSH or in pH5.0 release medium. Moreover, the release of DOX was further improved in pH5.0 PBS with 10mM GSH. The HMSN-SS-CS@PEG could markedly decrease the hemolysis percent and protein adsorption, and increase the biocompatibility and stability of HMSN compared with the HMSN-SS-CS and bare HMSN. This work suggested an exploration about HMSN based stimuli-responsive drug delivery and these results demonstrated that HMSN-SS-CS@PEG exhibited dual-responsive drug release property and could be used as a promising carrier for cancer therapy. PMID:27287095

  12. Tissue uptake and catabolic studies of /sup 125/I SS-B (La) injected into mice

    SciTech Connect

    Schrieber, L.; Melsom, R.D.; Venables, P.J.; Maini, R.N.

    1984-04-01

    The radiolabeled soluble cellular antigen /sup 125/I SS-B (La) has a plasma half-life of 3 min following iv injection into BALB/C mice. Uptake by Kupffer cells (KC) and proximal renal tubular (PRT) cells was demonstrated by autoradiography (ARG). That trichloracetic acid (TCA)-soluble products of /sup 125/I SS-B appeared in plasma within 1 min of iv injection suggests rapid in vivo breakdown. Activated peritoneal macrophages (APM) degraded /sup 125/I SS-B in a time- and cell-dose-dependent fashion. These findings suggest that the plasma clearance and catabolism of /sup 125/I SS-B may be dependent on its interaction with phagocytic cells. This rapid antigen elimination may protect against harmful autoantibody responses.

  13. Damage Analysis of Tensile Deformation of Co-rolled SMATed 304SS

    NASA Astrophysics Data System (ADS)

    Guo, X.; Leung, A. Y. T.; Chen, A.; Ruan, H.; Lu, J.

    2010-05-01

    One of recent experimental progresses in strengthening and toughening metals simultaneously is to adopt techniques of surface mechanical attrition treatment (SMAT) and warm co-rolling to 304 stainless steel (SS). To capture deformation behavior and associated damage initiation/evolution process in the co-rolled SMATed 304SS, cohesive finite element method (CFEM) is employed in this paper and simulation results are in agreement with experimental results. Both strengthening effect due to high yield stress of the nanograin layer and toughening effect due to non-localized damage in the nanograin layer are captured. Effect of energy release rate of nanograin layer on failure strain of layered co-rolled SMATed 304SS is investigated. It is found that the more brittle the nanograin layer is, the more potential necking sites in the nanograin layer are, and the more ductile the layered co-rolled SMATed 304SS is.

  14. Analysis of ssDNA Gaps and DSBs in Genetically Unstable Yeast Cultures

    PubMed Central

    Peng, Jie; Raghuraman, M.K.; Feng, Wenyi

    2015-01-01

    DNA replication defects are an underlying cause of genome instability, which could stem from alterations in replication intermediates such as extensive single-stranded DNA (ssDNA). Under replication stress, ssDNA is a precursor of the ultimate double-strand breaks (DSBs). Indeed, mutations that render the cell incapable of mediating and protecting the replication forks produce ssDNA genome-wide at high frequency and cause lethality when encountering DNA damage or replication perturbation. Here we describe two related microarray-based methods to query genetically unstable yeast cultures, such as the mec1 and rad53 mutants. These mutants are defective in central protein kinases in the checkpoint pathway. To induce ssDNA and DSB formation in these mutants, we utilize hydroxyurea, a drug that causes nucleotide shortage in the cell. PMID:24906332

  15. The pH Game.

    ERIC Educational Resources Information Center

    Chemecology, 1996

    1996-01-01

    Describes a game that can be used to teach students about the acidity of liquids and substances around their school and enable them to understand what pH levels tell us about the environment. Students collect samples and measure the pH of water, soil, plants, and other natural material. (DDR)

  16. Integrated Composite Stiffener Structure (ICoSS) Concept for Planetary Entry Vehicles

    NASA Technical Reports Server (NTRS)

    Kellas, Sotiris

    2016-01-01

    Results from the design, manufacturing, and testing of a lightweight Integrated Composite Stiffened Structure (ICoSS) concept, intended for multi-mission planetary entry vehicles are presented. Tests from both component and full-scale tests for a typical Earth Entry Vehicle forward shell manufactured using the ICoSS concept are presented and advantages of the concept for the particular application of passive Earth Entry Vehicles over other structural concepts are discussed.

  17. Effects of carbon dioxide and pH variations in vitro on blood respiratory functions, red blood cell volume, transmembrane pH gradients, and sickling in sickle cell anemia

    SciTech Connect

    Ueda, Y.; Bookchin, R.M.

    1984-08-01

    An examination was made of the O/sub 2/ affinity, Bohr effect, transmembrane pH gradient, mean cell hemoglobin concentration, and red blood cell sickling at half O/sub 2/ saturation in whole sickle cell (SS) and normal (AA) blood during CO/sub 2/ titration and acid-base titration at three Pco/sub 2/ levels, 10, 40, and 80 mm Hg. The CO/sub 2/-induced Bohr effect of SS blood was considerably larger than normal (maximum, 0.91, referred to cell pH) and similar to that found with acid-base titration at Pco/sub 2/ of 40. In contrast to AA blood, SS blood showed an increased O/sub 2/ affinity when Pco/sub 2/ was raised from 40 to 80, and at half O/sub 2/ saturation showed biphasic or sigmoid Bohr curves, a fall in transmembrane pH gradient with rising Pco/sub 2/, and an absence of the normal cell volume increase at low pH and Pco/sub 2/. Sickling of SS cells at half O/sub 2/ saturation was partly inhibited by increasing Pc/sub 2/, particularly in the higher pH ranges. These complex differences in the behavior of SS blood are interpreted in terms of the balancing of several effects: the lowering of hemoglobin O/sub 2/-affinity by polymerization, low pH and increased CO/sub 2/ binding, inhibition of hemoglobin S polymerization by CO/sub 2/ binding to ..beta../sup s/-chain amino termini, differences between hemoglobin S and A in competitive binding of CO/sub 2/ and 2,3-diphosphoglycerate at different pH levels, and an increased net negative charge exhibited by intracellular deoxyhemoglobin S polymers. From a clinical standpoint, in the absence of hypoxia or acidosis, an increased blood Pco/sub 2/ might have a beneficial effect by inhibiting red blood cell sickling, whereas a metabolic acidosis, with low blood pH and Pco/sub 2/, would be very hazardous.

  18. DNA nanotubes and helical nanotapes via self-assembly of ssDNA-amphiphiles.

    PubMed

    Pearce, Timothy R; Kokkoli, Efrosini

    2015-01-01

    DNA nanotubes were created using molecular self-assembly of single-stranded DNA (ssDNA)-amphiphiles composed of a hydrophobic dialkyl tail and polycarbon spacer and a hydrophilic ssDNA headgroup. The nanotube structures were formed by bilayers of amphiphiles, with the hydrophobic components forming an inner layer that was shielded from the aqueous solvent by an outer layer of ssDNA. The nanotubes appeared to form via an assembly process that included transitions from twisted nanotapes to helical nanotapes to nanotubes. Amphiphiles that contained different ssDNA headgroups were created to explore the effect of the length and secondary structure of the ssDNA headgroup on the self-assembly behavior of the amphiphiles in the presence and absence of the polycarbon spacer. It was found that nanotubes could be formed using a variety of headgroup lengths and sequences. The ability to create nanotubes via ssDNA-amphiphile self-assembly offers an alternative to the other purely DNA-based approaches like DNA origami and DNA tile assembly for constructing these structures and may be useful for applications in drug delivery, biosensing, and electronics.

  19. PCR-derived ssDNA probes for fluorescent in situ hybridization to HIV-1 RNA.

    PubMed

    Knuchel, M C; Graf, B; Schlaepfer, E; Kuster, H; Fischer, M; Weber, R; Cone, R W

    2000-02-01

    We developed a simple and rapid technique to synthesize single-stranded DNA (ssDNA) probes for fluorescent in situ hybridization (ISH) to human immunodeficiency virus 1 (HIV-1) RNA. The target HIV-1 regions were amplified by the polymerase chain reaction (PCR) and were simultaneously labeled with dUTP. This product served as template for an optimized asymmetric PCR (one-primer PCR) that incorporated digoxigenin (dig)-labeled dUTP. The input DNA was subsequently digested by uracil DNA glycosylase, leaving intact, single-stranded, digoxigenin-labeled DNA probe. A cocktail of ssDNA probes representing 55% of the HIV-1 genome was hybridized to HIV-1-infected 8E5 T-cells and uninfected H9 T-cells. For comparison, parallel hybridizations were done with a plasmid-derived RNA probe mix covering 85% of the genome and a PCR-derived RNA probe mix covering 63% of the genome. All three probe types produced bright signals, but the best signal-to-noise ratios and the highest sensitivities were obtained with the ssDNA probe. In addition, the ssDNA probe syntheses generated large amounts of probe (0.5 to 1 microg ssDNA probe per synthesis) and were easier to perform than the RNA probe syntheses. These results suggest that ssDNA probes may be preferable to RNA probes for fluorescent ISH. (J Histochem Cytochem 48:285-293, 2000)

  20. Promotion of plant growth by Pseudomonas fluorescens strain SS101 via novel volatile organic compounds.

    PubMed

    Park, Yong-Soon; Dutta, Swarnalee; Ann, Mina; Raaijmakers, Jos M; Park, Kyungseok

    2015-05-29

    Volatile organic compounds (VOCs) from plant growth-promoting rhizobacteria (PGPR) play key roles in modulating plant growth and induced systemic resistance (ISR) to pathogens. Despite their significance, the physiological functions of the specific VOCs produced by Pseudomonas fluorescens SS101 (Pf.SS101) have not been precisely elucidated. The effects of Pf.SS101 and its VOCs on augmentation of plant growth promotion were investigated in vitro and in planta. A significant growth promotion was observed in plants exposed Pf.SS101 under both conditions, suggesting that its VOCs play a key role in promoting plant growth. Solid-phase micro-extraction (SPME) and a gas chromatography-mass spectrophotometer (GC-MS) system were used to characterize the VOCs emitted by Pf.SS101 and 11 different compounds were detected in samples inoculated this bacterium, including 13-Tetradecadien-1-ol, 2-butanone and 2-Methyl-n-1-tridecene. Application of these compounds resulted in enhanced plant growth. This study suggests that Pf.SS101 promotes the growth of plants via the release of VOCs including 13-Tetradecadien-1-ol, 2-butanone and 2-Methyl-n-1-tridecene, thus increasing understanding of the role of VOCs in plant-bacterial inter-communication.

  1. VMD-SS: A graphical user interface plug-in to calculate the protein secondary structure in VMD program

    PubMed Central

    Yahyavi, Masoumeh; Falsafi-Zadeh, Sajad; Karimi, Zahra; Kalatarian, Giti; Galehdari, Hamid

    2014-01-01

    The investigation on the types of secondary structure (SS) of a protein is important. The evolution of secondary structures during molecular dynamics simulations is a useful parameter to analyze protein structures. Therefore, it is of interest to describe VMD-SS (a software program) for the identification of secondary structure elements and its trajectories during simulation for known structures available at the Protein Data Bank (PDB). The program helps to calculate (1) percentage SS, (2) SS occurrence in each residue, (3) percentage SS during simulation, and (4) percentage residues in all SS types during simulation. The VMD-SS plug-in was designed using TCL script and stride to calculate secondary structure features. Availability The database is available for free at http://science.scu.ac.ir/HomePage.aspx?TabID=13755 PMID:25258493

  2. Carbon Dioxide, Hydrographic, and Chemical Data Obtained During the R/V Maurice Ewing Cruise in the Atlantic Ocean (WOCE Section A17, 4 January - 21 March 1994)

    SciTech Connect

    Kozyr, Alex

    2005-06-30

    This documentation discusses the procedures and methods used to measure total carbon dioxide (TCO2), total alkalinity (TALK), and pH at hydrographic stations during the R/V Maurice Ewing cruise in the South Atlantic Ocean on the A17 WOCE section. Conducted as part of the World Ocean Circulation Experiment (WOCE), this cruise was also a part of the French WOCE program consisting of three expeditions (CITHER 1, 2, and 3) focused on the South Atlantic Ocean. The A17 section was occupied during the CITHER 2 expedition, which began in Montevideo, Uruguay, on January 4, 1994 and finished in Cayenne, French Guyana, on March 21, 1994. During this period the ship stopped in Salvador de Bahia and Recife, Brazil, to take on supplies and exchange personnel. Upon completion of the cruise the ship transited to Fort de France, Martinique. Instructions for accessing the data are provided.

  3. The effects of pH and surface composition on Pb adsorption to natural freshwater biofilms.

    PubMed

    Wilson, A R; Lion, L W; Nelson, Y M; Shuler, M L; Ghiorse, W C

    2001-08-01

    Two dominant variables that control the adsorption of toxic trace metals to suspended particulate materials and aquatic surface coatings are surface composition and solution pH. A model for the pH-dependent adsorption of Pbto heterogeneous particulate surface mixtures was derived from experimental evaluation of Pb adsorption to laboratory-derived surrogates. The surrogate materials were selected to represent natural reactive surface components. Pb adsorption to both the laboratory surrogates and natural biofilms was determined in chemically defined solutions under controlled laboratory conditions. Pb adsorption was measured over a pH range of 5-8, with an initial Pb concentration in solution of 2.0 microM. The surface components considered include amorphous Fe oxide, biogenic Mn oxide produced by a Mn(II) oxidizing bacterium (Leptothrix discophora SS-1), Al oxide, the common green alga Chlorella vulgaris, and Leptothrix discophora SS-1 cells. A linearization of Pb adsorption data for each adsorbent was used to quantify the relationship between Pb adsorption and pH. The parameters for individual adsorbents were incorporated into an additive model to predict the total Pb adsorption in multiple-adsorbent natural surface coatings that were collected from Cayuga Lake, NY. Pb adsorption experiments on the natural surface coatings at variable pH were utilized to verify the additive model predictions based on the pH dependent behavior of the experimental laboratory surrogates. Observed Pb adsorption is consistent with the model predictions (within 1-24%) over the range of solution pH values considered. The experimental results indicate that the combination of Fe and biogenic Mn oxides can contribute as much as 90% of Pb adsorbed on Cayuga Lake biofilms, with the dominant adsorbent switching from Mn to Fe oxide with increasing pH. PMID:11505999

  4. RecA protein filaments: end-dependent dissociation from ssDNA and stabilization by RecO and RecR proteins.

    PubMed

    Shan, Q; Bork, J M; Webb, B L; Inman, R B; Cox, M M

    1997-02-01

    RecA protein filaments formed on circular (ssDNA) in the presence of ssDNA binding protein (SSB) are generally stable as long as ATP is regenerated. On linear ssDNA, stable RecA filaments are believed to be formed by nucleation at random sites on the DNA followed by filament extension in the 5' to 3' direction. This view must now be enlarged as we demonstrate that RecA filaments formed on linear ssDNA are subject to a previously undetected end-dependent disassembly process. RecA protein slowly dissociates from one filament end and is replaced by SSB. The results are most consistent with disassembly from the filament end nearest the 5' end of the DNA. The bound SSB prevents re-formation of the RecA filaments, rendering the dissociation largely irreversible. The dissociation requires ATP hydrolysis. Disassembly is not observed when the pH is lowered to 6.3 or when dATP replaces ATP. Disassembly is not observed even with ATP when both the RecO and RecR proteins are present in the initial reaction mixture. When the RecO and RecR proteins are added after most of the RecA protein has already dissociated, RecA protein filaments re-form after a short lag. The newly formed filaments contain an amount of RecA protein and exhibit an ATP hydrolysis rate comparable to that observed when the RecO and RecR proteins are included in the initial reaction mixture. The RecO and RecR proteins thereby stabilize RecA filaments even at the 5' ends of ssDNA, a fact which should affect the recombination potential of 5' ends relative to 3' ends. The location and length of RecA filaments involved in recombinational DNA repair is dictated by both the assembly and disassembly processes, as well as by the presence or absence of a variety of other proteins that can modulate either process. PMID:9048946

  5. An improved DNA force field for ssDNA interactions with gold nanoparticles.

    PubMed

    Jiang, Xiankai; Gao, Jun; Huynh, Tien; Huai, Ping; Fan, Chunhai; Zhou, Ruhong; Song, Bo

    2014-06-21

    The widespread applications of single-stranded DNA (ssDNA) conjugated gold nanoparticles (AuNPs) have spurred an increasing interest in the interactions between ssDNA and AuNPs. Despite extensive studies using the most sophisticated experimental techniques, the detailed molecular mechanisms still remain largely unknown. Large scale molecular dynamics (MD) simulations can thus be used to supplement experiments by providing complementary information about ssDNA-AuNP interactions. However, up to now, all modern force fields for DNA were developed based on the properties of double-stranded DNA (dsDNA) molecules, which have hydrophilic outer backbones "protecting" hydrophobic inner nucleobases from water. Without the double-helix structure of dsDNA and thus the "protection" by the outer backbone, the nucleobases of ssDNA are directly exposed to solvent, and their behavior in water is very different from that of dsDNA, especially at the interface with nanoparticles. In this work, we have improved the force field of ssDNA for use with nanoparticles, such as AuNPs, based on recent experimental results and quantum mechanics calculations. With the new improved force field, we demonstrated that a poly(A) sequence adsorbed on a AuNP surface is much more stable than a poly(T) sequence, which is consistent with recent experimental observations. On the contrary, the current standard force fields, including AMBER03, CHARMM27, and OPLSAA, all gave erroneous results as compared to experiments. The current improved force field is expected to have wide applications in the study of ssDNA with nanomaterials including AuNPs, which might help promote the development of ssDNA-based biosensors and other bionano-devices.

  6. An improved DNA force field for ssDNA interactions with gold nanoparticles

    SciTech Connect

    Jiang, Xiankai; Huai, Ping; Fan, Chunhai; Song, Bo E-mail: bosong@sinap.ac.cn; Gao, Jun; Huynh, Tien; Zhou, Ruhong E-mail: bosong@sinap.ac.cn

    2014-06-21

    The widespread applications of single-stranded DNA (ssDNA) conjugated gold nanoparticles (AuNPs) have spurred an increasing interest in the interactions between ssDNA and AuNPs. Despite extensive studies using the most sophisticated experimental techniques, the detailed molecular mechanisms still remain largely unknown. Large scale molecular dynamics (MD) simulations can thus be used to supplement experiments by providing complementary information about ssDNA-AuNP interactions. However, up to now, all modern force fields for DNA were developed based on the properties of double-stranded DNA (dsDNA) molecules, which have hydrophilic outer backbones “protecting” hydrophobic inner nucleobases from water. Without the double-helix structure of dsDNA and thus the “protection” by the outer backbone, the nucleobases of ssDNA are directly exposed to solvent, and their behavior in water is very different from that of dsDNA, especially at the interface with nanoparticles. In this work, we have improved the force field of ssDNA for use with nanoparticles, such as AuNPs, based on recent experimental results and quantum mechanics calculations. With the new improved force field, we demonstrated that a poly(A) sequence adsorbed on a AuNP surface is much more stable than a poly(T) sequence, which is consistent with recent experimental observations. On the contrary, the current standard force fields, including AMBER03, CHARMM27, and OPLSAA, all gave erroneous results as compared to experiments. The current improved force field is expected to have wide applications in the study of ssDNA with nanomaterials including AuNPs, which might help promote the development of ssDNA-based biosensors and other bionano-devices.

  7. Esophageal pH monitoring

    MedlinePlus

    pH monitoring - esophageal; Esophageal acidity test ... esophagitis You may need to have the following tests if your doctor suspects esophagitis : Barium swallow Esophagogastroduodenoscopy (also called upper GI endoscopy)

  8. PhEDEx Data Service

    NASA Astrophysics Data System (ADS)

    Egeland, Ricky; Wildish, Tony; Huang, Chih-Hao

    2010-04-01

    The PhEDEx Data Service provides access to information from the central PhEDEx database, as well as certificate-authenticated managerial operations such as requesting the transfer or deletion of data. The Data Service is integrated with the "SiteDB" service for fine-grained access control, providing a safe and secure environment for operations. A plug-in architecture allows server-side modules to be developed rapidly and easily by anyone familiar with the schema, and can automatically return the data in a variety of formats for use by different client technologies. Using HTTP access via the Data Service instead of direct database connections makes it possible to build monitoring web-pages with complex drill-down operations, suitable for debugging or presentation from many aspects. This will form the basis of the new PhEDEx website in the near future, as well as providing access to PhEDEx information and certificate-authenticated services for other CMS dataflow and workflow management tools such as CRAB, WMCore, DBS and the dashboard. A PhEDEx command-line client tool provides one-stop access to all the functions of the PhEDEx Data Service interactively, for use in simple scripts that do not access the service directly. The client tool provides certificate-authenticated access to managerial functions, so all the functions of the PhEDEx Data Service are available to it. The tool can be expanded by plug-ins which can combine or extend the client-side manipulation of data from the Data Service, providing a powerful environment for manipulating data within PhEDEx.

  9. A visual assay to monitor T6SS-mediated bacterial competition.

    PubMed

    Hachani, Abderrahman; Lossi, Nadine S; Filloux, Alain

    2013-03-20

    Type VI secretion systems (T6SSs) are molecular nanomachines allowing Gram-negative bacteria to transport and inject proteins into a wide variety of target cells(1,2). The T6SS is composed of 13 core components and displays structural similarities with the tail-tube of bacteriophages(3). The phage uses a tube and a puncturing device to penetrate the cell envelope of target bacteria and inject DNA. It is proposed that the T6SS is an inverted bacteriophage device creating a specific path in the bacterial cell envelope to drive effectors and toxins to the surface. The process could be taken further and the T6SS device could perforate other cells with which the bacterium is in contact, thus injecting the effectors into these targets. The tail tube and puncturing device parts of the T6SS are made with Hcp and VgrG proteins, respectively(4,5). The versatility of the T6SS has been demonstrated through studies using various bacterial pathogens. The Vibrio cholerae T6SS can remodel the cytoskeleton of eukaryotic host cells by injecting an "evolved" VgrG carrying a C-terminal actin cross-linking domain(6,7). Another striking example was recently documented using Pseudomonas aeruginosa which is able to target and kill bacteria in a T6SS-dependent manner, therefore promoting the establishment of bacteria in specific microbial niches and competitive environment(8,9,10). In the latter case, three T6SS-secreted proteins, namely Tse1, Tse2 and Tse3 have been identified as the toxins injected in the target bacteria (Figure 1). The donor cell is protected from the deleterious effect of these effectors via an anti-toxin mechanism, mediated by the Tsi1, Tsi2 and Tsi3 immunity proteins(8,9,10). This antimicrobial activity can be monitored when T6SS-proficient bacteria are co-cultivated on solid surfaces in competition with other bacterial species or with T6SS-inactive bacteria of the same species(8,11,12,13). The data available emphasized a numerical approach to the bacterial

  10. Echinococcus granulosus sensu stricto (s.s.) from the critically endangered antelope Addax nasomaculatus in Tunisia.

    PubMed

    Boufana, Belgees; Saïd, Yousra; Dhibi, Mokhtar; Craig, Philip S; Lahmar, Samia

    2015-12-01

    Echinococcus granulosus sensu lato (s.l.) is a zoonotic disease highly endemic in Tunisia. Canids including stray and semi-stray dogs, jackals and foxes are known as definitive hosts and a wide range of ungulates have been shown to harbour the metacestode hydatid stage and may serve as intermediate hosts. Fertile hydatid cysts of Echinococcus equinus and E. granulosus sensu stricto (s.s.) were recently molecularly identified for the first time from Tunisian donkeys. E. granulosus (s.s.) was also identified from wild boars in Tunisia. Here we report the confirmation of hydatid cysts caused by E. granulosus (s.s.) in the critically endangered antelope, Addax nasomaculatus in Tunisia. DNA-based molecular analysis revealed that A.nasomaculatus was infected with E. granulosus (s.s.) which had a 100% identity with the main globally distributed E. granulosus (s.s.) (EgTu01) haplotype. Cysts of Taenia hydatigena (n=33) were also observed on the liver and in the body cavity. Due to their endangered status and their relatively small numbers, it is unlikely that hydatid infection of A. nasomaculatus will form a major contribution to the epidemiology and transmission of E. granulosus in Tunisia, but infection may result in pathology, morbidity and early mortality, and may still play a role in the perpetuation of the parasite in wildlife cycles. PMID:26314229

  11. Ocular surface and intraocular inflammation are related in SS-I and rheumatoid arthritis patients.

    PubMed

    Cellini, Mauro; Versura, Piera; Leonetti, Pietro; Frigato, Marilena; Manfredini, Elena; Malavolta, Nazzarena; Campos, Emilio C

    2007-07-01

    The purpose of this study is to evaluate the intraocular inflammation at a sub clinical level, in patients suffering from Sjogren's syndrome (SS-I) and Rheumatoid Arthritis (RA), to relate it with the ocular surface status and to verify the diagnostic performance of the method. Twenty-eight patients suffering from SS-I, 31 patients suffering from RA and 31 normal subjects matched in age and gender were included in the study. A Kowa 500F laser cell flare meter was utilized to quantify the aqueous cells and flare in vivo, ocular surface inflammation was graded by conjunctival cytology and dosage of serum albumin in tears, eye dryness was scored with Tear Function Index. All data resulted significantly different in both SS-I and RA patients vs. control group and also different comparing SS-I vs. RA patients group, except for the Flare values. A blood-aqueous barrier breakdown occurs either in SS-I and RA patients; the degree of the damage is related with ocular surface inflammation and dryness. We recommend the aqueous flare be analysed in those rheumatic patients where an ocular surface inflammation has been documented.

  12. ReSS: Resource Selection Service for National and Campus Grid Infrastructure

    SciTech Connect

    Mhashilkar, Parag; Garzoglio, Gabriele; Levshina, Tanya; Timm, Steve; /Fermilab

    2009-05-01

    The Open Science Grid (OSG) offers access to around hundred Compute elements (CE) and storage elements (SE) via standard Grid interfaces. The Resource Selection Service (ReSS) is a push-based workload management system that is integrated with the OSG information systems and resources. ReSS integrates standard Grid tools such as Condor, as a brokering service and the gLite CEMon, for gathering and publishing resource information in GLUE Schema format. ReSS is used in OSG by Virtual Organizations (VO) such as Dark Energy Survey (DES), DZero and Engagement VO. ReSS is also used as a Resource Selection Service for Campus Grids, such as FermiGrid. VOs use ReSS to automate the resource selection in their workload management system to run jobs over the grid. In the past year, the system has been enhanced to enable publication and selection of storage resources and of any special software or software libraries (like MPI libraries) installed at computing resources. In this paper, we discuss the Resource Selection Service, its typical usage on the two scales of a National Cyber Infrastructure Grid, such as OSG, and of a campus Grid, such as FermiGrid.

  13. ReSS: Resource Selection Service for National and Campus Grid Infrastructure

    NASA Astrophysics Data System (ADS)

    Mhashilkar, Parag; Garzoglio, Gabriele; Levshina, Tanya; Timm, Steve

    2010-04-01

    The Open Science Grid (OSG) offers access to around hundred Compute elements (CE) and storage elements (SE) via standard Grid interfaces. The Resource Selection Service (ReSS) is a push-based workload management system that is integrated with the OSG information systems and resources. ReSS integrates standard Grid tools such as Condor, as a brokering service and the gLite CEMon, for gathering and publishing resource information in GLUE Schema format. ReSS is used in OSG by Virtual Organizations (VO) such as Dark Energy Survey (DES), DZero and Engagement VO. ReSS is also used as a Resource Selection Service for Campus Grids, such as FermiGrid. VOs use ReSS to automate the resource selection in their workload management system to run jobs over the grid. In the past year, the system has been enhanced to enable publication and selection of storage resources and of any special software or software libraries (like MPI libraries) installed at computing resources. In this paper, we discuss the Resource Selection Service, its typical usage on the two scales of a National Cyber Infrastructure Grid, such as OSG, and of a campus Grid, such as FermiGrid.

  14. Methanol oxidation by pEDOT-pSS/PtRu in DMFC

    NASA Astrophysics Data System (ADS)

    Arbizzani, Catia; Biso, Maurizio; Manferrari, Elisa; Mastragostino, Marina

    Direct methanol fuel cells (DMFCs) are attracting more and more attention because of their operating temperature and easy fuel management. While carbons are the most widely used supports for both metal catalysts, i.e. PtRu for methanol oxidation and Pt for oxygen reduction, conducting polymers also can act as suitable supports for catalyst particles because of their conductive and stable three-dimensional structure. We thus chemically synthesized poly(3,4-ethylenedioxythiophene)-polystyrene-4-sulfonate (pEDOT-pSS) with different (3,4-ethylenedioxythiophene):styrene-4-sulfonate (EDOT:SS) molar ratios and prepared the electrocatalytic systems pEDOT-pSS/PtRu and pEDOT-pSS/Pt, the former by both electrochemical and chemical deposition of PtRu and the latter by chemical deposition of Pt. The results of the electrocatalytic activity tests of the pEDOT-pSS/PtRu composite electrodes performed in 0.1 M H 2SO 4-0.5 M CH 3OH liquid solution and in passive, air-breathing DMFC configuration with Nafion ® 115 protonic membrane and 1 M CH 3OH are reported and discussed.

  15. Previously unknown and highly divergent ssDNA viruses populate the oceans.

    PubMed

    Labonté, Jessica M; Suttle, Curtis A

    2013-11-01

    Single-stranded DNA (ssDNA) viruses are economically important pathogens of plants and animals, and are widespread in oceans; yet, the diversity and evolutionary relationships among marine ssDNA viruses remain largely unknown. Here we present the results from a metagenomic study of composite samples from temperate (Saanich Inlet, 11 samples; Strait of Georgia, 85 samples) and subtropical (46 samples, Gulf of Mexico) seawater. Most sequences (84%) had no evident similarity to sequenced viruses. In total, 608 putative complete genomes of ssDNA viruses were assembled, almost doubling the number of ssDNA viral genomes in databases. These comprised 129 genetically distinct groups, each represented by at least one complete genome that had no recognizable similarity to each other or to other virus sequences. Given that the seven recognized families of ssDNA viruses have considerable sequence homology within them, this suggests that many of these genetic groups may represent new viral families. Moreover, nearly 70% of the sequences were similar to one of these genomes, indicating that most of the sequences could be assigned to a genetically distinct group. Most sequences fell within 11 well-defined gene groups, each sharing a common gene. Some of these encoded putative replication and coat proteins that had similarity to sequences from viruses infecting eukaryotes, suggesting that these were likely from viruses infecting eukaryotic phytoplankton and zooplankton.

  16. Differential Role of the T6SS in Acinetobacter baumannii Virulence

    PubMed Central

    Foucault-Grunenwald, Marie-Laure; Borges, Vitor; Charpentier, Xavier; Limansky, Adriana S.; Gomes, João Paulo; Viale, Alejandro M.; Salcedo, Suzana P.

    2015-01-01

    Gram-negative bacteria, such as Acinetobacter baumannii, are an increasing burden in hospitals worldwide with an alarming spread of multi-drug resistant (MDR) strains. Herein, we compared a type strain (ATCC17978), a non-clinical isolate (DSM30011) and MDR strains of A. baumannii implicated in hospital outbreaks (Ab242, Ab244 and Ab825), revealing distinct patterns of type VI secretion system (T6SS) functionality. The T6SS genomic locus is present and was actively transcribed in all of the above strains. However, only the A. baumannii DSM30011 strain was capable of killing Escherichia coli in a T6SS-dependent manner, unlike the clinical isolates, which failed to display an active T6SS in vitro. In addition, DSM30011 was able to outcompete ATCC17978 as well as Pseudomonas aeruginosa and Klebsiella pneumoniae, bacterial pathogens relevant in mixed nosocomial infections. Finally, we found that the T6SS of DSM30011 is required for host colonization of the model organism Galleria mellonella suggesting that this system could play an important role in A. baumannii virulence in a strain-specific manner. PMID:26401654

  17. Functional analysis of sucrose phosphate synthase (SPS) and sucrose synthase (SS) in sugarcane (Saccharum) cultivars.

    PubMed

    Verma, A K; Upadhyay, S K; Verma, P C; Solomon, S; Singh, S B

    2011-03-01

    Sucrose phosphate synthase (SPS; EC 2.4.1.14) and sucrose synthase (SS; EC 2.4.1.13) are key enzymes in the synthesis and breakdown of sucrose in sugarcane. The activities of internodal SPS and SS, as well as transcript expression were determined using semi-quantitative RT-PCR at different developmental stages of high and low sucrose accumulating sugarcane cultivars. SPS activity and transcript expression was higher in mature internodes compared with immature internodes in all the studied cultivars. However, high sugar cultivars showed increased transcript expression and enzyme activity of SPS compared to low sugar cultivars at all developmental stages. SS activity was higher in immature internodes than in mature internodes in all cultivars; SS transcript expression showed a similar pattern. Our studies demonstrate that SPS activity was positively correlated with sucrose and negatively correlated with hexose sugars. However, SS activity was negatively correlated with sucrose and positively correlated with hexose sugars. The present study opens the possibility for improvement of sugarcane cultivars by increasing expression of the respective enzymes using transgene technology.

  18. Previously unknown and highly divergent ssDNA viruses populate the oceans

    PubMed Central

    Labonté, Jessica M; Suttle, Curtis A

    2013-01-01

    Single-stranded DNA (ssDNA) viruses are economically important pathogens of plants and animals, and are widespread in oceans; yet, the diversity and evolutionary relationships among marine ssDNA viruses remain largely unknown. Here we present the results from a metagenomic study of composite samples from temperate (Saanich Inlet, 11 samples; Strait of Georgia, 85 samples) and subtropical (46 samples, Gulf of Mexico) seawater. Most sequences (84%) had no evident similarity to sequenced viruses. In total, 608 putative complete genomes of ssDNA viruses were assembled, almost doubling the number of ssDNA viral genomes in databases. These comprised 129 genetically distinct groups, each represented by at least one complete genome that had no recognizable similarity to each other or to other virus sequences. Given that the seven recognized families of ssDNA viruses have considerable sequence homology within them, this suggests that many of these genetic groups may represent new viral families. Moreover, nearly 70% of the sequences were similar to one of these genomes, indicating that most of the sequences could be assigned to a genetically distinct group. Most sequences fell within 11 well-defined gene groups, each sharing a common gene. Some of these encoded putative replication and coat proteins that had similarity to sequences from viruses infecting eukaryotes, suggesting that these were likely from viruses infecting eukaryotic phytoplankton and zooplankton. PMID:23842650

  19. Dose-related growth deficits in LS but not SS mice prenatally exposed to alcohol.

    PubMed

    Gilliam, D M; Kotch, L E

    1996-01-01

    Genetically based alcohol sensitivity may influence the severity of alcohol-related birth defects. To examine this question, measures of growth and survival were examined in offspring of the alcohol sensitive Long-Sleep (LS) and alcohol-resistant Short-Sleep (SS) mouse lines following prenatal ethanol exposure. Pregnant LS and SS mice received an ethanol dose of either 6 or 8 g/kg/day from days 7 through 18 of pregnancy. Control groups received a maltose-dextran solution made isocaloric to the 8 g/kg/day dose. Ethanol and maltose-dextrin solutions were administered as split doses, 6 h apart, via gavage. Nonintubated lab chow control groups were also included for both mouse lines. Offspring were fostered at birth to lactating mice of an outbred stock. Pregnancy was longer for ethanol-treated LS dams compared to maltose-dextrin and lab chow LS control groups, whereas pregnancy length for ethanol-treated SS dams was similar to SS controls. Prenatal ethanol exposure resulted in dose-related growth deficits in LS but not in SS litters. Line differences in postnatal growth deficits in response to prenatal alcohol exposure suggest maternal or fetal alcohol sensitivity influence alcohol-related birth defects. PMID:8837934

  20. Echinococcus granulosus sensu stricto (s.s.) from the critically endangered antelope Addax nasomaculatus in Tunisia.

    PubMed

    Boufana, Belgees; Saïd, Yousra; Dhibi, Mokhtar; Craig, Philip S; Lahmar, Samia

    2015-12-01

    Echinococcus granulosus sensu lato (s.l.) is a zoonotic disease highly endemic in Tunisia. Canids including stray and semi-stray dogs, jackals and foxes are known as definitive hosts and a wide range of ungulates have been shown to harbour the metacestode hydatid stage and may serve as intermediate hosts. Fertile hydatid cysts of Echinococcus equinus and E. granulosus sensu stricto (s.s.) were recently molecularly identified for the first time from Tunisian donkeys. E. granulosus (s.s.) was also identified from wild boars in Tunisia. Here we report the confirmation of hydatid cysts caused by E. granulosus (s.s.) in the critically endangered antelope, Addax nasomaculatus in Tunisia. DNA-based molecular analysis revealed that A.nasomaculatus was infected with E. granulosus (s.s.) which had a 100% identity with the main globally distributed E. granulosus (s.s.) (EgTu01) haplotype. Cysts of Taenia hydatigena (n=33) were also observed on the liver and in the body cavity. Due to their endangered status and their relatively small numbers, it is unlikely that hydatid infection of A. nasomaculatus will form a major contribution to the epidemiology and transmission of E. granulosus in Tunisia, but infection may result in pathology, morbidity and early mortality, and may still play a role in the perpetuation of the parasite in wildlife cycles.

  1. Electrochemical and spectroscopic studies of ssDNA damage induced by hydrogen peroxide using graphene based nanomaterials.

    PubMed

    Berghian-Grosan, Camelia; Biris, Alexandru Radu; Coros, Maria; Pogacean, Florina; Pruneanu, Stela

    2015-06-01

    The oxidative damage of deoxyribonucleic acid (DNA) has been intensively studied due to its role in the occurrence of some diseases. The hydrogen peroxide (H2O2) is one of the reactive oxygen species (ROS). It can induce oxidation of DNA bases, sugar lesions or DNA strand breaks. The Pt/Gr-Au-3 modified electrode was employed for the analysis of four ssDNA samples: single-stranded DNA (ssDNA), ssDNA pre-treated with hydrogen peroxide (ssDNA-H2O2), ssDNA pre-treated with graphene-gold nanoparticles (ssDNA-Gr-Au) and ssDNA-Gr-Au complex pre-treated with hydrogen peroxide (ssDNA-Gr-Au-H2O2). By monitoring the changes of the purine oxidation peaks currents, we obtained valuable information about the damage induced by the hydrogen peroxide onto the un-treated or graphene pre-treated ssDNA and also about the interaction between ssDNA and graphene-based nanomaterial. The FTIR analysis has been also used to obtain information about the ssDNA damage. These findings allowed us to prove the utility of graphene-based nanomaterials (mainly Gr-Au-3) not only for the investigation of the oxidative damage induced by a non-radical oxidant, but also for the determination of the type of interaction between ssDNA and graphene surface. The stability of the ssDNA-Gr-Au-3 complex against the damage induced by H2O2, in the absence of reduced transition metals, was also established.

  2. SlyA Regulates Type III Secretion System (T3SS) Genes in Parallel with the T3SS Master Regulator HrpL in Dickeya dadantii 3937

    PubMed Central

    Zou, Lifang; Zeng, Quan; Lin, Haiping; Gyaneshwar, Prasad

    2012-01-01

    The hypersensitive response and pathogenicity (hrp) genes of Dickeya dadantii 3937 encode a type III secretion system (T3SS) which is essential for its full virulence. Previous studies of the T3SS regulation in D. dadantii 3937 revealed that the expression of the hrp genes is regulated by a master regulator, HrpL, through the HrpX-HrpY-HrpS-HrpL and GacS-GacA-rsmB-RsmA pathways. In this work, we identified a novel regulator of the SlyA/MarR family, SlyA, which regulates hrp genes of the HrpL regulon in parallel with HrpL in D. dadantii. SlyA regulates the T3SS in a two-tier manner. It negatively regulates the expression of hrpL by downregulating hrpS and upregulating rsmA. Interestingly, concomitant with its downregulation of the hrpL, SlyA positively regulates the expression of hrpA and hrpN, two hrp genes located in the HrpL regulon. In contrast to Pectobacterium carotovorum, the expression of slyA is not controlled by ExpR and ExpI in D. dadantii 3937. We further show that SlyA is involved in controlling swimming motility and pellicle formation in D. dadantii 3937. PMID:22267675

  3. SWIFT Observations of a Far UV Luminosity Component in SS433

    NASA Technical Reports Server (NTRS)

    Cannizzo, J. K.; Boyd, P. T.; Dolan, J. F.

    2007-01-01

    SS433 is a binary system showing relativistic Doppler shifts in its two sets of emission lines. The origin of its UV continuum is not well established. We observed SS433 to determine the emission mechanism responsible for its far UV spectrum. The source was observed at several different phases of both its 13 d orbital period and 162.5 d precession period using the UVOT and XRT detector systems on Swift. The far UV spectrum down to 1880 Angstrom lies significantly above the spectral flux distribution predicted by extrapolating the reddened blackbody continuum that fits the spectrum above 3500 Angstroms. The intensity of the far UV flux varies over a period of days and the variability is correlated with the variability of the soft X-ray flux from the source. An emission mechanism in addition to those previously detected in the optical and X-ray regions must exist in the far UV spectrum of SS433.

  4. Plasmon-driven dimerization via S-S chemical bond in an aqueous environment

    PubMed Central

    Cui, Lin; Wang, Peijie; Chen, Xiaowei; Fang, Yurui; Zhang, Zhenglong; Sun, Mengtao

    2014-01-01

    The surface-enhanced Raman scattering (SERS) spectra of thioanisole are experimentally investigated in an electrochemical environment in this study. Two Raman peaks, which depend strongly not only on electric potential but also on the local surface plasmon resonances (LSPR), have been observed. Theoretical calculations reveal that thioanisole is first dissociated from thiophenol via the S-CH3 bond; plasmons then drive the dimerisation of thiophenol via the S-S bond, which is strongly potential dependent. One Raman peak corresponds to the S-S vibrational mode of the thiophenol dimer, and the other corresponds to the asymmetric C-C stretching modes of the benzenyl of the thiophenol dimer. The potential-dependent two Raman modes is the potential-dependent dimerisation dynamics of thiophenol via the S-S bond. Our experimental findings provide insight into the structural elucidation of adsorbed molecules and molecular surface reaction dynamics. PMID:25427897

  5. Influence of consolidation method on structure/properties of rapidly solidified Type 304 SS powders

    SciTech Connect

    Flinn, J.E.; Korth, G.E.; Wright, R.N.

    1988-01-01

    The structure/properties of consolidated, centrifugally atomized (CA) Type 304 SS powders containing approx.8 appM helium entrapped during powder processing were evaluated. Three powder consolidation methods were used in the study: hot extrusion, hot isostatic pressing (HIPping), and dynamic (using explosives). In addition, cold-rolled 50% HIPped material was included in the evaluation. The four forms of consolidated powders were fully dense and possessed good bond strengths. The bond strength of the HIPped powders was the lowest. The consolidated materials were subjected to 1 h heat treatments and their grain growth, tensile, and creep behaviors were compared with those of wrought ingot metallurgy Type 304 SS materials. Grain growth of the CA Type 304 SS consolidated powders was substantially lower than for the wrought material. Similarly, significant strengthening was observed for the powder materials. The apparent microstructure stability and strengthening observed for the consolidated powder materials is attributed to the entrapped helium. 5 figs., 4 tabs.

  6. Resistance of superhydrophobic and oleophobic surfaces to varied temperature applications on 316L SS

    NASA Astrophysics Data System (ADS)

    Shams, Hamza; Basit, Kanza; Saleem, Sajid; Siddiqui, Bilal A.

    316L SS also called Marine Stainless Steel is an important material for structural and marine applications. When superhydrophobic and oleophobic coatings are applied on 316L SS it shows significant resistance to wear and corrosion. This paper aims to validate the coatings manufacturer's information on optimal temperature range and test the viability of coating against multiple oil based cleaning agents. 316L SS was coated with multiple superhydrophic and oleohobic coatings and observed under SEM for validity of adhesion and thickness and then scanned under FFM to validate the tribological information. The samples were then dipped into multiple cleaning agents maintained at the range of operating temperatures specified by the manufacturer. Coating was observed for deterioration over a fixed time intervals through SEM and FFM. A comparison was drawn to validate the most critical cleaning agent and the most critical temperature at which the coating fails to leave the base substrate exposed to the environment.

  7. Characterization of extracellular Mn2+-oxidizing activity and isolation of an Mn2+-oxidizing protein from Leptothrix discophora SS-1.

    PubMed

    Adams, L F; Ghiorse, W C

    1987-03-01

    Supernatant fluid from Leptothrix discophora SS-1 cultures possessed high Mn2+-ozidizing activity. Studies of temperature and pH optima, chemical inhibition, and protease sensitivity suggested that the activity may be enzymatic. Kinetic studies of unconcentrated supernatant fluid indicated an apparent Km of 7 microM Mn2+ in the 1 to 200 microM Mn2+ range. The greatest Vmax value observed was 1.4 nmol of Mn2+ oxidized min-1 micrograms of protein-1 in unconcentrated samples. When the supernatant fluid was concentrated on DEAE-cellulose and the activity was eluted with MgSO4, an Mn2+-oxidizing protein was detected in the concentrate by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The Mn2+-oxidizing protein appeared to have a molecular weight of 110,000 in 10% polyacrylamide gels and of 100,000 in 8% gels. Periodic acid-Schiff base staining of overloaded polyacrylamide gels showed that the DEAE-cellulose concentrate contained abundant high-molecular-weight polysaccharides; concurrent staining of the Mn2+-oxidizing band suggested that it too contained carbohydrate components. Isolation of the protein was achieved by subjecting the DEAE-cellulose concentrate to Sephacryl gel filtration in the presence of 1% sodium dodecyl sulfate, followed by preparative electrophoresis and reverse-polarity elution. However, these procedures resulted in loss of a large proportion of the activity, which precluded recovery of the protein in significant quality. PMID:3818545

  8. Development of Ss-NIE-1 recombinant antigen based assays for immunodiagnosis of strongyloidiasis.

    PubMed

    Rascoe, Lisa N; Price, Courtney; Shin, Sun Hee; McAuliffe, Isabel; Priest, Jeffrey W; Handali, Sukwan

    2015-04-01

    Strongyloides stercoralis is a widely distributed parasite that infects 30 to 100 million people worldwide. In the United States strongyloidiasis is recognized as an important infection in immigrants and refugees. Public health and commercial reference laboratories need a simple and reliable method for diagnosis of strongyloidiasis to identify and treat cases and to prevent transmission. The recognized laboratory test of choice for diagnosis of strongyloidiasis is detection of disease specific antibodies, most commonly using a crude parasite extract for detection of IgG antibodies. Recently, a luciferase tagged recombinant protein of S. stercoralis, Ss-NIE-1, has been used in a luciferase immunoprecipitation system (LIPS) to detect IgG and IgG4 specific antibodies. To promote wider adoption of immunoassays for strongyloidiasis, we used the Ss-NIE-1 recombinant antigen without the luciferase tag and developed ELISA and fluorescent bead (Luminex) assays to detect S. stercoralis specific IgG4. We evaluated the assays using well-characterized sera from persons with or without presumed strongyloidiasis. The sensitivity and specificity of Ss-NIE-1 IgG4 ELISA were 95% and 93%, respectively. For the IgG4 Luminex assay, the sensitivity and specificity were 93% and 95%, respectively. Specific IgG4 antibody decreased after treatment in a manner that was similar to the decrease of specific IgG measured in the crude IgG ELISA. The sensitivities of the Ss-NIE-1 IgG4 ELISA and Luminex assays were comparable to the crude IgG ELISA but with improved specificities. However, the Ss-NIE-1 based assays are not dependent on native parasite materials and can be performed using widely available laboratory equipment. In conclusion, these newly developed Ss-NIE-1 based immunoassays can be readily adopted by public health and commercial reference laboratories for routine screening and clinical diagnosis of S. stercoralis infection in refugees and immigrants in the United States.

  9. Association analysis of polymorphisms in caprine KiSS1 gene with reproductive traits.

    PubMed

    Maitra, A; Sharma, Rekha; Ahlawat, Sonika; Tantia, M S; Roy, Manoranjan; Prakash, Ved

    2014-12-10

    KiSS1 is considered to be a key mediator of molecular mechanism of reproduction (puberty and prolificacy) in mammals. Kisspeptins are a family of structurally related peptides, encoded by KiSS1 gene, with ability to regulate gonadotropin-releasing hormone and hence hypothalamic-pituitary-gonadal axis. The present study investigated the polymorphism of caprine KiSS1 gene in 9 Indian goat breeds differing in sexual precocity and prolificacy. Comparison of KiSS1 amplified sequences of indigenous goats resulted in identification of nine SNPs (intron (1) G296C, T455G, T505A, T693C, T950C and intron (2) T1125C, A2510G, C2540T, A2803G) of which four are novel. These loci were not segregating together (r(2)<0.33). Mutations existed in both, sexually precocious and late-maturing goat breeds as well as low and high prolificacy goat breeds. Three loci reported to be associated with goat litter size (G296C, G2510A and C2540T) were identified in Indian goats as well. Association between loci of KiSS1 gene and age of puberty as well as litter size was explored in Black Bengal (N=158), a sexually precocious and prolific goat breed of India by designing PCR-RFLP. None of the mutations were found to be associated with reproductive traits however, difference in litter size as well age of sexual maturity for different genotypes indicates that the study on additional data based on more number of breeds and animals would be interesting to perform. Considering the importance of the reproductive trait in small ruminants, the results extend the limited information on genetic variation of the caprine KiSS1, which might contribute toward molecular breeding to enhance productivity of goat.

  10. Production of biogenic Mn oxides by leptothrix discophora SS-1 in a chemically defined growth medium and evaluation of their Pb adsorption characteristics

    PubMed

    Nelson; Lion; Ghiorse; Shuler

    1999-01-01

    Biogenic Mn oxides were produced by the bacterium Leptothrix discophora SS-1 (= ATCC 3182) in a chemically defined mineral salts medium, and the Pb binding and specific surface area of these oxides were characterized. Growth of SS-1 in the defined medium with pyruvate as a carbon and energy source required the addition of vitamin B12. Complete oxidation of Mn(II) within 60 h required the addition of >/=0.1 &mgr;M FeSO4. Pb adsorption isotherms were determined for the biogenic Mn oxides (and associated cells with their extracellular polymer) and compared to the Pb adsorption isotherms of cells and exopolymer alone, as well as to abiotic Mn oxides. The Pb adsorption to cells and exopolymer with biogenic Mn oxides (0.8 mmol of Mn per g) at pH 6.0 and 25 degreesC was 2 orders of magnitude greater than the Pb adsorption to cells and exopolymer alone (on a dry weight basis). The Pb adsorption to the biogenic Mn oxide was two to five times greater than the Pb adsorption to a chemically precipitated abiotic Mn oxide and several orders of magnitude greater than the Pb adsorption to two commercially available crystalline MnO2 minerals. The N2 Brunauer-Emmet-Teller specific surface areas of the biogenic Mn oxide and fresh Mn oxide precipitate (224 and 58 m2/g, respectively) were significantly greater than those of the commercial Mn oxide minerals (0.048 and 4. 7 m2/g). The Pb adsorption capacity of the biogenic Mn oxide also exceeded that of a chemically precipitated colloidal hydrous Fe oxide under similar solution conditions. These results show that amorphous biogenic Mn oxides similar to those produced by SS-1 may play a significant role in the control of trace metal phase distribution in aquatic systems. PMID:9872777

  11. Production of Biogenic Mn Oxides by Leptothrix discophora SS-1 in a Chemically Defined Growth Medium and Evaluation of Their Pb Adsorption Characteristics

    PubMed Central

    Nelson, Yarrow M.; Lion, Leonard W.; Ghiorse, William C.; Shuler, Michael L.

    1999-01-01

    Biogenic Mn oxides were produced by the bacterium Leptothrix discophora SS-1 (= ATCC 3182) in a chemically defined mineral salts medium, and the Pb binding and specific surface area of these oxides were characterized. Growth of SS-1 in the defined medium with pyruvate as a carbon and energy source required the addition of vitamin B12. Complete oxidation of Mn(II) within 60 h required the addition of ≥0.1 μM FeSO4. Pb adsorption isotherms were determined for the biogenic Mn oxides (and associated cells with their extracellular polymer) and compared to the Pb adsorption isotherms of cells and exopolymer alone, as well as to abiotic Mn oxides. The Pb adsorption to cells and exopolymer with biogenic Mn oxides (0.8 mmol of Mn per g) at pH 6.0 and 25°C was 2 orders of magnitude greater than the Pb adsorption to cells and exopolymer alone (on a dry weight basis). The Pb adsorption to the biogenic Mn oxide was two to five times greater than the Pb adsorption to a chemically precipitated abiotic Mn oxide and several orders of magnitude greater than the Pb adsorption to two commercially available crystalline MnO2 minerals. The N2 Brunauer-Emmet-Teller specific surface areas of the biogenic Mn oxide and fresh Mn oxide precipitate (224 and 58 m2/g, respectively) were significantly greater than those of the commercial Mn oxide minerals (0.048 and 4.7 m2/g). The Pb adsorption capacity of the biogenic Mn oxide also exceeded that of a chemically precipitated colloidal hydrous Fe oxide under similar solution conditions. These results show that amorphous biogenic Mn oxides similar to those produced by SS-1 may play a significant role in the control of trace metal phase distribution in aquatic systems. PMID:9872777

  12. Production of biogenic Mn oxides by Leptothrix discophora SS-1 in a chemically defined growth medium and evaluation of their Pb adsorption characteristics

    SciTech Connect

    Nelson, Y.M.; Lion, L.W.; Ghiorse, W.C.; Shuler, M.L.

    1999-01-01

    Biogenic Mn oxides were produced by the bacterium Leptothrix discophora SS-1 (= ATCC 3182) in a chemically defined mineral salts medium, and the Pb binding and specific surface area of these oxides were characterized. Growth of SS-1 in the defined medium with pyruvate as a carbon and energy source required the addition of vitamin B{sub 12}. Complete oxidation of Mn(II) within 60 h required the addition of {ge}0.1 {micro}M FeSO{sub 4}. Pb adsorption isotherms were determined for the biogenic Mn oxides (and associated cells with their extracellular polymer) and compared to the Pb adsorption isotherms of cells and exopolymer alone, as well as to abiotic Mn oxides. The Pb adsorption to cells and exopolymer with biogenic Mn oxides at pH 6.0 and 25 C was 2 orders of magnitude greater than the Pb adsorption to cells and exopolymer alone. The Pb adsorption to the biogenic Mn oxide was two to five times greater than the Pb adsorption to a chemically precipitated abiotic Mn oxide and several orders of magnitude greater than the Pb adsorption to two commercially available crystalline MnO{sub 2} minerals. The N{sub 2} Brunauer-Emmet-Teller specific surface areas of the biogenic Mn oxide and fresh Mn oxide precipitate were significantly greater than those of the commercial Mn oxide minerals. The Pb adsorption capacity of the biogenic Mn oxide also exceeded that of a chemically precipitated colloidal hydrous Fe oxide under similar solution conditions. These results show that amorphous biogenic Mn oxides similar to those produced by SS-1 may play a significant rule in the control of trace metal phase distribution in aquatic systems.

  13. True logarithmic amplification of frequency clock in SS-OCT for calibration

    PubMed Central

    Liu, Bin; Azimi, Ehsan; Brezinski, Mark E.

    2011-01-01

    With swept source optical coherence tomography (SS-OCT), imprecise signal calibration prevents optimal imaging of biological tissues such as coronary artery. This work demonstrates an approach using a true logarithmic amplifier to precondition the clock signal, with the effort to minimize the noises and phase errors for optimal calibration. This method was validated and tested with a high-speed SS-OCT. The experimental results manifest its superior ability on optimization of the calibration and improvement of the imaging performance. Particularly, this hardware-based approach is suitable for real-time calibration in a high-speed system where computation time is constrained. PMID:21698036

  14. Scalable and reusable emulator for evaluating the performance of SS7 networks

    NASA Astrophysics Data System (ADS)

    Lazar, Aurel A.; Tseng, Kent H.; Lim, Koon Seng; Choe, Winston

    1994-04-01

    A scalable and reusable emulator was designed and implemented for studying the behavior of SS7 networks. The emulator design was largely based on public domain software. It was developed on top of an environment supported by PVM, the Parallel Virtual Machine, and managed by OSIMIS-the OSI Management Information Service platform. The emulator runs on top of a commercially available ATM LAN interconnecting engineering workstations. As a case study for evaluating the emulator, the behavior of the Singapore National SS7 Network under fault and unbalanced loading conditions was investigated.

  15. pH Optrode Instrumentation

    NASA Technical Reports Server (NTRS)

    Tabacco, Mary Beth; Zhou, Quan

    1995-01-01

    pH-sensitive chromophoric reagents immobilized in porous optical fibers. Optoelectronic instrumentation system measures acidity or alkalinity of aqueous nutrient solution. Includes one or more optrodes, which are optical-fiber chemical sensors, in sense, analogous to electrodes but not subject to some of spurious effects distorting readings taken by pH electrodes. Concept of optrodes also described in "Ethylene-Vapor Optrodes" (KSC-11579). pH optrode sensor head, with lead-in and lead-out optical fibers, convenient for monitoring solutions located away from supporting electronic equipment.

  16. Making pH Tangible.

    ERIC Educational Resources Information Center

    McIntosh, Elizabeth; Moss, Robert

    1995-01-01

    Presents a laboratory exercise in which students test the pH of different substances, study the effect of a buffer on acidic solutions by comparing the behavior of buffered and unbuffered solutions upon the addition of acid, and compare common over-the-counter antacid remedies. (MKR)

  17. A new human erythrocyte variant (Ph) containing an abnormal membrane sialoglycoprotein

    PubMed Central

    Tanner, Michael J. A.; Anstee, David J.; Mawby, William J.

    1980-01-01

    1. A new human erythrocyte variant (Ph) is described. The variant contains an unusual sialic acid-rich glycoprotein in addition to the blood-group-MN([unk])- and blood-group-Ss(δ)-active sialoglycoproteins found in normal erythrocytes. 2. The unusual component Ph has an apparent mol.wt. of 32000 on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The Ph component is not degraded during trypsin treatment of intact erythrocytes. 3. The Ph component was labelled by lacto-peroxidase-mediated radioiodination of intact erythrocytes and was found to be present in amounts approximately equimolar to α-sialoglycoprotein in the variant erythrocytes. 4. The Ph component had receptors for the lectins from Maclura aurantiaca (osage orange) and Triticum vulgaris (wheat-germ), but lacked a receptor for the Phaseolus vulgaris (red kidney bean) lectin, suggesting that it carries only O-linked oligosaccharides. 5. The presence of the Ph component in these erythrocytes does not correspond to any of the known blood-group-MNSs-related antigens examined. 6. We suggest that this component may be a hybrid polypeptide containing the N-terminal portion derived from normal δ-sialoglycoprotein, and the C-terminal portion from normal α-sialoglycoprotein, in a manner similar to the anti-Lepore haemoglobin. ImagesFig. 3.Fig. 4.Fig. 5. PMID:7396858

  18. The respiratory system of the piezophile Photobacterium profundum SS9 grown under various pressures.

    PubMed

    Tamegai, Hideyuki; Nishikawa, Shun; Haga, Minami; Bartlett, Douglas H

    2012-01-01

    It is known that the facultative piezophile Shewanella violacea DSS12 alters its respiratory components under the influence of hydrostatic pressure during growth. This can be considered one of the mechanisms of bacterial adaptation to high pressure. In this study, we investigated the respiratory system of another well-studied piezophile, Photobacterium profundum SS9. We analyzed cytochrome contents, the expression of genes encoding respiratory components in P. profundum SS9 grown under various conditions, and the pressure dependency of the terminal oxidase activities. Activity was more tolerant of relatively high pressures, such as 125 MPa when the cells were grown under high pressure as compared with cells grown under atmospheric pressure. Such properties observed are similar to the case of S. violacea. However, the contents of the cytochromes and expression of the respiratory genes were not influenced by growth pressure in P. profundum SS9, inconsistent with the case of S. violacea. We suggest that the mechanism of the piezoadaptation of the respiratory system of P. profundum SS9 differs from that of S. violacea, as described above, and that each strain chooses its own strategy. PMID:22878211

  19. In vitro selection of ssDNA aptamers using biotinylated target proteins.

    PubMed

    Mayer, Günter; Höver, Thomas

    2009-01-01

    Aptamers are single-stranded nucleic acids that bind specifically to a target molecule and thus often inhibit target-associated biological functions. Aptamers have been described for a series of target molecules including peptides, proteins, and even living cells. Besides RNA and 20-modified RNA molecules also ssDNA molecules can be subjected to in vitro selection protocols aiming at the enrichment of ssDNA aptamers. ssDNA aptamers can be selected using the SELEX procedure (systematic enrichment of ligands by exponential amplification) from libraries of randomized single-stranded DNA with a diversity of up to 10(16) different molecules. In repetitive selection cycles, the library is incubated with the target of choice and separation of non-binding sequences from bound sequences is achieved by distinct separation methods. The bound molecules are specifically eluted and amplified, thus representing the starting library for the next cycle. Thereby, an enriched population of aptamers is evolved. Here we describe a generalized in vitro selection experiment aiming at the enrichment of ssDNA aptamers using biotinylated target molecules. This procedure allows the application of streptavidin-biotin chemistry to separate bound from unbound DNA species during the selection process.

  20. Development of a genetic system for a model manganese-oxidizing proteobacterium, Leptothrix discophora SS1.

    PubMed

    Bocioaga, Daniela; El Gheriany, Iman A; Lion, Leonard W; Ghiorse, William C; Shuler, Michael L; Hay, Anthony G

    2014-11-01

    Understanding the molecular underpinnings of manganese oxidation in Leptothrix discophora SS1 has been hampered by the lack of a genetic system. In this report, we describe the development of a genetic system for L. discophora SS1. The antibiotic sensitivity was characterized, and a procedure for transformation with exogenous DNA via conjugation was developed and optimized, resulting in a maximum transfer frequency of 5.2×10(-1) and a typical transfer frequency of the order of 1×10(-3) transconjugants per donor. Genetic manipulation of L. discophora SS1 was demonstrated by disrupting pyrF via chromosomal integration with a plasmid containing a R6Kγ origin of replication through homologous recombination. This resulted in resistance to 5-fluoroorotidine, which was abolished by complementation with an ectopically expressed copy of pyrF cloned into pBBR1MCS. This system is expected to be amenable to a systematic genetic analysis of L. discophora SS1, including those genes responsible for manganese oxidation. PMID:25149187

  1. Study of advanced communications satellite systems based on SS-FDMA

    NASA Technical Reports Server (NTRS)

    Kiesling, J.

    1980-01-01

    A satellite communication system based on the use of a multiple, contiguous beam satellite antenna and frequency division multiple access (FDMA) is studied. Emphasis is on the evaluation of the feasibility of SS (satellite switching) FDMA technology, particularly the multiple, contiguous beam antenna, the onboard switch and channelization, and on methods to overcome the effects of severe Ka band fading caused by precipitation. This technology is evaluated and plans for technology development and evaluation are given. The application of SS-FDMA to domestic satellite communications is also evaluated. Due to the potentially low cost Earth stations, SS-FDMA is particularly attractive for thin route applications up to several hundred kilobits per second, and offers the potential for competing with terrestrial facilities at low data rates and over short routes. The onboard switch also provides added route flexibility for heavy route systems. The key beneficial SS-FDMA strategy is to simplify and thus reduce the cost of the direct access Earth station at the expense of increased satellite complexity.

  2. Atomic Structure and Mutagenesis of T6SS Reveals Interlaced Array Essential to Function

    PubMed Central

    Lee, Bai-Yu; Horwitz, Marcus A.; Zhou, Z. Hong

    2015-01-01

    Summary Type VI secretion systems (T6SSs) are newly identified contractile nanomachines that translocate effector proteins across bacterial membranes. The Francisella pathogenicity island, required for bacterial phagosome escape, intracellular replication and virulence, was presumed to encode a T6SS-like apparatus. Here, we experimentally confirm the identity of this T6SS and, by cryo electron microscopy (cryoEM), show the structure of its post-contraction sheath at 3.7 Å resolution. We demonstrate the assembly of this T6SS by IglA/IglB and secretion of its putative effector proteins in response to environmental stimuli. The sheath has a quaternary structure with handedness opposite that of contracted sheath of T4 phage tail and is organized in an interlaced two-dimensional array by means of β sheet augmentation. By structure-based mutagenesis, we show that this interlacing is essential to secretion, phagosomal escape, and intracellular replication. Our atomic model of the T6SS will facilitate design of drugs targeting this highly prevalent secretion apparatus. PMID:25723168

  3. PU/SS EUTECTIC ASSESSMENT IN 9975 PACKAGINGS IN A STORAGE FACILITY DURING EXTENDED FIRE

    SciTech Connect

    Gupta, N.

    2012-03-26

    In a radioactive material (RAM) packaging, the formation of eutectic at the Pu/SS (plutonium/stainless steel) interface is a serious concern and must be avoided to prevent of leakage of fissile material to the environment. The eutectic temperature for the Pu/SS is rather low (410 C) and could seriously impact the structural integrity of the containment vessel under accident conditions involving fire. The 9975 packaging is used for long term storage of Pu bearing materials in the DOE complex where the Pu comes in contact with the stainless steel containment vessel. Due to the serious consequences of the containment breach at the eutectic site, the Pu/SS interface temperature is kept well below the eutectic formation temperature of 410 C. This paper discusses the thermal models and the results for the extended fire conditions (1500 F for 86 minutes) that exist in a long term storage facility and concludes that the 9975 packaging Pu/SS interface temperature is well below the eutectic temperature.

  4. Screening and Identification of ssDNA Aptamer for Human GP73

    PubMed Central

    Du, Jingchun; Hong, Jianming; Xu, Chun; Cai, Yuanyuan; Xiang, Bo; Zhou, Chengbo; Xu, Xia

    2015-01-01

    As one tumor marker of HCC, Golgi Protein 73 (GP73) is given more promise in the early diagnosis of HCC, and aptamers have been developed to compete with antibodies as biorecognition probes in different detection system. In this study, we utilized GP73 to screen specific ssDNA aptamers by SELEX technique. First, GP73 proteins were expressed and purified by prokaryotic expression system and Nickle ion affinity chromatography, respectively. At the same time, the immunogenicity of purified GP73 was confirmed by Western blotting. The enriched ssDNA library with high binding capacity for GP73 was obtained after ten rounds of SELEX. Then, thirty ssDNA aptamers were sequenced, in which two ssDNA aptamers with identical DNA sequence were confirmed, based on the alignment results, and designated as A10-2. Furthermore, the specific antibody could block the binding of A10-2 to GP73, and the specific binding of A10-2 to GP73 was also supported by the observation that several tumor cell lines exhibited variable expression level of GP73. Significantly, the identified aptamer A10-2 could distinguish normal and cancerous liver tissues. So, our results indicate that the aptamer A10-2 might be developed into one molecular probe to detect HCC from normal liver specimens. PMID:26583119

  5. Screening and Identification of ssDNA Aptamer for Human GP73.

    PubMed

    Du, Jingchun; Hong, Jianming; Xu, Chun; Cai, Yuanyuan; Xiang, Bo; Zhou, Chengbo; Xu, Xia

    2015-01-01

    As one tumor marker of HCC, Golgi Protein 73 (GP73) is given more promise in the early diagnosis of HCC, and aptamers have been developed to compete with antibodies as biorecognition probes in different detection system. In this study, we utilized GP73 to screen specific ssDNA aptamers by SELEX technique. First, GP73 proteins were expressed and purified by prokaryotic expression system and Nickle ion affinity chromatography, respectively. At the same time, the immunogenicity of purified GP73 was confirmed by Western blotting. The enriched ssDNA library with high binding capacity for GP73 was obtained after ten rounds of SELEX. Then, thirty ssDNA aptamers were sequenced, in which two ssDNA aptamers with identical DNA sequence were confirmed, based on the alignment results, and designated as A10-2. Furthermore, the specific antibody could block the binding of A10-2 to GP73, and the specific binding of A10-2 to GP73 was also supported by the observation that several tumor cell lines exhibited variable expression level of GP73. Significantly, the identified aptamer A10-2 could distinguish normal and cancerous liver tissues. So, our results indicate that the aptamer A10-2 might be developed into one molecular probe to detect HCC from normal liver specimens.

  6. Multifunctional DNA-based biomemory device consisting of ssDNA/Cu heterolayers.

    PubMed

    Lee, Taek; El-Said, Waleed Ahmed; Min, Junhong; Choi, Jeong-Woo

    2011-01-15

    In the present study, we developed a novel DNA-based biomemory device that was comprised of ssDNA/Cu heterolayers on Au electrodes. As a conducting material, a thiol-modified single strand DNA (26 bp) was designed and immobilized on the Au electrode without the need for any linker material. Cu(2+) ions, which acted as the active site, were then chemically absorbed on the external structure of ssDNA through electrostatic interactions. The presence of the fabricated ssDNA/Cu heterolayer was confirmed by surface plasmon resonance (SPR) spectroscopy and Raman spectroscopy. Cyclic voltammetry experiments were carried out to investigate the redox properties of ssDNA/Cu hybrids to obtain the oxidation and reduction potential. Based on measured oxidation and reduction potential, a ROM-type, 3-state type, and WORM type DNA memory functions were demonstrated by chronoamperometry (CA) and open circuit potential amperometry (OCPA). This proposed device acts and operates the memory function very well. In the near future, DNA based biomemory device in this study could provide the alternative to the inorganic electronic device when molecular scaled immobilization control and signal measurement are achieved. PMID:21051218

  7. 47. Photograph of a line drawing. '304 S.S. NUTSCHE BOX ...

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

    47. Photograph of a line drawing. '304 S.S. NUTSCHE BOX AND FILTER PROBES, BUILDING H.' Holston Defense Corporation. June 24, 1955; revised 1958, 1960, 1965, 1968, 1982. Delineator: G. Sahlin. Drawing # 7651-1008/262. - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  8. High activity and stability of codon-optimized phosphoenolpyruvate carboxylase from Photobacterium profundum SS9 at low temperatures and its application for in vitro production of oxaloacetate.

    PubMed

    Park, Soohyun; Hong, Soohye; Pack, Seung Pil; Lee, Jinwon

    2014-02-01

    Phosphoenolpyruvate carboxylase (PEPC) of Photobacterium profundum SS9 can be expressed and purified using the Escherichia coli expression system. In this study, a codon-optimized PEPC gene (OPPP) was used to increase expression levels. We confirmed OPPP expression and purified it from extracts of recombinant E. coli SGJS117 harboring the OPPP gene. The purified OPPP showed a specific activity value of 80.3 U/mg protein. The OPPP was stable under low temperature (5-30 °C) and weakly basic conditions (pH 8.5-10). The enzymatic ability of OPPP was investigated for in vitro production of oxaloacetate using phosphoenolpyruvate (PEP) and bicarbonate. Only samples containing the OPPP, PEP, and bicarbonate resulted in oxaloacetate production. OPPP production system using E. coli could be a platform technology to produce high yields of heterogeneous gene and provide the PEPC enzyme, which has high enzyme activity.

  9. Synthesis and Functionalization of Gold Nanoparticles Using Chemically Modified ssDNA

    NASA Astrophysics Data System (ADS)

    Calabrese, P. G.

    In the first part of this thesis, methods for functionalizing spherical gold nanoparticles with nucleic acid binding ligands (aptamers) that target the VEGF receptor complex were developed. In order to provide a multiplexed labeling strategy for imaging the VEGF receptor complex in electron microscopy, gold nanoparticles of distinct sizes were conjugated to modified ssDNA aptamers that target the VEGF-A cytokine, the VEGFR-2 RTK receptor and a membrane associated co-receptor, Nrp-1. The modified ssDNA gold nanoparticle conjugates were applied to a human lung carcinoma cell line (A549) which has been shown to express each of these proteins and used as a model system for VEGF signaling. Binding constants for the modified aptamers were also determined using a fluorescence polarization anisotropy assay to determine KD and KOFF for the aptamers with their respective proteins. In the latter part of this thesis, a modied ssDNA SELEX protocol was also developed in order to evolve imidazole modied ssDNA sequences that assemble gold nanoparticles from Au3+ precursor ions in aqueous solution. Active sequences bound to nanoparticles were partitioned from inactive sequences based on density via ultracentrifugation through a discontinuous sucrose gradient. Colloidal gold solutions produced by the evolved pool had a distinct absorbance spectra and produced nanoparticles with a narrower distribution of sizes compared to colloidal gold solutions produced by the starting randomized pool of imidazole modified ssDNA. Sequencing data from the evolved pool shows that conserved 5 and 6 nt motifs were shared amongst many of the isolates, which indicates that these motifs could serve as chelation sites for gold atoms or help stabilize colloidal gold solutions in a base specific manner.

  10. Molecular characterisation of a novel cassava associated circular ssDNA virus.

    PubMed

    Dayaram, Anisha; Opong, Allen; Jäschke, Anja; Hadfield, James; Baschiera, Marianna; Dobson, Renwick C J; Offei, Samuel K; Shepherd, Dionne N; Martin, Darren P; Varsani, Arvind

    2012-06-01

    The application of sequence non-specific rolling circle amplification of circular single stranded (ss) DNA molecules to viral metagenomics has facilitated the discovery in various ecosystems of what is probably a diverse array of novel ssDNA viruses. Here we describe a putative novel ssDNA virus (at a genome level), cassava associated circular DNA virus (CasCV), isolated from cassava leaf samples infected with the fungi Collectotrichum and Plectosphaerella. CasCV has a circular ambisense genome and shares significant genome similarities with Sclerotinia sclerotiorum hypovirulence-associated DNA virus 1 (SsHADV-1), Mosquito VEM virus SDBVL and Meles meles faecal virus (MmFV). The CasCV genome (2220 nt) has three large open reading frames. While it is probable that one of these encodes a capsid protein, the other two probably express a replication associated protein (Rep) following the removal of an intron such as that found in the Rep encoding genes of some geminiviruses. This Rep would contain four conserved rolling circle replication (RCR) related motifs that have previously been identified in geminivirus, circovirus and nanovirus Reps. Given both that the CasCV Rep and CP share 62.7% and 39.8% amino acid identity respectively with the Rep and CP of SsHADV-1, and that CasCV was discovered associated with cassava infecting fungi, we suggest that CasCV should be classified within the mycovirus taxonomic family. However, host range studies using infectious clones will be required to demonstrate the novel virus' likely origin and actual host species.

  11. Summary of Tests to Determine Effectiveness of Gelatin Strike on SS{ampersand}C Dissolver Solutions

    SciTech Connect

    Murray, A.M.; Karraker, D.G.

    1998-05-01

    The solutions from the dissolution of sand, slag, and crucible (SS&C) material are sufficiently different from previous solutions processed via the F-Canyon Purex process that the effectiveness of individual process steps needed to be ascertained. In this study, the effectiveness of gelatin strike was tested under a variety of conditions. Specifically, several concentrations of silica, fluoride, nitric acid (HNO{sub 3}), boric acid (H{sub 3}BO{sub 3}), and aluminium nitrate nonahydrate (ANN) were studied. The disengagement times of surrogate and plant SS&C dissolver solutions from plant solvent also were measured. The results of the tests indicate that gelatin strike does not coagulate the silica at the low concentration of silica ({tilde 30} ppm) expected in the SS&C dissolver solutions because the silicon is complexed with fluoride ions (e.g., SiF{sub 6}{sup -2}). The silicon fluoride complex is expected to remain with the aqueous phase during solvent extraction. The disengagement times of the dissolver solutions from the plant solvent were not affected by the presence of low concentrations of silica and no third phase formation was observed in the disengagement phase with the low silica concentrations. Tests of surrogate SS&C dissolver solutions with higher concentration of silica (less than 150 ppm) did show that gelatin strike followed by centrifugation resulted in good phase disengagement of the surrogate SS{ampersand}C dissolver solution from the plant dissolver solution. At the higher silica concentrations, there is not sufficient fluoride to complex with the silica, and the silica must be entrained by the gelatin and removed from the dissolver solution prior to solvent extraction.

  12. Use of hazard assessments to achieve risk reduction in the USDOE Stockpile Stewardship (SS-21) Program

    SciTech Connect

    Fischer, S.R.; Konkel, H.; Bott, T.; Eisenhawer, S.W.; DeYoung, L.; Hockert, J.

    1995-07-01

    This paper summarizes the nuclear explosive hazard assessment activities performed to support US Department of Energy (DOE) Stockpile Stewardship Demonstration Project SS-21, better known as the ``Seamless Safety`` program. Past practice within the DOE Complex has dictated the use of a significant number of post-design/fabrication safety reviews to analyze the safety associated with operations on nuclear explosives and to answer safety questions. These practices have focused on reviewing-in or auditing-in safety vs incorporating safety in the design process. SS-21 was proposed by the DOE as an avenue to develop a program to ``integrate established, recognized, verifiable safety criteria into the process at the design stage rather than continuing the reliance on reviews, evaluations and audits.`` The entire Seamless Safety design and development process is verified by a concurrent hazard assessment (HA). The primary purpose of the SS-21 Demonstration Project HA was to demonstrate the feasibility of performing concurrent HAs as part of an engineering design and development effort and then to evaluate the use of the HA to provide an indication in the risk reduction or gain in safety achieved. To accomplish this objective, HAs were performed on both baseline (i.e., old) and new (i.e. SS-21) B61-0 Center Case Section disassembly processes. These HAs were used to support the identification and documentation of weapon- and process-specific hazards and safety-critical operating steps. Both HAs focused on identifying accidents that had the potential for worker injury, public health effects, facility damage, toxic gas release, and dispersal of radioactive materials. A comparison of the baseline and SS-21 process risks provided a semi-quantitative estimate of the risk reduction gained via the Seamless Safety process.

  13. First insights into the genetic diversity of Echinococcus granulosus sensu stricto (s.s.) in Serbia.

    PubMed

    Debeljak, Zoran; Boufana, Belgees; Interisano, Maria; Vidanovic, Dejan; Kulisic, Zoran; Casulli, Adriano

    2016-06-15

    Cystic echinococcosis (CE) caused by Echinococcus granulosus sensu stricto (s.s.) is a cosmopolitan zoonotic infection which is endemic in Serbia where it is subject to mandatory reporting. However, information on the incidence of the disease in humans and prevalence of hydatid infection in livestock remains limited. We used sequenced data of the cytochrome c oxidase subunit 1 (cox 1) mitochondrial gene to examine the genetic diversity and population structure of E. granulosus (s.s.) from intermediate hosts from Serbia. We also compared our generated nucleotide sequences with those reported for neighbouring European countries. Echinococcus canadensis was molecularly confirmed from pig and human hydatid isolates. E. granulosus (G1) was confirmed from sheep and cattle hydatid isolates as well as the first molecular confirmation in Serbia of E. granulosus G2 in sheep and E. granulosus G3 in sheep and cattle hydatid isolates. The Serbian E. granulosus (s.s.) parsimony network displayed 2 main haplotypes (SB02 and SB05) which together with the neutrality indices were suggestive of bottleneck and/or balancing selection. Haplotype analysis showed the presence of the common E. granulosus haplotype described from other worldwide regions. Investigation of the pairwise fixation (Fst) index suggested that Serbian populations of E. granulosus (s.s.) from sheep and cattle hosts showed moderate genetic differentiation. Six of the Serbian haplotypes (SB02-SB07) were shared with haplotypes from Bulgaria, Hungary and/or Romania. Further studies using a larger number of hydatid isolates from various locations across Serbia will provide more information on the genetic structure of E. granulosus (s.s.) within this region.

  14. Fatigue Crack Propagation from Notched Specimens of 304 SS in elevated Temperature Aqueous Environment

    SciTech Connect

    Wire, G. L.; Mills, W. J.

    2002-08-01

    Fatigue crack propagation (FCP) rates for 304 stainless steel (304SS) were determined in 24 degree C and 288 degree C air and 288 degree C water using double-edged notch (DEN) specimens of 304 stainless steel (304 SS). Test performed at matched loading conditions in air and water at 288 degree C with 20-6- cc h[sub]2/kg h[sub]2O provided a direct comparison of the relative crack growth rates in air and water over a wide range of crack growth rates. The DEN crack extension ranged from short cracks (0.03-0.25 mm) to long cracks up to 4.06 mm, which are consistent with conventional deep crack tests. Crack growth rates of 304 SS in water were about 12 times the air rate. This 12X environmental enhancement persisted to crack extensions up to 4.06 mm, far outside the range associated with short crack effects. The large environmental degradation for 304 SS crack growth is consistent with the strong reduction of fatigue life in high hydrogen water. Further, very similar environmental effects w ere reported in fatigue crack growth tests in hydrogen water chemistry (HWC). Most literature data in high hydrogen water show only a mild environmental effect for 304 SS, of order 2.5 times air or less, but the tests were predominantly performed at high cyclic stress intensity or equivalently, high air rates. The environmental effect in low oxygen environments at low stress intensity depends strongly on both the stress ratio, R, and the load rise time, T[sub]r, as recently reported for austenitic stainless steel in BWR water. Fractography was performed for both tests in air and water. At 288 degree C in water, the fracture surfaces were crisply faceted with a crystallographic appearance, and showed striations under high magnification. The cleavage-like facets on the fracture surfaces suggest that hydrogen embrittlement is the primary cause of accelerated cracking.

  15. Group 2 PH: Medical Therapy.

    PubMed

    Guazzi, Marco; Labate, Valentina

    2016-01-01

    Pulmonary hypertension (PH) secondary to left heart disease, classified as Group 2, is a widely underestimated target of therapy. Prevention and treatment of initial subclinical stages are not valued as a priority in the management of this chronic disease population, whereas attention is high for PH consequences in patients with advanced heart failure (HF) requiring a left ventricular mechanical assist device or heart transplant candidates. Even so, there is a growing interest toward the evidence of a clinical and prognostic role of PH in the elderly populations and in HF with preserved ejection fraction (HFpEF). Certainly, along with a prevalence definition not yet defined, the search for effective pharmacological approaches that might favorably affect the aging process and the natural history of HFpEF from earlier stages is not an easy task. Pharmacological studies that have tested some traditional pulmonary arterial hypertension approved drugs (i.e., prostanoids and endothelin-1 receptor blockers) primarily in PH and HF with reduced ejection fraction have not been positive, especially because of concomitant side effects, i.e., systemic hypotension, fluid retention and hepatic toxicity. In recent years, interest has moved toward drugs overexpressing the nitric oxide (NO)-cyclic guanosine monophosphate pathway with recent availability of well-tolerated selective pulmonary vasodilators, such as phosphodiesterase type 5 inhibitors and guanylate cyclase stimulators. Single center studies performed with these drugs have shown good tolerability and safety profile providing alternating hemodynamic results mainly because of recruitment of patients at different stages of the pulmonary vascular disease. Nonetheless, the overexpression of NO pathway appears to remain the most solid background for targeting lung microvessel dysfunction and treating RV dysfunction since the earliest stages of the disease. PMID:27389809

  16. Molecular cloning, characterization and differential expression of a Sporothrix schenckii STE20-like protein kinase SsSte20.

    PubMed

    Zhang, Zhenying; Hou, Binbin; Zheng, Fangliang; Yu, Xiaohong; Liu, Xiaoming

    2013-06-01

    Dimorphic switching requires fungal cells to undergo changes in polarized growth in response to environmental stimuli. The Ste20-related kinases are involved in signaling through mitogen-activated protein kinase pathways and in morphogenesis through the regulation of cytokinesis and actin-dependent polarized growth. In this report, we isolated and characterized an Ste20 homologue gene, designated SsSte20, from yeast-form Sporothrix schenckii (S. schenckii). The full length SsSte20 cDNA sequence is 2846 bp in size, and contains an open reading frame of 2505 bp encoding 835 amino acids. The predicted molecular mass of SsSte20 is 91.31 kDa with an estimated theoretical isoelectric point of 5.76. SsSte20 kinase domain shows 63% identity with that of Don3, a germinal centre kinase (GCK) from Ustilago maydis. Two exons and one intron are identified within the 2578 bp SsSte20 genomic DNA sequence of S. schenckii. Differential expression of the SsSte20 was demonstrated by real-time RT-PCR. The expression of SsSte20 was much higher in the yeast stage compared with that in the mycelial stage, which indicated that the SsSte20 may be involved in the pathogenesis of the yeast phase of S. schenckii.

  17. ss-siRNAs allele selectively inhibit ataxin-3 expression: multiple mechanisms for an alternative gene silencing strategy.

    PubMed

    Liu, Jing; Yu, Dongbo; Aiba, Yuichiro; Pendergraff, Hannah; Swayze, Eric E; Lima, Walt F; Hu, Jiaxin; Prakash, Thazha P; Corey, David R

    2013-11-01

    Single-stranded silencing RNAs (ss-siRNAs) provide an alternative approach to gene silencing. ss-siRNAs combine the simplicity and favorable biodistribution of antisense oligonucleotides with robust silencing through RNA interference (RNAi). Previous studies reported potent and allele-selective inhibition of human huntingtin expression by ss-siRNAs that target the expanded CAG repeats within the mutant allele. Mutant ataxin-3, the genetic cause of Machado-Joseph Disease, also contains an expanded CAG repeat. We demonstrate here that ss-siRNAs are allele-selective inhibitors of ataxin-3 expression and then redesign ss-siRNAs to optimize their selectivity. We find that both RNAi-related and non-RNAi-related mechanisms affect gene expression by either blocking translation or affecting alternative splicing. These results have four broad implications: (i) ss-siRNAs will not always behave similarly to analogous RNA duplexes; (ii) the sequences surrounding CAG repeats affect allele-selectivity of anti-CAG oligonucleotides; (iii) ss-siRNAs can function through multiple mechanisms and; and (iv) it is possible to use chemical modification to optimize ss-siRNA properties and improve their potential for drug discovery.

  18. The Safe Schools/Healthy Students (SS/HS) Initiative: Lessons Learned form Implementing Comprehensive Youth Development Programs.

    ERIC Educational Resources Information Center

    Furlong, Michael; Paige, Leslie Z.; Osher, David

    2003-01-01

    Provides an overview of this special issue that examines the implementation of the Safe Schools/Healthy Students (SS/HS) Initiative in seven local communities. An overview of the SS/HS Initiative is provided. Critical lessons learned from the seven sites are discussed with a focus on the special role that school psychologists can play in…

  19. [Psychogram of the Auschwitz commander: insight and confrontation through destruction. On the autobiography of Rudolf Höss].

    PubMed

    Zeiler, J

    1991-04-01

    By reference to the personality of Rudolf Höss, the author illuminates once again the terrifying juxtaposition of criminality and apparent normality in the psychic life of a Nazi criminal. The inferno of the concentration camp is interpreted as a perverse explication and staging of split-off ideational contents in the mind of Höss.

  20. The Methods Behind PH WINS

    PubMed Central

    Leider, Jonathon P.; Bharthapudi, Kiran; Pineau, Vicki; Liu, Lin; Harper, Elizabeth

    2015-01-01

    The Public Health Workforce Interests and Needs Survey (PH WINS) has yielded the first-ever nationally representative sample of state health agency central office employees. The survey represents a step forward in rigorous, systematic data collection to inform the public health workforce development agenda in the United States. PH WINS is a Web-based survey and was developed with guidance from a panel of public health workforce experts including practitioners and researchers. It draws heavily from existing and validated items and focuses on 4 main areas: workforce perceptions about training needs, workplace environment and job satisfaction, perceptions about national trends, and demographics. This article outlines the conceptualization, development, and implementation of PH WINS, as well as considerations and limitations. It also describes the creation of 2 new data sets that will be available in public use for public health officials and researchers—a nationally representative data set for permanently employed state health agency central office employees comprising over 10 000 responses, and a pilot data set with approximately 12 000 local and regional health department staff responses. PMID:26422490

  1. Analysis of metabolites in plasma reveals distinct metabolic features between Dahl salt-sensitive rats and consomic SS.13(BN) rats.

    PubMed

    Wang, Le; Hou, Entai; Wang, Zhengjun; Sun, Na; He, Liqing; Chen, Lan; Liang, Mingyu; Tian, Zhongmin

    2014-07-18

    Salt-sensitive hypertension is a major risk factor for cardiovascular disorders. Our previous proteomic study revealed substantial differences in several proteins between Dahl salt-sensitive (SS) rats and salt-insensitive consomic SS.13(BN) rats. Subsequent experiments indicated a role of fumarase insufficiency in the development of hypertension in SS rats. In the present study, a global metabolic profiling study was performed using gas chromatography/mass spectrometry (GC/MS) in plasma of SS rats (n=9) and SS.13(BN) rats (n=8) on 0.4% NaCl diet, designed to gain further insights into the relationship between alterations in cellular intermediary metabolism and predisposition to hypertension. Principal component analysis of the data sets revealed a clear clustering and separation of metabolic profiles between SS rats and SS.13(BN) rats. 23 differential metabolites were identified (P<0.05). Higher levels of five TCA cycle metabolites, fumarate, cis-aconitate, isocitrate, citrate and succinate, were observed in SS rats. Pyruvate, which connects TCA cycle and glycolysis, was also increased in SS rats. Moreover, lower activity levels of fumarase, aconitase, α-ketoglutarate dehydrogenase and succinyl-CoA synthetase were detected in the heart, liver or skeletal muscles of SS rats. The distinct metabolic features in SS and SS.13(BN) rats indicate abnormalities of TCA cycle in SS rats, which may play a role in predisposing SS rats to developing salt-sensitive hypertension.

  2. Development of Ss-NIE-1 recombinant antigen based assays for immunodiagnosis of strongyloidiasis.

    PubMed

    Rascoe, Lisa N; Price, Courtney; Shin, Sun Hee; McAuliffe, Isabel; Priest, Jeffrey W; Handali, Sukwan

    2015-04-01

    Strongyloides stercoralis is a widely distributed parasite that infects 30 to 100 million people worldwide. In the United States strongyloidiasis is recognized as an important infection in immigrants and refugees. Public health and commercial reference laboratories need a simple and reliable method for diagnosis of strongyloidiasis to identify and treat cases and to prevent transmission. The recognized laboratory test of choice for diagnosis of strongyloidiasis is detection of disease specific antibodies, most commonly using a crude parasite extract for detection of IgG antibodies. Recently, a luciferase tagged recombinant protein of S. stercoralis, Ss-NIE-1, has been used in a luciferase immunoprecipitation system (LIPS) to detect IgG and IgG4 specific antibodies. To promote wider adoption of immunoassays for strongyloidiasis, we used the Ss-NIE-1 recombinant antigen without the luciferase tag and developed ELISA and fluorescent bead (Luminex) assays to detect S. stercoralis specific IgG4. We evaluated the assays using well-characterized sera from persons with or without presumed strongyloidiasis. The sensitivity and specificity of Ss-NIE-1 IgG4 ELISA were 95% and 93%, respectively. For the IgG4 Luminex assay, the sensitivity and specificity were 93% and 95%, respectively. Specific IgG4 antibody decreased after treatment in a manner that was similar to the decrease of specific IgG measured in the crude IgG ELISA. The sensitivities of the Ss-NIE-1 IgG4 ELISA and Luminex assays were comparable to the crude IgG ELISA but with improved specificities. However, the Ss-NIE-1 based assays are not dependent on native parasite materials and can be performed using widely available laboratory equipment. In conclusion, these newly developed Ss-NIE-1 based immunoassays can be readily adopted by public health and commercial reference laboratories for routine screening and clinical diagnosis of S. stercoralis infection in refugees and immigrants in the United States. PMID

  3. Effect of Chewing Bicarbonate-containing Sugar-free Gum on the Salivary pH: An in vivo Study

    PubMed Central

    Bhat, Sham S; Ramdas, Shenoy Shailesh; Ballal, Shrinidhi

    2016-01-01

    ABSTRACT The objective of the study was to evaluate the effect of chewing gum on the salivary pH and to compare the effect of chewing bicarbonate-containing sugar-free gum on salivary pH against that of standard sugar-free gum. The experiment was carried out on 30 volunteers aged 20-22 years (mean age = 21 years) who fulfilled the inclusion criteria. The test gum was sugar-free greenmint-flavored bicarbonate-containing gum and the standard control was sugar-free spearmint-flavored gum. The pH was measured immediately using pH strips. According to statistical analysis, the mean salivary pH of the bicarbonate gum at 0, 5, 10, 15 and 20 minutes is 6.9713, 6.5667, 6.4267, 6.3867 and 6.3233 respectively. There is decrease in pH from 0 to 20 minutes. According to Bonferroni, there was no significant difference in pH from 0 to 20 minutes, 10 to 20 minutes and 15 to 20 minutes, but there was a significant difference in salivary pH from 5 to 20 minutes (p = 0.014). The mean salivary pH of the standard gum at 0, 5, 10, 15 and 20 minutes is 6.8767, 6.6067, 6.4200, 6.4027 and 6.3000 respectively. There is decrease in pH from 0 to 20 minutes. According to Bonferroni, there was no significant difference in pH from 0 to 20 minutes, 5 to 20 minutes, 10 to 20 minutes and 15 to 20 minutes. Thus, the higher salivary pH achieved with chewing bicarbonate gum compared with a standard sugar-free gum may have important oral health implications. How to cite this article: Ballal RK, Bhat SS, Ramdas SS, Ballal S. Effect of Chewing Bicarbonate-containing Sugar-free Gum on the Salivary pH: An in vivo Study. Int J Clin Pediatr Dent 2016;9(1):35-38. PMID:27274153

  4. Alkaline pH sensor molecules.

    PubMed

    Murayama, Takashi; Maruyama, Ichiro N

    2015-11-01

    Animals can survive only within a narrow pH range. This requires continual monitoring of environmental and body-fluid pH. Although a variety of acidic pH sensor molecules have been reported, alkaline pH sensor function is not well understood. This Review describes neuronal alkaline pH sensors, grouped according to whether they monitor extracellular or intracellular alkaline pH. Extracellular sensors include the receptor-type guanylyl cyclase, the insulin receptor-related receptor, ligand-gated Cl- channels, connexin hemichannels, two-pore-domain K+ channels, and transient receptor potential (TRP) channels. Intracellular sensors include TRP channels and gap junction channels. Identification of molecular mechanisms underlying alkaline pH sensing is crucial for understanding how animals respond to environmental alkaline pH and how body-fluid pH is maintained within a narrow range.

  5. Expanding the scope of CE reactor to ssDNA-binding protein-ssDNA complexes as exemplified for a tool for direct measurement of dissociation kinetics of biomolecular complexes.

    PubMed

    Takahashi, Toru; Ohtsuka, Kei-Ichirou; Tomiya, Yoriyuki; Iki, Nobuhiko; Hoshino, Hitoshi

    2009-09-01

    CE reactor (CER), which was developed as a tool for direct measurement of the dissociation kinetics of metal complexes, was successfully applied to the complexes of Escherichia coli ssDNA-binding protein (SSB) with ssDNA. The basic concept of CER is the application of CE separation process as a dissociation kinetic reactor for the complex, and the observation of the on-capillary dissociation reaction profile of the complex as the decrease of the peak height of the complex with increase of the migration time. The peak height of [SSB-ssDNA] decreases as the migration time increases since the degree of the decrease of [SSB-ssDNA] through the on-capillary dissociation reaction is proportional to the degree of the decrease of the peak height of [SSB-ssDNA]. The dissociation degree-time profiles for the complexes are quantitatively described by analyzing a set of electropherograms with different migration times. Dissociation rate constants of [SSB-ssDNA] consisting of 20-mer, 25-mer and 31-mer ssDNA were directly determined to be 3.99x10(-4), 4.82x10(-4) and 1.50x10(-3)/s, respectively. CER is a concise and effective tool for dissociation kinetic analysis of biomolecular complexes.

  6. Sewage sludge pretreatment by microwave irradiation combined with activated carbon fibre at alkaline pH for anaerobic digestion.

    PubMed

    Sun, Dedong; Guo, Sixiao; Ma, Nina; Wang, Guowen; Ma, Chun; Hao, Jun; Xue, Mang; Zhang, Xinxin

    2016-01-01

    This research focuses on the effects of microwave-assisted activated carbon fibre (ACF) (MW-ACF) treatment on sewage sludge at alkaline pH. The disintegration and biodegradability of sewage sludge were studied. It was found that the MW-ACF process at alkaline pH provided a rapid and efficient process to disrupt the microbial cells in the sludge. The results suggested that when irradiated at 800 W MW for 110 s with a dose of 1.0 g ACF/g solid concentration (SS) at pH 10.5, the MW-ACF pretreatment achieved 55% SS disintegration, 23% greater than the value of MW alone (32%). The concentration of total nitrogen, total phosphorus, supernatant soluble chemical oxygen demand, protein, and polysaccharide increased by 60%, 144%, 145%, 74%, and 77%, respectively. An increase in biogas production by 63.7% was achieved after 20 days of anaerobic digestion (AD), compared to the control. The results indicated that the MW-ACF pretreatment process at alkaline pH provides novel sludge management options in disintegration of sewage sludge for further AD.

  7. Sewage sludge pretreatment by microwave irradiation combined with activated carbon fibre at alkaline pH for anaerobic digestion.

    PubMed

    Sun, Dedong; Guo, Sixiao; Ma, Nina; Wang, Guowen; Ma, Chun; Hao, Jun; Xue, Mang; Zhang, Xinxin

    2016-01-01

    This research focuses on the effects of microwave-assisted activated carbon fibre (ACF) (MW-ACF) treatment on sewage sludge at alkaline pH. The disintegration and biodegradability of sewage sludge were studied. It was found that the MW-ACF process at alkaline pH provided a rapid and efficient process to disrupt the microbial cells in the sludge. The results suggested that when irradiated at 800 W MW for 110 s with a dose of 1.0 g ACF/g solid concentration (SS) at pH 10.5, the MW-ACF pretreatment achieved 55% SS disintegration, 23% greater than the value of MW alone (32%). The concentration of total nitrogen, total phosphorus, supernatant soluble chemical oxygen demand, protein, and polysaccharide increased by 60%, 144%, 145%, 74%, and 77%, respectively. An increase in biogas production by 63.7% was achieved after 20 days of anaerobic digestion (AD), compared to the control. The results indicated that the MW-ACF pretreatment process at alkaline pH provides novel sludge management options in disintegration of sewage sludge for further AD. PMID:27332832

  8. Oxidation state of Mn in the Mn oxide produced by Leptothrix discophora SS-1

    NASA Astrophysics Data System (ADS)

    Adams, Lee F.; Ghiorse, William C.

    1988-08-01

    Leptothrix discophora SS-1 excretes at least one Mn 2+-oxidizing protein that, in association with acidic exopolymers, catalyzes a rapid oxidation of Mn 2+. Iodometric titration of Mn oxide product showed that the oxidation state of Mn increased with age of the oxide from 3.32 in samples 11 hours old to 3.62 in samples formed over a period of 30 days. Electron diffraction of 90-day old samples showed evidence of poorly crystalline Mn(IV) oxides. Simultaneous measurement of oxygen consumption and Mn oxide formation during 15 min reaction periods indicated that the initial Mn product possessed an average oxidation state no greater than 3.6. Results suggest that the Mn 2+-oxidizing system of Leptothrix discophora SS-1 first generates Mn oxide with an average oxidation state close to Mn(III). Aging increases this oxidation state to give the mixed Mn(III, IV) oxide product observed in older samples.

  9. Facilitation of Electron Transfer in the Presence of Mitochondria-Targeting Molecule SS31

    NASA Astrophysics Data System (ADS)

    Nosach, Tetiana; Ebrahim, Mark; Ren, Yuhang; Darrah, Shaun; Szeto, Hazel

    2010-03-01

    Electron transfer (ET) processes in mitochondria are very important for the production of adenosine triphosphate (ATP), the common source of the chemical energy. The inability to transfer electrons efficiently in mitochondrial ET chain plays a major role in age associated diseases, including diabetes and cancer. In this work, we used the time dependent absorption and photoluminescence spectroscopy to study the electron transfer kinetics along the ET chain of mitochondria. Our spectroscopic results suggest that SS31, a small peptide molecule targeting to the mitochondrial inner membrane, can facilitate electron transfer and increase ATP production. We show that SS31 targets cytochrome c to both increase the availability of state and also potentially reduce the energy barrier required to reduce cytochrome c.

  10. KiSS-1: a likely candidate for the photoperiodic control of reproduction in seasonal breeders.

    PubMed

    Revel, Florent G; Saboureau, Michel; Masson-Pévet, Mireille; Pévet, Paul; Mikkelsen, Jens D; Simonneaux, Valérie

    2006-01-01

    In seasonal species, photoperiod exerts tight regulation of reproduction to ensure that birth occurs at the most favorable time of yr. A distinct photoneuroendocrine circuit composed of the retina, suprachiasmatic nucleus (SCN) of the hypothalamus, and pineal gland transduces daylength into a rhythmic secretion of melatonin. The duration of the night-time rise of this hormone conveys daylength information to the organism. Melatonin is known to mediate the control of seasonal reproduction, but how it modulates sexual activity is far from understood. Recent data indicate that the product of the KiSS-1 gene is a potent stimulator of the hypothalamic-pituitary-gonadal axis and may play, together with its receptor GPR54, a central role in the neuroendocrine regulation of gonadotropin secretion. This article briefly reviews these findings and presents arguments that KiSS-1 could take part in the seasonal control of reproduction.

  11. The SSES-E: a measure of sexual self-efficacy in erectile functioning.

    PubMed

    Libman, E; Rothenberg, I; Fichten, C S; Amsel, R

    1985-01-01

    The purpose of this study was to develop and validate the Sexual Self-Efficacy Scale (SSES-E) for erectile disorder. The subjects consisted of 15 heterosexual couples with nonproblematic sexual functioning (normal group) and a sexually dysfunctional sample consisting of nine heterosexual couples and eight heterosexual single males (dysfunctional group). Most of the males in the dysfunctional sample were diagnosed as suffering from erectile disorder. Reliability of the SSES-E, based on test-retest and split-half correlations and on item analyses, appears to be reasonable. Validity, measured in three different ways, is also acceptably high. Suggestions for the use of this instrument in clinical practice and for future research are made.

  12. Experimental investigation of machining parameter under MQL milling of SS304

    NASA Astrophysics Data System (ADS)

    Gatade, Vivek T.; Patil, Vikas T.; Kuppan, P.; Balan, A. S. S.; Oyyaravelu, R.

    2016-09-01

    Minimum quantity lubrication (MQL) or near dry machining has been recognized by many researchers and industrialist in order to move one step ahead towards the green manufacturing. MQL assisted machining reduces the harmful environmental impact caused by flood coolant and machining cost. In this paper an attempt has been made to study the impact of oxygen as a carrier gas in MQL during end milling of austenitic stainless steel grade SS304. Also, the machining performance under conventional MQL with air and dry machining have been studied. The evaluation was done on tool wear, surface roughness and cutting forces under two distinct cutting speeds i.e. 75 m/min and 100 m/min. Investigation brings to light that presence of oxygen is susceptible in the case of machining of SS304, it provides extra protective oxide layer near the tool chip interface. Consequently, increased tool life, reduced surface roughness and cutting forces when compared to conventional MQL assisted milling.

  13. Bioconversion of glycerol for bioethanol production using isolated Escherichia coli ss1

    PubMed Central

    Suhaimi, Sheril Norliana; Phang, Lai-Yee; Maeda, Toshinari; Abd-Aziz, Suraini; Wakisaka, Minato; Shirai, Yoshihito; Hassan, Mohd Ali

    2012-01-01

    Bioconverting glycerol into various valuable products is one of glycerol's promising applications due to its high availability at low cost and the existence of many glycerol-utilizing microorganisms. Bioethanol and biohydrogen, which are types of renewable fuels, are two examples of bioconverted products. The objectives of this study were to evaluate ethanol production from different media by local microorganism isolates and compare the ethanol fermentation profile of the selected strains to use of glucose or glycerol as sole carbon sources. The ethanol fermentations by six isolates were evaluated after a preliminary screening process. Strain named SS1 produced the highest ethanol yield of 1.0 mol: 1.0 mol glycerol and was identified as Escherichia coli SS1 Also, this isolated strain showed a higher affinity to glycerol than glucose for bioethanol production. PMID:24031858

  14. An accurate geometric distance to the compact binary SS Cygni vindicates accretion disc theory.

    PubMed

    Miller-Jones, J C A; Sivakoff, G R; Knigge, C; Körding, E G; Templeton, M; Waagen, E O

    2013-05-24

    Dwarf novae are white dwarfs accreting matter from a nearby red dwarf companion. Their regular outbursts are explained by a thermal-viscous instability in the accretion disc, described by the disc instability model that has since been successfully extended to other accreting systems. However, the prototypical dwarf nova, SS Cygni, presents a major challenge to our understanding of accretion disc theory. At the distance of 159 ± 12 parsecs measured by the Hubble Space Telescope, it is too luminous to be undergoing the observed regular outbursts. Using very long baseline interferometric radio observations, we report an accurate, model-independent distance to SS Cygni that places the source substantially closer at 114 ± 2 parsecs. This reconciles the source behavior with our understanding of accretion disc theory in accreting compact objects.

  15. QUANTIFYING THE CARBON ABUNDANCES IN THE SECONDARY STARS OF SS CYGNI, RU PEGASI, AND GK PERSEI

    SciTech Connect

    Harrison, Thomas E.; Hamilton, Ryan T. E-mail: rthamilton@sofia.usra.edu

    2015-11-15

    We use a modified version of MOOG to generate large grids of synthetic spectra in an attempt to derive quantitative abundances for three CVs (GK Per, RU Peg, and SS Cyg) by comparing the models to moderate resolution (R ∼ 25,000) K-band spectra obtained with NIRSPEC on Keck. For each of the three systems we find solar, or slightly sub-solar values for [Fe/H], but significant deficits of carbon: for SS Cyg we find [C/Fe] = −0.50, for RU Peg [C/Fe] = −0.75, and for GK Per [C/Fe] = −1.00. We show that it is possible to use lower resolution (R ∼ 2000) spectra to quantify carbon deficits. We examine realistic veiling scenarios and find that emission from H i or CO cannot reproduce the observations.

  16. An accurate geometric distance to the compact binary SS Cygni vindicates accretion disc theory.

    PubMed

    Miller-Jones, J C A; Sivakoff, G R; Knigge, C; Körding, E G; Templeton, M; Waagen, E O

    2013-05-24

    Dwarf novae are white dwarfs accreting matter from a nearby red dwarf companion. Their regular outbursts are explained by a thermal-viscous instability in the accretion disc, described by the disc instability model that has since been successfully extended to other accreting systems. However, the prototypical dwarf nova, SS Cygni, presents a major challenge to our understanding of accretion disc theory. At the distance of 159 ± 12 parsecs measured by the Hubble Space Telescope, it is too luminous to be undergoing the observed regular outbursts. Using very long baseline interferometric radio observations, we report an accurate, model-independent distance to SS Cygni that places the source substantially closer at 114 ± 2 parsecs. This reconciles the source behavior with our understanding of accretion disc theory in accreting compact objects. PMID:23704566

  17. Is SS-A/Ro52 a hydrogen peroxide-sensitive signaling molecule?

    PubMed

    Nobuhara, Yumiko; Kawano, Seiji; Kageyama, Goichi; Sugiyama, Daisuke; Saegusa, Jun; Kumagai, Shunichi

    2007-03-01

    SS-A/Ro52 (Ro52) protein is one of the targets of autoantibodies in Sjogren's syndrome and systemic lupus erythematosus. Ro52 structurally belongs to the RING-B-box/coiled-coil family, which appears to carry out diverse functions, but the physiological function of Ro52 remains largely unknown. Here, the authors demonstrate that hydrogen peroxide but not other oxidative stressors induced translocation of Ro52 protein from the cytoplasm to the nucleus and this phenomenon was attenuated by inhibition of MAP kinases, ERK in particular. These findings raise the possibility that SS-A/Ro52 may function as a hydrogen peroxide-selective, oxidative stress-sensitive signaling molecule that is activated via the MAP kinase pathway.

  18. BLM SUMOylation regulates ssDNA accumulation at stalled replication forks.

    PubMed

    Ouyang, Karen J; Yagle, Mary K; Matunis, Michael J; Ellis, Nathan A

    2013-01-01

    Polymerase stalling results in uncoupling of DNA polymerase and the replicative helicase, which generates single-stranded DNA (ssDNA). After stalling, RAD51 accumulates at stalled replication forks to stabilize the fork and to repair by homologous recombination (HR) double-strand breaks (DSBs) that accumulate there. We showed recently that SUMO modification of the BLM helicase is required in order for RAD51 to accumulate at stalled forks. In order to investigate how BLM SUMOylation controls RAD51 accumulation, we characterized the function of HR proteins and ssDNA-binding protein RPA in cells that stably expressed either normal BLM (BLM+) or SUMO-mutant BLM (SM-BLM). In HU-treated SM-BLM cells, mediators BRCA2 and RAD52, which normally substitute RAD51 for RPA on ssDNA, failed to accumulate normally at stalled forks; instead, excess RPA accumulated. SM-BLM cells also exhibited higher levels of HU-induced chromatin-bound RPA than BLM+ cells did. The excess RPA did not result from excessive intrinsic BLM helicase activity, because in vitro SUMOylated BLM unwound similar amounts of replication-fork substrate as unSUMOylated BLM. Nor did BLM SUMOylation inhibit binding of RPA to BLM in vitro; however, in immunoprecipitation experiments, more BLM-RPA complex formed in HU-treated SM-BLM cells, indicating that BLM SUMOylation controls the amount of BLM-RPA complex normally formed at stalled forks. Together, these results showed that BLM SUMOylation regulates the amount of ssDNA that accumulates during polymerase stalling. We conclude that BLM SUMOylation functions as a licensing mechanism that permits and regulates HR at damaged replication forks.

  19. Baseband processor development/test performance for 30/20 GHz SS-TDMA communication system

    NASA Technical Reports Server (NTRS)

    Brown, L.; Sabourin, D.; Attwood, S.

    1984-01-01

    The baseband processor (BBP) development for the 30/20 GHz Satellite Communication System is described. The SS-TDMA concept for future satellite communications is reviewed, describing the overall system, the satellite payload, and the frequency plan. A brief general description of the BBP is given, and the proof-of-concept model of the BBP is summarized. Key technologies and custom LSI developed for the BBP are listed. Finally, key technology developments and test data are reported for the BBP.

  20. Differential Codon Adaptation between dsDNA and ssDNA Phages in Escherichia coli

    PubMed Central

    Chithambaram, Shivapriya; Prabhakaran, Ramanandan; Xia, Xuhua

    2014-01-01

    Because phages use their host translation machinery, their codon usage should evolve toward that of highly expressed host genes. We used two indices to measure codon adaptation of phages to their host, rRSCU (the correlation in relative synonymous codon usage [RSCU] between phages and their host) and Codon Adaptation Index (CAI) computed with highly expressed host genes as the reference set (because phage translation depends on host translation machinery). These indices used for this purpose are appropriate only when hosts exhibit little mutation bias, so only phages parasitizing Escherichia coli were included in the analysis. For double-stranded DNA (dsDNA) phages, both rRSCU and CAI decrease with increasing number of transfer RNA genes encoded by the phage genome. rRSCU is greater for dsDNA phages than for single-stranded DNA (ssDNA) phages, and the low rRSCU values are mainly due to poor concordance in RSCU values for Y-ending codons between ssDNA phages and the E. coli host, consistent with the predicted effect of C→T mutation bias in the ssDNA phages. Strong C→T mutation bias would improve codon adaptation in codon families (e.g., Gly) where U-ending codons are favored over C-ending codons (“U-friendly” codon families) by highly expressed host genes but decrease codon adaptation in other codon families where highly expressed host genes favor C-ending codons against U-ending codons (“U-hostile” codon families). It is remarkable that ssDNA phages with increasing C→T mutation bias also increased the usage of codons in the “U-friendly” codon families, thereby achieving CAI values almost as large as those of dsDNA phages. This represents a new type of codon adaptation. PMID:24586046

  1. Intermittency in 200 GeV/nucleon S+S collisions

    SciTech Connect

    Jacobs, P.; Bloomer, M.A.

    1992-03-01

    We have studied one and two-dimensional intermittency in S+S collisions at 200 GeV/nucleon in a high statistics electronic measurement at the CERN SPS using pad-readout streamer tubes. We observe no intermittency signal beyond that produced by folding the Fritiof event generator with a detailed model of our detector. Even though the observed signal contains significant distortions due to experimental effects, we show that we are sensitive to intermittency in the collision.

  2. EBSD analysis of magnesium addition on inclusion formation in SS400 structural steel

    SciTech Connect

    Luo, Sin-Jie; Su, Yen-Hao Frank; Lu, Muh-Jung; Kuo, Jui-Chao

    2013-08-15

    In this study, the effect of magnesium addition on the inclusion formation in SS400 steel was investigated. The experimental specimens with and without Mg addition treatment were compared. The microstructure was observed using optical microscopy after etching with 3% nital. The morphology and chemical composition of the inclusions were analyzed via scanning electron microscopy and energy dispersive spectrometry. The lattice structure and orientation of the inclusions were identified by electron backscattering diffraction. The average size of inclusions in SS400 was between 0.67 and 0.75 μm, and between 0.65 and 0.68 μm in SS400 + Mg. The 2 ppm Mg addition resulted in the oxide formation change from Al{sub 2}O{sub 3} to MgO·Al{sub 2}O{sub 3} and in the inclusion formation change from Al{sub 2}O{sub 3}–MnS to MgO·Al{sub 2}O{sub 3}–MnS. Moreover, a simple-phase MnS with an average grain size of 1 μm to 2 μm was observed in rod-like, globular, and polyhedron forms. - Highlights: • The effect of magnesium addition was investigated for SS400 steel. • 2 ppm Mg addition changes the inclusion formation from Al2O3-MnS to MgO·Al2O3-MnS. • MnS observed in inclusions exhibits rod-like, globular, and polyhedron forms.

  3. 4D dynamic imaging of the eye using ultrahigh speed SS-OCT

    NASA Astrophysics Data System (ADS)

    Liu, Jonathan J.; Grulkowski, Ireneusz; Potsaid, Benjamin; Jayaraman, Vijaysekhar; Cable, Alex E.; Kraus, Martin F.; Hornegger, Joachim; Duker, Jay S.; Fujimoto, James G.

    2013-03-01

    Recent advances in swept-source / Fourier domain optical coherence tomography (SS-OCT) technology enable in vivo ultrahigh speed imaging, offering a promising technique for four-dimensional (4-D) imaging of the eye. Using an ultrahigh speed tunable vertical cavity surface emitting laser (VCSEL) light source based SS-OCT prototype system, we performed imaging of human eye dynamics in four different imaging modes: 1) Pupillary reaction to light at 200,000 axial scans per second and 9 μm resolution in tissue. 2) Anterior eye focusing dynamics at 100,000 axial scans per second and 9 μm resolution in tissue. 3) Tear film break up at 50,000 axial scans per second and 19 μm resolution in tissue. 4) Retinal blood flow at 800,000 axial scans per second and 12 μm resolution in tissue. The combination of tunable ultrahigh speeds and long coherence length of the VCSEL along with the outstanding roll-off performance of SS-OCT makes this technology an ideal tool for time-resolved volumetric imaging of the eye. Visualization and quantitative analysis of 4-D OCT data can potentially provide insight to functional and structural changes in the eye during disease progression. Ultrahigh speed imaging using SS-OCT promises to enable novel 4-D visualization of realtime dynamic processes of the human eye. Furthermore, this non-invasive imaging technology is a promising tool for research to characterize and understand a variety of visual functions.

  4. ON THE HUBBLE SPACE TELESCOPE TRIGONOMETRIC PARALLAX OF THE DWARF NOVA SS CYGNI

    SciTech Connect

    Nelan, Edmund P.; Bond, Howard E. E-mail: heb11@psu.edu

    2013-08-20

    SS Cygni is one of the brightest dwarf novae (DNe), and one of the best studied prototypes of the cataclysmic variables. Astrometric observations with the Fine Guidance Sensors (FGSs) on the Hubble Space Telescope (HST), published in 2004, gave an absolute trigonometric parallax of 6.06 {+-} 0.44 mas. However, recent very long baseline interferometry (VLBI), obtained during radio outbursts of SS Cyg, has yielded a significantly larger absolute parallax of 8.80 {+-} 0.12 mas, as well as a large difference in the direction of the proper motion (PM) compared to the HST result. The VLBI distance reduces the implied luminosity of SS Cyg by about a factor of two, giving good agreement with predictions based on accretion-disk theory in order to explain the observed DN outburst behavior. This discrepancy raises the possibility of significant systematic errors in FGS parallaxes and PMs. We have reanalyzed the archival HST/FGS data, including (1) a critical redetermination of the parallaxes of the background astrometric reference stars, (2) updated input values of the reference-star PMs, and (3) correction of the position measurements for color-dependent shifts. Our new analysis yields a PM of SS Cyg that agrees well with the VLBI motion, and an absolute parallax of 8.30 {+-} 0.41 mas, also statistically concordant with the VLBI result at the {approx}1.2 {sigma} level. Our results suggest that HST/FGS parallaxes are free of large systematic errors, when the data are reduced using high-quality input values for the astrometry of the reference stars, and when instrumental signatures are properly removed.

  5. Dramatic improvement of anti-SS-A/Ro-associated interstitial lung disease after immunosuppressive treatment.

    PubMed

    Paola, Caramaschi; Giuliana, Festi; Giovanni, Orsolini; Cristian, Caimmi; Domenico, Biasi

    2016-07-01

    The aim of the study was to report three patients affected by interstitial lung disease associated with positive anti-SS-A/Ro autoantibody who showed a dramatic improvement after immunosuppressive treatment. Medical charts were reviewed to obtain clinical data, laboratory parameters, lung function tests, high-resolution computed tomography results and response to immunosuppressive treatment. The three patients showed a clinical picture of a lung-dominant connective tissue disease characterized by a sudden onset with dyspnea, cough and subtle extrathoracic features together with positive anti-SS-A/Ro antibody and weak titer antinuclear antibodies. All three patients responded favorably to immunosuppressive therapy: Two cases were treated with a combination of corticosteroid and cyclophosphamide followed by mycophenolate mofetil; in the third patient, clinical benefit was obtained after rituximab was added to corticosteroid and immunosuppressant drug. In spite of an abrupt onset with significant lung function impairment, all three patients had a favorable clinical response to immunosuppressive therapy. This report may be useful in making therapeutic decisions in case of interstitial lung disease associated with anti-SS-A antibody.

  6. Defining the Content of an Online Sexual Health Intervention: The MenSS Website

    PubMed Central

    Gerressu, Makeda; Michie, Susan; Estcourt, Claudia; Anderson, Jane; Ang, Chee Siang; Murray, Elizabeth; Rait, Greta; Stephenson, Judith; Bailey, Julia V

    2015-01-01

    Background Health promotion and risk reduction are essential components of sexual health care. However, it can be difficult to prioritize these within busy clinical services. Digital interventions may provide a new method for supporting these. Objective The MenSS (Men’s Safer Sex) website is an interactive digital intervention developed by a multidisciplinary team, which aims to improve condom use in men who have sex with women (MSW). This paper describes the content of this intervention, and the rationale for it. Methods Content was informed by a literature review regarding men’s barriers to condom use, workshops with experts in sexual health and technology (N=16) and interviews with men in sexual health clinics (N=20). Data from these sources were analyzed thematically, and synthesized using the Behavior Change Wheel framework. Results The MenSS intervention is a website optimized for delivery via tablet computer within a clinic waiting room setting. Key targets identified were condom use skills, beliefs about pleasure and knowledge about risk. Content was developed using behavior change techniques, and interactive website features provided feedback tailored for individual users. Conclusions This paper provides a detailed description of an evidence-based interactive digital intervention for sexual health, including how behavior change techniques were translated into practice within the design of the MenSS website. Triangulation between a targeted literature review, expert workshops, and interviews with men ensured that a range of potential influences on condom use were captured. PMID:26142304

  7. Coordinated X-ray, ultraviolet and optical observations of AM Herculis, U Geminorum, and SS Cygni

    NASA Technical Reports Server (NTRS)

    Fabbiano, G.; Hartmann, L.; Raymond, J.; Branduardi-Raymont, G.; Matilsky, T.; Steiner, J.

    1981-01-01

    Simultaneous and quasi-simultaneous optical, UV and X-ray observations of the accreting degenerate dwarf stars AM Herculis, U Geminorum and SS Cygni are reported. The observations were obtained in March 1979, by instruments on board the Einstein Observatory and the IUE satellite, and optical properties were monitored on the ground. AM Her was found to be in a high state at the time of the observations, while SS Cyg and U Gem appeared to be in the optical low state. The presence of a strong UV excess is found in SS Cyg, U Gem and AM Her, which most likely originates from the boundary of the accretion disk in U Gem. The observed excess, with a blackbody component greater than 10 eV, is noted to be inconsistent with standard accretion disk and column models. It is suggested that nuclear burning at the surface of the white dwarf may be responsible for the excess UV flux in the three systems, with differences in spectral distributions resulting from different levels of magnetic field intensity and accretion rate.

  8. Bithermal Low-Cycle Fatigue Evaluation of Automotive Exhaust System Alloy SS409

    NASA Technical Reports Server (NTRS)

    Lu, Gui-Ying; Behling, Mike B.; Halford, Gary R.

    2000-01-01

    This investigation provides, for the first time, cyclic strainrange-controlled, thermomechanical fatigue results for the ferritic stainless steel alloy SS409. The alloy has seen extensive application for automotive exhaust system components. The data were generated to calibrate the Total Strain Version of the Strainrange Partitioning (TS-SRP) method for eventual application to the design and durability assessment of automotive exhaust systems. The thermomechanical cyclic lifetime and cyclic stress-strain constitutive behavior for alloy SS409 were measured using bithermal tests cycling between isothermal extremes of 400 and 800 C. Lives ranged up to 10,000 cycles to failure with hold-times of 0.33 to 2.0 minutes. The bithermal fatigue behavior is compared to isothermal, strain-controlled fatigue behavior at both 400 and 800 C. Thermomechanical cycling was found to have a profound detrimental influence on the fatigue failure resistance of SS409 compared to isothermal cycling. Supplementary bithermal cyclic stress-strain constitutive tests with hold-times ranging from 40 seconds up to 1.5 hours were conducted to calibrate the TS-SRP equation for extrapolation to longer lifetime predictions. Observed thermomechanical (bithermal) fatigue lives correlated well with lives calculated using the calibrated TS-SRP equations: 70% of the bithermal fatigue data fall within a factor of 1.2 of calculated life; 85% within a factor of 1.4; and 100% within a factor of 1.8.

  9. Mechanism of homologous recombination from the RecA-ssDNA/dsDNA structures

    SciTech Connect

    Chen, Zhucheng; Yang, Haijuan; Pavletich, Nikola P

    2008-07-08

    The RecA family of ATPases mediates homologous recombination, a reaction essential for maintaining genomic integrity and for generating genetic diversity. RecA, ATP and single-stranded DNA (ssDNA) form a helical filament that binds to double-stranded DNA (dsDNA), searches for homology, and then catalyses the exchange of the complementary strand, producing a new heteroduplex. Here we have solved the crystal structures of the Escherichia coli RecA-ssDNA and RecA-heteroduplex filaments. They show that ssDNA and ATP bind to RecA-RecA interfaces cooperatively, explaining the ATP dependency of DNA binding. The ATP {gamma}-phosphate is sensed across the RecA-RecA interface by two lysine residues that also stimulate ATP hydrolysis, providing a mechanism for DNA release. The DNA is underwound and stretched globally, but locally it adopts a B-DNA-like conformation that restricts the homology search to Watson-Crick-type base pairing. The complementary strand interacts primarily through base pairing, making heteroduplex formation strictly dependent on complementarity. The underwound, stretched filament conformation probably evolved to destabilize the donor duplex, freeing the complementary strand for homology sampling.

  10. DETECTION OF PERSISTENT GAMMA-RAY EMISSION TOWARD SS433/W50

    SciTech Connect

    Bordas, P.; Yang, R.; Kafexhiu, E.; Aharonian, F. E-mail: ryang@mpi-hd.mpg.de

    2015-07-01

    The microquasar SS433 features the most energetic jets known in our Galaxy. A large fraction of the jet kinetic power is delivered to the surrounding W50 nebula at the jet termination shock, from which high-energy emission and cosmic-ray production have been anticipated. Here, we report on the detection of a persistent gamma-ray signal obtained with the Fermi Large Area Telescope from an unidentified source that we tentatively associate, given its 99.9% confidence level position accuracy and the lack of any other high-energy emitter counterpart in the studied region, with SS433. The obtained spectral energy distribution displays a distinct maximum at ∼250 MeV and only extends up to ∼800 MeV. We discuss the possibility that the observed gamma-ray emission is produced through proton–proton collisions at the SS433/W50 interaction regions. If the same mechanism is operating in other baryon-loaded microquasar jets, their collective contribution could represent a significant fraction of the total galactic cosmic-ray flux at GeV energies.

  11. Pseudomonas aeruginosa uses T3SS to inhibit diabetic wound healing.

    PubMed

    Goldufsky, Josef; Wood, Stephen J; Jayaraman, Vijayakumar; Majdobeh, Omar; Chen, Lin; Qin, Shanshan; Zhang, Chunxiang; DiPietro, Luisa A; Shafikhani, Sasha H

    2015-01-01

    Diabetic foot ulcers are responsible for more hospitalizations than any other complication of diabetes. Bacterial infection is recognized as an important factor associated with impaired healing in diabetic ulcers. Pseudomonas aeruginosa is the most frequently detected Gram-negative pathogen in diabetic ulcers. P. aeruginosa infection has been shown to impair healing in diabetic wounds in a manner that correlates with its ability to form biofilm. While the majority of infections in diabetic ulcers are biofilm associated, 33% of infections are nonbiofilm in nature. P. aeruginosa is the most prevalent Gram-negative pathogen in all diabetic wound types, which suggests that the deleterious impact of P. aeruginosa on healing in diabetic wounds goes beyond its ability to form biofilm and likely involves other factors. The Type III Secretion System (T3SS) virulence structure is required for the pathogenesis of all P. aeruginosa clinical isolates, suggesting that it may also play a role in the inhibition of wound repair in diabetic skin ulcers. We evaluated the role of T3SS in mediating P. aeruginosa-induced tissue damage in the wounds of diabetic mice. Our data demonstrate that P. aeruginosa establishes a robust and persistent infection in diabetic wounds independent of its ability to form biofilm and causes severe wound damage in a manner that primarily depends on its T3SS.

  12. A novel, highly divergent ssDNA virus identified in Brazil infecting apple, pear and grapevine.

    PubMed

    Basso, Marcos Fernando; da Silva, José Cleydson Ferreira; Fajardo, Thor Vinícius Martins; Fontes, Elizabeth Pacheco Batista; Zerbini, Francisco Murilo

    2015-12-01

    Fruit trees of temperate and tropical climates are of great economical importance worldwide and several viruses have been reported affecting their productivity and longevity. Fruit trees of different Brazilian regions displaying virus-like symptoms were evaluated for infection by circular DNA viruses. Seventy-four fruit trees were sampled and a novel, highly divergent, monopartite circular ssDNA virus was cloned from apple, pear and grapevine trees. Forty-five complete viral genomes were sequenced, with a size of approx. 3.4 kb and organized into five ORFs. Deduced amino acid sequences showed identities in the range of 38% with unclassified circular ssDNA viruses, nanoviruses and alphasatellites (putative Replication-associated protein, Rep), and begomo-, curto- and mastreviruses (putative coat protein, CP, and movement protein, MP). A large intergenic region contains a short palindromic sequence capable of forming a hairpin-like structure with the loop sequence TAGTATTAC, identical to the conserved nonanucleotide of circoviruses, nanoviruses and alphasatellites. Recombination events were not detected and phylogenetic analysis showed a relationship with circo-, nano- and geminiviruses. PCR confirmed the presence of this novel ssDNA virus in field plants. Infectivity tests using the cloned viral genome confirmed its ability to infect apple and pear tree seedlings, but not Nicotiana benthamiana. The name "Temperate fruit decay-associated virus" (TFDaV) is proposed for this novel virus.

  13. A novel, highly divergent ssDNA virus identified in Brazil infecting apple, pear and grapevine.

    PubMed

    Basso, Marcos Fernando; da Silva, José Cleydson Ferreira; Fajardo, Thor Vinícius Martins; Fontes, Elizabeth Pacheco Batista; Zerbini, Francisco Murilo

    2015-12-01

    Fruit trees of temperate and tropical climates are of great economical importance worldwide and several viruses have been reported affecting their productivity and longevity. Fruit trees of different Brazilian regions displaying virus-like symptoms were evaluated for infection by circular DNA viruses. Seventy-four fruit trees were sampled and a novel, highly divergent, monopartite circular ssDNA virus was cloned from apple, pear and grapevine trees. Forty-five complete viral genomes were sequenced, with a size of approx. 3.4 kb and organized into five ORFs. Deduced amino acid sequences showed identities in the range of 38% with unclassified circular ssDNA viruses, nanoviruses and alphasatellites (putative Replication-associated protein, Rep), and begomo-, curto- and mastreviruses (putative coat protein, CP, and movement protein, MP). A large intergenic region contains a short palindromic sequence capable of forming a hairpin-like structure with the loop sequence TAGTATTAC, identical to the conserved nonanucleotide of circoviruses, nanoviruses and alphasatellites. Recombination events were not detected and phylogenetic analysis showed a relationship with circo-, nano- and geminiviruses. PCR confirmed the presence of this novel ssDNA virus in field plants. Infectivity tests using the cloned viral genome confirmed its ability to infect apple and pear tree seedlings, but not Nicotiana benthamiana. The name "Temperate fruit decay-associated virus" (TFDaV) is proposed for this novel virus. PMID:26186890

  14. Synonymous Mutations Reduce Genome Compactness in Icosahedral ssRNA Viruses

    PubMed Central

    Tubiana, Luca; Božič, Anže Lošdorfer; Micheletti, Cristian; Podgornik, Rudolf

    2015-01-01

    Recent studies have shown that single-stranded (ss) viral RNAs fold into more compact structures than random RNA sequences with similar chemical composition and identical length. Based on this comparison, it has been suggested that wild-type viral RNA may have evolved to be atypically compact so as to aid its encapsidation and assist the viral assembly process. To further explore the compactness selection hypothesis, we systematically compare the predicted sizes of >100 wild-type viral sequences with those of their mutants, which are evolved in silico and subject to a number of known evolutionary constraints. In particular, we enforce mutation synonynimity, preserve the codon-bias, and leave untranslated regions intact. It is found that progressive accumulation of these restricted mutations still suffices to completely erase the characteristic compactness imprint of the viral RNA genomes, making them in this respect physically indistinguishable from randomly shuffled RNAs. This shows that maintaining the physical compactness of the genome is indeed a primary factor among ssRNA viruses’ evolutionary constraints, contributing also to the evidence that synonymous mutations in viral ssRNA genomes are not strictly neutral. PMID:25564866

  15. A comparative toxicity evaluation of Escherichia coli-targeted ssDNA and chlorine in HepG2 cells.

    PubMed

    Kaushik, Rajni; Balasubramanian, Rajasekhar

    2014-01-01

    In this study, a comparative assessment of the effectiveness of ssDNA and chlorine as disinfectants for treating water contaminated with Escherichia coli (E. coli) was investigated on the basis of cytotoxicity and genotoxicity. The gene targets addressed for the ssDNA based inhibition method were marA (multiple antibiotic resistance) and groL (essential gene Hsp60) in E. coli. Based on the maximum log reduction in E. coli cell numbers when compared to no ssDNA control, groL-1 was chosen as the optimized ssDNA for gene silencing-based inactivation. For toxicity assessment, HepG2 cells were exposed to extracts corresponding to concentrations of 0.2, 1, 5, 25 and 50 mL water/mL medium of chlorine doped water and 1, 10, 100, 300 nM of ssDNA. Compared with ssDNA, HepG2 cells exposed to extracts of chlorine doped water for 24 h showed higher cytotoxicity, caspase 3/7 levels, DNA damage, micronuclei frequency, and decreased cell viability. Water doped with chlorine was found to be more toxic than that by ssDNA when exposed to HepG2 cells. The results of this study provide a scientific basis for comparative evaluation of new and conventional disinfection methods by taking into consideration the outcome of cytotoxicity and genotoxicity assessments.

  16. Observation of white spot lesions using swept source optical coherence tomography (SS-OCT): in vitro and in vivo study.

    PubMed

    Ibusuki, Takahide; Kitasako, Yuichi; Sadr, Alireza; Shimada, Yasushi; Sumi, Yasunori; Tagami, Junji

    2015-01-01

    This study aimed to assess swept source optical coherence tomography (SS-OCT) for in vitro and in vivo detection of enamel white spot lesion (WSL). WSLs without surface breakdown on 33 extracted human posterior teeth were non-invasively scanned using SSOCT. The teeth were then cross-sectioned and imaged under confocal laser scanning microscope (CLSM) and light microscopy (LM). SS-OCT cross-sectional images were compared with CLSM and LM. WSL shapes in SS-OCT images closely corresponded to those of LM. There were significant correlations (p<0.001) in WSLs depth between SS-OCT and LM (r=0.92), SS-OCT and CLSM (r=0.80) and CLSM and LM (r=0.85). Six WSLs were also evaluated clinically using SS-OCT; clear in-depth images of these natural WSLs were obtained in vivo. SS-OCT appears to be an effective tool for observation of the internal structure of WSLs, enabling quantitative assessment of WSL depth. Such data can be considered in the clinical management of WSLs.

  17. Salmonella Typhimurium utilizes a T6SS-mediated antibacterial weapon to establish in the host gut.

    PubMed

    Sana, Thibault G; Flaugnatti, Nicolas; Lugo, Kyler A; Lam, Lilian H; Jacobson, Amanda; Baylot, Virginie; Durand, Eric; Journet, Laure; Cascales, Eric; Monack, Denise M

    2016-08-23

    The mammalian gastrointestinal tract is colonized by a high-density polymicrobial community where bacteria compete for niches and resources. One key competition strategy includes cell contact-dependent mechanisms of interbacterial antagonism, such as the type VI secretion system (T6SS), a multiprotein needle-like apparatus that injects effector proteins into prokaryotic and/or eukaryotic target cells. However, the contribution of T6SS antibacterial activity during pathogen invasion of the gut has not been demonstrated. We report that successful establishment in the gut by the enteropathogenic bacterium Salmonella enterica serovar Typhimurium requires a T6SS encoded within Salmonella pathogenicity island-6 (SPI-6). In an in vitro setting, we demonstrate that bile salts increase SPI-6 antibacterial activity and that S Typhimurium kills commensal bacteria in a T6SS-dependent manner. Furthermore, we provide evidence that one of the two T6SS nanotube subunits, Hcp1, is required for killing Klebsiella oxytoca in vitro and that this activity is mediated by the specific interaction of Hcp1 with the antibacterial amidase Tae4. Finally, we show that K. oxytoca is killed in the host gut in an Hcp1-dependent manner and that the T6SS antibacterial activity is essential for Salmonella to establish infection within the host gut. Our findings provide an example of pathogen T6SS-dependent killing of commensal bacteria as a mechanism to successfully colonize the host gut. PMID:27503894

  18. Salmonella Typhimurium utilizes a T6SS-mediated antibacterial weapon to establish in the host gut

    PubMed Central

    Flaugnatti, Nicolas; Lugo, Kyler A.; Lam, Lilian H.; Jacobson, Amanda; Baylot, Virginie; Durand, Eric; Journet, Laure; Cascales, Eric; Monack, Denise M.

    2016-01-01

    The mammalian gastrointestinal tract is colonized by a high-density polymicrobial community where bacteria compete for niches and resources. One key competition strategy includes cell contact-dependent mechanisms of interbacterial antagonism, such as the type VI secretion system (T6SS), a multiprotein needle-like apparatus that injects effector proteins into prokaryotic and/or eukaryotic target cells. However, the contribution of T6SS antibacterial activity during pathogen invasion of the gut has not been demonstrated. We report that successful establishment in the gut by the enteropathogenic bacterium Salmonella enterica serovar Typhimurium requires a T6SS encoded within Salmonella pathogenicity island-6 (SPI-6). In an in vitro setting, we demonstrate that bile salts increase SPI-6 antibacterial activity and that S. Typhimurium kills commensal bacteria in a T6SS-dependent manner. Furthermore, we provide evidence that one of the two T6SS nanotube subunits, Hcp1, is required for killing Klebsiella oxytoca in vitro and that this activity is mediated by the specific interaction of Hcp1 with the antibacterial amidase Tae4. Finally, we show that K. oxytoca is killed in the host gut in an Hcp1-dependent manner and that the T6SS antibacterial activity is essential for Salmonella to establish infection within the host gut. Our findings provide an example of pathogen T6SS-dependent killing of commensal bacteria as a mechanism to successfully colonize the host gut. PMID:27503894

  19. The pH of antiseptic cleansers

    PubMed Central

    Kulthanan, Kanokvalai; Varothai, Supenya; Nuchkull, Piyavadee

    2014-01-01

    Background Daily bathing with antiseptic cleansers are proposed by some physicians as an adjunctive management of atopic dermatitis (AD). As atopic skin is sensitive, selection of cleansing products becomes a topic of concern. Objective Our purpose is to evaluate the pH of various antiseptic body cleansers to give an overview for recommendation to patients with AD. Methods Commonly bar and liquid cleansers consisted of antiseptic agents were measured for pH using pH meter and pH-indicator strips. For comparison, mild cleansers and general body cleansers were also measured. Results All cleansing bars had pH 9.8-11.3 except syndet bar that had neutral pH. For liquid cleansers, three cleansing agents had pH close to pH of normal skin, one of antiseptic cleansers, one of mild cleansers and another one of general cleansers. The rest of antiseptic cleansers had pH 8.9-9.6 while mild cleansers had pH 6.9-7.5. Syndet liquid had pH 7 and general liquid cleansers had pH 9.6. Conclusion The pH of cleanser depends on composition of that cleanser. Adding antiseptic agents are not the only factor determining variation of pH. Moreover, benefit of antiseptic properties should be considered especially in cases of infected skin lesions in the selection of proper cleansers for patients with AD. PMID:24527408

  20. 43 CFR 17.4 - Assurances required.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... the provision of similar services or benefits, or for as long as the recipient retains ownership or... Federal Government, the instrument effecting or recording the transfer shall contain a covenant running... provision of similar services or benefits. Where no transfer of property or interest therein from...

  1. Acid loading test (pH)

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003615.htm Acid loading test (pH) To use the sharing features on this page, please enable JavaScript. The acid loading test (pH) measures the ability of the ...

  2. The Greek Database of Seismogenic Sources (GreDaSS): the new version.

    NASA Astrophysics Data System (ADS)

    Caputo, Riccardo; Pavlides, Spyros; GreDaSS Working Group

    2014-05-01

    The Greek Database of Seismogenic Sources (GreDaSS) is a repository of geological, tectonic and active fault data for the Greek territory and its surroundings including sectors of western Anatolia, southern Bulgaria, FYR of Macedonia and Albania. The principal aim of this international project is to create a homogenized framework of all data relevant to the seismotectonics, and especially the seismic hazard assessment, of Greece and its surroundings as well as a common research platform for performing seismic hazard analyses, modelling and scenarios from specific seismogenic structures. GreDaSS represents an on-going project based on the results of decades of investigations by the GreDaSS Working Group* and by numerous other researchers working on the active tectonics of the broader Aegean Region. Members of the WG have contributed in several national and European projects like FAUST (Faults as a seismological tool, 1998-2000) and SHARE (Seismic Hazard and Armonization in Europe, 2009-2012). The database is continuously updated by the WG, with the aim of improving its completeness in terms of seismogenic sources analysed and included, but also of enriching and better defining all parametric and ancillary information on each source. Preliminary and partial versions of GreDaSS have been already presented at previous congresses (Pavlides et al., 2010; Caputo et al., 2012; Sboras et al., 2013), but at next EGU the whole area and the most recent version of the database will be displayed. *) the principal scientific contributors belonging to the GreDaSS WG are: Sboras. S., Chatzipetros A., Koukouvelas I., Michailidou A., Valkaniotis S., Tarabusi G. Caputo R., Chatzipetros A., Pavlides S. and Sboras S. (2012): Ann. Geophysics, 55(5), 859-894, doi: 10.4401/ag-5168 Pavlides S., Caputo R., Sboras S., Chatzipetros A., Papathanasiou G. & Valkaniotis S. (2010): Bull. Geol. Soc. Greece, 43(1), 486-494 Sboras S., Pavlides S., Caputo R., Chatzipetros A., Michailidou A

  3. Capillary zone electrophoresis in non-aqueous solutions: pH of the background electrolyte.

    PubMed

    Porras, Simo P; Kenndler, Ernst

    2004-05-28

    Although the establishment of a pH scale and the determination of the pH in water is not problematic, it is not a straightforward task in non-aqueous solvents. As capillary zone electrophoresis (CZE) in organic solvents has gained increasing interest, it seems to be valuable to re-discuss the concept of the pH in such media, especially pointing to those aspects, which make pH measurement uncertain in non-aqueous solvents. In this review, the relevant aspects when dealing with primary standard (PS) and secondary standard (SS) as recommended by the International Union of Pure and Applied Chemistry (IUPAC), and the usage of the operational pH are discussed with special emphasis to non-aqueous solvents. Here, different liquid junction potentials, incomplete dissociation of the electrolytes (especially in solvents with low or moderate relative permittivity) and the occurrence of homo- and heteroconjugation must be taken into account. Problems arising in capillary zone electrophoresis practice are addressed, e.g. when the background electrolyte (BGE) consists of organic solvents, but the measuring electrode (normally the glass electrode) is calibrated with aqueous buffers, and the liquid junction potentials between the solvents do not cancel each other. The alternative concept of establishing a certain pH is described, using mixtures of reference acids or bases with known pKa in the organic solvent, and their respective salts, at a certain concentration ratio, relying to the Henderson-Hasselbalch equation. Special discussion is directed to those organic solvents most common in capillary zone electrophoresis, methanol (MeOH) and acetonitrile (ACN), but other solvents are included as well. The potential significance of small amounts of water present in the organic solvent on changes in pKa values, and thus on the pH of the buffering components is pointed out. PMID:15214682

  4. KiSS-1-mediated suppression of the invasive ability of human pancreatic carcinoma cells is not dependent on the level of KiSS-1 receptor GPR54

    PubMed Central

    WANG, CHUN-HUI; QIAO, CHONG; WANG, RUO-CHEN; ZHOU, WEN-PING

    2016-01-01

    The onset of local invasion and lymphatic metastasis in pancreatic cancer limits survival following surgical intervention and additional therapies. Reduced expression of KiSS-1 in pancreatic cancer is associated with cancer metastasis. Previous studies have indicated that kisspeptin, the KiSS-1 peptide, is able to bind to its receptor-GPR54 (hOT7T175) and suppress the migration of PANC-1 pancreatic cancer cells. Whether the metastatic suppression of KiSS-1 is dependent on the levels of GPR54 in pancreatic cancer cell lines remains unclear. Human BxPC-3 pancreatic carcinoma cells are highly differentiated without exhibiting metastasis, however PANC-1 pancreatic carcinoma cells are poorly differentiated and exhibit local and lymph node metastasis. Compared with primary cultured trophoblasts, BxPc-3 and PANC-1 cells were observed to express low levels of KiSS-1 mRNA and protein, measured using reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. However, greater mRNA and protein expression levels of GPR54 were observed in PANC-1 cells compared with BxPc-3 cells. An MTT assay was used to investigate the effect of KiSS-1 on BxPc-3 and PANC-1 cell proliferation. There were no significant differences in proliferation following transfection with KiSS-1 in BxPc-3 and PANC-1 cells compared with the controls (P>0.05). A Transwell assay with chambers coated with Matrigel was used to evaluate the in vitro invasive ability of BxPc-3 and PANC-1 cells, with the invasion index of BxPc-3 and PANC-1 cells significantly reduced following 48 h of KiSS-1 overexpression (P<0.05). The mRNA and protein expression levels of KiSS-1 were significantly increased in BxPc-3 and PANC-1 cells 48 h subsequent to transfection with KiSS-1 (P<0.05), while GPR54 expression was not altered (P>0.05). KiSS-1 is a metastasis suppressor gene of pancreatic cancer, and this suppression is not dependent on the expression levels of GPR54. Therefore, KiSS-1 is

  5. 75 FR 51531 - Proposed Collection; Comment Request for Forms 941, 941-PR, 941-SS, 941-X, 941-X(PR), Schedule B...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-20

    ... Internal Revenue Service Proposed Collection; Comment Request for Forms 941, 941-PR, 941- SS, 941-X, 941-X... Seguro Social Y Al Seguro Medicare), 941-SS (Employer's Quarterly Federal Tax Return-American Samoa, Guam... Number: 1545-0029. Form Numbers: 941, 941-PR, 941-SS, 941-X, 941-X(PR), Schedule R (Form 941), Schedule...

  6. 78 FR 47056 - Proposed Collection; Comment Request for Forms 941, 941-PR, 941-SS, 941-X, 941-X(PR), Schedule B...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-02

    ... Internal Revenue Service Proposed Collection; Comment Request for Forms 941, 941-PR, 941- SS, 941-X, 941-X... Federal Tax Return), 941-PR, 941-SS (Employer's Quarterly Federal Tax Return-American Samoa, Guam, the... Quarterly Federal Tax Return. OMB Number: 1545-0029. Form Numbers: 941, 941-PR, 941-SS, 941-X,...

  7. Binding of antibodies to the extractable nuclear antigens SS-A/Ro and SS-B/La is induced on the surface of human keratinocytes by ultraviolet light (UVL): Implications for the pathogenesis of photosensitive cutaneous lupus

    SciTech Connect

    Furukawa, F.; Kashihara-Sawami, M.; Lyons, M.B.; Norris, D.A. )

    1990-01-01

    Autoantibodies to the non-histone nucleoprotein antigens SS-A/Ro, SS-B/La, and RNP are highly associated with photosensitive cutaneous lupus erythematosus (LE). In order to better understand the potential mechanisms of ultraviolet (UV) light on photosensitivity in patients with cutaneous LE, we designed immunopathologic in vitro and in vivo experiments to evaluate the effects of UV on the binding of such autoantibodies to the surface of human keratinocytes, one major target of immunologic damage in photosensitive LE. Short-term 2% paraformaldehyde fixation of suspensions of cultured human keratinocytes previously incubated with monospecific antiserum probes enabled the detection of ENA expression on the cell surface by flow-cytometry analysis. UVB light (280-320 nm) induced the binding of monospecific antibody probes for SS-A/Ro and SS-B/La on keratinocytes in a dose-dependent pattern with maximal induction observed at the dose of 200 mJ/cm2 UVB. Binding of SS-A/Ro, SS-B/La, and RNP antibody was augmented strongly, but binding of anti-Sm was very weak. In contrast, UVA (320-400 nm) light had no effect on the induction of binding of these antibody probes. Identical results were seen by standard immunofluorescence techniques. Hydroxyurea-treated keratinocytes showed similar induction of those antigens by UVB irradiation, which suggested that ENA expression on cultured keratinocytes by UVB were cell-cycle independent. Tunicamycin, an inhibitor of glycosylation of proteins, reduced UVB light effect on the SS-A/Ro and SS-B/La antigen's expression. These in vitro FACS analyses revealed that ENA augmentation on the keratinocyte cell surface was dose dependent, UVB dependent, glycosylation dependent, and cell-cycle independent. In vivo ENA augmentation on the keratinocyte surface was examined in suction blister epidermal roofs.

  8. Mechanical properties of Cu sbnd Cr sbnd Zr alloy and SS316 joints fabricated by friction welding method

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Kunihiko; Kawamura, Hiroshi

    1996-10-01

    Copper alloys with high-strength and high-conductivity are being considered for several magnetic fusion energy applications such as the first wall in high power-density devices, resistive magnetic coils, and high-heat flux components. For example, the stainless steel is a structural material while Cu-alloy acts as a heat sink material for the surface heat flux in the first wall. Therefore, development of reliable joints between Cu-alloys and stainless steel (SS316) is required. In the present work, joining tests on Cu—1%Cr—1%Zr/SS316 by friction welding were performed, and optimum fabricating conditions of the Cu-alloy/SS316 joint were determined. Additionally, the characteristics of tensile strength, hardness, metallographical observation and SEM/EPMA analyses on Cu—1%Cr—1%Zr/SS316 fabricated by friction welding were evaluated.

  9. [Comparison of tests for SS-A/Ro, Ro52 and Ro60 in predicting congenital heart block].

    PubMed

    Miyano, Akira; Nakayama, Masahiro; Waguri, Masako; Nakanishi, Isao

    2014-04-01

    Neonatal lupus erythematosus (NLE) is a rare syndrome caused by the transplacental passage of maternal autoantibodies. Anti SS-A antibodies of a mother with Sjögren syndrome are associated with congenital heart block (CHB) in the newborns with NLE. The purpose of this study was to investigate the utility of maternal antibody titers for SS-A, Ro52 and Ro60 in mothers of newborns with CHB. The study involved a total of 304 cases, 25 from mothers of newborns with CHB, 104 from mothers of newborns without and 175 from mothers suspected to have connective tissue diseases. All sera were tested with the EliA SS-A, EliA Ro52, EliA Ro60, MESACUP Ro52 and MESACUP Ro60. The concordance rate of Ro52 assays was 93.4%, whereas Ro60 assays showed a lower concordance rate (74.7%). The areas under the curve (AUC) of the EliA assays were higher than those of the MESACUP assays. The optimal cut-off values for EliA SS-A/Ro and EliA Ro60 as derived from the ROC analysis were 2027 U/mL and 2446 U/mL, respectively. The sensitivity and specificity for EliA SS-A using optimal cut-off values were 96.0% and 92.3%, respectively. A titer of 90% positive predictive value for EliA SS-A was reached at a cut-off of 9897.1 U/mL, corresponding to sensitivity and specificity values of 36.0% and 100%, respectively. In conclusion, the optimal cut-off value for EliA SS-A is likely to be useful for application in clinical practice for the EliA SS-A measurements in mothers to evaluate the risk of NLE for their newborns.

  10. Dahl SS rats demonstrate enhanced aortic perivascular adipose tissue-mediated buffering of vasoconstriction through activation of NOS in the endothelium.

    PubMed

    Spradley, Frank T; Ho, Dao H; Pollock, Jennifer S

    2016-02-01

    Perivascular adipose tissue (PVAT) mediates buffering of vasoconstriction through activation of endothelium-derived factors. We hypothesized that the PVAT of Dahl salt-sensitive (Dahl SS) rats has reduced ability to buffer vasoconstriction. Vascular reactivity experiments were performed on aortic rings with PVAT intact (+PVAT) or removed (-PVAT), and endothelium intact (+ENDO) or removed (-ENDO) from Dahl SS rats and control SS.13(BN) rats (Dahl SS rats that have had chromosome 13 completely replaced with that of the Brown Norway rat, rendering this strain insensitive to high-salt or high-fat diet-induced hypertension). Endothelial dysfunction, assessed by ACh-mediated vasorelaxation, was confirmed in aortic rings of Dahl SS rats. The +PVAT+ENDO aortic rings had indistinguishable phenylephrine-induced vasoconstriction between genotypes. In both strains, removal of PVAT significantly enhanced vasoconstriction. Dahl SS rat -PVAT+ENDO aortic rings displayed exaggerated vasoconstriction to phenylephrine vs. SS.13(BN) rats, indicating that PVAT-mediated buffering of vasoconstriction was greater in Dahl SS rats. Removal of both the ENDO and PVAT restored vasoconstriction in both strains. The nitric oxide synthase (NOS) inhibitor, N(ω)-nitro-L-arginine methyl ester (L-NAME), produced a similar effect as that seen with -ENDO. These data indicate that the function of the PVAT to activate endothelium-derived NOS is enhanced in Dahl SS compared with SS.13(BN) rats and, most likely, occurs through a pathway that is distinct from ACh-mediated activation of NOS. PVAT weight and total PVAT leptin levels were greater in Dahl SS rats. Leptin induced a significantly decreased vasoconstriction in -PVAT+ENDO aortic rings from Dahl SS rats, but not SS.13(BN) rats. In contrast to our initial hypothesis, PVAT in Dahl SS rats buffers vasoconstriction by activating endothelial NOS via mechanisms that may include the involvement of leptin. Thus, the PVAT serves a vasoprotective role in

  11. Dahl SS rats demonstrate enhanced aortic perivascular adipose tissue-mediated buffering of vasoconstriction through activation of NOS in the endothelium.

    PubMed

    Spradley, Frank T; Ho, Dao H; Pollock, Jennifer S

    2016-02-01

    Perivascular adipose tissue (PVAT) mediates buffering of vasoconstriction through activation of endothelium-derived factors. We hypothesized that the PVAT of Dahl salt-sensitive (Dahl SS) rats has reduced ability to buffer vasoconstriction. Vascular reactivity experiments were performed on aortic rings with PVAT intact (+PVAT) or removed (-PVAT), and endothelium intact (+ENDO) or removed (-ENDO) from Dahl SS rats and control SS.13(BN) rats (Dahl SS rats that have had chromosome 13 completely replaced with that of the Brown Norway rat, rendering this strain insensitive to high-salt or high-fat diet-induced hypertension). Endothelial dysfunction, assessed by ACh-mediated vasorelaxation, was confirmed in aortic rings of Dahl SS rats. The +PVAT+ENDO aortic rings had indistinguishable phenylephrine-induced vasoconstriction between genotypes. In both strains, removal of PVAT significantly enhanced vasoconstriction. Dahl SS rat -PVAT+ENDO aortic rings displayed exaggerated vasoconstriction to phenylephrine vs. SS.13(BN) rats, indicating that PVAT-mediated buffering of vasoconstriction was greater in Dahl SS rats. Removal of both the ENDO and PVAT restored vasoconstriction in both strains. The nitric oxide synthase (NOS) inhibitor, N(ω)-nitro-L-arginine methyl ester (L-NAME), produced a similar effect as that seen with -ENDO. These data indicate that the function of the PVAT to activate endothelium-derived NOS is enhanced in Dahl SS compared with SS.13(BN) rats and, most likely, occurs through a pathway that is distinct from ACh-mediated activation of NOS. PVAT weight and total PVAT leptin levels were greater in Dahl SS rats. Leptin induced a significantly decreased vasoconstriction in -PVAT+ENDO aortic rings from Dahl SS rats, but not SS.13(BN) rats. In contrast to our initial hypothesis, PVAT in Dahl SS rats buffers vasoconstriction by activating endothelial NOS via mechanisms that may include the involvement of leptin. Thus, the PVAT serves a vasoprotective role in

  12. The simultaneous production of sphingan Ss and poly(R-3-hydroxybutyrate) in Sphingomonas sanxanigenens NX02.

    PubMed

    Wu, Mengmeng; Li, Guoqiang; Huang, Haidong; Chen, Sibin; Luo, Ying; Zhang, Wenwen; Li, Keran; Zhou, Jiefang; Ma, Ting

    2016-01-01

    Sphingans and poly(R-3-hydroxybutyrate) (PHB) are both widely used biopolymers produced by bacteria. In the batch fermentation of Sphingomonas sanxanigenens NX02 in a 5L fermenter using glucose as carbon source, ivory colored sphingan Ss production was a growth-associated process with a maximum purified production of 14.88 ± 0.83 g/L, while 6.08 ± 0.23 g/L PHB was simultaneously produced. Sphingan Ss and PHB were separated by a simple dilution, heating and centrifugation or filtration process, and sphingan Ss can be cost-effectively extracted using a small amount of acid rather than multi-fold volumes of alcohols. From ultrathin sections of S. sanxanigenens NX02, we found that the interior space of the cells was filled with PHB granules, and the outside was surrounded by abundant Ss. The purified sphingan Ss can be used as an excellent gelling and emulsifying agent in biotechnology applications such as food, personal care and production processes. Proposed pathways of Ss and PHB biosynthesis from glucose are also presented.

  13. Mycophenolate mofetil prevents high-fat diet-induced hypertension and renal glomerular injury in Dahl SS rats.

    PubMed

    Spradley, Frank T; De Miguel, Carmen; Hobbs, Janet; Pollock, David M; Pollock, Jennifer S

    2013-11-01

    We designed experiments to test the hypothesis that Dahl salt-sensitive (SS) rats are sensitive to high-fat diet (HFD)-induced hypertension and renal injury via an inflammatory mechanism. Twelve-week-old Dahl SS rats were maintained on a normal diet (ND; 14% fat), HFD (59% fat), or HFD supplemented with the lymphocyte immunosuppressive agent, mycophenolate mofetil (HFD + MMF; 30 mg/kg/day orally in diet), for a period of 4 weeks. Mean arterial pressure (MAP), metabolic parameters, T lymphocyte (CD3(+)) localization, and renal structural damage were assessed during the studies. Four weeks of HFD significantly elevated MAP and visceral adiposity without changing circulating levels of lipids or adipokines. Immunohistochemical analysis demonstrated that SS rats on HFD had significantly greater numbers of CD3(+) cells in renal glomerular and medullary areas compared to ND SS rats. Additionally, HFD led to increased glomerular injury, but did not alter renal medullary injury. Chronic MMF treatment in HFD-fed Dahl SS rats reduced MAP, visceral adiposity, infiltration of CD3(+) cells in the glomerulus, as well as glomerular injury. However, MMF treatment did not alter HFD-induced infiltration of CD3(+) cells in the renal medulla. In conclusion, Dahl SS rats are sensitized to HFD-induced hypertension and renal glomerular injury via infiltration of T lymphocytes.

  14. Noninvasive cross-sectional imaging of proximal caries using swept-source optical coherence tomography (SS-OCT) in vivo.

    PubMed

    Shimada, Yasushi; Nakagawa, Hisaichi; Sadr, Alireza; Wada, Ikumi; Nakajima, Masatoshi; Nikaido, Toru; Otsuki, Masayuki; Tagami, Junji; Sumi, Yasunori

    2014-07-01

    The aim of this study was to determine the diagnostic accuracy of swept-source optical coherent tomography (SS-OCT) in detecting and estimating the depth of proximal caries in posterior teeth in vivo. SS-OCT images and bitewing radiographs were obtained from 86 proximal surfaces of 53 patients. Six examiners scored the locations according to a caries lesion depth scale (0-4) using SS-OCT and the radiographs. The results were compared with clinical observations obtained after the treatment. SS-OCT could detect the presence of proximal caries in tomograms that were synthesized based on the backscatter signal obtained from the proximal carious lesion through occlusal enamel. SS-OCT showed significantly higher sensitivity and larger area under the receiver operating characteristic curve than radiographs for the detection of cavitated enamel lesions and dentin caries (Student's t -test, p < 0.05). SS-OCT appears to be a more reliable and accurate method than bitewing radiographs for the detection and estimation of the depth of proximal lesions in the clinical environment.

  15. The SsDREB Transcription Factor from the Succulent Halophyte Suaeda salsa Enhances Abiotic Stress Tolerance in Transgenic Tobacco

    PubMed Central

    Zhang, Xu; Liu, Xiaoxue; Wu, Lei; Yu, Guihong; Wang, Xiue; Ma, Hongxiang

    2015-01-01

    Dehydration-responsive element-binding (DREB) transcription factor (TF) plays a key role for abiotic stress tolerance in plants. In this study, a novel cDNA encoding DREB transcription factor, designated SsDREB, was isolated from succulent halophyte Suaeda salsa. This protein was classified in the A-6 group of DREB subfamily based on multiple sequence alignments and phylogenetic characterization. Yeast one-hybrid assays showed that SsDREB protein specifically binds to the DRE sequence and could activate the expression of reporter genes in yeast, suggesting that the SsDREB protein was a CBF/DREB transcription factor. Real-time RT-PCR showed that SsDREB was significantly induced under salinity and drought stress. Overexpression of SsDREB cDNA in transgenic tobacco plants exhibited an improved salt and drought stress tolerance in comparison to the nontransformed controls. The transgenic plants revealed better growth, higher chlorophyll content, and net photosynthesis rate, as well as higher level of proline and soluble sugars. The semiquantitative PCR of transgenics showed higher expression of stress-responsive genes. These data suggest that the SsDREB transcription factor is involved in the regulation of salt stress tolerance in tobacco by the activation of different downstream gene expression. PMID:26504772

  16. ssODN-mediated knock-in with CRISPR-Cas for large genomic regions in zygotes.

    PubMed

    Yoshimi, Kazuto; Kunihiro, Yayoi; Kaneko, Takehito; Nagahora, Hitoshi; Voigt, Birger; Mashimo, Tomoji

    2016-01-01

    The CRISPR-Cas system is a powerful tool for generating genetically modified animals; however, targeted knock-in (KI) via homologous recombination remains difficult in zygotes. Here we show efficient gene KI in rats by combining CRISPR-Cas with single-stranded oligodeoxynucleotides (ssODNs). First, a 1-kb ssODN co-injected with guide RNA (gRNA) and Cas9 messenger RNA produce GFP-KI at the rat Thy1 locus. Then, two gRNAs with two 80-bp ssODNs direct efficient integration of a 5.5-kb CAG-GFP vector into the Rosa26 locus via ssODN-mediated end joining. This protocol also achieves KI of a 200-kb BAC containing the human SIRPA locus, concomitantly knocking out the rat Sirpa gene. Finally, three gRNAs and two ssODNs replace 58-kb of the rat Cyp2d cluster with a 6.2-kb human CYP2D6 gene. These ssODN-mediated KI protocols can be applied to any target site with any donor vector without the need to construct homology arms, thus simplifying genome engineering in living organisms. PMID:26786405

  17. Imaging and energetics of single SSB-ssDNA molecules reveal intramolecular condensation and insight into RecOR function.

    PubMed

    Bell, Jason C; Liu, Bian; Kowalczykowski, Stephen C

    2015-01-01

    Escherichia coli single-stranded DNA (ssDNA) binding protein (SSB) is the defining bacterial member of ssDNA binding proteins essential for DNA maintenance. SSB binds ssDNA with a variable footprint of ∼30-70 nucleotides, reflecting partial or full wrapping of ssDNA around a tetramer of SSB. We directly imaged single molecules of SSB-coated ssDNA using total internal reflection fluorescence (TIRF) microscopy and observed intramolecular condensation of nucleoprotein complexes exceeding expectations based on simple wrapping transitions. We further examined this unexpected property by single-molecule force spectroscopy using magnetic tweezers. In conditions favoring complete wrapping, SSB engages in long-range reversible intramolecular interactions resulting in condensation of the SSB-ssDNA complex. RecO and RecOR, which interact with SSB, further condensed the complex. Our data support the idea that RecOR--and possibly other SSB-interacting proteins-function(s) in part to alter long-range, macroscopic interactions between or throughout nucleoprotein complexes by microscopically altering wrapping and bridging distant sites. PMID:26381353

  18. Imaging and energetics of single SSB-ssDNA molecules reveal intramolecular condensation and insight into RecOR function

    PubMed Central

    Bell, Jason C; Liu, Bian; Kowalczykowski, Stephen C

    2015-01-01

    Escherichia coli single-stranded DNA (ssDNA) binding protein (SSB) is the defining bacterial member of ssDNA binding proteins essential for DNA maintenance. SSB binds ssDNA with a variable footprint of ∼30–70 nucleotides, reflecting partial or full wrapping of ssDNA around a tetramer of SSB. We directly imaged single molecules of SSB-coated ssDNA using total internal reflection fluorescence (TIRF) microscopy and observed intramolecular condensation of nucleoprotein complexes exceeding expectations based on simple wrapping transitions. We further examined this unexpected property by single-molecule force spectroscopy using magnetic tweezers. In conditions favoring complete wrapping, SSB engages in long-range reversible intramolecular interactions resulting in condensation of the SSB-ssDNA complex. RecO and RecOR, which interact with SSB, further condensed the complex. Our data support the idea that RecOR--and possibly other SSB-interacting proteins—function(s) in part to alter long-range, macroscopic interactions between or throughout nucleoprotein complexes by microscopically altering wrapping and bridging distant sites. DOI: http://dx.doi.org/10.7554/eLife.08646.001 PMID:26381353

  19. Rad52-mediated DNA annealing after Rad51-mediated DNA strand exchange promotes second ssDNA capture.

    PubMed

    Sugiyama, Tomohiko; Kantake, Noriko; Wu, Yun; Kowalczykowski, Stephen C

    2006-11-29

    Rad51, Rad52, and RPA play central roles in homologous DNA recombination. Rad51 mediates DNA strand exchange, a key reaction in DNA recombination. Rad52 has two distinct activities: to recruit Rad51 onto single-strand (ss)DNA that is complexed with the ssDNA-binding protein, RPA, and to anneal complementary ssDNA complexed with RPA. Here, we report that Rad52 promotes annealing of the ssDNA strand that is displaced by DNA strand exchange by Rad51 and RPA, to a second ssDNA strand. An RPA that is recombination-deficient (RPA(rfa1-t11)) failed to support annealing, explaining its in vivo phenotype. Escherichia coli RecO and SSB proteins, which are functional homologues of Rad52 and RPA, also facilitated the same reaction, demonstrating its conserved nature. We also demonstrate that the two activities of Rad52, recruiting Rad51 and annealing DNA, are coordinated in DNA strand exchange and second ssDNA capture. PMID:17093500

  20. The SsDREB Transcription Factor from the Succulent Halophyte Suaeda salsa Enhances Abiotic Stress Tolerance in Transgenic Tobacco.

    PubMed

    Zhang, Xu; Liu, Xiaoxue; Wu, Lei; Yu, Guihong; Wang, Xiue; Ma, Hongxiang

    2015-01-01

    Dehydration-responsive element-binding (DREB) transcription factor (TF) plays a key role for abiotic stress tolerance in plants. In this study, a novel cDNA encoding DREB transcription factor, designated SsDREB, was isolated from succulent halophyte Suaeda salsa. This protein was classified in the A-6 group of DREB subfamily based on multiple sequence alignments and phylogenetic characterization. Yeast one-hybrid assays showed that SsDREB protein specifically binds to the DRE sequence and could activate the expression of reporter genes in yeast, suggesting that the SsDREB protein was a CBF/DREB transcription factor. Real-time RT-PCR showed that SsDREB was significantly induced under salinity and drought stress. Overexpression of SsDREB cDNA in transgenic tobacco plants exhibited an improved salt and drought stress tolerance in comparison to the nontransformed controls. The transgenic plants revealed better growth, higher chlorophyll content, and net photosynthesis rate, as well as higher level of proline and soluble sugars. The semiquantitative PCR of transgenics showed higher expression of stress-responsive genes. These data suggest that the SsDREB transcription factor is involved in the regulation of salt stress tolerance in tobacco by the activation of different downstream gene expression. PMID:26504772

  1. ssODN-mediated knock-in with CRISPR-Cas for large genomic regions in zygotes

    PubMed Central

    Yoshimi, Kazuto; Kunihiro, Yayoi; Kaneko, Takehito; Nagahora, Hitoshi; Voigt, Birger; Mashimo, Tomoji

    2016-01-01

    The CRISPR-Cas system is a powerful tool for generating genetically modified animals; however, targeted knock-in (KI) via homologous recombination remains difficult in zygotes. Here we show efficient gene KI in rats by combining CRISPR-Cas with single-stranded oligodeoxynucleotides (ssODNs). First, a 1-kb ssODN co-injected with guide RNA (gRNA) and Cas9 messenger RNA produce GFP-KI at the rat Thy1 locus. Then, two gRNAs with two 80-bp ssODNs direct efficient integration of a 5.5-kb CAG-GFP vector into the Rosa26 locus via ssODN-mediated end joining. This protocol also achieves KI of a 200-kb BAC containing the human SIRPA locus, concomitantly knocking out the rat Sirpa gene. Finally, three gRNAs and two ssODNs replace 58-kb of the rat Cyp2d cluster with a 6.2-kb human CYP2D6 gene. These ssODN-mediated KI protocols can be applied to any target site with any donor vector without the need to construct homology arms, thus simplifying genome engineering in living organisms. PMID:26786405

  2. ssODN-mediated knock-in with CRISPR-Cas for large genomic regions in zygotes.

    PubMed

    Yoshimi, Kazuto; Kunihiro, Yayoi; Kaneko, Takehito; Nagahora, Hitoshi; Voigt, Birger; Mashimo, Tomoji

    2016-01-01

    The CRISPR-Cas system is a powerful tool for generating genetically modified animals; however, targeted knock-in (KI) via homologous recombination remains difficult in zygotes. Here we show efficient gene KI in rats by combining CRISPR-Cas with single-stranded oligodeoxynucleotides (ssODNs). First, a 1-kb ssODN co-injected with guide RNA (gRNA) and Cas9 messenger RNA produce GFP-KI at the rat Thy1 locus. Then, two gRNAs with two 80-bp ssODNs direct efficient integration of a 5.5-kb CAG-GFP vector into the Rosa26 locus via ssODN-mediated end joining. This protocol also achieves KI of a 200-kb BAC containing the human SIRPA locus, concomitantly knocking out the rat Sirpa gene. Finally, three gRNAs and two ssODNs replace 58-kb of the rat Cyp2d cluster with a 6.2-kb human CYP2D6 gene. These ssODN-mediated KI protocols can be applied to any target site with any donor vector without the need to construct homology arms, thus simplifying genome engineering in living organisms.

  3. Differential sensitivity of the nicotinic receptor of long (LS) and short (SS) sleep mice to ethanol (E) and forane (F)

    SciTech Connect

    McArdle, J.J.; Choi, J.J. )

    1989-02-09

    Studies of inbred mice indicate that heredity determines the behavioral response to CNS depressants. For example, LS mice lose their righting reflex at blood levels of E having no effect on this reflex of SS mice. In order to determine if such differential sensitivity extends to the effects of depressants known to alter the mean open time (tau) of the ion channel activated by the nicotinic acetylcholine receptor (AR), we used an extracellular electrode to record miniature end-plate currents (23 C) from the triangularis sterni muscle of adult male LS and SS mice. The average decay time constant (tau) of 70 currents was calculated before, during and after drug exposure. Tau was the same for LS and SS mice (1.41 {plus minus} 0.03 mS and 1.47 {plus minus} 0.02 mS, respectively) prior to treatment and was reversible prolonged by E and shortened by F as expected. However, tau of SS mice was more responsive. For example, 25 mM of E increased tau by 12.9% and 3.8% in SS and LS mice, respectively. Likewise, the decrease of tau in response to 3 mM F was 18.5% and 9.2%. The net result was that the curve relating tau for LS mice to drug concentration was to the right of the for SS mice. These data suggest that the sensitivity of the peripheral AR to CNS depressants can be genetically controlled.

  4. Initial experiences with RoSS surgical simulator in residency training: a validity and model analysis.

    PubMed

    Colaco, Marc; Balica, Adrian; Su, Daniel; Barone, Joseph

    2013-03-01

    Robotic surgery is an important new tool in many surgical procedures, and training curriculums must adapt to this new technology. Robotic surgical simulators have been developed as a means of providing training without the inherent risks of actual surgery. The purpose of this study is to evaluate the construct validity of the RoSS surgical simulator by correlating simulator performance with amount of time in training and to create a performance model in which time in training is a parameter. A total of eight residents with varying amounts of training were given access to the RoSS surgical simulator and were evaluated on performance of a simulated surgical task. This data was then used to create Akaike information criteria to compare goodness of fit. Participants were also given a questionnaire as to their experience with the simulator and their feelings about the use of simulators in training. Training time and performance within the simulator were shown to have a linear relationship. Correlations were high, with R (2) values of 0.95, 0.94, and 0.86 for each of the three performance metrics. Likelihood ratios were similarly high at 4.25 × 10(9), 10,950, and 362. Participant opinion showed that residents feel that robotic training is an important part of their education and that the simulator is an effective supplement. The RoSS surgical simulator accurately corresponds to training level and is a valid evaluation tool of training experience. These findings are encouraging for the use of robotic simulators in surgical training. PMID:27000895

  5. Thick SS316 materials TIG welding development activities towards advanced fusion reactor vacuum vessel applications

    NASA Astrophysics Data System (ADS)

    Kumar, B. Ramesh; Gangradey, R.

    2012-11-01

    Advanced fusion reactors like ITER and up coming Indian DEMO devices are having challenges in terms of their materials design and fabrication procedures. The operation of these devices is having various loads like structural, thermo-mechanical and neutron irradiation effects on major systems like vacuum vessel, divertor, magnets and blanket modules. The concept of double wall vacuum vessel (VV) is proposed in view of protecting of major reactor subsystems like super conducting magnets, diagnostic systems and other critical components from high energy 14 MeV neutrons generated from fusion plasma produced by D-T reactions. The double walled vacuum vessel is used in combination with pressurized water circulation and some special grade borated steel blocks to shield these high energy neutrons effectively. The fabrication of sub components in VV are mainly used with high thickness SS materials in range of 20 mm- 60 mm of various grades based on the required protocols. The structural components of double wall vacuum vessel uses various parts like shields, ribs, shells and diagnostic vacuum ports. These components are to be developed with various welding techniques like TIG welding, Narrow gap TIG welding, Laser welding, Hybrid TIG laser welding, Electron beam welding based on requirement. In the present paper the samples of 20 mm and 40 mm thick SS 316 materials are developed with TIG welding process and their mechanical properties characterization with Tensile, Bend tests and Impact tests are carried out. In addition Vickers hardness tests and microstructural properties of Base metal, Heat Affected Zone (HAZ) and Weld Zone are done. TIG welding application with high thick SS materials in connection with vacuum vessel requirements and involved criticalities towards welding process are highlighted.

  6. KiSS-1 in the mammalian ovary: distribution of kisspeptin in human and marmoset and alterations in KiSS-1 mRNA levels in a rat model of ovulatory dysfunction.

    PubMed

    Gaytán, F; Gaytán, M; Castellano, J M; Romero, M; Roa, J; Aparicio, B; Garrido, N; Sánchez-Criado, J E; Millar, R P; Pellicer, A; Fraser, H M; Tena-Sempere, M

    2009-03-01

    Kisspeptins, the products of the KiSS-1 gene acting via G protein-coupled receptor 54 (GPR54), have recently emerged as pivotal signals in the hypothalamic network triggering the preovulatory surge of gonadotropins and, hence, ovulation. Additional actions of kisspeptins at other levels of the hypothalamic-pituitary-ovarian axis have been suggested but remain to date scarcely studied. We report herein the pattern of expression of KiSS-1 and GPR54 in the human and nonhuman primate ovary and evaluate changes in ovarian KiSS-1 expression in a rat model of ovulatory dysfunction. KiSS-1 and GPR54 mRNAs were detected in human ovarian tissue and cultured granulosa-lutein cells. In good agreement, kisspeptin immunoreactivity was observed in cyclic human and marmoset ovaries, with prominent signals in the theca layer of growing follicles, corpora lutea, interstitial gland, and ovarian surface epithelium. GPR54 immunoreactivity was also found in human theca and luteal cells. Administration of indomethacin to cyclic female rats disturbed ovulation and resulted in a dramatic drop in ovarian KiSS-1, but not GPR54, cyclooxygenase-2 (COX-2), or progesterone receptor, mRNA levels at the time of ovulation; an effect mimicked by the selective COX-2 inhibitor NS398 and rescued by coadministration of PGE(2). Likewise, the stimulatory effect of human choriogonadotropin on ovarian KiSS-1 expression was partially blunted by indomethacin. In contrast, KiSS-1 mRNA levels remained unaltered in another model of ovulatory failure, i.e., the RU486-treated rat. In summary, we document for the first time the expression of KiSS-1/kisspeptin and GPR54 in the human and nonhuman primate ovary. In addition, we provide evidence for the ability of inhibitors of COX-2, known to disturb follicular rupture and ovulation, to selectively alter the expression of KiSS-1 gene in rat ovary. Altogether, our results are suggestive of a conserved role of local KiSS-1 in the direct control of ovarian functions in

  7. Multiresolution imaging of mantle reflectivity structure using SS and P'P' precursors

    NASA Astrophysics Data System (ADS)

    Schultz, Ryan; Gu, Yu J.

    2013-10-01

    Knowledge of the mantle reflectivity structure is highly dependent on our ability to efficiently extract, and properly interpret, small seismic arrivals. Among the various data types and techniques, long-period SS/PP precursors and high-frequency receiver functions are routinely utilized to increase the confidence of the recovered mantle stratifications at distinct spatial scales. However, low resolution and a complex Fresnel zone are glaring weaknesses of SS precursors, while over-reliance on receiver distribution is a formidable challenge for the analysis of converted waves from oceanic regions. A promising high frequency alternative to receiver functions is P'P' precursors, which are capable of resolving mantle structures at vertical and lateral resolution of ˜5 and ˜200 km, respectively, owing to their spectral content, shallow angle of incidence and near-symmetric Fresnel zones. This study presents a novel processing method for both SS (or PP) and P'P' precursors based on deconvolution, stacking, Radon transform and depth migration. A suite of synthetic tests is performed to quantify the fidelity and stability of this method under different data conditions. Our multiresolution survey of the mantle at targeted areas near Nazca-South America subduction zone reveal both olivine and garnet related transitions at depths below 400 km. We attribute a depressed 660 to thermal variations, whereas compositional variations atop the upper-mantle transition zone are needed to explain the diminished or highly complex reflected/scattered signals from the 410 km discontinuity. We also observe prominent P'P' reflections within the transition zone, and the anomalous amplitudes near the plate boundary zone indicate a sharp (˜10 km thick) transition that likely resonates with the frequency content of P'P' precursors. The migration of SS precursors in this study shows no evidence of split 660 reflections, but potential majorite-ilmenite (590-640 km) and ilmenite

  8. An evaluation of microbial growth and corrosion of 316L SS in glycol/seawater mixtures

    NASA Technical Reports Server (NTRS)

    Lee, Jason S.; Ray, Richard I.; Lowe, Kristine L.; Jones-Meehan, Joanne; Little, Brenda J.

    2003-01-01

    Glycol/seawater mixtures containing > 50% glycol inhibit corrosion of 316L stainless steel and do not support bacterial growth. The results indicate bacteria are able to use low concentrations of glycol (10%) as a growth medium, but bacterial growth decreased with increasing glycol concentration. Pitting potential, determined by anodic polarization, was used to evaluate susceptibility of 316L SS to corrosion in seawater-contaminated glycol. Mixture containing a minimum concentration of 50% propylene glycol-based coolant inhibited pitting corrosion. A slightly higher minimum concentration (55%) was needed for corrosion protection in ethylene glycol mixtures.

  9. Upper Mantle Discontinuity Structure Beneath the Western Atlantic Ocean and Eastern North America from SS Precursors

    NASA Astrophysics Data System (ADS)

    Schmerr, N. C.; Beghein, C.; Kostic, D.; Baldridge, A. M.; West, J. D.; Nittler, L. R.; Bull, A. L.; Montesi, L.; Byrne, P. K.; Hummer, D. R.; Plescia, J. B.; Elkins-Tanton, L. T.; Lekic, V.; Schmidt, B. E.; Elkins, L. J.; Cooper, C. M.; ten Kate, I. L.; Van Hinsbergen, D. J. J.; Parai, R.; Glass, J. B.; Ni, J.; Fuji, N.; McCubbin, F. M.; Michalski, J. R.; Zhao, C.; Arevalo, R. D., Jr.; Koelemeijer, P.; Courtier, A. M.; Dalton, H.; Waszek, L.; Bahamonde, J.; Schmerr, B.; Gilpin, N.; Rosenshein, E.; Mach, K.; Ostrach, L. R.; Caracas, R.; Craddock, R. A.; Moore-Driskell, M. M.; Du Frane, W. L.; Kellogg, L. H.

    2015-12-01

    Seismic discontinuities within the mantle arise from a wide range of mechanisms, including changes in mineralogy, major element composition, melt content, volatile abundance, anisotropy, or a combination of the above. In particular, the depth and sharpness of upper mantle discontinuities at 410 and 660 km depth are attributed to solid-state phase changes sensitive to both mantle temperature and composition, where regions of thermal heterogeneity produce topography and chemical heterogeneity changes the impedance contrast across the discontinuity. Seismic mapping of this topography and sharpness thus provides constraint on the thermal and compositional state of the mantle. The EarthScope USArray is providing unprecedented access to a wide variety of new regions previously undersampled by the SS precursors. This includes the boundary between the oceanic plate in the western Atlantic Ocean and continental margin of eastern North America. Here we use a seismic array approach to image the depth, sharpness, and topography of the upper mantle discontinuities, as well as other possible upper mantle reflectors beneath this region. This array approach utilizes seismic waves that reflect off the underside of a mantle discontinuity and arrive several hundred seconds prior to the SS seismic phase as precursory energy. In this study, we collected high-quality broadband data SS precursors data from shallow focus (< 30 km deep), mid-Atlantic ridge earthquakes recorded by USArray seismometers in Alaska. We generated 4th root vespagrams to enhance the SS precursors and determine how they sample the mantle. Our data show detection of localized structure on the discontinuity boundaries as well as additional horizons, such as the X-discontinuity and a potential reflection from a discontinuity near the depth of the lithosphere-asthenosphere boundary. These structures are related to the transition from predominantly old ocean lithosphere to underlying continental lithosphere, as while

  10. SS 433: Total Coverage of 162-Day Precession Phase in Four Years

    NASA Technical Reports Server (NTRS)

    Band, David L.

    1997-01-01

    The observations prior to AO-4 covered a number of precession phases, leaving a gap at phase 0.8. In addition, ASCA and previous observations of SS 433 did not observe the spectrum above approx. 10 keV, and consequently the continuum underlying the spectral lines was poorly constrained. Therefore RXTE observations were scheduled for April 1997 to extend the observed spectrum to higher energies; these observations were planned to sample the X-ray lightcurve during the 13.08 day binary period, concentrating on the eclipse of the compact object which emits the jets. We proposed and were awarded ASCA observations simultaneous with the RXTE observations; the purpose of the ASCA observations was to provide greater spectral resolution at the low end of the spectrum observed by RXTE, and to complete the phase coverage of SS 433. As a result of scheduling difficulties early in the mission the RXTE observations were confined to a much shorter time range than originally planned, April 18-91 1997. Optical observations of SS 433 were performed at a number of observatories. The ASCA observations occurred from April 18 13:10 (UT) to April 21 13:20 (UT) for a total effective exposure of 120 ks. The continuum X-ray light curve shows that the ASCA observations started shortly before the ingress into the X-ray partial eclipse, and ended approximately at the time of the egress. Light curves were also obtained for the prominent Fe emission lines in the blue-shifted frame (approaching jet), red-shifted frame (receding jet), and the stationary frame (fluorescent line from the ambient matter). Through the eclipse mapping technique using the light curves, the parameters of the jet emission model were constrained, showing that the kinetic power in the jet exceeds 104? erg s-l. If the energy source is gravitational accretion, as is commonly believed, the derived l;inetic power implies extremely supercritical accretion even for a black; hole with 10M. These results will be described more

  11. Seismic Constraints on the Japan Subduction Zone from Waveform Inversions of SS precursors

    NASA Astrophysics Data System (ADS)

    Dokht, R.; Gu, Y. J.; Sacchi, M. D.

    2014-12-01

    Arrival times of long-period secondary mantle reflections such as SS and PP precursors have made significant contributions to the understanding of the mantle structure and slab dynamics beneath the Pacific Northwest. Due to strong sensitivities to discontinuity depths, the timing information is often correlated with P/S velocity models from high-resolution seismic tomography while stacked reflection amplitudes provide a measure of impedance contrast. A potential pitfall in the interpretations of SS-precursor measurements is velocity-discontinuity depth ambiguity, as the timing of secondary reflections is mainly 'corrected' based on existing smoothed velocity estimates. In this study we quantitatively investigate the amplitude information of a dense SS precursor data set sampling the northwestern Pacific region. We model the full waveforms of SS precursors using the Genetic Algorithm (GA), an effective nonlinear inversion technique, and properly account for the tradeoff between shear wave velocity and discontinuity depth perturbation. The inverted shear velocities clearly show a consistent high-velocity, dipping structure along the Wadati-Benioff zone, likely in connection with the descending Japan slab. The slab appears to stagnate and horizontally deflect within the upper mantle transition zone beneath northeastern China. The integrity of the deflected slab appears to be compromised beneath the Changbai hotspot where a low velocity anomaly interrupts the flat lying high velocity structure and extends upward to, at least, mid MTZ depths. This anomaly does not appear to reach the Changbai hotspot, though its connection with observed low velocities in the lithosphere and asthenosphere may not be ruled out. Our nonlinear waveform inversion results also show a 600-km wide low velocity zone (up to -4% relative to the Preliminary Reference Earth Model (PREM)) atop the 660-km discontinuity on the oceanic side of the subducting Japan slab. The cause of this anomaly remains

  12. Nucleobase recognition in ssDNA at the central constriction of the αhemolysin pore

    PubMed Central

    Stoddart, David; Heron, Andrew J.; Klingelhoefer, Jochen; Mikhailova, Ellina; Maglia, Giovanni; Bayley, Hagan

    2010-01-01

    Nanopores are under investigation for single-molecule DNA sequencing. The α-hemolysin (αHL) protein nanopore contains three recognition points capable of nucleobase discrimination in individual immobilized ssDNA molecules. We have modified the recognition point R1 by extensive mutagenesis of residue 113. Amino acids that provide an energy barrier to ion flow (e.g. bulky or hydrophobic residues) strengthen base identification, while amino acids that lower the barrier weaken it. Amino acids with related side chains produce similar patterns of nucleobase recognition providing a rationale for the redesign of recognition points. PMID:20704324

  13. Functional photoacoustic microscopy of pH

    NASA Astrophysics Data System (ADS)

    Chatni, M. Rameez; Yao, Junjie; Danielli, Amos; Favazza, Christopher P.; Maslov, Konstantin I.; Wang, Lihong V.

    2012-02-01

    pH is a tightly regulated indicator of metabolic activity. In mammalian systems, imbalance of pH regulation may result from or result in serious illness. Even though the regulation system of pH is very robust, tissue pH can be altered in many diseases such as cancer, osteoporosis and diabetes mellitus. Traditional high-resolution optical imaging techniques, such as confocal microscopy, routinely image pH in cells and tissues using pH sensitive fluorescent dyes, which change their fluorescence properties with the surrounding pH. Since strong optical scattering in biological tissue blurs images at greater depths, high-resolution pH imaging is limited to penetration depths of 1mm. Here, we report photoacoustic microscopy (PAM) of commercially available pH-sensitive fluorescent dye in tissue phantoms. Using both opticalresolution photoacoustic microscopy (OR-PAM), and acoustic resolution photoacoustic microscopy (AR-PAM), we explored the possibility of recovering the pH values in tissue phantoms. In this paper, we demonstrate that PAM was capable of recovering pH values up to a depth of 2 mm, greater than possible with other forms of optical microscopy.

  14. Comparison of the microbial communities in solid-state anaerobic digestion (SS-AD) reactors operated at mesophilic and thermophilic temperatures.

    PubMed

    Li, Yueh-Fen; Nelson, Michael C; Chen, Po-Hsu; Graf, Joerg; Li, Yebo; Yu, Zhongtang

    2015-01-01

    The microbiomes involved in liquid anaerobic digestion process have been investigated extensively, but the microbiomes underpinning solid-state anaerobic digestion (SS-AD) are poorly understood. In this study, microbiome composition and temporal succession in batch SS-AD reactors, operated at mesophilic or thermophilic temperatures, were investigated using Illumina sequencing of 16S rRNA gene amplicons. A greater microbial richness and evenness were found in the mesophilic than in the thermophilic SS-AD reactors. Firmicutes accounted for 60 and 82 % of the total Bacteria in the mesophilic and in the thermophilic SS-AD reactors, respectively. The genus Methanothermobacter dominated the Archaea in the thermophilic SS-AD reactors, while Methanoculleus predominated in the mesophilic SS-AD reactors. Interestingly, the data suggest syntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis as an important pathway for biogas production during the thermophilic SS-AD. Canonical correspondence analysis (CCA) showed that temperature was the most influential factor in shaping the microbiomes in the SS-AD reactors. Thermotogae showed strong positive correlation with operation temperature, while Fibrobacteres, Lentisphaerae, Spirochaetes, and Tenericutes were positively correlated with daily biogas yield. This study provided new insight into the microbiome that drives SS-AD process, and the findings may help advance understanding of the microbiome in SS-AD reactors and the design and operation of SS-AD systems.

  15. The Borrelia burgdorferi telomere resolvase, ResT, anneals ssDNA complexed with its cognate ssDNA-binding protein

    PubMed Central

    Huang, Shu Hui; Kobryn, Kerri

    2016-01-01

    Spirochetes of the genus Borrelia possess unusual genomes that consist in a linear chromosome and multiple linear and circular plasmids. The linear replicons are terminated by covalently closed hairpin ends, referred to as hairpin telomeres. The hairpin telomeres represent a simple solution to the end-replication problem. Deoxyribonucleic acid replication initiates internally and proceeds bidirectionally toward the hairpin telomeres. The telomere resolvase, ResT, forms the hairpin telomeres from replicated telomere intermediates in a reaction with similarities to those promoted by type IB topoisomerases and tyrosine recombinases. ResT has also been shown to possess DNA single-strand annealing activity. We report here that ResT promotes single-strand annealing of both free DNA strands and ssDNA complexed with single-stranded DNA binding protein (SSB). The annealing of complementary strands bound by SSB requires a ResT–SSB interaction that is mediated by the conserved amphipathic C-terminal tail of SSB. These properties of ResT are similar to those demonstrated for the recombination mediator protein, RecO, of the RecF pathway. Borrelia burgdorferi is unusual in lacking identifiable homologs of the RecFOR proteins. We propose that ResT may provide missing RecFOR functions. PMID:27131360

  16. The Borrelia burgdorferi telomere resolvase, ResT, anneals ssDNA complexed with its cognate ssDNA-binding protein.

    PubMed

    Huang, Shu Hui; Kobryn, Kerri

    2016-06-20

    Spirochetes of the genus Borrelia possess unusual genomes that consist in a linear chromosome and multiple linear and circular plasmids. The linear replicons are terminated by covalently closed hairpin ends, referred to as hairpin telomeres. The hairpin telomeres represent a simple solution to the end-replication problem. Deoxyribonucleic acid replication initiates internally and proceeds bidirectionally toward the hairpin telomeres. The telomere resolvase, ResT, forms the hairpin telomeres from replicated telomere intermediates in a reaction with similarities to those promoted by type IB topoisomerases and tyrosine recombinases. ResT has also been shown to possess DNA single-strand annealing activity. We report here that ResT promotes single-strand annealing of both free DNA strands and ssDNA complexed with single-stranded DNA binding protein (SSB). The annealing of complementary strands bound by SSB requires a ResT-SSB interaction that is mediated by the conserved amphipathic C-terminal tail of SSB. These properties of ResT are similar to those demonstrated for the recombination mediator protein, RecO, of the RecF pathway. Borrelia burgdorferi is unusual in lacking identifiable homologs of the RecFOR proteins. We propose that ResT may provide missing RecFOR functions. PMID:27131360

  17. Caffeine inhibits gene conversion by displacing Rad51 from ssDNA.

    PubMed

    Tsabar, Michael; Mason, Jennifer M; Chan, Yuen-Ling; Bishop, Douglas K; Haber, James E

    2015-08-18

    Efficient repair of chromosomal double-strand breaks (DSBs) by homologous recombination relies on the formation of a Rad51 recombinase filament that forms on single-stranded DNA (ssDNA) created at DSB ends. This filament facilitates the search for a homologous donor sequence and promotes strand invasion. Recently caffeine treatment has been shown to prevent gene targeting in mammalian cells by increasing non-productive Rad51 interactions between the DSB and random regions of the genome. Here we show that caffeine treatment prevents gene conversion in yeast, independently of its inhibition of the Mec1(ATR)/Tel1(ATM)-dependent DNA damage response or caffeine's inhibition of 5' to 3' resection of DSB ends. Caffeine treatment results in a dosage-dependent eviction of Rad51 from ssDNA. Gene conversion is impaired even at low concentrations of caffeine, where there is no discernible dismantling of the Rad51 filament. Loss of the Rad51 filament integrity is independent of Srs2's Rad51 filament dismantling activity or Rad51's ATPase activity and does not depend on non-specific Rad51 binding to undamaged double-stranded DNA. Caffeine treatment had similar effects on irradiated HeLa cells, promoting loss of previously assembled Rad51 foci. We conclude that caffeine treatment can disrupt gene conversion by disrupting Rad51 filaments.

  18. ReSS: A Resource Selection Service for the Open Science Grid

    SciTech Connect

    Garzoglio, Gabriele; Levshina, Tanya; Mhashilkar, Parag; Timm, Steve; /Fermilab

    2008-01-01

    The Open Science Grid offers access to hundreds of computing and storage resources via standard Grid interfaces. Before the deployment of an automated resource selection system, users had to submit jobs directly to these resources. They would manually select a resource and specify all relevant attributes in the job description prior to submitting the job. The necessity of a human intervention in resource selection and attribute specification hinders automated job management components from accessing OSG resources and it is inconvenient for the users. The Resource Selection Service (ReSS) project addresses these shortcomings. The system integrates condor technology, for the core match making service, with the gLite CEMon component, for gathering and publishing resource information in the Glue Schema format. Each one of these components communicates over secure protocols via web services interfaces. The system is currently used in production on OSG by the DZero Experiment, the Engagement Virtual Organization, and the Dark Energy. It is also the resource selection service for the Fermilab Campus Grid, FermiGrid. ReSS is considered a lightweight solution to push-based workload management. This paper describes the architecture, performance, and typical usage of the system.

  19. Oxidation state of Mn in the Mn oxide produced by Leptothrix discophora SS-1

    SciTech Connect

    Adams, L.F.; Ghiorse, W.C. )

    1988-08-01

    Leptothrix discophora SS-1 excretes at least one Mn{sup 2+}-oxidizing protein that, in association with acidic exopolymers, catalyzes a rapid oxidation of Mn{sup 2+}. Iodometric titration of Mn oxide product showed that the oxidation state of Mn increased with age of the oxide from 3.32 in samples 11 hours old to 3.62 in samples formed over a period of 30 days. Electron diffraction of 90-day old samples showed evidence of poorly crystalline Mn(IV) oxides. Simultaneous measurement of oxygen consumption and Mn oxide formation during 15 min reaction periods indicated that the initial Mn product possessed an average oxidation state no greater than 3.6. Results suggest that the Mn{sup 2+}-oxidizing system of Leptothrix discophora SS-1 first generates Mn oxide with an average oxidation state close to Mn(III). Aging increases this oxidation state to give the mixed Mn(III, IV) oxide product observed in older samples.

  20. Corrosion Fatigue Behavior of 316LN SS in Acidified Sodium Chloride Solution at Applied Potential

    NASA Astrophysics Data System (ADS)

    Poonguzhali, A.; Pujar, M. G.; Mallika, C.; Mudali, U. Kamachi

    2015-05-01

    The influence of acidified 1 M NaCl solution by addition of 2 ml/L of HCl on the cyclic plastic deformation of AISI Type 316LN SS containing 0.07 wt.% and 0.22 wt.% N was investigated as a function of the applied potentials. The corrosion fatigue (CF) behavior of stainless steel (SS) was explained vis-a-vis the dislocation behavior, the propensity to form microcracks, and the evolution of the current transients based on the studies carried out at both room-temperature and boiling conditions. CF experiments were conducted using round tensile specimens at a stress ratio of 0.5 and a frequency of 0.1 Hz. Two different kinds of damage mechanisms were observed (I) the damage mechanism in the stable-passive state was correlated with the localization of the anodic dissolution due to a depassivation-repassivation process, whereas (II) the cyclic stress induced pitting corrosion in the metastable pitting state, which resulted in formation of microcracks. The study of the microcracking process and its evolution is a key to the physical mechanism by which the fatigue life of stainless steels would be affected in an aqueous corrosive solution under the applied potential.

  1. X-ray variability of SS 433: Evidence for supercritical accretion

    NASA Astrophysics Data System (ADS)

    Atapin, K. E.; Fabrika, S. N.

    2016-08-01

    We study the X-ray variability of SS 433 based on data from the ASCA observatory and the MAXI and RXTE/ASM monitoring missions. Based on the ASCA data, we have constructed the power spectrum of SS 433 in the frequency range from 10-6 to 0.1 Hz, which confirms the presence of a flat portion in the spectrum at frequencies 3 × 10-5-10-3 Hz. The periodic variability (precession, nutation, eclipses) begins to dominate significantly over the stochastic variability at lower frequencies, which does not allow the stochastic variability to be studied reliably. The model in which the flat portion extends to 9.5 × 10-6 Hz, while a power-law rise with an index of 2.6 occurs below provides the best agreement with the observations. The nutational oscillations of the jets with a period of about three days suggests that the time for the passage of material through the disk is less than this value. At frequencies below 4 × 10-6 Hz, the shape of the power spectrum probably does not reflect the disk structure but is determined by external factors, for example, by a change in the amount of material supplied by the donor. The flat portion can arise from a rapid decrease in the viscous time in the supercritical or radiative disk zones. The flat spectrum is associated with the variability of the X-ray jets that are formed in the supercritical disk region.

  2. Mitochondria-Targeted Antioxidant SS-31 is a Potential Novel Ophthalmic Medication for Neuroprotection in Glaucoma.

    PubMed

    Pang, Yu; Wang, Chao; Yu, Ling

    2015-01-01

    Glaucoma is the second leading cause of irreversible blindness and a neurodegenerative disease with a complex pathogenesis. Increasing evidence suggests that oxidative stress and mitochondrial dysfunction have crucial roles in most neurodegenerative diseases such as glaucoma. The conventional clinical treatment for glaucoma is lowering the intraocular pressure (IOP). Some patients have normal IOP, whereas other patients appear to obtain adequate control of IOP after filtration surgery or medication. However, these patients still experience progressive visual field loss. Vision field loss in glaucoma is attributed to retinal ganglion cell (RGC) apoptosis. Many recent researches demonstrated that the link between mitochondrial dysfunction and oxidative stress was a major cause of RGCs apoptosis. How oxidative stress leads to RGCs apoptosis in glaucoma is unclear but may involve the neurotoxic effects of oxidative stress-induced mitochondrial dysfunction and/or damage from reactive oxygen species (ROS). Investigations are needed concerning the mitochondria as effective targets for potential therapeutic interventions to maintain mitochondrial function and reduce oxidative stress, and thereby delay or stop RGC loss and prolong visual function. The mitochondria-targeted antioxidant Szeto-Schiller (SS) peptide is a candidate molecule. Szeto-Schiller-31 (H-D-Arg-Dmt-Lys-Phe-NH2) is an attractive mitochondria-targeted antioxidant that can protect the mitochondria and RGCs against oxidative damage. Therefore, we suggest SS-31 as a novel neuroprotective ophthalmic drug for protecting RGCs in glaucoma.

  3. RXTE/ASM Observations Of SS 433 And Cygnus X-2

    NASA Astrophysics Data System (ADS)

    Hoffman, Lisa; Mason, P. A.

    2010-01-01

    We present a dynamic period search analysis of the X-ray binaries SS 433 and Cygnus X-2 using data from the Rossi X-Ray Timing Explorer All Sky Monitor (RXTE/ASM) spanning over 13 years. We report the detection of a period in SS 433 near 162 days. This may be the first detection of the disk precession period in X-rays. We detect an 81.8 day period in the object Cygnus X-2. The RXTE/ASM light curve is inconsistent with the 77.7 day X-ray period of Wijnands et al. (1996), which was based on a small subset of the RXTE/ASM data combined with data from VELA 5B, and Ariel 5 All-Sky Monitors. Since Cygnus X-2 displays periodic behavior that seems to come and go, producing different best-fit periods on time scales of a few years; we suggest that Cygnus X-2 exhibits quasi-periodic oscillations of about 80 days. This research is supported by a grant from the New Mexico Space Grant Consortium.

  4. SS/RCS surface tension propellant acquisition/expulsion tankage technology program

    NASA Technical Reports Server (NTRS)

    1974-01-01

    An evaluation of published propellant physical property data together with bubble point tests of fine-mesh screen in propellants, was conducted. The effort consisted of: (1) the collection and evaluation of pertinent physical property data for hydrazine (N2H4), monomethylhydrazine (MMH), and nitrogen tetroxide (N2O4); (2) testing to determine the effect of dissolved pressurant gas, temperature, purity, and system cleanliness or contamination on system bubble point, and (3) the compilation and publishing of both the literature and test results. The space shuttle reaction control system (SS/RCS) is a bipropellant system using N2O4 and MMH, while the auxiliary power system (SS/APU) employs monopropellant N2H4. Since both the RCS and the APU use a surface tension device for propellant acquisition, the propellant properties of interest are those which impact the design and operation of surface tension systems. Information on propellant density, viscosity, surface tension, and contact angle was collected, compiled, and evaluated.

  5. Localized Corrosion Behavior of Type 304SS with a Silica Layer Under Atmospheric Corrosion Environments

    SciTech Connect

    E. Tada; G.S. Frankel

    2006-03-13

    The U.S. Department of Energy (DOE) has proposed a potential repository for spent nuclear fuel and high-level radioactive waste at the Yucca Mountain site in Nevada. [I] The temperature could be high on the waste packages, and it is possible that dripping water or humidity could interact with rock dust particulate to form a thin electrolyte layer with concentrated ionic species. Under these conditions, it is possible that highly corrosion-resistant alloys (CRAs) used as packages to dispose the nuclear waste could suffer localized corrosion. Therefore, to better understand long-term corrosion performance of CRAs in the repository, it is important to investigate localized corrosion under a simulated repository environment. We measured open circuit potential (OCP) and galvanic current (i{sub g}) for silica-coated Type 304SS during drying of salt solutions under controlled RH environments to clarify the effect of silica layer as a dust layer simulant on localized corrosion under atmospheric environments. Type 304SS was used as a relatively susceptible model CRA instead of the much more corrosion resistant alloys, such as Alloy 22, that are being considered as, waste package materials.

  6. Caffeine inhibits gene conversion by displacing Rad51 from ssDNA

    PubMed Central

    Tsabar, Michael; Mason, Jennifer M.; Chan, Yuen-Ling; Bishop, Douglas K.; Haber, James E.

    2015-01-01

    Efficient repair of chromosomal double-strand breaks (DSBs) by homologous recombination relies on the formation of a Rad51 recombinase filament that forms on single-stranded DNA (ssDNA) created at DSB ends. This filament facilitates the search for a homologous donor sequence and promotes strand invasion. Recently caffeine treatment has been shown to prevent gene targeting in mammalian cells by increasing non-productive Rad51 interactions between the DSB and random regions of the genome. Here we show that caffeine treatment prevents gene conversion in yeast, independently of its inhibition of the Mec1ATR/Tel1ATM-dependent DNA damage response or caffeine's inhibition of 5′ to 3′ resection of DSB ends. Caffeine treatment results in a dosage-dependent eviction of Rad51 from ssDNA. Gene conversion is impaired even at low concentrations of caffeine, where there is no discernible dismantling of the Rad51 filament. Loss of the Rad51 filament integrity is independent of Srs2's Rad51 filament dismantling activity or Rad51's ATPase activity and does not depend on non-specific Rad51 binding to undamaged double-stranded DNA. Caffeine treatment had similar effects on irradiated HeLa cells, promoting loss of previously assembled Rad51 foci. We conclude that caffeine treatment can disrupt gene conversion by disrupting Rad51 filaments. PMID:26019181

  7. Mitochondria-Targeted Antioxidant SS-31 is a Potential Novel Ophthalmic Medication for Neuroprotection in Glaucoma.

    PubMed

    Pang, Yu; Wang, Chao; Yu, Ling

    2015-01-01

    Glaucoma is the second leading cause of irreversible blindness and a neurodegenerative disease with a complex pathogenesis. Increasing evidence suggests that oxidative stress and mitochondrial dysfunction have crucial roles in most neurodegenerative diseases such as glaucoma. The conventional clinical treatment for glaucoma is lowering the intraocular pressure (IOP). Some patients have normal IOP, whereas other patients appear to obtain adequate control of IOP after filtration surgery or medication. However, these patients still experience progressive visual field loss. Vision field loss in glaucoma is attributed to retinal ganglion cell (RGC) apoptosis. Many recent researches demonstrated that the link between mitochondrial dysfunction and oxidative stress was a major cause of RGCs apoptosis. How oxidative stress leads to RGCs apoptosis in glaucoma is unclear but may involve the neurotoxic effects of oxidative stress-induced mitochondrial dysfunction and/or damage from reactive oxygen species (ROS). Investigations are needed concerning the mitochondria as effective targets for potential therapeutic interventions to maintain mitochondrial function and reduce oxidative stress, and thereby delay or stop RGC loss and prolong visual function. The mitochondria-targeted antioxidant Szeto-Schiller (SS) peptide is a candidate molecule. Szeto-Schiller-31 (H-D-Arg-Dmt-Lys-Phe-NH2) is an attractive mitochondria-targeted antioxidant that can protect the mitochondria and RGCs against oxidative damage. Therefore, we suggest SS-31 as a novel neuroprotective ophthalmic drug for protecting RGCs in glaucoma. PMID:27350953

  8. Flow of simple liquids down narrow {ital ssV} grooves

    SciTech Connect

    Mann, J.A. Jr.; Romero, L.; Rye, R.R.; Yost, F.G. |

    1995-10-01

    The dynamics of spreading of simple liquids down straight, narrow {ital ssV} grooves open at the top were captured by real-time video imaging. Groove depths in polished copper ranged between 40 and 100 {mu}m and extended approximately 2 cm with {ital ssV} angles of 30{degree}, 60{degree}, and 90{degree}. The surface tension to viscosity ratios ranged from 46 to 970 cm/sec and the capillary number was small, Ca{much_lt}1 in all cases. The length of the spreading liquid scaled with {radical}{ital t} accurately for every case examined; the dynamics were well represented by two numbers, the location of the front in reduced coordinates and a diffusion coefficient. A simple theory is presented for the dynamics of the advancing front that requires no adjustable parameters and fits well the experimental data collected with six alcohols. Unlike drop spreading, the {ital ad} {ital hoc} slip boundary condition of that theory is not invoked for the open groove problem; only the static advancing contact angle is used.

  9. Image-tube spectroscopic studies of rapid variables. III Hydrogen bombs in SS Cygni

    NASA Astrophysics Data System (ADS)

    Walker, M. F.

    1981-08-01

    Radial-velocity observations of SS Cyg made in 1970 and 1971 are discussed. Time-resolved spectra in 1970 furnish additional examples of the 'ultraviolet flares' observed previously by Walker and Chincarini (1968), and detailed analysis indicates that these flares are caused by the brief appearance of extremely broad H and sometimes Ca II and He I emission features with total widths of approximately 94 A, often accompanied by a much smaller increase in continuum emission. The form of the line profiles suggests that the broadening is due to mass motions of up to about 3500 km/sec with a non-Maxwellian distribution of velocities. Inspection of similar time-resolved spectra of AE Aqr, T CrB, MV Lyr, RW Tri, and UX UMa suggests that this type of broad-line hydrogen emission flare occurs in at least two other nova-like systems, RW Tri and AE Aqr. In these stars, the frequency of occurrence of this type of flare is lower, being, respectively, about two-thirds and one-tenth of the frequency in SS Cyg.

  10. ssDNA and the Argonautes: The Quest for the Next Golden Editor.

    PubMed

    Martínez-Gálvez, Gabriel; Ata, Hirotaka; Campbell, Jarryd M; Ekker, Stephen C

    2016-06-01

    Genome engineering has gone mainstream because of breakthroughs in defining and harnessing naturally occurring, customizable DNA recognition cursors (protein or RNA-guided). At present, most gene editing relies on these cursors to direct custom DNA endonucleases to a specific genomic sequence to induce a double-strand break. New tools for genome engineering are continuously being explored, and another advance in DNA targeting has recently been described. Argonaute isolated from Natronobacterium gregoryi (NgAgo) is an ssDNA-based cursor that thus far has no known limitations in sequence recognition, shows promise for high specificity, and for many applications may represent a potentially more accessible genome-editing system over prior tools as it requires only a single, 24-base, 5' phosphorylated ssDNA for DNA targeting. Genome engineering is in a remarkable moment of unprecedented growth with exponential reduction in costs reminiscent of Moore's law in electronics. Many questions remain with regard to Argonaute utility in specific systems, but there is no doubt that genome engineering is expanding into new and exciting areas from synthetic biology to gene therapy.

  11. Sensitive Detection of ssDNA Using an LRET-Based Upconverting Nanohybrid Material.

    PubMed

    Jesu Raj, Joe Gerald; Quintanilla, Marta; Mahmoud, Khaled A; Ng, Andy; Vetrone, Fiorenzo; Zourob, Mohammed

    2015-08-26

    Water-dispersible, optical hybrid nanoparticles are preferred materials for DNA biosensing due to their biocompatibility. Upconverting nanoparticles are highly desirable optical probes in sensors and bioimaging owing to their sharp emission intensity in the visible region. We herein report a highly sensitive ss-DNA detection based on an energy transfer system that uses a nanohybrid material synthesized by doping NaYF4:Tm(3+)/Yb(3+) upconverting nanoparticles (UCNPs) on silica coated polystyrene-co-acrylic acid (PSA) nanoparticles (PSA/SiO2) as the donor, and gold nanoparticles (AuNPs) decorated with Ir(III) complex as the acceptor. UCNPs tagged on PSA/SiO2 and the cyclometalated Ir(III)/AuNP conjugates were then linked through the ss-DNA sequence. Sequential addition of the target DNA to the probe molecular beacon complex resulted in the separation of the optical nanohybrid material and the quencher, leading to a measurable increase in the blue fluorescence emission intensity. Our results have shown a linear relationship between the fluorescence intensity and target DNA concentration down to the picomolar.

  12. Sequence specific recognition of ssDNA by a lupus autoantibody: kinetics and mechanism of binding.

    PubMed

    Beckingham, J A; Glick, G D

    2001-09-01

    11F8 is a pathogenic anti-ssDNA monoclonal autoantibody isolated from a lupus-prone mouse. Previous studies have established that 11F8 is sequence specific. To determine the basis for the observed binding specificity, stopped-flow fluorescence spectroscopy was used to measure the kinetic parameters and establish the mechanisms for the association of 11F8 with its target sequence, noncognate, and nonspecific ssDNA ligands. The data revealed that sequence-specific binding follows a two-step mechanism where the initial association step is second order. Values of k(1) are fast and above the modified Smoluchowski limit for a diffusion limited interaction (10(5)-10(6)M(-1)s(-1)). The dependency of k(1) on [salt] and solvent polarity indicates that electrostatic steering is responsible for this rapid association rate. The second association step is rate limiting and is characteristic of an isomerization process during which binding interfaces are optimized. This step apparently is driven by the desolvation of hydrophobic surfaces within the binding interface. The differences in the rate of dissociation for the various DNA ligands suggest that specificity is governed primarily through the dissociation of the final complexes.

  13. Molecular determinants of the DprA−RecA interaction for nucleation on ssDNA

    PubMed Central

    Lisboa, Johnny; Andreani, Jessica; Sanchez, Dyana; Boudes, Marion; Collinet, Bruno; Liger, Dominique; van Tilbeurgh, Herman; Guérois, Raphael; Quevillon-Cheruel, Sophie

    2014-01-01

    Natural transformation is a major mechanism of horizontal gene transfer in bacteria that depends on DNA recombination. RecA is central to the homologous recombination pathway, catalyzing DNA strand invasion and homology search. DprA was shown to be a key binding partner of RecA acting as a specific mediator for its loading on the incoming exogenous ssDNA. Although the 3D structures of both RecA and DprA have been solved, the mechanisms underlying their cross-talk remained elusive. By combining molecular docking simulations and experimental validation, we identified a region on RecA, buried at its self-assembly interface and involving three basic residues that contact an acidic triad of DprA previously shown to be crucial for the interaction. At the core of these patches, DprAM238 and RecAF230 are involved in the interaction. The other DprA binding regions of RecA could involve the N-terminal α-helix and a DNA-binding region. Our data favor a model of DprA acting as a cap of the RecA filament, involving a DprA−RecA interplay at two levels: their own oligomeric states and their respective interaction with DNA. Our model forms the basis for a mechanistic explanation of how DprA can act as a mediator for the loading of RecA on ssDNA. PMID:24782530

  14. A capsidless ssRNA virus hosted by an unrelated dsRNA virus.

    PubMed

    Zhang, Rui; Hisano, Sakae; Tani, Akio; Kondo, Hideki; Kanematsu, Satoko; Suzuki, Nobuhiro

    2016-01-01

    Viruses typically encode the capsid that encases their genome, while satellite viruses do not encode a replicase and depend on a helper virus for their replication(1). Here, we report interplay between two RNA viruses, yado-nushi virus 1 (YnV1) and yado-kari virus 1 (YkV1), in a phytopathogenic fungus, Rosellinia necatrix(2). YkV1 has a close phylogenetic affinity to positive-sense, single-stranded (+)ssRNA viruses such as animal caliciviruses(3), while YnV1 has an undivided double-stranded (ds) RNA genome with a resemblance to fungal totiviruses(4). Virion transfection and infectious full-length cDNA transformation has shown that YkV1 depends on YnV1 for viability, although it probably encodes functional RNA-dependent RNA polymerase (RdRp). Immunological and molecular analyses have revealed trans-encapsidation of not only YkV1 RNA but also RdRp by the capsid protein of the other virus (YnV1), and enhancement of YnV1 accumulation by YkV1. This study demonstrates interplay in which the capsidless (+)ssRNA virus (YkV1), hijacks the capsid protein of the dsRNA virus (YnV1), and replicates as if it were a dsRNA virus. PMID:27571749

  15. Biosynthesis, characterization and antimicrobial activity of silver nanoparticles by Streptomyces sp. SS2.

    PubMed

    Mohanta, Yugal Kishore; Behera, Sujit Kumar

    2014-11-01

    In the present study the microbial biosynthesis of silver nanoparticles (AgNPs) by secondary metabolites of Streptomyces sp. SS2 in an eco-friendly approach has been reported. The Streptomyces sp. SS2 was isolated from the soil sediment of Similipal Biosphere Reserve. The identification of this strain was determined by phenotypical characteristics (morphological and biochemical) and molecular characterization method using 16 s rDNA sequencing. The morphological study was also done by high-resolution scanning electron microscopy. The preliminary characterization of biosynthesized silver nanoparticle was carried out using UV-Vis spectrum analysis, which showed an absorption peak at 420 nm corresponding to plasmon absorption of silver. The average size and charge (zeta potential) of the particles were found to be 67.95 ± 18.52 nm and -17.7 ± 5.30 mV, respectively. The functional groups were identified by FTIR studies and their morphology (round and spherical shape) was determined by scanning electron microscopy. The synthesized AgNPs exhibited excellent antibacterial activity against Escherichia coli (MTCC 1089), Bacillus subtilis (MTCC 7164), Staphylococcus epidermis (MTCC 3615), Vibrio cholerae (MTCC 3904) and Staphylococcus aureus (MTCC 1144). These biotechnological approaches of synthesis of nanoparticles can direct a new path in biomaterial sciences and enrich biomedical applications. PMID:24842223

  16. Metabolic and Transcriptomic Changes Induced in Arabidopsis by the Rhizobacterium Pseudomonas fluorescens SS1011[W][OA

    PubMed Central

    van de Mortel, Judith E.; de Vos, Ric C.H.; Dekkers, Ester; Pineda, Ana; Guillod, Leandre; Bouwmeester, Klaas; van Loon, Joop J.A.; Dicke, Marcel; Raaijmakers, Jos M.

    2012-01-01

    Systemic resistance induced in plants by nonpathogenic rhizobacteria is typically effective against multiple pathogens. Here, we show that root-colonizing Pseudomonas fluorescens strain SS101 (Pf.SS101) enhanced resistance in Arabidopsis (Arabidopsis thaliana) against several bacterial pathogens, including Pseudomonas syringae pv tomato (Pst) and the insect pest Spodoptera exigua. Transcriptomic analysis and bioassays with specific Arabidopsis mutants revealed that, unlike many other rhizobacteria, the Pf.SS101-induced resistance response to Pst is dependent on salicylic acid signaling and not on jasmonic acid and ethylene signaling. Genome-wide transcriptomic and untargeted metabolomic analyses showed that in roots and leaves of Arabidopsis plants treated with Pf.SS101, approximately 1,910 genes and 50 metabolites were differentially regulated relative to untreated plants. Integration of both sets of “omics” data pointed to a prominent role of camalexin and glucosinolates in the Pf.SS101-induced resistance response. Subsequent bioassays with seven Arabidopsis mutants (myb51, cyp79B2cyp79B3, cyp81F2, pen2, cyp71A12, cyp71A13, and myb28myb29) disrupted in the biosynthesis pathways for these plant secondary metabolites showed that camalexin and glucosinolates are indeed required for the induction of Pst resistance by Pf.SS101. Also for the insect S. exigua, the indolic glucosinolates appeared to play a role in the Pf.SS101-induced resistance response. This study provides, to our knowledge for the first time, insight into the substantial biochemical and temporal transcriptional changes in Arabidopsis associated with the salicylic acid-dependent resistance response induced by specific rhizobacteria. PMID:23073694

  17. Redox-sensitive micelles assembled from amphiphilic mPEG-PCL-SS-DTX conjugates for the delivery of docetaxel.

    PubMed

    Zhang, Huiyuan; Wang, Kaiming; Zhang, Pei; He, Wenxiu; Song, Aixin; Luan, Yuxia

    2016-06-01

    Docetaxel (DTX) can produce anti-tumor effects by inhibiting cell growth and inducing apoptosis. However, the poor solubility of DTX restricts its application and its clinical formulation has caused serious adverse reaction due to the use of Tween-80. In the present study, DTX was conjugated to an amphiphilic di-block polymer to solve these problems. Methoxy poly(ethylene glycol)-poly(ε-caprolactone) (mPEG-PCL) was selected as the polymer skeleton and a redox sensitive disulfide bond was used as the linker between DTX and mPEG-PCL. The synthesized mPEG-PCL-SS-DTX conjugates were characterized by (1)H-nuclear magnetic resonance ((1)H NMR) and Fourier transform infrared spectroscopy (FTIR). Interestingly, the mPEG-PCL-SS-DTX conjugates could self-assemble into micelles in aqueous solution. The critical micelle concentration (CMC) of mPEG-PCL-SS-DTX micelles was about 2.3mgL(-1) determined using pyrene molecule fluorescent probe method while the size of mPEG-PCL-SS-DTX micelles was determined to be ca. 17.6nm and 116.0nm with a bimodal distribution by dynamic light scattering (DLS). The in vitro release results indicated that the as-prepared micelles exhibited a sustained release profile with good redox sensitive properties. In particular, the hemolytic toxicity test indicated the as-prepared mPEG-PCL-SS-DTX micelles had negligible hemolytic activity, demonstrating their safety in drug delivery system. Cytotoxicity assay of the mPEG-PCL-SS-DTX micelles verified their highly enhanced cytotoxicity to MCF-7/A and A549 cells. These results thus demonstrated that the present redox-sensitive mPEG-PCL-SS-DTX micelle was an efficient and safe sustained drug delivery system in the biomedical area.

  18. Serotoninergic neuronal systems and ethanol sensitivity in long-sleep (LS) and short-sleep (SS) mice

    SciTech Connect

    French, T.A.; Weiner, N.

    1986-03-01

    LS and SS mice selectively bred for differences in CNS sensitivity to ethanol (EtOH) exhibit markedly different sleep times (LS = 120 min; SS = 13 min) and differ considerably in hypothermic response following EtOH< 4 g/kg i.p. Basal levels of serotonin (5HT), 5-hydroxyindole acetic acid and 5HT turnover (defined as 5-hydroxy-tryptophan accumulation after inhibition of aromatic L-amino acid decarboxylase) in 6 brain regions (hypthalamus (HYP), dorsal raphe (DR), pontine-medullary raphe (PMR), striatum (STR), hippocampus (HIP) and cortex (CTX)) differ minimally between the two lines. 5 HT turnover in STR, HIP, CTX and PMR of either LS or SS mice or in HYP or DR of SS mice was not altered at either 20 or 120 min after EtOH, 4 g/kg. However, in LS mice, 5HT turnover was decreased 23% in HYP at 20 min and 30-34% in HYP and DR at 120 min. LS mice become 1.2 and 2.2/sup 0/ more hypothermic than SS mice at 20 and 120 min after EtOH, 4 g/kg. When approximately equi-effective hypothermic doses of EtOH were administered to LS (3.5 g/kg) and SS (5.0 g/kg) mice, differences in 5HT turnover were still apparent. Pentobarbital administration (65 mg/kg) both decreased brain 5HT turnover 30-60% and produced comparable degrees of hypothermia in LS and SS mice. These data suggest that the apparent increase in sensitivity to inhibition by EtOH of 5HT neurons of HYP and DR of LS mice may contribute to the greater degree of hypothermia induced in this line.

  19. HIV-Derived ssRNA Binds to TLR8 to Induce Inflammation-Driven Macrophage Foam Cell Formation

    PubMed Central

    Bernard, Mark A.; Han, Xinbing; Inderbitzin, Sonya; Agbim, Ifunanya; Zhao, Hui; Koziel, Henry; Tachado, Souvenir D.

    2014-01-01

    Even though combined anti-retroviral therapy (cART) dramatically improves patient survival, they remain at a higher risk of being afflicted with non-infectious complications such as cardiovascular disease (CVD). This increased risk is linked to persistent inflammation and chronic immune activation. In this study, we assessed whether this complication is related to HIV-derived ssRNAs inducing in macrophages increases in TNFα release through TLR8 activation leading to foam cell formation. HIV ssRNAs induced foam cell formation in monocyte-derived macrophages (MDMs) in a dose-dependent manner. This response was reduced when either endocytosis or endosomal acidification was inhibited by dynasore or chloroquine, respectively. Using a flow cytometry FRET assay, we demonstrated that ssRNAs bind to TLR8 in HEK cells. In MDMs, ssRNAs triggered a TLR8-mediated inflammatory response that ultimately lead to foam cell formation. Targeted silencing of the TLR8 and MYD88 genes reduced foam cell formation. Furthermore, foam cell formation induced by these ssRNAs was blocked by an anti-TNFα neutralizing antibody. Taken together in MDMs, HIV ssRNAs are internalized; bind TLR8 in the endosome followed by endosomal acidification. TLR8 signaling then triggers TNFα release and ultimately leads to foam cell formation. As this response was inhibited by a blocking anti-TNFα antibody, drug targeting HIV ssRNA-driven TLR8 activation may serve as a potential therapeutic target to reduce chronic immune activation and inflammation leading to CVD in HIV+ patients. PMID:25090652

  20. pH Meter probe assembly

    DOEpatents

    Hale, C.J.

    1983-11-15

    An assembly for mounting a pH probe in a flowing solution, such as a sanitary sewer line, which prevents the sensitive glass portion of the probe from becoming coated with grease, oil, and other contaminants, whereby the probe gives reliable pH indication over an extended period of time. The pH probe assembly utilizes a special filter media and a timed back-rinse feature for flushing clear surface contaminants of the filter. The flushing liquid is of a known pH and is utilized to check performance of the probe. 1 fig.

  1. pH Meter probe assembly

    DOEpatents

    Hale, Charles J.

    1983-01-01

    An assembly for mounting a pH probe in a flowing solution, such as a sanitary sewer line, which prevents the sensitive glass portion of the probe from becoming coated with grease, oil, and other contaminants, whereby the probe gives reliable pH indication over an extended period of time. The pH probe assembly utilizes a special filter media and a timed back-rinse feature for flushing clear surface contaminants of the filter. The flushing liquid is of a known pH and is utilized to check performance of the probe.

  2. Introgression of Brown Norway CYP4A genes on to the Dahl salt-sensitive background restores vascular function in SS-5(BN) consomic rats.

    PubMed

    Lukaszewicz, Kathleen M; Falck, John R; Manthati, Vijaya L; Lombard, Julian H

    2013-03-01

    The present study tested the hypothesis that the Dahl SS (salt-sensitive) rat has vascular dysfunction due, in part, to the up-regulation of the CYP4A/20-HETE (cytochrome P450 ω-hydroxylase 4A)/20-hydroxyeicosatetraenoic acid) system. To assess the role of vascular 20-HETE, SS rats were compared with SS-5(BN) consomic rats, carrying CYP4A alleles on chromosome 5 from the normotensive BN (Brown Norway) introgressed on to the SS genetic background. Cerebral arteries from SS-5(BN) rats had less CYP4A protein than arteries from SS rats fed either NS (normal-salt, 0.4% NaCl) or HS (high-salt, 4.0% NaCl) diet. ACh (acetylcholine)-induced dilation of MCAs (middle cerebral arteries) from SS and SS-5(BN) rats was present in SS-5(BN) rats fed on either an NS or HS diet, but absent in SS rats. In SS rats fed on either diet, ACh-induced dilation was restored by acute treatment with the CYP4A inhibitor DDMS (N-methyl-sulfonyl-12,12-dibromododec-11-enamide) or the 20-HETE antagonist 20-HEDE [20-hydroxyeicosa-6(Z),15(Z)-dienoic acid]. The restored response to ACh in DDMS-treated SS rats was inhibited by L-NAME (N(G)nitro-L-arginine methyl ester) and unaffected by indomethacin or MS-PPOH [N-methylsulfonyl-6-(2-propargyloxyphenyl)hexanamide]. Vascular relaxation responses to the NO donor C(5)FeN(6)Na(2)O were intact in both SS and SS-5(BN) rats and unaffected by the acute addition of DDMS, indicating that the vascular dysfunction of the SS rat is due to a reduced bioavailability of NO instead of failure of the VSMCs (vascular smooth muscle cells) to respond to the vasodilator. Superoxide levels in cerebral arteries of SS-5(BN) rats [evaluated semi-quantitatively by DHE (dihydroethidium) fluorescence] were lower than those in the arteries of SS rats. These findings indicate that SS rats have an up-regulation of the CYP4A/20-HETE pathway resulting in elevated ROS (reactive oxygen species) and reduced NO bioavailability causing vascular dysfunction.

  3. Synthesis of novel 17-(4'-formyl)pyrazolylandrosta-5,16-dienes and their derivatives as potent 17α-hydroxylase/C17,20-lyase inhibitors or antiproliferative agents depending on the substitution pattern of the heteroring.

    PubMed

    Kovács, Dóra; Wölfling, János; Szabó, Nikoletta; Szécsi, Mihály; Schelz, Zsuzsanna; Zupkó, István; Frank, Éva

    2016-09-14

    A series of novel 17-(4'-formyl)pyrazolylandrosta-5,16-dienes were efficiently synthesized in two steps from pregnadienolone acetate with monosubstituted hydrazines via the cyclization/formylation sequence of the primarily formed hydrazones on treatment with the Vilsmeier-Haack reagent. The products were further transformed by deacetylation and subsequent reduction in order to enlarge the compound library available for pharmacological studies. Moreover, 4'-formylpyrazoles containing H or Me on the heteroring-N were subjected to oxime formation and Ac2O-induced dehydration to furnish the corresponding 4'-cyano derivatives in good yields. The antiproliferative activities of the structurally related steroidal 17-exo-pyrazole derivatives were tested in vitro on four human adherent breast cancer cell lines (MCF7, T47D, MDA-MB-231 and MDA-MB-361): the microculture tetrazolium assay revealed that seven compounds exerted better cell growth-inhibitory effects on some or all these cell lines than those of the reference cisplatin. With regard to the well-known structural features that a potent C17,20-lyase inhibitor should possess, some relevant derivatives were tested in vitro from the aspects of their inhibitory effects on rat testicular enzyme, and one of them proved to exert noteworthy enzyme-inhibitory action, with an IC50 (26 nM) of the same order of magnitude as that of abiraterone. PMID:27209562

  4. The eSS rat, a nonobese model of disordered glucose and lipid metabolism and fatty liver

    PubMed Central

    2010-01-01

    Background eSS is a rat model of type 2 diabetes characterized by fasting hyperglycemia, glucose intolerance, hyperinsulinemia and early hypertriglyceridemia. Diabetic symptoms worsen during the second year of life as insulin release decreases. In 12-month-old males a diffuse hepatic steatosis was detected. We report the disturbances of lipid metabolism of the model with regard to the diabetic syndrome. Methods The study was conducted in eight 12-month-old eSS male rats and seven age/weight matched eumetabolic Wistar rats fed with a complete commercial diet al libitum. Fasting plasmatic glucose, insulin, triglycerides, total cholesterol, low-density and high-density lipoprotein, and nonesterified fatty acids levels were measured. Very low density and intermediate-density lipoproteins were analyzed and hepatic lipase activity was determined. Results eSS rats developed hyperglycemia and hyperinsulinemia, indicating insulin resistance. Compared with controls, diabetic rats exhibited high plasmatic levels of NEFA, triglycerides (TG), total cholesterol (Chol) and LDL-Chol while high-density lipoprotein (HDL) cholesterol values were reduced. eSS rats also displayed TG-rich VLDL and IDL particles without changes in hepatic lipase activity. Conclusion The nonobese eSS rats develop a syndrome characterized by glucose and lipid disorders and hepatic steatosis that may provide new opportunities for studying the pathogenesis of human type 2 diabetes. PMID:20236525

  5. Corrosion-erosion test of SS316L grain boundary engineering material (GBEM) in lead bismuth flowing loop

    NASA Astrophysics Data System (ADS)

    Saito, Shigeru; Kikuchi, Kenji; Hamaguchi, Dai; Tezuka, Masao; Miyagi, Masanori; Kokawa, Hiroyuki; Watanabe, Seiichi

    2012-12-01

    To evaluate the lifetime of structural materials utilized in a spallation neutron source, corrosion tests in lead-bismuth eutectic (LBE) have been done at JAEA. Austenitic steels are preferable as the structural material for ADS. However, previous studies have revealed that austenitic steel SS316 shows severe corrosion-erosion in LBE because of LBE penetration through grain boundaries and separation of grains. So it was considered that GBE (grain-boundary engineered) materials may be effective to improve the corrosion resistance of austenitic steels in LBE. In this study, the results of corrosion tests on austenitic steel SS316L-BM (base metal) and SS316L-GBEM (grain-boundary-engineered material) under flowing LBE conditions will be reported. The corrosion test was performed using the JAEA lead-bismuth material corrosion loop (JLBL-1). The experimental conditions were as follows: The high and low temperature parts of the loop were 450 °C and 350 °C, respectively. The flow velocity at the test specimens was about 0.7 m/s. The oxygen concentration in LBE was not controlled and was estimated to have been very low. After the 3600 h of operation, macroscopic, SEM, and SIM observations and EDX analysis were carried out. The results showed that the corrosion depth and LBE penetration through the grain boundaries of the 316SS-GBEM were smaller than those of the 316SS-BM.

  6. Fetal scalp pH testing

    MedlinePlus

    ... Normal pH: 7.25 to 7.35 Borderline pH: 7.20 to 7.25 The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some ...

  7. pH [Measure of Acidity].

    ERIC Educational Resources Information Center

    Henderson, Paula

    This autoinstructional program deals with the study of the pH of given substances by using litmus and hydrion papers. It is a learning activity directed toward low achievers involved in the study of biology at the secondary school level. The time suggested for the unit is 25-30 minutes (plus additional time for further pH testing). The equipment…

  8. pH. Agricultural Lesson Plans.

    ERIC Educational Resources Information Center

    Southern Illinois Univ., Carbondale. Dept. of Agricultural Education and Mechanization.

    This lesson plan is intended for use in conducting classes on the effect of pH on plant growth. Presented first are an attention step/problem statement and a series of questions and answers designed to convey general information about soil pH and its effect on plants. The following topics are among those discussed: acidity and alkalinity; the…

  9. Middle School and pH?

    ERIC Educational Resources Information Center

    Herricks, Susan

    2007-01-01

    A local middle school requested that the Water Center of Advanced Materials for Purification of Water With Systems (WaterCAMPWS), a National Science Foundation Science and Technology Center, provide an introduction to pH for their seventh-grade water-based service learning class. After sorting through a multitude of information about pH, a…

  10. Response to the "Responsive PhD"

    ERIC Educational Resources Information Center

    Huyssen, David

    2007-01-01

    In June 2005, 50 graduate school deans gathered at Princeton to address the fact that the number of new PhDs conferred each year far exceeds the number of tenure-track academic jobs on offer. Under the auspices of the Woodrow Wilson National Fellowship Foundation's Responsive PhD Project, these deans spoke passionately about how American…

  11. Inexpensive and Disposable pH Electrodes

    ERIC Educational Resources Information Center

    Goldcamp, Michael J.; Conklin, Alfred; Nelson, Kimberly; Marchetti, Jessica; Brashear, Ryan; Epure, Emily

    2010-01-01

    Inexpensive electrodes for the measurement of pH have been constructed using the ionophore tribenzylamine for sensing H[superscript +] concentrations. Both traditional liquid-membrane electrodes and coated-wire electrodes have been constructed and studied, and both exhibit linear, nearly Nernstian responses to changes in pH. Measurements of pH…

  12. Proteome of Salmonella enterica serotype Tyhimurium Grown in Low Mg2+/pH Medium

    SciTech Connect

    Shi, Liang; Ansong, Charles; Smallwood, Heather S.; Rommereim, Leah M.; McDermott, Jason E.; Brewer, Heather M.; Norbeck, Angela D.; Taylor, Ronald C.; Gustin, Jean K.; Heffron, Fred; Smith, Richard D.; Adkins, Joshua N.

    2009-09-04

    To determine the impact of a low Mg2+/pH defined growth medium (MgM) on the proteome of Salmonella enterica serotype Typhimurium, we cultured S. Typhimurium cells in the medium under two different conditions termed MgM Shock and MgM Dilution and then comparatively analyzed the bacterial cells harvested from these conditions by a global proteomic approach. Proteomic results showed that MgM Shock and MgM Dilution differentially affected the S. Typhimurium proteome. MgM Shock induced a group of proteins whose induction usually occurred at low O2 level, while MgM Dilution induced those related to the type III secretion system (T3SS) of Salmonella Pathogenicity Island 2 (SPI2) and those involved in thiamine or biotin biosynthesis. The metabolic state of the S. Typhimurium cells grown under MgM Shock condition also differed significantly from that under MgM Dilution condition. Western blot analysis not only confirmed the proteomic results, but also showed that the abundances of SPI2-T3SS proteins SsaQ and SseE and biotin biosynthesis proteins BioB and BioD increased after S. Typhimurium infection of RAW 264.7 macrophages. Deletion of the gene encoding BioB reduced the bacterial ability to replicate inside the macrophages, suggesting a biotin-limited environment encountered by S. Typhimurium within RAW 264.7 macrophages.

  13. Colorimetric determination of pH

    SciTech Connect

    Baumann, E.W.; Buchanan, B.R.

    1991-12-31

    There is a need for a simple, rapid, reliable means for determining pH values of concentrated, high salt solutions without reliance on human eye and ambient light. The method comprises the steps of preparing a set of reference solutions, measuring the light absorption by each reference solution, adding indicator dye to each reference solution, measuring the light absorption by each such reference mixture, comparing the two solutions to determine the dye color at each pH, normalizing the spectra of mixture to the isosbestic point, and matching the color of the pH of the solution to one of the colors of the pHs in the reference solution set. In this way, the pH can be determined to within 0.1 pH unit, a far more precise method than using the human eye.

  14. Intracellular pH modulates quinary structure

    PubMed Central

    Cohen, Rachel D; Guseman, Alex J; Pielak, Gary J

    2015-01-01

    NMR spectroscopy can provide information about proteins in living cells. pH is an important characteristic of the intracellular environment because it modulates key protein properties such as net charge and stability. Here, we show that pH modulates quinary interactions, the weak, ubiquitous interactions between proteins and other cellular macromolecules. We use the K10H variant of the B domain of protein G (GB1, 6.2 kDa) as a pH reporter in Escherichia coli cells. By controlling the intracellular pH, we show that quinary interactions influence the quality of in-cell 15N–1H HSQC NMR spectra. At low pH, the quality is degraded because the increase in attractive interactions between E. coli proteins and GB1 slows GB1 tumbling and broadens its crosspeaks. The results demonstrate the importance of quinary interactions for furthering our understanding of protein chemistry in living cells. PMID:26257390

  15. Determination Of Ph Including Hemoglobin Correction

    DOEpatents

    Maynard, John D.; Hendee, Shonn P.; Rohrscheib, Mark R.; Nunez, David; Alam, M. Kathleen; Franke, James E.; Kemeny, Gabor J.

    2005-09-13

    Methods and apparatuses of determining the pH of a sample. A method can comprise determining an infrared spectrum of the sample, and determining the hemoglobin concentration of the sample. The hemoglobin concentration and the infrared spectrum can then be used to determine the pH of the sample. In some embodiments, the hemoglobin concentration can be used to select an model relating infrared spectra to pH that is applicable at the determined hemoglobin concentration. In other embodiments, a model relating hemoglobin concentration and infrared spectra to pH can be used. An apparatus according to the present invention can comprise an illumination system, adapted to supply radiation to a sample; a collection system, adapted to collect radiation expressed from the sample responsive to the incident radiation; and an analysis system, adapted to relate information about the incident radiation, the expressed radiation, and the hemoglobin concentration of the sample to pH.

  16. A hybrid microbial fuel cell stack based on single and double chamber microbial fuel cells for self-sustaining pH control

    NASA Astrophysics Data System (ADS)

    Yang, Wei; Li, Jun; Ye, Dingding; Zhang, Liang; Zhu, Xun; Liao, Qiang

    2016-02-01

    Proton accumulation in the anode chamber is the major problem that affects the operational stability and electricity generation performance of double chamber microbial fuel cells (MFCs). In this study, a hybrid microbial fuel cell stack (DS-DS stack) based on single (SCMFCs) and double chamber MFCs (DCMFCs) is proposed for self-sustaining pH control in the MFC stack. It is found that the aerobic microbial oxidation of acetate by the biofilm that is attached to the air cathode of SCMFCs is responsible for the self-sustaining removal of accumulated H+ in the effluent of DCMFCs. Compared with the stack that solely consists of SCMFCs (SS-SS stack) or DCMFCs (DD-DD stack), the hybrid stack exhibits the highest electricity output performance and the most effective conversion of acetate into electricity at high power levels. Furthermore, the hybrid stack demonstrates the operation time of 15.7 ± 1.1 h when the operating voltage is above 0.8 V. This value is much higher than that of the DD-DD (8.5 ± 2.4 h) and SS-SS (8.1 ± 1.4 h) stacks, which suggests that the hybrid stack had a good operational stability.

  17. Isolation, Identification, and Characterization of a Cellulolytic Bacillus amyloliquefaciens Strain SS35 from Rhinoceros Dung

    PubMed Central

    Singh, Shuchi; Moholkar, Vijayanand S.; Goyal, Arun

    2013-01-01

    Cellulose hydrolyzing bacteria were isolated from rhinoceros dung and tested for clear zone formation around the colonies on the agar plates containing the medium amended with carboxymethylcellulose as a sole carbon source. Isolates were further screened on the basis of carboxymethylcellulase production in liquid medium. Out of 36 isolates, isolate no. 35 exhibited maximum enzyme activity of 0.079 U/mL and was selected for further identification by using conventional biochemical tests and phylogenetic analyses. This was a Gram-positive, spore forming bacterium with rod-shaped cells. The isolate was identified as Bacillus amyloliquefaciens SS35 based on nucleotide homology and phylogenetic analysis using 16S rDNA and gyrase A gene sequences. PMID:23762763

  18. An SS-TDMA system using onboard regenerative repeaters and baseband switch

    NASA Astrophysics Data System (ADS)

    Kato, S.; Samejima, S.; Yamamoto, H.

    A system configuration of a Satellite Switched Time Division Multiple Access (SS-TDMA) satellite communication system employing onboard regenerative repeaters, a baseband switch and IF switch is proposed and discussed. The system proposed in this paper utilizes 30/20 GHz frequency bands and is composed of Trunk Transmission Systems and Satellite Digital Communication Systems which provide wide band digital communication links between customers directly. Interface conditions between terrestrial digital terminals and TDMA traffic terminals, and a TDMA frame structure for Trunk Transmission Systems are proposed and discussed. Moreover, a transmission power control scheme for multibeam satellite communication systems is proposed. Furthermore, the experimental results for a prototype onboard burst modem are presented showing good bit error ratio and weight performance.

  19. Quantifying the Interfacial Strength of Oxide Scale and SS 441 Substrate Used in SOFC

    SciTech Connect

    Liu, Wenning N.; Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2009-08-15

    Under a typical SOFC working environment, oxide scale will grow on the metallic interconnects in oxidant environment. The growth of the oxide scale induces the growth stresses in the oxide scale and on the scale/substrate interface combined with the thermal stresses induced by thermal expansion coefficient mismatch between the oxide scale and the substrate, which may lead to scale delamination/buckling and eventual spallation during stack cooling, even leading to serious cell performance degradation. Therefore, the interfacial adhesion strength between the oxide scale and substrate is crucial to the reliability and durability of the metallic interconnect in SOFC operating environments. As a powerful contender of ferritic interconnects used in SOFC, its interfacial strength between the oxide scale and SS 441 substrate is very important for its application. In this paper, we applied an integrated experimental/analytical methodology to quantify the interfacial adhesion strength between oxide scale and metallic interconnect. The predicted interfacial strength is discussed in detailed

  20. PREFACE: The 4th Symposium on the Mechanics of Slender Structures (MoSS2013)

    NASA Astrophysics Data System (ADS)

    Cao, Dengqing; Kaczmarczyk, Stefan

    2013-07-01

    This volume of Journal of Physics: Conference Series contains papers presented at the 4th Symposium on the Mechanics of Slender Structures (MoSS2013) run under the auspices of the Institute of Physics Applied Mechanics Group and hosted by Harbin Institute of Technology (China) from 7-9 January 2013. The conference has been organized in collaboration with the Technical Committee on Vibration and Sound of the American Society of Mechanical Engineers and follows a one day seminar on Ropes, Cables, Belts and Chains: Theory and Applications and the MoSS2006 symposium held at the University of Northampton (UK) in 2004 and 2006, respectively, the MoSS2008 symposium held at the University of Maryland Baltimore County (USA) in 2008 and the MoSS2010 symposium hosted by Mondragon University and held in San Sebastian (Spain) in 2010. The remit of the Symposium on the Mechanics of Slender Structures series involves a broad range of scientific areas. Applications of slender structures include terrestrial, marine and space systems. Moving elastic elements such as ropes, cables, belts and tethers are pivotal components of many engineering systems. Their lengths often vary when the system is in operation. The applications include vertical transportation installations and, more recently, space tether propulsion systems. Traction drive elevator installations employ ropes and belts of variable length as a means of suspension, and also for the compensation of tensile forces over the traction sheave. In cranes and mine hoists, cables and ropes are subject to length variation in order to carry payloads. Tethers experiencing extension and retraction are important components of offshore and marine installations, as well as being proposed for a variety of different space vehicle propulsion systems based on different applications of momentum exchange and electrodynamic interactions with planetary magnetic fields. Furthermore, cables and slender rods are used extensively in civil engineering

  1. Classification of integrable super-systems using the SsTools environment

    NASA Astrophysics Data System (ADS)

    Kiselev, A. V.; Wolf, T.

    2007-08-01

    A classification problem is proposed for supersymmetric evolutionary PDE that satisfy the assumptions of nonlinearity, nondegeneracy, and homogeneity. Four classes of nonlinear coupled boson-fermion systems are discovered under the weighting assumption |f|=|b|=|D|=1/2 >. The syntax of the REDUCE package SSTOOLS, which was used for intermediate computations, and the applicability of its procedures to the calculus of super-PDE are described. Program summaryProgram title:SsTools Catalogue identifier:ADYY_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADYY_v1_0.html Program obtainable from:CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions:Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.:89 178 No. of bytes in distributed program, including test data, etc.:869 212 Distribution format:tar.gz Programming language:REDUCE 3.7, REDUCE 3.8 Computer:(i) IBM PC, (ii) cluster Operating system:LINUX RAM:problem dependent (10 Mb-1 Gb), typical working size <100 Mb Word size:32, 64 bits Nature of problem:The program allows the classification of N⩾1 supersymmetric nonlinear scaling-invariant evolution equations {f=φ,b=φ} that admit infinitely many local symmetries propagated by recursion operators; here b(x,t;θ) is the set of bosonic super-fields and f(x;t;θ) are fermionic super-fields. Solution method:First, (half-)integer weights |f|,|b|,…,|D|,|D|≡1 are assigned to all variables and derivatives and then pairs of commuting flows that are homogeneous w.r.t. these weights are constructed. Secondly, the seeds of higher symmetry sequences [P.J. Olver, Applications of Lie Groups to Differential Equations, second ed., Springer, Berlin, 1993] for the systems are sorted out, and finally the recursion operators that generate the symmetries are obtained [I.S. Krasil'shchik, P.H.M. Kersten, Symmetries and Recursion Operators for Classical and Supersymmetric

  2. Observation of tree-level B decays with ss production from gluon radiation.

    PubMed

    Aubert, B; Bona, M; Boutigny, D; Karyotakis, Y; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Garra Tico, J; Grauges, E; Lopez, L; Palano, A; Eigen, G; Stugu, B; Sun, L; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Ronan, M T; Tackmann, K; Wenzel, W A; Del Amo Sanchez, P; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Schroeder, T; Steinke, M; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Khan, A; Saleem, M; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Zhang, L; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Williams, D C; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Gabareen, A M; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Brandt, T; Klose, V; Kobel, M J; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Lombardo, V; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Santoro, V; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Nikolich, M B; Panduro Vazquez, W; Tibbetts, M; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Guo, Z J; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Béquilleux, J; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Paramesvaran, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Dujmic, D; Fisher, P H; Koeneke, K; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Zhao, M; Zheng, Y; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; De Nardo, G; Fabozzi, F; Lista, L; Monorchio, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Benelli, G; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gagliardi, N; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Calderini, G; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; Leruste, Ph; Malclès, J; Ocariz, J; Perez, A; Gladney, L; Biasini, M; Covarelli, R; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Cenci, R; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Biesiada, J; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Baracchini, E; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Castelli, G; Franek, B; Olaiya, E O; Ricciardi, S; Roethel, W; Wilson, F F; Aleksan, R; Emery, S; Escalier, M; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Hast, C; Hryn'ova, T; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ofte, I; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Neal, H

    2008-05-01

    We report on our search for decays proceeding via a tree-level b-->c quark transition in which a gluon radiates into an ss[over ] pair. We present observations of the decays B;{-}-->D_{s};{+}K;{-}pi;{-} and B[over ];{0}-->D_{s};{+}K_{S};{0}pi;{-} and evidence for B;{-}-->D_{s};{+}K;{-}K;{-} and set upper limits on the branching fractions for B[over ];{0}-->D_{s};{+}K_{S};{0}pi;{-} and B;{-}-->D_{s};{+}K;{-}K;{-} using 383x10;{6} Upsilon(4S)-->BB[over ] events collected by the BABAR detector at SLAC. We present evidence that the invariant mass distributions of D_{s};{+}K;{-} pairs from B;{-}-->D_{s};{+}K;{-}pi;{-} decays are inconsistent with the phase-space model, suggesting the presence of charm resonances lying below the D_{s};{+}K;{-} threshold. PMID:18518280

  3. Sheet-scanned dual-axis confocal (SS-DAC) microscopy using Richardson-Lucy deconvolution

    PubMed Central

    Wang, Danni; Meza, Daphne; Wang, Yu; Gao, Liang; Liu, Jonathan T.C.

    2015-01-01

    We have previously developed a line-scanned dual-axis confocal (LS-DAC) microscope with subcellular resolution suitable for high-frame-rate diagnostic imaging at shallow depths. Due to the loss of confocality along one dimension, the contrast (signal-to-background ratio) of a LS-DAC microscope is deteriorated compared to a point-scanned DAC microscope. However, by using a sCMOS camera for detection, a short oblique light-sheet is imaged at each scanned position. Therefore, by scanning the light sheet in only one dimension, a thin 3D volume is imaged. Both sequential two-dimensional deconvolution and three-dimensional deconvolution are performed on the thin image volume to improve the resolution and contrast of one en face confocal image section at the center of the volume, a technique we call sheet-scanned dual-axis confocal (SS-DAC) microscopy. PMID:26466290

  4. Migration and release behavior of tritium in SS316 at ambient temperature

    NASA Astrophysics Data System (ADS)

    Torikai, Y.; Murata, D.; Penzhorn, R.-D.; Akaishi, K.; Watanabe, K.; Matsuyama, M.

    2007-06-01

    BIXS measurements indicate that immersion into water or chemical etching of SS316 contaminated with tritium at moderate temperatures causes an immediate reduction of the outermost surface concentration of tritium. The fraction of surface tritium removed by water, i.e. 30-50%, is small in comparison to the total tritium present in the specimen. Allowing a specimen to age whose surface and subsurface had been removed by etching up to a depth where the concentration of tritium is mostly constant revealed that within a few months a re-growth of tritium up to a saturation value higher than half of that originally present on the specimen takes place. Concurrently, a small but steady liberation of tritium at rates increasing from 0.1 to 0.3 kBq/h was noticed.

  5. Reweldability test of irradiated SS316 by the TIG welding method

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Kunihiko; Kawamura, Hiroshi; Oyamada, Rokuro

    1996-10-01

    Stainless steel is a candidate material for the structural material in fusion reactors. Rewelding of irradiated materials will have a large impact on the design and the maintenance of in-vessel components. In the present work, the welding specimens made of type 316 stainless steel were irradiated in JMTR (Japan materials testing reactor) to a fast neutron fluence of ˜2.0 × 10 20 n/cm 2 ( E > 1 MeV) at a temperature of ˜200°C. The rewelding of unirradiated and/or irradiated stainless steel was performed by the tungsten inert gas (TIG) welding method and the weldments of unirradiated and/or irradiated SS316 were characterized by tensile testing (test temp.: 20°C and 200°C), hardness, metallographical observation and SEM/XMA analyses.

  6. Evaluation of liquid metal embrittlement of SS304 by Cd and Cd-Al solutions

    SciTech Connect

    Thomas, J.K.; Iyer, N.C.; Begley, J.A.

    1992-07-01

    The susceptibility of stainless steel 304 to liquid metal embrittlement (LME) by cadmium (Cd) and cadmium-aluminum (Cd-Al) solutions was examined as part of a failure evaluation for SS304-clad cadmium reactor safety rods which had been exposed to elevated temperatures. The active, or cadmium (Cd) bearing, portion of the safety rod consists of a 0.756 in. diameter aluminum allow (Al-6061) core, a 0.05 in. thick Cd layer, and a 0.042 in. thick Type 304 stainless steel cladding. The safety rod thermal tests were conducted as part of a program to define the response of reactor core components to a hypothetical LOCA for the Savannah River Site (SRS) production reactor. LME was considered as a potential failure mechanism based on the nature of the failure and susceptibility of austenitic stainless steels to embrittlement by other liquid metals.

  7. Evaluation of liquid metal embrittlement of SS304 by Cd and Cd-Al solutions

    SciTech Connect

    Thomas, J.K.; Iyer, N.C. ); Begley, J.A. )

    1992-01-01

    The susceptibility of stainless steel 304 to liquid metal embrittlement (LME) by cadmium (Cd) and cadmium-aluminum (Cd-Al) solutions was examined as part of a failure evaluation for SS304-clad cadmium reactor safety rods which had been exposed to elevated temperatures. The active, or cadmium (Cd) bearing, portion of the safety rod consists of a 0.756 in. diameter aluminum allow (Al-6061) core, a 0.05 in. thick Cd layer, and a 0.042 in. thick Type 304 stainless steel cladding. The safety rod thermal tests were conducted as part of a program to define the response of reactor core components to a hypothetical LOCA for the Savannah River Site (SRS) production reactor. LME was considered as a potential failure mechanism based on the nature of the failure and susceptibility of austenitic stainless steels to embrittlement by other liquid metals.

  8. An atlas of H-alpha-emitting regions in M33: A systematic search for SS433 star candidates

    NASA Technical Reports Server (NTRS)

    Calzetti, Daniela; Kinney, Anne L.; Ford, Holland; Doggett, Jesse; Long, Knox S.

    1995-01-01

    We report finding charts and accurate positions for 432 compact H-alpha emitting regions in the Local Group galaxy M 33 (NGC 598), in an effort to isolate candidates for an SS433-like stellar system. The objects were extracted from narrow band images, centered in the rest-frame H-alpha (lambda 6563 A) and in the red continuum at 6100 A. The atlas is complete down to V approximately equal to 20 and includes 279 compact HII regions and 153 line emitting point-like sources. The point-like sources undoubtedly include a variety of objects: very small HII regions, early type stars with intense stellar winds, and Wolf-Rayet stars, but should also contain objects with the characteristics of SS433. This extensive survey of compact H-alpha regions in M 33 is a first step towards the identification of peculiar stellar systems like SS433 in external galaxies.

  9. The effect of topography of upper-mantle discontinuities on SS precursors

    NASA Astrophysics Data System (ADS)

    Koroni, Maria; Trampert, Jeannot

    2016-01-01

    Using the spectral-element method, we explored the effect of topography of upper-mantle discontinuities on the traveltimes of SS precursors recorded on transverse component seismograms. The latter are routinely used to infer the topography of mantle transition zone discontinuities. The step from precursory traveltimes to topographic changes is mainly done using linearised ray theory, or sometimes using finite-frequency kernels. We simulated exact seismograms in 1-D and 3-D elastic models of the mantle. In a second simulation, we added topography to the discontinuities. We compared the waveforms obtained with and without topography by cross correlation of the SS precursors. Since we did not add noise, the precursors are visible in individual seismograms without the need of stacking. The resulting time anomalies were then converted into topographic variations and compared to the original topographic models. Based on the correlation between initial and inferred models, and provided that ray coverage is good, we found that linearised ray theory gives a relatively good idea on the location of the uplifts and depressions of the discontinuities. It seriously underestimates the amplitude of the topographic variations by a factor ranging between 2 and 7. Real data depend on the 3-D elastic structure and the topography. All studies to date correct for the 3-D elastic effects assuming that the traveltimes can be linearly decomposed into a structure and a discontinuity part. We found a strong non-linearity in this decomposition which cannot be modelled without a fully non-linear inversion for elastic structure and discontinuities simultaneously.

  10. Discriminative feeding behaviour of Anopheles gambiae s.s. on endemic plants in western Kenya

    PubMed Central

    Manda, H.; Gouagna, L. C.; Nyandat, E.; Kabiru, E. W.; Jackson, R. R.; Foster, W. A.; Githure, J. I.; Beier, J. C.; Hassanali, A.

    2009-01-01

    Anopheles gambiae Giles s.s. (Diptera: Culicidae) is known to feed on plant sugars, but this is the first experimental study to consider whether it discriminates between plant species. Thirteen perennial plant species were selected on the basis of their local availability within the vicinity of human dwellings and larval habitats of An. gambiae s.s. in western Kenya. Groups of 100 or 200 mosquitoes were released into cages either with a cutting of one plant type at a time (single-plant assay) or with cuttings of all 13 plants simultaneously (choice assay), respectively, and left overnight. In the choice assay, direct observations of the percentages of mosquitoes perching or feeding on each plant were recorded over four 1-h periods each night. For both types of assay, mosquitoes were recaptured and the percentage that had fed on plants was assessed by testing them individually for the presence of fructose. To identify which plants the choice-assay mosquitoes had fed on, gas chromatography (GC) profiles of samples of mosquito homogenates were compared with GC profiles of extracts from relevant parts of each plant. Four of the plants that were observed to have been fed on most frequently in the choice assay (Parthenium hysterophorus L., Tecoma stans L., Ricinus communis L., and Senna didymobotrya Fresen) were also shown to have been ingested most often by mosquitoes in both types of assay, suggesting that An. gambiae is differentially responsive to this range of plants, regardless of whether the plants were presented singly or mixed together. Significantly more females than males fed on plants, with the exception of P. hysterophorus L., one of the plants most frequently fed on. For most plant species (ten of 13), GC profiles indicated that An. gambiae obtained sugars primarily from flowers. The exceptions were P. hysterophorus L., Lantana camara L. and R. communis L., on which An. gambiae fed more often from leaves and stems than from flowers. PMID:17373953

  11. MicNeSs: genotyping microsatellite loci from a collection of (NGS) reads.

    PubMed

    Suez, Marie; Behdenna, Abdelkader; Brouillet, Sophie; Graça, Paula; Higuet, Dominique; Achaz, Guillaume

    2016-03-01

    Microsatellites are widely used in population genetics to uncover recent evolutionary events. They are typically genotyped using capillary sequencer, which capacity is usually limited to 9, at most 12 loci for each run, and which analysis is a tedious task that is performed by hand. With the rise of next-generation sequencing (NGS), a much larger number of loci and individuals are available from sequencing: for example, on a single run of a GS Junior, 28 loci from 96 individuals are sequenced with a 30X cover. We have developed an algorithm to automatically and efficiently genotype microsatellites from a collection of reads sorted by individual (e.g. specific PCR amplifications of a locus or a collection of reads that encompass a locus of interest). As the sequencing and the PCR amplification introduce artefactual insertions or deletions, the set of reads from a single microsatellite allele shows several length variants. The algorithm infers, without alignment, the true unknown allele(s) of each individual from the observed distributions of microsatellites length of all individuals. MicNeSs, a python implementation of the algorithm, can be used to genotype any microsatellite locus from any organism and has been tested on 454 pyrosequencing data of several loci from fruit flies (a model species) and red deers (a nonmodel species). Without any parallelization, it automatically genotypes 22 loci from 441 individuals in 11 hours on a standard computer. The comparison of MicNeSs inferences to the standard method shows an excellent agreement, with some differences illustrating the pros and cons of both methods.

  12. The Accretion Flow and Boundary Layer Structure in the Dwarf Nova SS Aur

    NASA Astrophysics Data System (ADS)

    Nabizadeh, Armin; Balman, Solen; Godon, Patrick; Sion, Edward; Hertfelder, Marius

    2016-07-01

    We present X-ray analysis of dwarf novae SS Aur (51 ksec) using XMM-Newton Observatory archival data obtained in quiescence for a better understanding of the accretion flow structure. We find X-ray orbital modulations. We report power spectral analysis for EPIC (X-ray) and OM (UV) light curves suggesting high levels of red noise with no significant QPO or periodicities. We simultaneously fitted EPIC pn, MOS1 and MOS2 data using a model for interstellar medium absorption (tbabs) and a multi-temperature plasma emission model (cevmkl) as expected from low accretion rate quiescent dwarf novae. However, the composite model fit yields unacceptable reduced χ ^{2} values due to the existence of soft excess. The soft excess is well modeled using a blackbody model (kT˜˜24 eV) giving a better reduced χ ^{2} value over 3σ significance level. This may indicate the existence of optically thick boundary layer emission. We will discuss the origin of this excess. The best fitting model is a combination of a blackbody, a cevmkl and a power law with an interstellar absorption which yields a reduced χ ^{2} of 1.05. The fit also shows some oxygen and iron over abundances. SS Aur has a maximum thermal plasma temperature of ˜22 keV. The X-ray luminosity in the 0.1 to 50.0 keV energy band is ˜2.0×10 ^{33} ergs ^{-1}. Finally, we discuss these characteristics in the light of standard disk models and accretion flows and geometry in nonmagnetic cataclysmic variables.

  13. ROP and ATRP Fabricated Dual Targeted Redox Sensitive Polymersomes Based on pPEGMA-PCL-ss-PCL-pPEGMA Triblock Copolymers for Breast Cancer Therapeutics.

    PubMed

    Kumar, Arun; Lale, Shantanu V; Mahajan, Shveta; Choudhary, Veena; Koul, Veena

    2015-05-01

    To minimize cardiotoxicity and to increase the bioavailability of doxorubicin, polymersomes based on redox sensitive amphiphilic triblock copolymer poly(polyethylene glycol methacrylate)-poly(caprolactone)-s-s-poly(caprolactone)-poly(polyethylene glycol methacrylate) (pPEGMA-PCL-ss-PCL-pPEGMA) with disulfide linkage were designed and developed. The polymers were synthesized by ring opening polymerization (ROP) of ε-caprolactone followed by atom transfer radical polymerization (ATRP) of PEGMA. The triblock copolymers demonstrated various types of nanoparticle morphologies by varying hydrophobic/hydrophilic content of polymer blocks, with PEGMA content of ∼18% in the triblock copolymer leading to the formation of polymersomes in the size range ∼150 nm. High doxorubicin loading content of ∼21% was achieved in the polymersomes. Disulfide linkages were incorporated in the polymeric backbone to facilitate degradation of the nanoparticles by the intracellular tripeptide glutathione (GSH), leading to intracellular drug release. Release studies showed ∼59% drug release in pH 5.5 in the presence of 10 mM GSH, whereas only ∼19% was released in pH 7.4. In cellular uptake studies, dual targeted polymersomes showed ∼22-fold increase in cellular uptake efficiency in breast cancer cell lines (BT474 and MCF-7) as compared to nontargeted polymersomes with higher apoptosis rates. In vivo studies on Ehrlich's ascites tumor (EAT) bearing Swiss albino mouse model showed ∼85% tumor regression as compared to free doxorubicin (∼42%) without any significant cardiotoxicity associated with doxorubicin. The results indicate enhanced antitumor efficacy of the redox sensitive biocompatible nanosystem and shows promise as a potential drug nanocarrier in cancer therapeutics.

  14. Impact of cagPAI and T4SS on the Inflammatory Response of Human Neutrophils to Helicobacter pylori Infection

    PubMed Central

    Sánchez-Zauco, Norma Angélica; Torres, Javier; Pérez-Figueroa, Gloria Erandi; Álvarez-Arellano, Lourdes; Camorlinga-Ponce, Margarita; Gómez, Alejandro; Giono-Cerezo, Silvia; Maldonado-Bernal, Carmen

    2013-01-01

    Helicobacter pylori contains a pathogenicity island, cagPAI, with genes homologous to components of the type IV secretion system (T4SS) of Agrobacterium tumefaciens. The T4SS components assemble a structure that transfers CagA protein and peptidoglycan into host epithelial cells, causing the increased release of interleukin 8 (IL8) from the cells. The Toll-like receptors on neutrophils recognize H. pylori, initiating signaling pathways that enhance the activation of NF-κB. However, the roles of cagPAI and T4SS in the inflammatory response of neutrophils are unknown. We evaluated the participation of cagPAI and T4SS in the response of human neutrophils to H. pylori infection. Neutrophils were isolated from the blood of healthy donors and infected with H. pylori cagPAI+, cagPAI–, and cagPAI mutant strains virB4– and virD4–. Whereas cagPAI+ strain 26695 induced the greatest IL8 production, a proinflammatory response, cagPAI– strain 8822 induced the greatest IL10 production, an anti-inflammatory response. In contrast, the virB4– and virD4– mutant strains produced significantly more of the two proinflammatory cytokines IL1β and tumor necrosis factor αthan the cagPAI+ strain 26695. We observed that H. pylori downregulated the expression of TLRs 2 and 5 but upregulated TLR9 expression in a cagPAI and T4SS-independent manner. These results show for the first time that the response of human neutrophils to H. pylori may vary from a pro-inflammatory to an anti-inflammatory response, depending on cagPAI and the integrity of T4SS. PMID:23755130

  15. Investigating the presence of predatory bacteria on algal bloom samples using a T6SS gene marker.

    NASA Astrophysics Data System (ADS)

    Hendricks, J.; Sison-Mangus, M.; Mehic, S.; McMahon, E.

    2015-12-01

    Predation is considered to be a major driving force in evolution and ecology, which has been observed affecting individual organisms, communities, and entire ecosystems. The type VI secretion system (T6SS) is an intermembranal protein complex identified in certain bacteria, which appears to have evolved strictly as a mechanism of predation. The effects of bacteria on phytoplankton physiology are still understudied, however, studies have shown that the interactions between bacteria that inhabit the phycosphere of phytoplankton can possibly result in coevolution of native host and microbiota. It is unclear if bacteria can prey upon other bacteria to gain advantages during periods of high phytoplankton density. Here, we investigate the predatory interactions between bacteria and analyze environmental samples for the presence of predatory bacterial genes in an effort to understand bacteria-bacteria and phytoplankton interactions during algal blooms. DNA were extracted from bacterial samples collected weekly from size-fractionated samples using 3.0 um and 0.2 um membrane filters at the Santa Cruz wharf. PCR amplification and gel visualization for the presence of T6SS gene was carried out on bloom and non-bloom samples. Moreover, we carried out a lab- based experiment to observe bacteria-bacteria interaction that may hint for the presence of predatory behavior between bacterial taxa. We observed what appeared to be a predatory biofilm formation between certain bacterial species. These bacteria, however, did not contain the T6SS genes. On the contrary the T6SS gene was discovered in some of the bloom samples gathered from the Santa Cruz wharf. It is still unclear if the predatory mechanisms facilitate the abundance of certain groups of bacteria that contain the T6SS genes during algal blooms, but our evidence suggest that bacterial predation through T6SS mechanism is present during bloom events.

  16. Biodegradable mixed MPEG-SS-2SA/TPGS micelles for triggered intracellular release of paclitaxel and reversing multidrug resistance

    PubMed Central

    Dong, Kai; Yan, Yan; Wang, Pengchong; Shi, Xianpeng; Zhang, Lu; Wang, Ke; Xing, Jianfeng; Dong, Yalin

    2016-01-01

    In this study, a type of multifunctional mixed micelles were prepared by a novel biodegradable amphiphilic polymer (MPEG-SS-2SA) and a multidrug resistance (MDR) reversal agent (d-α-tocopheryl polyethylene glycol succinate, TPGS). The mixed micelles could achieve rapid intracellular drug release and reversal of MDR. First, the amphiphilic polymer, MPEG-SS-2SA, was synthesized through disulfide bonds between poly (ethylene glycol) monomethyl ether (MPEG) and stearic acid (SA). The structure of the obtained polymer was similar to poly (ethylene glycol)-phosphatidylethanolamine (PEG-PE). Then the mixed micelles, MPEG-SS-2SA/TPGS, were prepared by MPEG-SS-2SA and TPGS through the thin film hydration method and loaded paclitaxel (PTX) as the model drug. The in vitro release study revealed that the mixed micelles could rapidly release PTX within 24 h under a reductive environment because of the breaking of disulfide bonds. In cell experiments, the mixed micelles significantly inhibited the activity of mitochondrial respiratory complex II, also reduced the mitochondrial membrane potential, and the content of adenosine triphosphate, thus effectively inhibiting the efflux of PTX from cells. Moreover, in the confocal laser scanning microscopy, cellular uptake and 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assays, the MPEG-SS-2SA/TPGS micelles achieved faster release and more uptake of PTX in Michigan Cancer Foundation-7/PTX cells and showed better antitumor effects as compared with the insensitive control. In conclusion, the biodegradable mixed micelles, MPEG-SS-2SA/TPGS, could be potential vehicles for delivering hydrophobic chemotherapeutic drugs in MDR cancer therapy. PMID:27785018

  17. Microstructural, thermo-optical, mechanical and tribological behaviours of vacuum heat treated ultra thin SS304 foils

    NASA Astrophysics Data System (ADS)

    Palai, Debajyoti; Bhattacharya, Manjima; Basu Mallick, Amitava; Bera, Parthasarathi; Sharma, Anand Kumar; Mukhopadhyay, Anoop Kumar; Dey, Arjun

    2016-09-01

    The purpose of this present study was to evaluate the effect of vacuum (i.e., 10-5 mbar) heat treatment at 300 to 1100 °C on morphological, thermo-optical, mechanical and tribological properties of 75 μm thin SS304 foils. Microstructural, morphological and surface properties of the foils were characterized by field emission scanning electron microscopy (FESEM), profilometry, x-ray photoelectron spectroscopy (XPS) and water contact angle (WCA) measurement techniques, respectively. The x-ray diffraction (XRD) was employed to identify the phase of SS304 foils after different heat treatment temperatures. Thermo-optical properties such as solar absorptance (α s), reflectance (ρ s) and IR emittance (ɛ ir) were also evaluated. The nanomechanical properties i.e., nanohardness (H) and Young’s modulus (E) of as-received and heat treated SS304 foils were evaluated by the nanoindentation technique. Tribological and tensile properties i.e., yield strength (σ y) and percentage of elongation of different heat treated foils were also investigated by single pass scratch tests and universal testing machine, respectively. Noteworthy grain growth of SS304 was observed beyond vacuum heat treatment temperature of 700 °C. As a consequence, the magnitudes of both H and E data of SS304 were significantly decreased beyond the vacuum heat treatment temperature of 700 °C. Further, the hardness data followed the well known Hall-Petch relationship. On the other hand, the tribological property of SS304 was significantly deteriorated beyond the vacuum heat treatment temperature of 700 °C. The tensile strength of the foils was also altered after the heat treatment.

  18. Microstructural, thermo-optical, mechanical and tribological behaviours of vacuum heat treated ultra thin SS304 foils

    NASA Astrophysics Data System (ADS)

    Palai, Debajyoti; Bhattacharya, Manjima; Basu Mallick, Amitava; Bera, Parthasarathi; Sharma, Anand Kumar; Mukhopadhyay, Anoop Kumar; Dey, Arjun

    2016-09-01

    The purpose of this present study was to evaluate the effect of vacuum (i.e., 10‑5 mbar) heat treatment at 300 to 1100 °C on morphological, thermo-optical, mechanical and tribological properties of 75 μm thin SS304 foils. Microstructural, morphological and surface properties of the foils were characterized by field emission scanning electron microscopy (FESEM), profilometry, x-ray photoelectron spectroscopy (XPS) and water contact angle (WCA) measurement techniques, respectively. The x-ray diffraction (XRD) was employed to identify the phase of SS304 foils after different heat treatment temperatures. Thermo-optical properties such as solar absorptance (α s), reflectance (ρ s) and IR emittance (ε ir) were also evaluated. The nanomechanical properties i.e., nanohardness (H) and Young’s modulus (E) of as-received and heat treated SS304 foils were evaluated by the nanoindentation technique. Tribological and tensile properties i.e., yield strength (σ y) and percentage of elongation of different heat treated foils were also investigated by single pass scratch tests and universal testing machine, respectively. Noteworthy grain growth of SS304 was observed beyond vacuum heat treatment temperature of 700 °C. As a consequence, the magnitudes of both H and E data of SS304 were significantly decreased beyond the vacuum heat treatment temperature of 700 °C. Further, the hardness data followed the well known Hall–Petch relationship. On the other hand, the tribological property of SS304 was significantly deteriorated beyond the vacuum heat treatment temperature of 700 °C. The tensile strength of the foils was also altered after the heat treatment.

  19. Throughput gains obtained from dynamic reconfiguration of the switching mode allocation in a SS/TDMA satellite system

    NASA Astrophysics Data System (ADS)

    Maral, G.; Bousquet, M.; Wattier, P.

    Fully variable demand assignment in a SS/TDMA satellite system requires frequent burst time plan chanes with reconfiguration of the on-board switch matrix state sequence. This implies that the switching mode allocation which describes both the succession and the duration of each switch state be dynamically reconfigurated. Improved performance in terms of throughput gains is demonstrated from simulation results on three different SS/TDMA systems. The influencing factors are: time slot assignment algorithm, characteristics and nature of the traffic demand, reconfiguration criterions. Appropriate real time burst management strategies are proposed.

  20. Study of equilibrium geometries of diradicaloid systems via state specific multireference Møller-Plesset perturbation theory (SS-MRMPPT)

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, Sudip; Mahapatra, Uttam Sinha; Chaudhuri, Rajat K.

    2010-03-01

    The numerical gradient scheme for rigorously size-extensive spin-free state-specific multireference Møller-Plesset perturbation theory based on Rayleigh-Schrödinger expansion (termed as SS-MRMPPT) has been employed for calculating equilibrium geometrical parameters of diradical systems such as singlet CH 2, m-benzyne and 2,6-pyridyne. These systems possess quasi-degeneracy of varying degrees. A close and quantitative agreement of results obtained by low cost SS-MRMPPT method with the results of highly sophisticated ab initio methods is an encouraging reflection of the ability of the present method in studying geometrical parameters of states plagued by electronic degeneracy.

  1. Ab initio determination of mode coupling in HSSH - The torsional splitting in the first excited S-S stretching state

    NASA Technical Reports Server (NTRS)

    Herbst, Eric; Winnewisser, G.; Yamada, K. M. T.; Defrees, D. J.; Mclean, A. D.

    1989-01-01

    A mechanism for the enhanced splitting detected in the millimeter-wave rotational spectra of the first excited S-S stretching state of HSSH (disulfane) has been studied. The mechanism, which involves a potential coupling between the first excited S-S stretching state and excited torsional states, has been investigated in part by the use of ab initio theory. Based on an ab initio potential surface, coupling matrix elements have been calculated, and the amount of splitting has then been estimated by second-order perturbation theory. The result, while not in quantitative agreement with the measured splitting, lends plausibility to the assumed mechanism.

  2. On-Flow Synthesis of Co-Polymerizable Oligo-Microspheres and Application in ssDNA Amplification

    PubMed Central

    Lee, Se Hee; Lee, Jae Ha; Lee, Ho Won; Kim, Yang-Hoon; Jeong, Ok Chan; Ahn, Ji-Young

    2016-01-01

    We fabricated droplet-based microfluidic platform for copolymerizable microspheres with acrydite modified DNA probe. The copolymerizable 3-D polyacrylamide microspheres were successfully produced from microcontinuous-flow synthesis with on-channel solidification. DNA copolymerization activity, surface presentation and thermostability were assessed by using fluorescent labeled complementary probe. The binding performance was only visible on the surface area of oligo-microspheres. We show that the resulting oligo-microspheres can be directly integrated into a streamlined microsphere-PCR protocol for amplifying ssDNA. Our microspheres could be utilized as a potential material for ssDNA analysis such as DNA microarray and automatic DNA SELEX process. PMID:27447941

  3. Corrosion Inhibition by Tithonia diversifolia (Hemsl) A. Gray leaves extract for 304 SS in hydrochloric acid solution

    NASA Astrophysics Data System (ADS)

    Firdausi, S.; Kurniawan, F.

    2016-04-01

    The inhibition effect of Tithonia diversifolia (Hemsl) A. Gray leaves extract on the corrosion phenomena of 304 SS in 1 M HCl has been studied by polarization potentiodynamic. The powder of T. diversifolia was extracted by demineralized water which was cultivated in East Java, Indonesia. The extract was characterized by FTIR spectrophotometer. The presence of T. diversifolia can inhibit the corrosion rate of 304 SS. The efficiency inhibition value of 2 g/L T. diversifolia leaves extract reached up to 77.27% at room temperature.

  4. Ss-Sl2, a novel cell wall protein with PAN modules, is essential for sclerotial development and cellular integrity of Sclerotinia sclerotiorum.

    PubMed

    Yu, Yang; Jiang, Daohong; Xie, Jiatao; Cheng, Jiasen; Li, Guoqing; Yi, Xianhong; Fu, Yanping

    2012-01-01

    The sclerotium is an important dormant body for many plant fungal pathogens. Here, we reported that a protein, named Ss-Sl2, is involved in sclerotial development of Sclerotinia sclerotiorum. Ss-Sl2 does not show significant homology with any protein of known function. Ss-Sl2 contains two putative PAN modules which were found in other proteins with diverse adhesion functions. Ss-Sl2 is a secreted protein, during the initial stage of sclerotial development, copious amounts of Ss-Sl2 are secreted and accumulated on the cell walls. The ability to maintain the cellular integrity of RNAi-mediated Ss-Sl2 silenced strains was reduced, but the hyphal growth and virulence of Ss-Sl2 silenced strains were not significantly different from the wild strain. Ss-Sl2 silenced strains could form interwoven hyphal masses at the initial stage of sclerotial development, but the interwoven hyphae could not consolidate and melanize. Hyphae in these interwoven bodies were thin-walled, and arranged loosely. Co-immunoprecipitation and yeast two-hybrid experiments showed that glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Woronin body major protein (Hex1) and elongation factor 1-alpha interact with Ss-Sl2. GAPDH-knockdown strains showed a similar phenotype in sclerotial development as Ss-Sl2 silenced strains. Hex1-knockdown strains showed similar impairment in maintenance of hyphal integrity as Ss-Sl2 silenced strains. The results suggested that Ss-Sl2 functions in both sclerotial development and cellular integrity of S. sclerotiorum.

  5. A Neutralizing Monoclonal IgG1 Antibody of Platelet-Activating Factor Acetylhydrolase SsE Protects Mice against Lethal Subcutaneous Group A Streptococcus Infection

    PubMed Central

    Liu, Mengyao; Feng, Wenchao; Zhu, Hui

    2015-01-01

    Group A Streptococcus (GAS) can cause life-threatening invasive infections, including necrotizing fasciitis. There are no effective treatments for severe invasive GAS infections. The platelet-activating factor (PAF) acetylhydrolase SsE produced by GAS is required for invasive GAS to evade innate immune responses and to invade soft tissues. This study determined whether the enzymatic activity of SsE is critical for its function in GAS skin invasion and inhibition of neutrophil recruitment and whether SsE is a viable target for immunotherapy for severe invasive GAS infections. An isogenic derivative of M1T1 strain MGAS5005 producing SsE with an S178A substitution (SsES178A), an enzymatically inactive SsE mutant protein, was generated. This strain induced higher levels of neutrophil infiltration and caused smaller lesions than MGAS5005 in subcutaneous infections of mice. This phenotype is similar to that of MGAS5005 sse deletion mutants, indicating that the enzymatic activity of SsE is critical for its function. An anti-SsE IgG1 monoclonal antibody (MAb), 2B11, neutralized the PAF acetylhydrolase activity of SsE. Passive immunization with 2B11 increased neutrophil infiltration, reduced skin invasion, and protected mice against MGAS5005 infection. However, 2B11 did not protect mice when it was administered after MGAS5005 inoculation. MGAS5005 induced vascular effusion at infection sites at early hours after GAS inoculation, suggesting that 2B11 did not always have access to infection sites. Thus, the enzymatic activity of SsE mediates its function, and SsE has the potential to be included in a vaccine but is not a therapeutic target. An effective MAb-based immunotherapy for severe invasive GAS infections may need to target virulence factors that are critical for systemic survival of GAS. PMID:25916987

  6. A novel pathogenesis-related protein (SsPR10) from Solanum surattense with ribonucleolytic and antimicrobial activity is stress- and pathogen-inducible.

    PubMed

    Liu, Xiaojun; Huang, Beibei; Lin, Juan; Fei, Jiong; Chen, Zhonghai; Pang, Yongzhen; Sun, Xiaofen; Tang, Kexuan

    2006-03-01

    A cDNA clone (designated as SsPR10, GenBank Accession Number AY660753 ) encoding a PR10 protein from yellow-fruit nightshade (Solanum surattense) was isolated and characterized. SsPR10 encoded a 160-amino-acid polypeptide with a predicted molecular mass of 17.58 kDa and pI of 5.29. Sequence alignments showed that SsPR10 had high identity (68.1%) with CaPR10, but had only about 31.7% identity with JIOsPR10 at the amino acid level. Genomic DNA gel blot analysis indicated that SsPR10 belonged to a multigene family. The constitutively expressed SsPR10 was detected to be the highest in roots of the sterile seedlings cultured in jars, while SsPR10 expression was the highest in old yellow leaves from the seedlings incubated with sap containing TMV. SsPR10 always expressed at slightly higher level in senescent leaves than in tender ones under both conditions. Further expression analysis revealed that the signaling components of defense/stress pathways (MeJA, SA, ABA, GA3, H2O2 and Cu2+) up-regulated significantly the SsPR10 mRNA levels over the control. However, darkness failed to induce SsPR10 expression and its expression was also inhibited by cold treatment. The SsPR10 was successfully expressed in Eschericha coli and the expressed protein was purified to near homogeneity. The dialytically renatured SsPR10 protein without phosphorylation exhibited ribonucleolytic activity against S. surattense leaf total RNA preparations and could inhibit hyphal growth of Pyricularia oryzae. Our findings suggest that the novel stress- and pathogen-inducible SsPR10 with ribonucleolytic and antimicrobial activity participates not only in the defense/stress response pathways but also in plants' growth, development and senescence. PMID:16473659

  7. Ss-Sl2, a novel cell wall protein with PAN modules, is essential for sclerotial development and cellular integrity of Sclerotinia sclerotiorum.

    PubMed

    Yu, Yang; Jiang, Daohong; Xie, Jiatao; Cheng, Jiasen; Li, Guoqing; Yi, Xianhong; Fu, Yanping

    2012-01-01

    The sclerotium is an important dormant body for many plant fungal pathogens. Here, we reported that a protein, named Ss-Sl2, is involved in sclerotial development of Sclerotinia sclerotiorum. Ss-Sl2 does not show significant homology with any protein of known function. Ss-Sl2 contains two putative PAN modules which were found in other proteins with diverse adhesion functions. Ss-Sl2 is a secreted protein, during the initial stage of sclerotial development, copious amounts of Ss-Sl2 are secreted and accumulated on the cell walls. The ability to maintain the cellular integrity of RNAi-mediated Ss-Sl2 silenced strains was reduced, but the hyphal growth and virulence of Ss-Sl2 silenced strains were not significantly different from the wild strain. Ss-Sl2 silenced strains could form interwoven hyphal masses at the initial stage of sclerotial development, but the interwoven hyphae could not consolidate and melanize. Hyphae in these interwoven bodies were thin-walled, and arranged loosely. Co-immunoprecipitation and yeast two-hybrid experiments showed that glyceraldehyde-3-phosphate dehydrogenase (GAPDH), Woronin body major protein (Hex1) and elongation factor 1-alpha interact with Ss-Sl2. GAPDH-knockdown strains showed a similar phenotype in sclerotial development as Ss-Sl2 silenced strains. Hex1-knockdown strains showed similar impairment in maintenance of hyphal integrity as Ss-Sl2 silenced strains. The results suggested that Ss-Sl2 functions in both sclerotial development and cellular integrity of S. sclerotiorum. PMID:22558105

  8. Ectopic overexpression of SsCBF1, a CRT/DRE-binding factor from the nightshade plant Solanum lycopersicoides, confers freezing and salt tolerance in transgenic Arabidopsis.

    PubMed

    Zhang, Lili; Li, Zhenjun; Li, Jingfu; Wang, Aoxue

    2014-01-01

    The C-repeat (CRT)/dehydration-responsive element (DRE) binding factor (CBF/DREB1) transcription factors play a key role in cold response. However, the detailed roles of many plant CBFs are far from fully understood. A CBF gene (SsCBF1) was isolated from the cold-hardy plant Solanum lycopersicoides. A subcellular localization study using GFP fusion protein indicated that SsCBF1 is localized in the nucleus. We delimited the SsCBF1 transcriptional activation domain to the C-terminal segment comprising amino acid residues 193-228 (SsCBF1(193-228)). The expression of SsCBF1 could be dramatically induced by cold, drought and high salinity. Transactivation assays in tobacco leaves revealed that SsCBF1 could specifically bind to the CRT cis-elements in vivo to activate the expression of downstream reporter genes. The ectopic overexpression of SsCBF1 conferred increased freezing and high-salinity tolerance and late flowering phenotype to transgenic Arabidopsis. RNA-sequencing data exhibited that a set of cold and salt stress responsive genes were up-regulated in transgenic Arabidopsis. Our results suggest that SsCBF1 behaves as a typical CBF to contribute to plant freezing tolerance. Increased resistance to high-salinity and late flowering phenotype derived from SsCBF1 OE lines lend more credence to the hypothesis that plant CBFs participate in diverse physiological and biochemical processes related to adverse conditions.

  9. The structure of the XPF-ssDNA complex underscores the distinct roles of the XPF and ERCC1 helix- hairpin-helix domains in ss/ds DNA recognition.

    PubMed

    Das, Devashish; Folkers, Gert E; van Dijk, Marc; Jaspers, Nicolaas G J; Hoeijmakers, Jan H J; Kaptein, Robert; Boelens, Rolf

    2012-04-01

    Human XPF/ERCC1 is a structure-specific DNA endonuclease that nicks the damaged DNA strand at the 5' end during nucleotide excision repair. We determined the structure of the complex of the C-terminal domain of XPF with 10 nt ssDNA. A positively charged region within the second helix of the first HhH motif contacts the ssDNA phosphate backbone. One guanine base is flipped out of register and positioned in a pocket contacting residues from both HhH motifs of XPF. Comparison to other HhH-containing proteins indicates a one-residue deletion in the second HhH motif of XPF that has altered the hairpin conformation, thereby permitting ssDNA interactions. Previous nuclear magnetic resonance studies showed that ERCC1 in the XPF-ERCC1 heterodimer can bind dsDNA. Combining the two observations gives a model that underscores the asymmetry of the human XPF/ERCC1 heterodimer in binding at an ss/ds DNA junction. PMID:22483113

  10. The effect of pH on the corrosion behavior of intermetallic compounds Ni{sub 3}(Si,Ti) and Ni{sub 3}(Si,Ti) + 2Mo in sodium chloride solutions

    SciTech Connect

    Priyotomo, Gadang Nuraini, Lutviasari; Kaneno, Yasuyuki

    2015-12-29

    The corrosion behavior of the intermetallic compounds, Ni{sub 3}(Si,Ti) (L1{sub 2}: single phase) and Ni{sub 3}(Si,Ti) + 2Mo (L1{sub 2} and (L12 + Ni{sub ss}) mixture region), has been investigated using an immersion test, electrochemical method and surface analytical method (SEM; scanning electron microscope and EDAX: Energy Dispersive X-ray) in 0.5 kmol/m{sup 3} NaCl solutions at various pH. The corrosion behavior of nickel alloy C-276 was studied under the same experimental conditions as a reference. It was found that the uniform attack was observed on Ni{sub 3}(Si,Ti) for the immersion test at lower pH, while the pitting attack was observed on this compound for this test at neutral solution. Furthermore, Ni{sub 3}(Si,Ti)+2Mo had the preferential dissolution of L1{sub 2} compared to (L1{sub 2} + Ni{sub ss}) mixture region at lower pH, while pitting attack occurred in (L1{sub 2} + Ni{sub ss}) mixture region at neutral solution. For both intermetallic compounds, the magnitude of pitting and uniform attack decrease with increasing pH of solutions. From the immersion test and polarization curves, the corrosion resistance of Ni{sub 3}(Si,Ti)+2Mo is lower than that of Ni{sub 3}(Si,Ti), while the nickel alloy C-276 is the highest one at various pH of solutions. On the other hand, in the lower pH of solutions, the corrosion resistance of tested materials decreased significantly compared to those in neutral and higher pH of solutions.

  11. Brenda K. Edwards, PhD

    Cancer.gov

    Brenda K. Edwards, PhD, has been with the Surveillance Research Program (SRP) and its predecessor organizations at the National Cancer Institute (NCI) since 1989, serving as SRP’s Associate Director from 1990-2011.

  12. The pathogenicity factor HrpF interacts with HrpA and HrpG to modulate type III secretion system (T3SS) function and t3ss expression in Pseudomonas syringae pv. averrhoi.

    PubMed

    Huang, Yi-Chiao; Lin, Yuan-Chuen; Wei, Chia-Fong; Deng, Wen-Ling; Huang, Hsiou-Chen

    2016-09-01

    To ensure the optimal infectivity on contact with host cells, pathogenic Pseudomonas syringae has evolved a complex mechanism to control the expression and construction of the functional type III secretion system (T3SS) that serves as a dominant pathogenicity factor. In this study, we showed that the hrpF gene of P. syringae pv. averrhoi, which is located upstream of hrpG, encodes a T3SS-dependent secreted/translocated protein. Mutation of hrpF leads to the loss of bacterial ability on elicitation of disease symptoms in the host and a hypersensitive response in non-host plants, and the secretion or translocation of the tested T3SS substrates into the bacterial milieu or plant cells. Moreover, overexpression of hrpF in the wild-type results in delayed HR and reduced t3ss expression. The results of protein-protein interactions demonstrate that HrpF interacts directly with HrpG and HrpA in vitro and in vivo, and protein stability assays reveal that HrpF assists HrpA stability in the bacterial cytoplasm, which is reduced by a single amino acid substitution at the 67th lysine residue of HrpF with alanine. Taken together, the data presented here suggest that HrpF has two roles in the assembly of a functional T3SS: one by acting as a negative regulator, possibly involved in the HrpSVG regulation circuit via binding to HrpG, and the other by stabilizing HrpA in the bacterial cytoplasm via HrpF-HrpA interaction prior to the secretion and formation of Hrp pilus on the bacterial surface.

  13. Periodicity Analysis of X-ray Light Curves of SS 433

    NASA Astrophysics Data System (ADS)

    Wang, J. Y.; Lu, X. L.; Zhao, Q. W.; Dong, D. Q.; Lao, B. Q.; Lu, Y.; Wei, Y. H.; Wu, X. C.; An, T.

    2016-03-01

    SS 433 is the only X-ray binary to date that was detected to have a pair of well-collimated jets, and its orbital period, super orbital period, and nutation period were all detected at the same time. The study on the periodic X-ray variabilities is helpful for understanding its dynamic process of the central engine and the correlation with other bands. In the present paper, two time series analysis techniques, Lomb-Scargle periodogram and weighted wavelet Z-transform, are employed to search for the periodicities from the Swift/BAT (Burst Alert Telescope)(15--50 keV) and RXTE/ASM (Rossi X-Ray Timing Explorer/All-Sky Monitor)(1.5--3, 3--5 and 5--12 keV) light curves of SS 433, and the Monte Carlo simulation is performed. For the 15--50 keV energy band, five significant periodic signals are detected, which are P_1(˜6.29 d), P_2 (˜6.54 d), P_3 (˜13.08 d), P_4 (˜81.50 d), and P_5 (˜162.30 d). For the 3--5 and 5--12 keV energy bands, periodic signals P_3 (˜13 d) and P_5 (˜162 d) are detected in both energy bands. However, for the 1.5--3 keV energy band, no significant periodic signal is detected. P_5 has the strongest periodic signal in the power spectrum for all the energy bands of 3--5, 5--12, and 15--50 keV, and it is consistent with that obtained by previous study in optical band. Further, due to the existence of relativistic radio jets, the X-ray and optical band variability of P_5 (˜162 d) is probably related to the precession of the relativistic jets. High coherence between X-ray and optical light curves may also imply that the X-ray and optical emissions are of the same physical origin. P_3 shows a good agreement with the orbital period (˜13.07 d) first obtained by previous study, and P_2 and P_4 are the high frequency harmonic components of P_3 and P_5, respectively. P_1 is detected from the power spectrum of 15--50 keV energy band only, and it is consistent with the systematic nutation period. As the power of energy band decreases (from hard X-ray to

  14. Dynamic rockfall risk assessment along the SS113 coastal road (Northern Sicily)

    NASA Astrophysics Data System (ADS)

    Mastrolembo, V. Brunella; Penna, Ivanna; Voumard, Jérémie; Jaboyedoff, Michel

    2016-04-01

    Rockfalls are natural hazards that usually affect only small areas. However, due to the big amount of material that can be moved and the associated kinetic energy they can cost serious damages to infrastructures and people. Even fairly small rockfall fragments are a significant hazard if deposited on a highway or along a rail-road track since they are not easily detected and can cause accidents or derailments. Rockfalls can also cause the closure of streets resulting in long term indirect economic losses due to transportation delays as well as to the impact on the commercial and tourist activities. In letterature there are numerous examples of rockfall risk assessments along transportation corridors, most of them are based on the use of standard risk estimation methods. The latters are static approaches founded on a macroscopic view of road traffic, assumed as uniform in space and time, thus characterized by average values of parameters. Lately, a new dynamic approach has been developed within the 'risk analysis group' at the University of Lausanne (Voumard, 2013). It consists of a kinematic interpretation of road traffic where vehicles are parametrized as single entities with different characteristics, speed, dimensions and behaviour. We apply this new approach to estimate the dynamic risk due to rockfall occurrence on the SS113 national road running along the northern coast of Sicily. In this work we focus our attention on a ≈10 km section along which the SS113 road and a railway connect all the costal villages going through very steep cliffs and very close to the sea with evident problems of erosion and maintenance. The area is a tourist destination and many hotels and facilities are found along the road. Moreover the area was already hit in the past by numerous rockfalls resulting in the closure of the road for periods running from a few days up to a few years with big direct and indirect damages to the local socio-economic activities. In order to achieve a

  15. Influences of heating temperature, pH, and soluble solids on the decimal reduction times of acid-adapted and non-adapted Escherichia coli O157:H7 (HCIPH 96055) in a defined liquid heating medium.

    PubMed

    Gabriel, Alonzo A

    2012-11-01

    The study characterized the influences of various combinations of process and product parameters namely, heating temperature (53, 55, 57.5, 60, 62 °C), pH (2.0, 3.0, 4.5, 6.0, 7.0), and soluble solids (SS) (1.4, 15, 35, 55, 69°Brix) on the thermal inactivation of non-adapted and acid-adapted E. coli O157:H7 (HCIPH 96055) in a defined liquid heating medium (LHM). Acid adaptation was conducted by propagating cells in a gradually acidifying nutrient broth medium, supplemented with 1% glucose. The D values of non-adapted cells ranged from 1.43 s (0.02 min) to 304.89 s (5.08 min). Acid-adapted cells had D values that ranged from 1.33 s (0.02 min) to 2628.57 s (43.81 min). Adaptation did not always result in more resistant cells as indicated by the Log (D(adapted)/D(non-adapted)) values calculated in all combinations tested, with values ranging from -1.10 to 1.40. The linear effects of temperature and pH, and the joint effects of pH and SS significantly influenced the thermal resistance of non-adapted cells. Only the linear and quadratic effects of both pH and SS significantly influenced the D values of acid-adapted cells. Generally, the D values of acid-adapted cells decreased at SS greater than 55 °Brix, suggesting the possible cancelation of thermal cross protection by acid habituation at such SS levels. The relatively wide ranges of LHM pH and SS values tested in the study allowed for better examination of the effects of these factors on the thermal death of the pathogen. The results established in this work may be used in the evaluation, control and improvement of safety of juice products; and of other liquid foods with physicochemical properties that fall within the ranges tested in this work. PMID:23141645

  16. Electrochemical and in vitro bioactivity of polypyrrole/ceramic nanocomposite coatings on 316L SS bio-implants.

    PubMed

    Madhan Kumar, A; Nagarajan, S; Ramakrishna, Suresh; Sudhagar, P; Kang, Yong Soo; Kim, Hyongbum; Gasem, Zuhair M; Rajendran, N

    2014-10-01

    The present investigation describes the versatile fabrication and characterization of a novel composite coating that consists of polypyrrole (PPy) and Nb2O5 nanoparticles. Integration of the two materials is achieved by electrochemical deposition on 316L stainless steel (SS) from an aqueous solution of oxalic acid containing pyrrole and Nb2O5 nanoparticles. Fourier transform infrared spectral (FTIR) and X-ray diffraction (XRD) studies revealed that the existence of Nb2O5 nanoparticles in PPy matrix with hexagonal structure. Surface morphological analysis showed that the presence of Nb2O5 nanoparticles strongly influenced the surface nature of the nanocomposite coated 316L SS. Micro hardness results revealed the enhanced mechanical properties of PPy nanocomposite coated 316L SS due to the addition of Nb2O5 nanoparticles. The electrochemical studies were carried out using cyclic polarization and electrochemical impedance spectroscopy (EIS) measurements. In order to evaluate the biocompatibility, contact angle measurements and in vitro characterization were performed in simulated body fluid (SBF) and on MG63 osteoblast cells. The results showed that the nanocomposite coatings exhibit superior biocompatibility and enhanced corrosion protection performance over 316L SS than pure PPy coatings.

  17. SS316 structure fabricated by selective laser melting and integrated with strain isolated optical fiber high temperature sensor

    NASA Astrophysics Data System (ADS)

    Mathew, Jinesh; Havermann, Dirk; Polyzos, Dimitrios; MacPherson, William N.; Hand, Duncan P.; Maier, Robert R. J.

    2015-09-01

    Smart metal having integrated high temperature sensing capability is reported. The SS316 structure is made by additive layer manufacturing via selective laser melting (SLM). Sensor component is embedded in to the structure during the SLM build process. The strain isolated in-fiber Fabry-Perot cavity sensor measures temperature up to 1100 °C inside the metal.

  18. [Story of three SS dentists during World War II: Pr Hugo Blaschke, Dr Hermann Pook and Dr Willy Frank].

    PubMed

    Riaud, Xavier

    2006-12-01

    This story of three SS dentists shows very clearly that the medical code of ethics, under a totalitarian regime, ends where ideology begins. Professor Hugo Blaschke provided dental care to the most eminent Nazi leaders, but he also was the senior SS dentist. He was in charge of dental care in the Waffen-SS, and therefore, he had responsibility for the stocks of dental gold collected from the mouths of those who died in the concentration camps, in order to make dentures for his soldiers. Dr Hermann Pook was the dentist in charge of all the other dentists practising in the concentration camps. He was responsible for gathering statistics on the dental care provided for prisoners in the camps. His instructions were very clear: "No conservation or restorative treatment. Only extractions, and with no anaesthesia!" He was also in charge of gathering the gold that was collected in the camps, for the financial department of the SS. Dr Willy Frank, an Auschwitz dentist, took part in the selection of some of the convoys for the gas chambers. His participation in the collection of gold from the mouths of the dead was also established. These three men were sentenced to prison for War Crimes and Crimes against Humanity.

  19. Properties of pili from Escherichia coli SS142 that mediate mannose-resistant adhesion to mammalian cells.

    PubMed Central

    Mett, H; Kloetzlen, L; Vosbeck, K

    1983-01-01

    We isolated pili from Escherichia coli SS142. These pili had a diameter of 6 nm and an average length of 400 nm. They were composed of subunits with a molecular weight of 18,000. Their amino acid composition was determined; methionine and proline were not detected. The isolated pili retained mannose-resistant hemagglutinating activity. Proteolytic digestion and glutaraldehyde fixation led to partial or complete loss of the hemagglutinating activity of the pili without causing any detectable damage to their supramolecular structure, which was only disintegrated by treatment with hot sodium dodecyl sulfate. The hemagglutinating activity of E. coli SS142 was inhibited by the glycoproteins fetuin and Tamm-Horsfall protein, as well as by the glycolipids phytyl lactoside, dansyl-sphingosine lactoside, and digalactosyl diglyceride. Isolated pili inhibited the adhesion of the homologous strain E. coli SS142 to Intestine 407 cell monolayers, but did not inhibit the adhesion of E. coli strain B-413, B-506, or 2699. This indicates that E. coli SS142 binds to a receptor different from those recognized by the other strains and that mannose-resistant adhesion to tissue culture cells can be classified into different subtypes. Images PMID:6130060

  20. 3D evaluation of composite resin restoration at practical training using swept-source optical coherence tomography (SS-OCT).

    PubMed

    Shimada, Yasushi; Sadr, Alireza; Nazari, Amir; Nakagawa, Hisaichi; Otsuki, Masayuki; Tagami, Junji; Sumi, Yasunori

    2012-01-01

    Internal adaptation of restorations to the cavity wall is one of the important topics in clinical dentistry. The purpose of this study was to investigate the possibility to utilize the non-invasive tomographic imaging system for teaching the importance of cavity adaptation at dental school pre-clinical training. Swept-source optical coherence tomography (SS-OCT) was used for detection of marginal and internal defects in the composite resin restorations as an educational device. Class 1 and Class 2 composite restorations to melamine resin molar tooth were assigned to the students and prepared during the skill test, and SS-OCT imaging was performed to evaluate students' works. SS-OCT could detect the internal gaps and voids within the restorations in tomography images synthesized based on the backscatter signal from within the restoration. It is suggested that the SS-OCT is promising diagnostic modality, as well as educational imaging device for the detection of internal gaps in adhesive restorations.

  1. Identification of multi-locus genetic heterogeneity in anaplasma marginale ss. centrale and its restriction following tick-borne transmission.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anaplasma marginale ss. centrale was the first vaccine used to protect against a rickettsial disease and continues in widespread use a century after initial implementation. As its use preceded development of either cryopreservation or cell culture, the vaccine strain was maintained for decades by se...

  2. Polymorphisms rs12998 and rs5780218 in KiSS1 Suppressor Metastasis Gene in Mexican Patients with Breast Cancer

    PubMed Central

    Cruz Quevedo, Edhit Guadalupe; Mimendi Aguilar, Gabriela Monserrat; Juárez Aguilar, Luis Anselmo; Gutierrez Rubio, Susan Andrea; Flores Martínez, Silvia Esperanza; Dávalos Rodríguez, Ingrid Patricia; Sánchez Corona, José; Torres Morán, Martha Isabel; Rosales Gómez, Roberto Carlos; Morán Moguel, María Cristina

    2015-01-01

    Aims. KiSS1 is a metastasis suppressor gene associated with inhibition of cellular chemotaxis and invasion attenuating the metastasis in melanoma and breast cancer cell lines. Along the KiSS-1 gene at least 294 SNPs have been described; however the association of these polymorphisms as genetic markers for metastasis in breast cancer studies has not been investigated. Here we describe two simple PCR-RFLPs protocols to identify the rs5780218 (9DelT) and the rs12998 (E20K) KiSS1 polymorphisms and the allelic, genotypic, and haplotypic frequencies in Mexican general population (GP) and patients with benign breast disease (BBD) or breast cancer (BC). Results. The rs5780218 polymorphism was individually associated with breast cancer (P = 0.0332) and the rs12998 polymorphism shows statistically significant differences when GP versus case (BC and BBD) groups were compared (P < 0.0001). The H1 Haplotype (G/-) occurred more frequently in BC group (0.4256) whereas H2 haplotype (G/T) was the most prevalent in BBD group (0.4674). Conclusions. Our data indicated that the rs5780218 polymorphism individually confers susceptibility for development of breast cancer in Mexican population and a possible role as a genetic marker in breast cancer metastasis for H1 haplotype (Wt/variant) in KiSS1 gene must be analyzed in other populations. PMID:25810563

  3. Effects of Heat Treatments on Microstructure Changes in The Interface of Cu/SS316L Joint Materials

    SciTech Connect

    Xu, Q.; Yoshiie, T.; Edwards, Danny J.

    2000-09-01

    In both joints iron and chromium diffused from the stainless steel into the copper alloy, producing a narrow zone of about a 15 ?m containing FeCr precipitates and small voids. Failure in some bending tests occurred by a crack propagating through this zone in a direction parallel to the interface, indicating that the formation of these precipitates may not be conducive to good joint properties. The results of annealing experiments showed that temperatures # 673 K did not change the initial microstructure or composition of CuAl25/SS316L and CuNiBe/SS316L joints. Although there are no data from annealing experiments longer than 100 hours, it is expected that the microstructure and composition of CuAl25/SS316L and CuNiBe/SS316L are stable under the thermal operating conditions of fusion reactors. However, irradiation may lead to significant changes because of radiation-enhanced segregation, precipitation or dissolution near and at the interface that could alter the properties. In addition, the preexisting voids near the interface of the joints may coarsen under irradiation and enhance the sensitivity of joints to failure. Given the uncertainties in the response to irradiation, neutron irradiation experiments should be performed at appropriate temperatures to investigate the response of the different materials.

  4. Voyage on the SS "School Library Leadership": Collaboration in Teaching and Learning at the University of Vermont

    ERIC Educational Resources Information Center

    Kaplan, Judith L.; Ballard, Susan D.

    2012-01-01

    This article describes the SS "School Library Leadership" maiden voyage, which departed from the University of Vermont (UVM) during the 2010 fall semester. Twelve intrepid sailors followed their sense of adventure into uncharted waters with cocaptains Judy Kaplan and Susan Ballard in an online collaboration that provided a powerful learning…

  5. Thermal Analysis of Compressible CO2 Flow for PFE TeSS Nozzle of Fire Detection System

    NASA Technical Reports Server (NTRS)

    Zhang, Y. Michael; Lee, Wen-Chin; Keener, John F.; Smith, F. D.

    2002-01-01

    A thermal analysis of the compressible CO2 flow for the Portable Fire Extinguisher (PFE) system has been performed. A SINDA/FLUINT model has been developed for this analysis. The model includes the PFE tank and the TeSS nozzle, and both have initial temperature of 72 F. In order to investigate the thermal effect on the nozzle due to discharging CO2, the PFE TeSS nozzle pipe has been divided into three segments. This model also includes heat transfer predictions for PFE tank inner and outer wall surfaces. The simulation results show that the CO2 discharge rates have fulfilled the minimum flow requirements that the PFE system discharges 3.0 Ibm CO2 in 10 seconds and 5.5 Ibm of CO2 in 45 seconds during its operation. At 45 seconds, the PFE tank wall temperature is 63 F, and the TeSS nozzle cover wall temperatures for the three segments are 47 F, 53 F and 37 F, respectively. Thermal insulation for personal protection is used for the first two segments of the TeSS nozzle. The simulation results also indicate that at 50 seconds, the remaining CO2 in the tank may be near the triple point (gas, liquid and solid) state and, therefore, restricts the flow.

  6. [Story of three SS dentists during World War II: Pr Hugo Blaschke, Dr Hermann Pook and Dr Willy Frank].

    PubMed

    Riaud, Xavier

    2006-12-01

    This story of three SS dentists shows very clearly that the medical code of ethics, under a totalitarian regime, ends where ideology begins. Professor Hugo Blaschke provided dental care to the most eminent Nazi leaders, but he also was the senior SS dentist. He was in charge of dental care in the Waffen-SS, and therefore, he had responsibility for the stocks of dental gold collected from the mouths of those who died in the concentration camps, in order to make dentures for his soldiers. Dr Hermann Pook was the dentist in charge of all the other dentists practising in the concentration camps. He was responsible for gathering statistics on the dental care provided for prisoners in the camps. His instructions were very clear: "No conservation or restorative treatment. Only extractions, and with no anaesthesia!" He was also in charge of gathering the gold that was collected in the camps, for the financial department of the SS. Dr Willy Frank, an Auschwitz dentist, took part in the selection of some of the convoys for the gas chambers. His participation in the collection of gold from the mouths of the dead was also established. These three men were sentenced to prison for War Crimes and Crimes against Humanity. PMID:17575817

  7. Is SS 433 a misaligned ultraluminous X-ray source? Constraints from its reflected signal in the Galactic plane

    NASA Astrophysics Data System (ADS)

    Khabibullin, I.; Sazonov, S.

    2016-04-01

    We evaluate the emission that must arise due to reflection of the putative collimated X-ray radiation of SS 433 by atomic gas and molecular clouds in the Galactic plane and compare the predicted signal with existing RXTE and ASCA data for the region of interest. Assuming that the intrinsic X-ray spectrum of SS 433 is similar to that of ultraluminous X-ray sources (ULXs), we obtain an upper limit of ˜2 × 1039 erg s-1 on its total (angular-integrated) luminosity in the 2-10 keV energy band, which is only weakly dependent on the half-opening angle, Θr, of the emission cone. In contrast, the upper limit on the apparent luminosity of SS 433 (that would be perceived by an observer looking at its supercritical accretion disc face-on) decreases with increasing Θr and is ˜3 × 1040 erg s-1 for Θr ≳ Θp = 21°, where Θp is the precession angle of the baryonic jets (assuming that the emission cones precess in the same manner as the jets). This leaves open the possibility that SS 433 is a misaligned ULX. Further investigation of the reflection signal from the molecular clouds using higher angular resolution observations could improve these constraints with the potential to break the degeneracy between Θr and the apparent luminosity.

  8. HPLC Separation of the (S,S)- and (R,S)- forms of S-Adenosyl-L-methionine

    PubMed Central

    Zhang, Jianyu; Klinman, Judith P.

    2015-01-01

    S-Adenosyl-L-methionine, an important biological cofactor, exists in two chiral forms, (S,S)- and (R,S)-, only the former of which is biologically active. Herein, we develop a chromatographic method to obtain pure (S,S)-AdoMet using a single C18 column. PMID:25681113

  9. Administration of antioxidant peptide SS-31 attenuates transverse aortic constriction-induced pulmonary arterial hypertension in mice

    PubMed Central

    Lu, Hung-i; Huang, Tien-hung; Sung, Pei-hsun; Chen, Yung-lung; Chua, Sarah; Chai, Han-yan; Chung, Sheng-ying; Liu, Chu-feng; Sun, Cheuk-kwan; Chang, Hsueh-wen; Zhen, Yen-yi; Lee, Fan-yen; Yip, Hon-kan

    2016-01-01

    Aim: Antioxidant peptide SS-31 is a class of cell-permeable small peptides, which selectively resides on the inner mitochondrial membrane and possesses intrinsic mitochondrial protective capacities. In this study we investigated the therapeutic effects of antioxidant peptide SS-31 on transverse aortic constriction (TAC)-induced pulmonary arterial hypertension (PAH) in a murine model. Methods: Adult male mice were divided into 3 groups: sham-operated mice, TAC mice, and TAC+SS-31 mice that underwent TAC surgery and received SS-31 (2 mg/d, ip) for 60 d. The right ventricular systolic blood pressure (RVSBP) was measured on d 60 prior to sacrificing the mice; then their right heart and lung tissues were collected for histological and biochemical examinations. Lung injury scores were defined by the increased crowded area and decreased number of alveolar sacs. Results: TAC mice showed significantly higher RVSBP compared with sham-operated mice, the elevation was substantially suppressed in TAC+SS-31 mice. The same pattern of changes was found in pulmonary levels of oxidative stress proteins (NOX-1/NOX-2/oxidized proteins), cytosolic cytochrome c, biomarkers related to inflammation (MMP-9/TNF-α/iNOS), calcium overload index (TRPC1, 2, 4, 6), apoptosis (mitochondrial BAX, cleaved caspase 3/PARP), fibrosis (Smad3/TGF-β), hypoxic (HIF-1α), DNA damage (γ-H2AX) and endothelial function (eNOS/ET-1R), as well as in lung injury score, number of muscularized vessels in lungs, number of TRPC1+ and HIF-1α+ cells in pulmonary artery, and number of γ-H2AX+ and Ki-67+ cells in lung parenchyma. An opposite pattern of changes was observed in pulmonary anti-fibrotic markers (Smad1/5, BMP-2), number of small vessels, and number of alveolar sacs. In contrast, the levels of antioxidant proteins (HO-1/NQO-1/GR/GPx) in lung parenchyma were progressively and significantly increased from sham-operated mice, TAC mice to TAC+SS-31 mice. Conclusion: Antioxidant peptide SS-31 administration

  10. On the Nature of the Compact Object in SS 433. Observational Evidence of X-Ray Photon Index Saturation

    NASA Technical Reports Server (NTRS)

    Seifina, Elena; Titarchuk, Lev

    2010-01-01

    We present an analysis of the X-ray spectral properties observed from black hole , candidate (BHC) binary SS 433. We have analyzed Rossi X-ray Time Explorer (RXTE) data from this source, coordinated with Green Bank Interferometer/RATAN-600. We show that SS 433 undergoes a X-ray spectral transition from the low hard state (LHS) to the intermediate state (IS). We show that the X-ray broad-band energy spectra during all spectral states are well fit by a sum of so called "Bulk Motion Comptonization (BMC) component" and by two (broad and narrow) Gaussians for the continuum and line emissions respectively. In addition to these spectral model components we also find a strong feature that we identify as a" blackbody-like (BB)" component which color temperature is in the range of 4-5 keV in 24 IS spectra during the radio outburst decay in SS 433. Our observational results on the "high temperature BB" bump leads us to suggest the presence of gravitationally redshifted annihilation line emission in this source. In fact this spectral feature has been recently reproduced in Monte Carlo simulations by Laurent and Titarchuk. We have also established the photon index saturation at about 2.3 in index vs mass accretion correlation. This index-mass accretion correlation allows us to evaluate the low limit of black hole (BH) mass of compact object in SS 433, M(sub bh) approximately > 2 solar masses, using the scaling method using BHC GX 339-4 as a reference source. Our estimate of the BH mass in SS 433 is consistent with recent BH mass measurement using the radial-velocity measurements of the binary system by Hillwig & Gies who find that M(sub x)( = (4.3 +/- 0.8) solar masses. This is the smallest BH mass found up to now among all BH sources. Moreover, the index saturation effect versus mass accretion rate revealed in SS 433, like in a number of other BH candidates, is the strong observational evidence for the presence of a BH in SS 433.

  11. Direct imaging of RecA nucleation and growth on single molecules of SSB-coated ssDNA.

    PubMed

    Bell, Jason C; Plank, Jody L; Dombrowski, Christopher C; Kowalczykowski, Stephen C

    2012-11-01

    Escherichia coli RecA is the defining member of a ubiquitous class of DNA strand-exchange proteins that are essential for homologous recombination, a pathway that maintains genomic integrity by repairing broken DNA. To function, filaments of RecA must nucleate and grow on single-stranded DNA (ssDNA) in direct competition with ssDNA-binding protein (SSB), which rapidly binds and continuously sequesters ssDNA, kinetically blocking RecA assembly. This dynamic self-assembly on a DNA lattice, in competition with another protein, is unique for the RecA family compared to other filament-forming proteins such as actin and tubulin. The complexity of this process has hindered our understanding of RecA filament assembly because ensemble measurements cannot reliably distinguish between the nucleation and growth phases, despite extensive and diverse attempts. Previous single-molecule assays have measured the nucleation and growth of RecA--and its eukaryotic homologue RAD51--on naked double-stranded DNA and ssDNA; however, the template for RecA self-assembly in vivo is SSB-coated ssDNA. Using single-molecule microscopy, here we directly visualize RecA filament assembly on single molecules of SSB-coated ssDNA, simultaneously measuring nucleation and growth. We establish that a dimer of RecA is required for nucleation, followed by growth of the filament through monomer addition, consistent with the finding that nucleation, but not growth, is modulated by nucleotide and magnesium ion cofactors. Filament growth is bidirectional, albeit faster in the 5'→3' direction. Both nucleation and growth are repressed at physiological conditions, highlighting the essential role of recombination mediators in potentiating assembly in vivo. We define a two-step kinetic mechanism in which RecA nucleates on transiently exposed ssDNA during SSB sliding and/or partial dissociation (DNA unwrapping) and then the RecA filament grows. We further demonstrate that the recombination mediator protein pair

  12. SUBARU AND GEMINI OBSERVATIONS OF SS 433: NEW CONSTRAINT ON THE MASS OF THE COMPACT OBJECT

    SciTech Connect

    Kubota, K.; Ueda, Y.; Fabrika, S.; Barsukova, E. A.; Sholukhova, O.; Medvedev, A.; Goranskij, V. P.

    2010-02-01

    We present results of optical spectroscopic observations of the mass donor star in SS 433 with Subaru and Gemini, with an aim to best constrain the mass of the compact object. Subaru/Faint Object Camera and Spectrograph observations were performed on four nights of 2007 October 6-8 and 10, covering the orbital phase of phi = 0.96 - 0.26. We first calculate the cross-correlation function (CCF) of these spectra with that of the reference star HD 9233 in the wavelength range of 4740-4840 A. This region is selected to avoid 'strong' absorption lines accompanied with contaminating emission components, which most probably originate from the surroundings of the donor star, such as the wind and gas stream. The same analysis is applied to archive data of Gemini/GMOS taken at phi = 0.84 - 0.30 by Hillwig and Gies. From the Subaru and Gemini CCF results, the amplitude of the radial velocity curve of the donor star is determined to be 58.3 +- 3.8 km s{sup -1} with a systemic velocity of 59.2 +- 2.5 km s{sup -1}. Together with the radial velocity curve of the compact object, we derive the mass of the donor star and compact object to be M{sub O} = 12.4 +- 1.9 M{sub sun} and M{sub X} = 4.3 +- 0.6 M{sub sun}, respectively. We conclude, however, that these values should be taken as upper limits. From the analysis of the averaged absorption line profiles of strong lines (mostly ions) and weak lines (mostly neutrals) observed with Subaru, we find evidence for heating effects from the compact object. Using a simple model, we find that the true radial velocity amplitude of the donor star could be as low as 40 +- 5 km s{sup -1} in order to produce the observed absorption-line profiles. Taking into account the heating of the donor star may lower the derived masses to M{sub O} = 10.4{sup +2.3}{sub -1.9} M{sub sun} and M{sub X} = 2.5{sup +0.7}{sub -0.6} M{sub sun}. Our final constraint, 1.9 M{sub sun} <=M{sub X}<= 4.9 M{sub sun}, indicates that the compact object in SS 433 is most likely a

  13. Activity of Cinnamomum osmophloeum leaf essential oil against Anopheles gambiae s.s

    PubMed Central

    2014-01-01

    Background The increasing status of insecticide resistant mosquitoes in sub-Saharan Africa is a threatening alert to the existing control efforts. All sibling species of An. gambiae complex have evolved insecticide resistance in wild populations for different approved classes of the insecticides currently in use in the field. An alternative compound for vector control is absolutely urgently needed. In this study, the larvicidal activity and chemical composition of the Cinnamomum osmophloeum leaf essential oils were investigated. Methods C. osmophloeum leaf essential oils were extracted by hydrodistillation in a Clevenger-type apparatus for 6 hours, and their chemical compositions identified using GC-MS. These oils were evaluated against An. gambiae s.s. in both laboratory and semi-field situations. The WHO test procedures for monitoring larvicidal efficacy in malaria vectors were used. Results The composition of C. osmophloeum leaf essential oil has been found to have 11 active compounds. The most abundant compound was trans-cinnamaldehyde (70.20%) and the least abundant was caryophyllene oxide (0.08%). The larvicidal activity was found to be dosage and time dependant both in laboratory and semi-field environments with mortality ranging from 0% to 100%. The LC50 value was found to vary from 22.18 to 58.15 μg/ml in the laboratory while in semi-field environments it was 11.91 to 63.63 μg/ml. The LC90 value was found to range between 57.71 to 91.54 μg/ml in the laboratory while in semi-field environments was 52.07 to 173.77 μg/ml. Mortality ranged from 13% to 100% in the laboratory while in semi-field environments it ranged between 43% to 100% within mortality recording time intervals of 12, 24, 48, and 72 hours. Conclusions The larvicidal activity shown by C. osmophloeum leaf essential oil is a promising alternative to existing larvicides or to be incorporated in integrated larval source management compounds for An. gambiae s.s control. The efficacy

  14. Characterization of the potent luteinizing hormone-releasing activity of KiSS-1 peptide, the natural ligand of GPR54.

    PubMed

    Navarro, V M; Castellano, J M; Fernández-Fernández, R; Tovar, S; Roa, J; Mayen, A; Nogueiras, R; Vazquez, M J; Barreiro, M L; Magni, P; Aguilar, E; Dieguez, C; Pinilla, L; Tena-Sempere, M

    2005-01-01

    Loss-of-function mutations of the gene encoding GPR54, the putative receptor for the KiSS-1-derived peptide metastin, have been recently associated with hypogonadotropic hypogonadism, in both rodents and humans. Yet the actual role of the KiSS-1/GPR54 system in the neuroendocrine control of gonadotropin secretion remains largely unexplored. To initiate such analysis, the effects of KiSS-1 peptide on LH secretion were monitored using in vivo and in vitro settings under different experimental conditions. Central intracerebroventricular administration of KiSS-1 peptide potently elicited LH secretion in vivo over a range of doses from 10 pmol to 1 nmol. The effect of centrally injected KiSS-1 appeared to be mediated via the hypothalamic LHRH. However, no effect of central administration of KiSS-1 was detected on relative LHRH mRNA levels. Likewise, systemic (i.p. and i.v.) injection of KiSS-1 markedly stimulated LH secretion. This effect was similar in terms of maximum response to that of central administration of KiSS-1 and might be partially attributed to its ability to stimulate LH secretion directly at the pituitary. Finally, the LH-releasing activity of KiSS-1 was persistently observed after blockade of endogenous excitatory amino acid and nitric oxide pathways, i.e. relevant neurotransmitters in the neuroendocrine control of LH secretion. In summary, our results provide solid evidence for a potent stimulatory effect of KiSS-1 on LH release, acting at central levels (likely the hypothalamus) and eventually at the pituitary, and further document a novel role of the KiSS-1/GPR54 system as a relevant downstream element in the neuroendocrine network governing LH secretion. PMID:15375028

  15. Participation of liver progenitor cells in liver regeneration: lack of evidence in the AAF/PH rat model.

    PubMed

    Dusabineza, Ange-Clarisse; Van Hul, Noémi K; Abarca-Quinones, Jorge; Starkel, Peter; Najimi, Mustapha; Leclercq, Isabelle A

    2012-01-01

    When hepatocyte proliferation is impaired, liver progenitor cells (LPC) are activated to participate in liver regeneration. We used the 2-acetaminofluorene/partial hepatectomy (AAF/PH) model to evaluate the contribution of LPC to liver cell replacement and function restoration. Fischer rats subjected to AAF/PH (or PH alone) were investigated 7, 10 and 14 days post-hepatectomy. Liver mass recovery (LMR) was estimated, and the liver mass to body weight ratio calculated. We used serum albumin and bilirubin levels, and liver albumin mRNA levels to assess the liver function. LPC expansion was analyzed by cytokeratin 19 (CK19), glutathione S-transferase protein (GSTp) immunohistochemistry and by CK19, CD133, transforming growth factor-β1 and hepatocyte growth factor mRNA expression in livers. Cell proliferation was evaluated by Ki67 and BrdU immunostaining. Compared with PH alone where LMR was ∼100% 14 days post-PH, LMR was defective in AAF/PH rats (64.1±15.5%, P=0.0004). LPC expansion was scarce in PH livers (0.5±0.4% of CK19(+) area), but significant in AAF/PH livers (8.5±7.2% of CK19(+)), and inversely correlated to LMR (r(2)=0.63, P<0.0001). A quarter of AAF/PH animals presented liver failure (low serum albumin and high serum bilirubin) 14 days post-PH. Compared with animals with preserved function, this was associated with a lower LMR (50±6.8 vs 74.6±9.4%, P=0.0005), a decreased liver to body weight ratio (2±0.3 vs 3.5±0.6%, P=0.001), and a larger LPC expansion such as proliferating Ki67(+) LPC covered 17.4±4.2% of the liver parenchyma vs 3.1±1.5%, (P<0.0001). Amongst those, rare LPC with an intermediate hepatocyte-like phenotype were seen. Also, less than 2% of hepatocytes were engaged into the cell cycle (Ki67(+)), while more numerous (∼25% of hepatocytes) in the livers with preserved function. These observations suggest that, in this model, the efficient recovery of the liver function was ensured rather by the proliferation of mature hepatocytes

  16. Highlights on Novel Technologies for the Detection of Antibodies to Ro60, Ro52, and SS-B

    PubMed Central

    Infantino, M.; Bentow, C.; Seaman, A.; Benucci, M.; Atzeni, F.; Sarzi-Puttini, P.; Olivito, B.; Meacci, F.; Manfredi, M.; Mahler, M.

    2013-01-01

    Objective. We aimed to compare a chemiluminescent immunoassay (CIA, QUANTA Flash) on BIO-FLASH with a multiplex flow immunoassay (MFI) on BioPlex 2200 for the detection of antibodies to Ro60, Ro52, and SS-B. Methods. The study included 241 samples, from patients suffering from systemic autoimmune diseases (n = 108) as well as disease controls (n = 133). All samples were tested for anti-Ro52, anti-Ro60, and anti-SS-B (La) antibodies on QUANTA Flash (INOVA Diagnostics, San Diego, USA) and BioPlex 2200 (Bio-Rad Laboratories Inc., Hercules, USA). Discrepant samples were tested by two independent methods: BlueDot/ANA and QUANTRIX Microarray (both D-tek, Belgium). Results. The overall qualitative agreements were 95.4% (95% confidence interval, CI 92.0–97.7%) for anti-Ro52, 98.8% (95% CI 96.4–99.7%) for anti-Ro60, and 91.7% (95% CI 87.5–94.9%) for anti-SS-B antibodies. There were 34 discrepant samples among all assays (20 anti-SS-B, 11 anti-Ro52, 3 anti-Ro60). 30/33 of retested samples (by D-tek dot blot) agreed with the QUANTA Flash results. Similar findings were obtained with QUANTRIX Microarray kit. Conclusion. QUANTA Flash and BioPlex 2200 show good qualitative agreement. The clinical performances were similar for anti-Ro52 and anti-Ro60 autoantibodies while differences were observed for anti-SS-B (La) antibodies. PMID:24376466

  17. Rhizobium-legume symbiosis in the absence of Nod factors: two possible scenarios with or without the T3SS.

    PubMed

    Okazaki, Shin; Tittabutr, Panlada; Teulet, Albin; Thouin, Julien; Fardoux, Joël; Chaintreuil, Clémence; Gully, Djamel; Arrighi, Jean-François; Furuta, Noriyuki; Miwa, Hiroki; Yasuda, Michiko; Nouwen, Nico; Teaumroong, Neung; Giraud, Eric

    2016-01-01

    The occurrence of alternative Nod factor (NF)-independent symbiosis between legumes and rhizobia was first demonstrated in some Aeschynomene species that are nodulated by photosynthetic bradyrhizobia lacking the canonical nodABC genes. In this study, we revealed that a large diversity of non-photosynthetic bradyrhizobia, including B. elkanii, was also able to induce nodules on the NF-independent Aeschynomene species, A. indica. Using cytological analysis of the nodules and the nitrogenase enzyme activity as markers, a gradient in the symbiotic interaction between bradyrhizobial strains and A. indica could be distinguished. This ranged from strains that induced nodules that were only infected intercellularly to rhizobial strains that formed nodules in which the host cells were invaded intracellularly and that displayed a weak nitrogenase activity. In all non-photosynthetic bradyrhizobia, the type III secretion system (T3SS) appears required to trigger nodule organogenesis. In contrast, genome sequence analysis revealed that apart from a few exceptions, like the Bradyrhizobium ORS285 strain, photosynthetic bradyrhizobia strains lack a T3SS. Furthermore, analysis of the symbiotic properties of an ORS285 T3SS mutant revealed that the T3SS could have a positive or negative role for the interaction with NF-dependent Aeschynomene species, but that it is dispensable for the interaction with all NF-independent Aeschynomene species tested. Taken together, these data indicate that two NF-independent symbiotic processes are possible between legumes and rhizobia: one dependent on a T3SS and one using a so far unknown mechanism.

  18. Eukaryotic diversity at pH extremes.

    PubMed

    Amaral-Zettler, Linda A

    2012-01-01

    Extremely acidic (pH < 3) and extremely alkaline (pH > 9) environments support a diversity of single-cell and to a lesser extent, multicellular eukaryotic life. This study compared alpha and beta diversity in eukaryotic communities from seven diverse aquatic environments with pH values ranging from 2 to 11 using massively-parallel pyrotag sequencing targeting the V9 hypervariable region of the 18S ribosomal RNA (rRNA) gene. A total of 946 operational taxonomic units (OTUs) were recovered at a 6% cut-off level (94% similarity) across the sampled environments. Hierarchical clustering of the samples segregated the communities into acidic and alkaline groups. Similarity percentage (SIMPER) analysis followed by indicator OTU analysis (IOA) and non-metric multidimensional scaling (NMDS) were used to determine which characteristic groups of eukaryotic taxa typify acidic or alkaline extremes and the extent to which pH explains eukaryotic community structure in these environments. Spain's Rio Tinto yielded the fewest observed OTUs while Nebraska Sandhills alkaline lakes yielded the most. Distinct OTUs, including metazoan OTUs, numerically dominated pH extreme sites. Indicator OTUs included the diatom Pinnularia and unidentified opisthokonts (Fungi and Filasterea) in the extremely acidic environments, and the ciliate Frontonia across the extremely alkaline sites. Inferred from NMDS, pH explained only a modest fraction of the variation across the datasets, indicating that other factors influence the underlying community structure in these environments. The findings from this study suggest that the ability for eukaryotes to adapt to pH extremes over a broad range of values may be rare, but further study of taxa that can broadly adapt across diverse acidic and alkaline environments, respectively present good models for understanding adaptation and should be targeted for future investigations.

  19. Eukaryotic diversity at pH extremes

    PubMed Central

    Amaral-Zettler, Linda A.

    2013-01-01

    Extremely acidic (pH < 3) and extremely alkaline (pH > 9) environments support a diversity of single-cell and to a lesser extent, multicellular eukaryotic life. This study compared alpha and beta diversity in eukaryotic communities from seven diverse aquatic environments with pH values ranging from 2 to 11 using massively-parallel pyrotag sequencing targeting the V9 hypervariable region of the 18S ribosomal RNA (rRNA) gene. A total of 946 operational taxonomic units (OTUs) were recovered at a 6% cut-off level (94% similarity) across the sampled environments. Hierarchical clustering of the samples segregated the communities into acidic and alkaline groups. Similarity percentage (SIMPER) analysis followed by indicator OTU analysis (IOA) and non-metric multidimensional scaling (NMDS) were used to determine which characteristic groups of eukaryotic taxa typify acidic or alkaline extremes and the extent to which pH explains eukaryotic community structure in these environments. Spain's Rio Tinto yielded the fewest observed OTUs while Nebraska Sandhills alkaline lakes yielded the most. Distinct OTUs, including metazoan OTUs, numerically dominated pH extreme sites. Indicator OTUs included the diatom Pinnularia and unidentified opisthokonts (Fungi and Filasterea) in the extremely acidic environments, and the ciliate Frontonia across the extremely alkaline sites. Inferred from NMDS, pH explained only a modest fraction of the variation across the datasets, indicating that other factors influence the underlying community structure in these environments. The findings from this study suggest that the ability for eukaryotes to adapt to pH extremes over a broad range of values may be rare, but further study of taxa that can broadly adapt across diverse acidic and alkaline environments, respectively present good models for understanding adaptation and should be targeted for future investigations. PMID:23335919

  20. MRF with adjustable pH

    NASA Astrophysics Data System (ADS)

    Jacobs, Stephen D.

    2011-10-01

    Deterministic final polishing of high precision optics using sub-aperture processing with magnetorheological finishing (MRF) is an accepted practice throughout the world. A wide variety of materials can be successfully worked with aqueous (pH 10), magnetorheological (MR) fluids, using magnetic carbonyl iron (CI) and either ceria or nanodiamond nonmagnetic abrasives. Polycrystalline materials like zinc sulfide (ZnS) and zinc selenide (ZnSe) are difficult to polish at pH 10 with MRF, due to their grain size and the relatively low stiffness of the MR fluid lap. If microns of material are removed, the grain structure of the material begins to appear. In 2005, Kozhinova et al. (Appl. Opt. 44 4671-4677) demonstrated that lowering pH could improve MRF of ZnS. However, magnetic CI particle corrosion rendered their low pH approach unstable and unsuitable for commercial implementation. In 2009, Shafrir et al. described a sol-gel coating process for manufacturing a zirconia-coated CI particle that protects the magnetic core from aqueous corrosion (Appl. Opt .48 6797-6810). The coating process produces free nanozirconia polishing abrasives during the coating procedure, thereby creating an MR polishing powder that is "self-charged" with the polishing abrasive. By simply adding water, it was possible to polish optical glasses and ceramics with good stability at pH 8 for three weeks. The development of a corrosion resistant, MR polishing powder, opens up the possibility for polishing additional materials, wherein the pH may be adjusted to optimize effectiveness. In this paper we describe the CI coating process, the characterization of the coated powder, and procedures for making stable MR fluids with adjustable pH, giving polishing results for a variety of optical glasses and crystalline ceramics.

  1. SS-31 attenuates TNF-α induced cytokine release from C2C12 myotubes

    PubMed Central

    Lightfoot, Adam P.; Sakellariou, Giorgos K.; Nye, Gareth A.; McArdle, Francis; Jackson, Malcolm J.; Griffiths, Richard D.; McArdle, Anne

    2015-01-01

    TNF-α is a key inflammatory mediator and is proposed to induce transcriptional responses via the mitochondrial generation of Reactive Oxygen Species (ROS). The aim of this study was to determine the effect of TNF-α on the production of myokines by skeletal muscle. Significant increases were seen in the release of IL-6, MCP-1/CCL2, RANTES/CCL5 and KC/CXCL1 and this release was inhibited by treatment with Brefeldin A, suggesting a golgi-mediated release of cytokines by muscle cells. An increase was also seen in superoxide in response to treatment with TNF-α, which was localised to the mitochondria and this was also associated with activation of NF-κB. The changes in superoxide, activation of NF-kB and release of myokines were attenuated following pre-treatment with SS-31 peptide indicating that the ability of TNF-α to induce myokine release may be mediated through mitochondrial superoxide, which is, at least in part, associated with activation of the redox sensitive transcription factor NF-kB. PMID:26291279

  2. HEAO 3 upper limits to the expected 1634 KeV line from SS 483

    NASA Technical Reports Server (NTRS)

    Wheaton, W. A.; Ling, J. C.; Mahoney, W. A.; Jacobson, A. S.

    1985-01-01

    A model based on 24 Mg(1369) was developed as the source of the lines in which refractory grains in the jets, containing Mg and 0, are bombarded, by ambient protons in the local ISM. The narrowness of the features results because the recoil Mg nucleus is stopped in the grain before the 1369 keV excited state decays. A consequence of the 24 Mg interpretation is the expected appearance of other emission lines, due to 20 Ne and 20 Na, which are produced by proton bombardment of 24 Mg at the 33 MeV/nucleon energy corresponding to the velocity of the jets. These lines appear at rest energies of 1634 keV and 1636 keV, respectively, and should have essentially the same total flux as that emited at 1369 keV. The HEAO 3 data are examined to search for the 1634 keV (rest) emission. The observation and analysis, the results, and the implications for the understanding of SS 433 are discussed.

  3. Morphological Differentiation May Mediate Mate-Choice between Incipient Species of Anopheles gambiae s.s.

    PubMed Central

    Sanford, Michelle R.; Demirci, Berna; Marsden, Clare D.; Lee, Yoosook; Cornel, Anthony J.; Lanzaro, Gregory C.

    2011-01-01

    The M and S molecular forms of Anopheles gambiae s.s. have been considered incipient species for more than ten years, yet the mechanism underlying assortative mating of these incipient species has remained elusive. The discovery of the importance of harmonic convergence of wing beat frequency in mosquito mating and its relation to wing size have laid the foundation for exploring phenotypic divergence in wing size of wild populations of the two forms. In this study, wings from field collected mosquitoes were measured for wing length and wing width from two parts of the sympatric distribution, which differ with respect to the strength of assortative mating. In Mali, where assortative mating is strong, as evidenced by low rates of hybridization, mean wing lengths and wing widths were significantly larger than those from Guinea-Bissau. In addition, mean wing widths in Mali were significantly different between molecular forms. In Guinea-Bissau, assortative mating appears comparatively reduced and wing lengths and widths did not differ significantly between molecular forms. The data presented in this study support the hypothesis that wing beat frequency may mediate assortative mating in the incipient species of A. gambiae and represent the first documentation of a morphological difference between the M and S molecular forms. PMID:22132169

  4. DISCOVERY OF FAST, LARGE-AMPLITUDE OPTICAL VARIABILITY OF V648 Car (=SS73-17)

    SciTech Connect

    Angeloni, R.; Di Mille, F.; Ferreira Lopes, C. E.

    2012-09-01

    We report on the discovery of large-amplitude flickering from V648 Car (= SS73-17), a poorly studied object listed among the very few hard X-ray-emitting symbiotic stars. We performed millimagnitude precision optical photometry with the Swope Telescope at the Las Campanas Observatory, Chile, and found that V648 Car shows large U-band variability over timescales of minutes. To our knowledge, it exhibits some of the largest flickering of a symbiotic star ever reported. Our finding supports the hypothesis that symbiotic white dwarfs producing hard X-rays are predominantly powered by accretion, rather than quasi-steady nuclear burning, and have masses close to the Chandrasekhar limit. No significant periodicity is evident from the flickering light curve. The All Sky Automated Survey long-term V light curve suggests the presence of a tidally distorted giant accreting via Roche lobe overflow, and a binary period of {approx}520 days. On the basis of the outstanding physical properties of V648 Car as hinted at by its fast and long-term optical variability, as well as by its nature as a hard X-ray emitter, we therefore call for simultaneous follow-up observations in different bands, ideally combined with time-resolved optical spectroscopy.

  5. Mycobacterium avium ss. paratuberculosis Zoonosis - The Hundred Year War - Beyond Crohn's Disease.

    PubMed

    Sechi, Leonardo A; Dow, Coad Thomas

    2015-01-01

    The factitive role of Mycobacterium avium ss. paratuberculosis (MAP) in Crohn's disease has been debated for more than a century. The controversy is due to the fact that Crohn's disease is so similar to a disease of MAP-infected ruminant animals, Johne's disease; and, though MAP can be readily detected in the infected ruminants, it is much more difficult to detect in humans. Molecular techniques that can detect MAP in pathologic Crohn's specimens as well as dedicated specialty labs successful in culturing MAP from Crohn's patients have provided strong argument for MAP's role in Crohn's disease. Perhaps more incriminating for MAP as a zoonotic agent is the increasing number of diseases with which MAP has been related: Blau syndrome, type 1 diabetes, Hashimoto thyroiditis, and multiple sclerosis. In this article, we debate about genetic susceptibility to mycobacterial infection and human exposure to MAP; moreover, it suggests that molecular mimicry between protein epitopes of MAP and human proteins is a likely bridge between infection and these autoimmune disorders.

  6. Behaviour of SS316, with and without aluminization, in stagnant Pb17Li

    NASA Astrophysics Data System (ADS)

    Schreinlechner, I.; Sattler, P.

    1992-09-01

    Austenitic SS316 sheet material, partly aluminized, was tested in static Pb17Li (83 at% Pb and 17 at% Li), at 500°C. After 1000 h of exposure polished cross sections of pieces of the sample with and without aluminization were analysed by electron microscopy and compared with the as-received sample. The unprotected surface revealed the expected depletion of alloying elements and the formation of a porous ferritic zone to a depth of ≈ 200 μm into which Pb has penetrated. The aluminized suface does not show any attack by Pb17Li nor penetration of Pb into the grain boundaries. An intermediate layer is found between the matrix and the aluminum surface layer, with distinct borders on either side, consisting of Al+Ni-rich areas, believed to be an AlNi alloy between Cr-rich areas. Quantitative analyses revealed identical concentrations of Al and Ni, for exposed as well as unexposed samples, indicating no counter diffusion to have taken place during the test.

  7. The Effect of Surface Morphology on Corrosion Performance of SS 316 LVM Biomedical Devices

    NASA Astrophysics Data System (ADS)

    Toloei, Alisina; Guo, Mengnan; Rotermund, Harm H.

    2015-10-01

    In this study, in order to investigate the relationship between surface roughness and the corrosion resistance of the SS 316 LVM wires, samples have been prepared with different surface roughness by using different grits of SiC papers. In order to simulate the environment of implanted biomedical devices, a three-electrode electrochemical cell with 0.9% (by mass) NaCl solution has been used to test the corrosion resistance of the samples by potentiodynamic method and anodic polarization tests. SEM, EDS, and XPS have been performed to analyze the surfaces appearance and chemical elements on the surface before and after the corrosion. AFM was also used to get 3D images of the surface and to show the change in roughness of the samples after corrosion testing. Background-subtracted contrast-enhanced microscopy has been performed in situ to detect the pitting process happening on the surface of stainless steel samples. It was concluded that a relatively smoother surface can result in higher corrosion resistance and larger potential of stable pitting, whereas a rougher surface can easily go into stable pitting with lower pitting potentials. Rougher surfaces also showed a shorter time for the formation of stable pits. Microscopy observations illustrated more corrosion on rougher surfaces, and EDS showed more chloride ion remained on these surfaces.

  8. The Blattodea s.s. (Insecta, Dictyoptera) of the Guiana Shield

    PubMed Central

    Evangelista, Dominic A.; Chan, Kimberly; Kaplan, Kayla L.; Wilson, Megan M.; Ware, Jessica L.

    2015-01-01

    Abstract Here we provide a checklist of cockroach species known from areas within the Guiana Shield based on literature records and new field collection. We give records of sixteen species collected in Guyana, eight of which are new records for Guyana and one of which is a new generic record for the entire Guiana Shield. We also provide a description for a geographically disparate species of Calhypnorna Stal, and the new species Xestoblatta berenbaumae. The complete checklist contains 234 species of Blattodea s.s. currently known in the shield. This checklist shows particularly low richness in Guianan Venezuela, Roraima and Amapa Brazil, but this is likely an artifact due to under–sampling. Indeed, based on previously published data and current fieldwork, we believe that most regions of the Guiana Shield are under–sampled for cockroaches. Despite this, French Guiana (151 spp.) and Suriname (136 spp.) rank as the second and sixth most species dense faunas of cockroaches in the neotropics. PMID:25684997

  9. Bioreducible BPEI-SS-PEG-cNGR polymer as a tumor targeted nonviral gene carrier.

    PubMed

    Son, Sejin; Singha, Kaushik; Kim, Won Jong

    2010-08-01

    The work demonstrated development of multifunctional gene carrier which has incorporated reducible moiety, tumor targeting ligands as well as PEG to achieve efficient release of pDNA, enhanced tumor-specificity and long circulation, respectively. In our successful one-pot synthesis of multifunctional polymer, low molecular weight branched polyethylenimine (BPEI) was thiolated with propylene sulfide, and mixed with alpha-Maleimide-omega-N-hydroxysuccinimide ester polyethylene glycol (MAL-PEG-NHS, MW: 5000), and cyclic NGR peptide. The structural elucidation of the cNGR conjugated reducible BPEI containing disulfide bond (BPEI-SS-PEG-cNGR), was done by NMR and GPC study. Complex formation as well as reducible property of the polymer was confirmed by gel retardation assay. In order to achieve efficient tumor targeting, we have used cNGR peptide which is known to bind to CD13 overexpressed in neovasculature endothelial cells. Tumor target-specificity of polymer was established by carrying out competitive inhibition assay with free cNGR peptide. Cellular uptake of polymers was evaluated by confocal laser scanning microscope (CLSM). Finally, addition of free cNGR and buthionine sulfoximine (BSO) reduced transfection efficiency synergistically, which implied that multifunctional polymer-mediated gene transfection took place tumor-specifically and via GSH-dependent pathway.

  10. Combined slurry and cavitation erosion resistance of HVOF spray coated SS 410 steel

    NASA Astrophysics Data System (ADS)

    Amarendra, H. J.; Prathap, M. S.; Karthik, S.; Abhishek, A. M.; Madhu surya, K. C.; Gujjar gowda, S.; Anilkumar, T.

    2016-09-01

    The hydro turbine materials surface is degraded due to the slurry erosion and cavitation. The solid particles carried by water impacting the material results in slurry erosion. The damage occurred due to slurry erosion is the concern, when considered individually. The erosion damage is observed to be severe when slurry erosion and cavitation are combined. The hydro turbine material, martensitic stainless (SS 410) is surface modified with 80Ni-Cr by High Velocity Oxy Fuel spray process. The coated material subjected to post thermal treatment at a temperature of 950 ° C, soaked at 1 h, 2 h and 3 h are subjected to combined slurry and cavitation erosion test. The cavitation is created by using Cavitation Inducers. The tests are conducted by using silica sand as the erodent with three different sizes of 150, 200 and 300 μm. The results are compared with the as-received specimen. The results confirmed the effect of heat treatment on the end results, as the coated thermal treated specimens showed better erosion resistance against the as-received specimen. The eroded specimens are characterized by Scanning Electron Microscope. The thermal treated HVOF coated specimens shown the better erosion resistance.

  11. Mycobacterium avium ss. paratuberculosis Zoonosis – The Hundred Year War – Beyond Crohn’s Disease

    PubMed Central

    Sechi, Leonardo A.; Dow, Coad Thomas

    2015-01-01

    The factitive role of Mycobacterium avium ss. paratuberculosis (MAP) in Crohn’s disease has been debated for more than a century. The controversy is due to the fact that Crohn’s disease is so similar to a disease of MAP-infected ruminant animals, Johne’s disease; and, though MAP can be readily detected in the infected ruminants, it is much more difficult to detect in humans. Molecular techniques that can detect MAP in pathologic Crohn’s specimens as well as dedicated specialty labs successful in culturing MAP from Crohn’s patients have provided strong argument for MAP’s role in Crohn’s disease. Perhaps more incriminating for MAP as a zoonotic agent is the increasing number of diseases with which MAP has been related: Blau syndrome, type 1 diabetes, Hashimoto thyroiditis, and multiple sclerosis. In this article, we debate about genetic susceptibility to mycobacterial infection and human exposure to MAP; moreover, it suggests that molecular mimicry between protein epitopes of MAP and human proteins is a likely bridge between infection and these autoimmune disorders. PMID:25788897

  12. ssDNA-Functionalized Nanoceria: A Redox-Active Aptaswitch for Biomolecular Recognition.

    PubMed

    Bülbül, Gonca; Hayat, Akhtar; Andreescu, Silvana

    2016-04-01

    Quantification of biomolecular binding events is a critical step for the development of biorecognition assays for diagnostics and therapeutic applications. This paper reports the design of redox-active switches based on aptamer conjugated nanoceria for detection and quantification of biomolecular recognition. It is shown that the conformational transition state of the aptamer on nanoceria, combined with the redox properties of these particles can be used to create surface based structure switchable aptasensing platforms. Changes in the redox properties at the nanoceria surface upon binding of the ssDNA and its target analyte enables rapid and highly sensitive measurement of biomolecular interactions. This concept is demonstrated as a general applicable method to the colorimetric detection of DNA binding events. An example of a nanoceria aptaswitch for the colorimetric sensing of Ochratoxin A (OTA) and applicability to other targets is provided. The system can sensitively and selectivity detect as low as 0.15 × 10(-9) m OTA. This novel assay is simple in design and does not involve oligonucleotide labeling or elaborate nanoparticle modification steps. The proposed mechanism discovered here opens up a new way of designing optical sensing methods based on aptamer recognition. This approach can be broadly applicable to many bimolecular recognition processes and related applications. PMID:26844813

  13. Computaional Modeling of the Stability of Crevice Corrosion of Wetted SS316L

    SciTech Connect

    F. Cui; F.J. Presuel-Moreno; R.G. Kelly

    2006-04-17

    The stability of localized corrosion sites on SS 316L exposed to atmospheric conditions was studied computationally. The localized corrosion system was decoupled computationally by considering the wetted cathode and the crevice anode separately and linking them via a constant potential boundary condition at the mouth of the crevice. The potential of interest for stability was the repassivation potential. The limitations on the ability of the cathode that are inherent due to the restricted geometry were assessed in terms of the dependence on physical and electrochemical parameters. Physical parameters studied include temperature, electrolyte layer thickness, solution conductivity, and the size of the cathode, as well as the crevice gap for the anode. The current demand of the crevice was determined considering a constant crevice solution composition that simulates the critical crevice solution as described in the literature. An analysis of variance showed that the solution conductivity and the length of the cathode were the most important parameters in determining the total cathodic current capacity of the external surface. A semi-analytical equation was derived for the total current from a restricted geometry held at a constant potential at one end. The equation was able to reproduce all the model computation results both for the wetted external cathode and the crevice and give good explanation on the effects of physicochemical and kinetic parameters.

  14. Reliability performance evaluation of an on-board processor for SS-TDMA satellites

    NASA Astrophysics Data System (ADS)

    Garetti, E.; Ramello, B.; Settimo, F.

    1983-06-01

    A parametric approach is presented for assessing the reliability of the redundancy configurations of SS-TDMA telecommunication satellites. The system is assumed to have a ECL/LSI switching matrix and MOS/LSI for the control unit. The behavior of the system is described in terms of function for the failure rates of the system blocks over a 7 yr mission life. A reliability coefficient of 0.99 over 7 yr is shown to be available using a simple redundancy in both the switching matrix and the control unit, considering a 1000 failure/hr (Fit) rate in the electronic switching circuits. Attention is also given to the effects of the external redundancies on the overall system reliability, particularly with reference to the interconnections between the processor redundancies and the peripheral devices. An overall reliability of 0.9 is found available assuming a 500 Fit rate in the processor, a demodulator failure rate of 3000 Fit, and a modulator Fit rate of 1500. Selection of a three vote majority rule configuration is indicated for the system supervisory functions.

  15. Early diagnosis of primary Sjögren's syndrome: EULAR-SS task force clinical recommendations.

    PubMed

    Brito-Zerón, Pilar; Theander, Elke; Baldini, Chiara; Seror, Raphaèle; Retamozo, Soledad; Quartuccio, Luca; Bootsma, Hendrika; Bowman, Simon J; Dörner, Thomas; Gottenberg, Jacques-Eric; Mariette, Xavier; Bombardieri, Stefano; de Vita, Salvatore; Mandl, Thomas; Ng, Wan-Fai; Kruize, Aike A; Tzioufas, Athanasios; Vitali, Claudio; Buyon, Jill; Izmirly, Peter; Fox, Robert; Ramos-Casals, Manuel

    2016-01-01

    Sjögren's syndrome (SjS) is a systemic autoimmune disease that mainly affects the exocrine glands, leading to generalized mucosal dryness. However, primary SjS may initially present with non-sicca (systemic) manifestations. When these features appear before the onset of an overt sicca syndrome, we may talk of an underlying 'occult' SjS. The European League Against Rheumatism (EULAR) has promoted and supported an international collaborative study group (EULAR-SS Task Force) aimed at developing consensual recommendations to provide a homogeneous approach to the patient with primary SjS presenting with systemic involvement. This review summarizes the key factors that should be taken into account in the diagnostic approach in a patient with suspected SjS according to the main clinical patterns of presentation, and is especially focused on organ-specific systemic disease presentations, including a consensus set of recommendations in order to reach an early diagnosis. Close collaboration with the different specialties involved through a comprehensive multidisciplinary approach is essential in SjS patients presenting with systemic involvements.

  16. Electrostatic and hydrophobic interactions involved in CNT biofunctionalization with short ss-DNA.

    PubMed

    Carot, Maria Lucrecia; Torresi, Roberto M; Garcia, Carlos D; Esplandiu, Maria Jose; Giacomelli, Carla E

    2010-03-18

    This work is aimed at studying the adsorption mechanism of short chain 20-mer pyrimidinic homo-ss-DNA (oligodeoxyribonucleotide, ODN: polyC(20) and polyT(20)) onto CNT by reflectometry. To analyze the experimental data, the effective-medium theory using the Bruggemann approximation represents a suitable optical model to account for the surface properties (roughness, thickness and optical constants) and the size of the adsorbate. Systematic information about the involved interactions is obtained by changing the physico-chemical properties of the system. Hydrophobic and electrostatic interactions are evaluated by comparing the adsorption on hydrophobic CNT and on hydrophilic silica and by modulating the ionic strength with and without Mg(2+). The ODN adsorption process on CNT is driven by hydrophobic interactions only when the electrostatic repulsion is suppressed. The adsorption mode results in ODN molecules in a side-on orientation with the bases (non-polar region) towards the surface. This unfavorable orientation is partially reverse by adding Mg(2+). On the other hand, the adsorption on silica is dominated by the strong repulsive electrostatic interaction that is screened at high ionic strength or mediated by Mg(2+). The cation-mediated process induces the interaction of the phosphate backbone (polar region) with the surface, leaving the bases free for hybridization. Although the general adsorption behavior of the pyrimidine bases is the same, polyC(20) presents higher affinity for the CNT surface due to its acid-base properties. PMID:20563224

  17. Electrostatic and hydrophobic interactions involved in CNT biofunctionalization with short ss-DNA

    PubMed Central

    Carot, Maria Lucrecia; Torresi, Roberto M.; Garcia, Carlos D.; Esplandiu, Maria Jose; Giacomelli, Carla E.

    2010-01-01

    This work is aimed at studying the adsorption mechanism of short chain 20-mer pyrimidinic homo-ss-DNA (oligodeoxyribonucleotide, ODN: polyC20 and polyT20) onto CNT by reflectometry. To analyze the experimental data, the effective-medium theory using the Bruggemann approximation represents a suitable optical model to account for the surface properties (roughness, thickness and optical constants) and the size of the adsorbate. Systematic information about the involved interactions is obtained by changing the physico-chemical properties of the system. Hydrophobic and electrostatic interactions are evaluated by comparing the adsorption on hydrophobic CNT and on hydrophilic silica and by modulating the ionic strength with and without Mg2+. The ODN adsorption process on CNT is driven by hydrophobic interactions only when the electrostatic repulsion is suppressed. The adsorption mode results in ODN molecules in a side-on orientation with the bases (non-polar region) towards the surface. This unfavorable orientation is partially reverse by adding Mg2+. On the other hand, the adsorption on silica is dominated by the strong repulsive electrostatic interaction that is screened at high ionic strength or mediated by Mg2+. The cation-mediated process induces the interaction of the phosphate backbone (polar region) with the surface, leaving the bases free for hybridization. Although the general adsorption behavior of the pyrimidine bases is the same, polyC20 presents higher affinity for the CNT surface due to its acid-base properties. PMID:20563224

  18. Chandra Low Energy Transmission Grating Spectrum of SS Cygni in Outburst

    NASA Astrophysics Data System (ADS)

    Mauche, Christopher W.

    2004-07-01

    We have fitted the Chandra Low Energy Transmission Grating (LETG) spectrum of SS Cygni in outburst with a single-temperature blackbody suffering the photoelectric opacity of a neutral column density and the scattering opacity of an outflowing wind. We find that this simple model is capable of reproducing the essential features of the observed spectrum with the blackbody temperature Tbl~250+/-50 kK, hydrogen column density NH~5.0+2.9-1.5×1019cm-2, fractional emitting area f~5.6+60-4.5×10-3, boundary layer luminosity Lbl~5+18-3×1033ergss-1, wind velocity v~2500kms-1, wind mass-loss rate Mw~1.1×1016gs-1, and arbitrary values of the wind ionization fractions of 20 ions of O, Ne, Mg, Si, S, and Fe. Given that in outburst the accretion disk luminosity Ldisk~1×1035ergss-1, Lbl/Ldisk~0.05+0.18-0.03, which can be explained if the white dwarf (or an equatorial belt thereon) is rotating with an angular velocity Ωwd~0.7+0.1-0.2 Hz, hence Vrotsini~2300kms-1. This paper is dedicated to the memory and accomplishments of my colleague and friend Janet Akyüz Mattei, who died on 2004 March 22 after a long battle with acute myelogenous leukemia. Her passing is a great loss to the astronomical community, both amateur and professional.

  19. Synthesis of calcium hydrogen phosphate and hydroxyapatite coating on SS316 substrate through pulsed electrodeposition.

    PubMed

    Chakraborty, Rajib; Sengupta, Srijan; Saha, Partha; Das, Karabi; Das, Siddhartha

    2016-12-01

    The orthopaedic implants for human body are generally made of different biomaterials like stainless steels or Ti based alloys. However, it has been found that from surface properties point of view, none of these materials is attractive for fast tissue or cell growth on the surface of implant. This is one of the most important criteria to assure quick bonding between implant and body tissues vis-à-vis minimum recovery time for the patient. Keeping in view of the above facts, this work involves the pulsed electro-deposition coating of biocompatible hydroxyapatite and its group compounds from a diluted bath of calcium and phosphate salt at various current densities over the biomaterial sheet of SS316. SEM study confirms different morphologies of the coatings at different current densities. Characterization techniques like X-ray diffraction, SEM with EDX and FTIR have been used to confirm the phase and percentage quantity of hydroxyapatite compound in the depositions. This coating can serve as a medium for faster tissue growth over the metallic implants. PMID:27612782

  20. 4,4'-dithiodipyridine as a bridging ligand in osmium and ruthenium complexes: the electron conductor ability of the -S-S- bridge.

    PubMed

    Silva, Welter C; Lima, Joacy B; Moreira, Icaro S; Neto, Antônio M; Gandra, Flávio C G; Ferreira, Antônio G; McGarvey, Bruce R; Franco, Douglas W

    2003-10-20

    The compounds [Ru(NH(3))(5)(dtdp)](TFMS)(3), [Os(NH(3))(5)(dtdp)](TFMS)(3), [(NH(3))(5)Os(dtdp)Os(NH(3))(5)](TFMS)(6), [(NH(3))(5)Os(dtdp)Ru(NH(3))(5)](TFMS)(3)(PF(6))(2), and [(NH(3))(5)Os(dtdp)Fe(CN)(5)] (dtdp = 4,4'-dithiodipyridine, TFMS = trifluoromethanesulfonate) have been synthesized and characterized by elemental analysis, cyclic voltammetry, electronic, vibrational, EPR, and (1)H NMR spectroscopies. Changes in the electronic and voltammetric spectra of the ion complex [Os(NH(3))(5)(dtdp)](3+) as a function of the solution pH enable us to calculate the pK(a) for the [Os(NH(3))(5)(dtdpH)](4+) and [Os(NH(3))(5)(dtdpH)](3+) acids as 3.5 and 5.5, respectively. The comparison of the above pK(a) data with that for the free ligand (pK(1) = 4.8) provides evidence for the -S-S- bridge efficiency as an electron conductor between the two pyridine rings. The symmetric complex, [(NH(3))(5)Os(dtdp)Os(NH(3))(5)](6+), is found to exist in two geometric forms, and the most abundant form (most probably trans) has a strong conductivity through the -S-S- bridge, as is shown by EPR, which finds it to have an S = 1 spin state with a spin-spin interaction parameter of 150-200 G both in the solid sate and in frozen solution. Further the NMR of the same complex shows a large displacement of unpaired spin into the pi orbitals of the dttp ligand relative to that found in [Os(NH(3))(5)(dtdp)](3+). The comproportionation constant, K(c) = 2.0 x 10(5), for the equilibrium equation [Os(II)Os(II)] + [Os(III)Os(III)] right harpoon over left harpoon 2[Os(II)Os(III)] and the near-infrared band energy for the mixed-valence species (MMCT), [(NH(3))(5)Os(dtdp)Os(NH(3))(5)](5+) (lambda(MMCT) = 1665 nm, epsilon = 3.5 x 10(3) M(-)(1) cm(-)(1), deltanu(1/2) = 3.7 x 10(3) cm(-)(1), alpha = 0.13, and H(AB) = 7.8 x 10(2) cm(-)(1)), are quite indicative of strong electron delocalization between the two osmium centers. The electrochemical and spectroscopic data for the unsymmetrical binuclear complexes

  1. The Structure of a Type 3 Secretion System (T3SS) Ruler Protein Suggests a Molecular Mechanism for Needle Length Sensing.

    PubMed

    Bergeron, Julien R C; Fernández, Lucia; Wasney, Gregory A; Vuckovic, Marija; Reffuveille, Fany; Hancock, Robert E W; Strynadka, Natalie C J

    2016-01-22

    The type 3 secretion system (T3SS) and the bacterial flagellum are related pathogenicity-associated appendages found at the surface of many disease-causing bacteria. These appendages consist of long tubular structures that protrude away from the bacterial surface to interact with the host cell and/or promote motility. A proposed "ruler" protein tightly regulates the length of both the T3SS and the flagellum, but the molecular basis for this length control has remained poorly characterized and controversial. Using the Pseudomonas aeruginosa T3SS as a model system, we report the first structure of a T3SS ruler protein, revealing a "ball-and-chain" architecture, with a globular C-terminal domain (the ball) preceded by a long intrinsically disordered N-terminal polypeptide chain. The dimensions and stability of the globular domain do not support its potential passage through the inner lumen of the T3SS needle. We further demonstrate that a conserved motif at the N terminus of the ruler protein interacts with the T3SS autoprotease in the cytosolic side. Collectively, these data suggest a potential mechanism for needle length sensing by ruler proteins, whereby upon T3SS needle assembly, the ruler protein's N-terminal end is anchored on the cytosolic side, with the globular domain located on the extracellular end of the growing needle. Sequence analysis of T3SS and flagellar ruler proteins shows that this mechanism is probably conserved across systems. PMID:26589798

  2. Adaptation and Psychometric Properties of the Self-Efficacy/Social Support for Activity for Persons with Intellectual Disability Scale (SE/SS-AID) in a Spanish Sample

    ERIC Educational Resources Information Center

    Cuesta-Vargas, Antonio Ignacio; Paz-Lourido, Berta; Lee, Miyoung; Peterson-Besse, Jana J.

    2013-01-01

    Background: In this study we aimed to develop a Spanish version of the Self-Efficacy/Social Support Scales for Activity for persons with Intellectual Disability (SE/SS-AID). Method: A cross-sectional study was carried out in a sample of 117 individuals with intellectual disability (ID). The SE/SS-AID scales were translated into Spanish and their…

  3. Roles of C-Terminal Region of Yeast and Human Rad52 in Rad51-Nucleoprotein Filament Formation and ssDNA Annealing

    PubMed Central

    Khade, Nilesh V.; Sugiyama, Tomohiko

    2016-01-01

    Yeast Rad52 (yRad52) has two important functions at homologous DNA recombination (HR); annealing complementary single-strand DNA (ssDNA) molecules and recruiting Rad51 recombinase onto ssDNA (recombination mediator activity). Its human homolog (hRAD52) has a lesser role in HR, and apparently lacks mediator activity. Here we show that yRad52 can load human Rad51 (hRAD51) onto ssDNA complexed with yeast RPA in vitro. This is biochemically equivalent to mediator activity because it depends on the C-terminal Rad51-binding region of yRad52 and on functional Rad52-RPA interaction. It has been reported that the N-terminal two thirds of both yRad52 and hRAD52 is essential for binding to and annealing ssDNA. Although a second DNA binding region has been found in the C-terminal region of yRad52, its role in ssDNA annealing is not clear. In this paper, we also show that the C-terminal region of yRad52, but not of hRAD52, is involved in ssDNA annealing. This suggests that the second DNA binding site is required for the efficient ssDNA annealing by yRad52. We propose an updated model of Rad52-mediated ssDNA annealing. PMID:27362509

  4. The Rsm regulon of plant growth-promoting Pseudomonas fluorescens SS101: role of small RNAs in regulation of lipopeptide biosynthesis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rhizobacterium Pseudomonas fluorescens SS101 inhibits growth of oomycete and fungal pathogens, and induces resistance in plants against pathogens and insects. To unravel regulatory pathways of secondary metabolite production in SS101, we conducted a genome-wide search for sRNAs and performed tra...

  5. Immobilized pH gradients (IPG) simulator--an additional step in pH gradient engineering: II. Nonlinear pH gradients.

    PubMed

    Righetti, P G; Tonani, C

    1991-12-01

    While in the companion paper (Tonani, C. & Righetti, P. G., Electrophoresis 1991, 12, 1011-1021) we gave the general outline of our new computer program, immobilized pH gradients (IPG) simulator, able to simulate and optimize linear pH gradients for isoelectric focusing in immobilized pH gradients, in the present report we extend the application of such a program to: (i) convex exponential gradients, (ii) logarithmic and (iii) polynomial gradients. Such gradients are meant to give equal space to protein spots in complex protein mixtures (e.g., cell lysates, biological fluids) and follow the statistical distribution of protein pI values along the pH axis. They will prove of fundamental importance in two-dimensional maps, both because they optimize the spreading of spots in the two-dimensional plane and because of the excellent reproducibility of immobilized pH gradients. The following concave exponential recipes are given: pH 3-8, pH 3-9, pH 3-10, pH 3-11, pH 4-7, pH 4-8, pH 4-9, pH 4-10, pH 4-11, pH 5-8, pH 5-9, and pH 5-10, as well as the most extended pH 2.5-11 interval. Two interesting logarithmic gradients are described: pH 3-6 and pH 3-7 and one sigmoidal (derived with a polynomial of 5th degree): pH 3-11.

  6. pH fluorescent probes: chlorinated fluoresceins.

    PubMed

    Ge, Feng-Yan; Chen, Li-Gong

    2008-01-01

    A series of regiospecific chlorinated fluoresceins have been synthesized by the reaction of the regiospecific chlorinated resorcinols with chlorinated phthalic anhydride. The regioisomers were successfully separated by chromatography. The photophysical properties of the obtained chlorinated fluoresceins were examined and found their absorption and emission maxima at long wavelength with high fluorescence quantum yield. Especially, pH-dependent properties of chlorinated fluoresceins have been studied in detail. These compounds show strongly pH-sensitive range of 3.5-7.0, and have lower pK (a) values than fluorescein. Furthermore, their fluorescent intensity could reach the maximum in the physiological environment of pH range 6.8-7.4. Due to higher fluorescence quantum yield and lower pK (a) values, chlorinated fluoresceins will be expected to be used as excellent pH fluorescent probes for pH measurement of the acidic cell.

  7. Pattern recognition of ocean pH

    NASA Astrophysics Data System (ADS)

    Parker, Albert

    2016-09-01

    The manuscript shows how the few, scattered, latest measurements of ocean pH lacking a proper spatial and time coverage do not permit a meaningful computation of global trends, as the ocean pH is strongly variable in latitude, longitude and depth and very likely is subject to the multi-decadal oscillations that have been identified in the atmospheric and ocean systems. The proposed mathematical model is based on the assumption that the monthly averaged ocean pH may be described by the superposition of a linear trend and inter-annual, decadal and multi-decadal oscillations, with linear and sinusoidal regression coefficients requiring data that are presently unavailable.

  8. Effects of a new antiarrhythmic drug SS-68 on electrical activity in working atrial and ventricular myocardium of mouse and their ionic mechanisms.

    PubMed

    Bogus, Saida K; Abramochkin, Denis V; Galenko-Yaroshevsky, Pavel A; Suzdalev, Konstantin F

    2015-08-01

    SS-68 is a derivative of indole, which demonstrated strong antiarrhythmic effects not associated with significant QT prolongation in dog models of atrial fibrillation. Therefore, SS-68 was proposed as a new antiarrhythmic drug and the present study is the first describing its effects on action potentials (APs) configuration and elucidating the ionic mechanisms of these effects. Sharp microelectrodes were used to record APs in isolated preparations of mouse atrial and ventricular myocardium. In both types of myocardium 10(-6) M SS-68 produced reduction of AP duration, 3 × 10(-6) M failed to alter AP waveform and 10(-5) - 3 × 10(-5) M prolonged APs. Sensitivity of main ionic currents to SS-68 was determined using whole-cell patch clamp. Transient potassium current Ito was slightly inhibited by SS-68 with IC50 = 1.43 × 10(-4) M. IKur was more sensitive with IC50 = 1.84 × 10(-5) M. Background inward rectifier showed very low sensitivity to SS-68 - only 10(-4) M SS-68 caused significant reduction of IK1. ICaL was significantly inhibited by 10(-6)M - 3 × 10(-5) M SS-68. The IC50 value for the ICaL was 1.84 × 10(-6) M. Thus, main ionic currents of mouse cardiomyocytes are inhibited by SS-68 in the following order of potency: ICaL > IKur > Ito > IK1. While lower concentration of SS-68 shorten APs via suppression of ICaL, higher concentrations inhibit K(+)-currents leading to APs prolongation.

  9. Differential Ovarian Expression of KiSS-1 and GPR-54 During the Estrous Cycle and Photoperiod Induced Recrudescence in Siberian Hamsters (Phodopus sungorus)

    PubMed Central

    Shahed, Asha; Young, Kelly A.

    2008-01-01

    Kisspeptins, coded by the KiSS-1 gene, regulate aspects of the reproductive axis by stimulating GnRH release via the G protein coupled receptor, GPR54. Recent reports show that KiSS/GPR54 may be key mediators in photoperiod-controlled reproduction in seasonal breeders, and that KiSS-1/GPR54 are expressed in the hypothalamus, ovaries, placenta, and pancreas. This study examined the expression of KiSS-1/GPR54 mRNA and protein in ovaries of Siberian hamsters (Phodopus sungorus). Ovaries from cycling hamsters were collected during proestrus (P), estrus (E), diestrus I (DI), and diestrus II (DII). To examine KiSS-1/GPR54 during stimulated recrudescence, additional hamsters were maintained either in long day (LD 16L:8D, control) or short day (SD 8L:16D) for 14 weeks and then transferred to LD for 0–8 weeks. Staining of KiSS-1/GPR54 protein was detected by immunohistochemistry in steroidogenic cells of preantral and antral follicles, and corpora lutea. Immunostaining peaked in P and E, but decreased in the diestrus stages (p<0.05). In recrudescing ovaries, KiSS-1/GPR54 immunostaining was low after 14 wks of SD exposure (post transfer [PT] wk0), and increased during the early weeks of recrudescence. Expression of KiSS-1/GPR54 mRNA was low with short day exposure, but increased during recrudescence and was higher at PT wk8 as compared to PTwks 0 and 2 (p<0.05). The elevated KiSS-1/ GPR54 expression during P and E suggests a potential role in ovulation in Siberian hamsters. Transient increases in KiSS-1/GPR54 expression following LD stimulation are also suggestive of possible involvement in ovulation and/or restoration of ovarian function. PMID:18937338

  10. Ratiometric imaging of pH probes.

    PubMed

    Grillo-Hill, Bree K; Webb, Bradley A; Barber, Diane L

    2014-01-01

    Measurement of intracellular pH can be readily accomplished using tools and methods described in this chapter. We present a discussion of technical considerations of various ratiometric pH-sensitive probes including dyes and genetically encoded sensors. These probes can be used to measure pH across physical scales from macroscopic whole-mount tissues down to organelles and subcellular domains. We describe protocols for loading pH-sensitive probes into single cells or tissues and discuss ratiometric image acquisition and analysis.

  11. High dietary protein exacerbates hypertension and renal damage in Dahl SS rats by increasing infiltrating immune cells in the kidney.

    PubMed

    De Miguel, Carmen; Lund, Hayley; Mattson, David L

    2011-02-01

    The present study evaluated the influence and mechanism of action of dietary protein intake in Dahl SS hypertension and renal disease. Rats were fed isocaloric diets with low (6%), normal (18%), or high (30%) amounts of protein and 0.4% NaCl from 5 to 12 weeks of age; the NaCl content of the diets was then increased to 4.0% NaCl from 12 to 15 weeks of age. Rats fed the high-protein diet developed the highest mean arterial blood pressure and urine albumin-to-creatinine ratio when fed the 4.0% NaCl diet (153 ± 7 mm Hg and 8.0 ± 2.4, respectively) compared to rats fed normal protein (132 ± 3 mm Hg, 1.2 ± 0.3) or low-protein (132 ± 6 mm Hg, 0.3 ± 0.1) diets. Significantly greater numbers of infiltrating T lymphocytes were observed in kidneys of SS rats fed the high-protein diet (18.9 ± 3 × 10⁵ cells) than in rats fed the low-protein diet (9.1 ± 3 × 10⁵ cells). Furthermore, treatment of SS rats fed the high-protein diet with the immunosuppressant agent mycophenolate mofetil (20 mg/kg per day, ip) significantly reduced the number of infiltrating T cells in the kidneys (from 18.9 ± 2.7 to 10.6 ± 2.0 × 10⁵ cells) while decreasing blood pressure (from 133 ± 3 to 113 ± 4 mm Hg) and the albumin/creatinine ratio (from 10.9 ± 2.3 to 5.4 ± 1.2). These results demonstrate that restriction of protein intake protects the Dahl SS rats from hypertension and kidney disease and indicates that infiltrating immune cells play a pathological role in Dahl SS rats fed a high-protein diet. Moreover, the results show that hypertension in Dahl SS rats is sensitive to both NaCl and protein intake.

  12. Extended Emission from the PSR B1259-63/SS 2883 Binary Detected with Chandra

    NASA Astrophysics Data System (ADS)

    Pavlov, George G.; Chang, Chulhoon; Kargaltsev, Oleg

    2011-03-01

    PSR B1259-63 is a middle-aged radio pulsar (P = 48 ms, τ = 330 kyr, and \\dot{E}=8.3× 10^{35} erg s-1) in an eccentric binary (P orb = 3.4 yr, e = 0.87) with a high-mass Be companion, SS 2883. We observed the binary near apastron with the Chandra ACIS detector on 2009 May 14 for 28 ks. In addition to the previously studied point-like source at the pulsar's position, we detected extended emission on the south-southwest side of this source. The point-like source spectrum can be described by the absorbed power-law model with the hydrogen column density N H = (2.5 ± 0.6) × 1021 cm-2, photon index Γ = 1.6 ± 0.1, and luminosity L 0.5-8 keV ≈ 1.3 × 1033 d 2 3 erg s-1, where d 3 is the distance scaled to 3 kpc. This emission likely includes an unresolved part of the pulsar wind nebula (PWN) created by the colliding winds from the pulsar and the Be companion, and a contribution from the pulsar magnetosphere. The extended emission apparently consists of two components. The highly significant compact component looks like a southward extension of the point-like source image, seen up to ~4'' from the pulsar position. Its spectrum has about the same slope as the point-like source spectrum, while its luminosity is a factor of 10 lower. We also detected an elongated feature extended ~15'' southwest of the pulsar, but the significance of this detection is marginal. We tentatively interpret the resolved compact PWN component as a shocked pulsar wind blown out of the binary by the wind of the Be component, while the elongated component could be a pulsar jet.

  13. Iron requirement for Mn(II) oxidation by Leptothrix discophora SS-1.

    PubMed

    El Gheriany, Iman A; Bocioaga, Daniela; Hay, Anthony G; Ghiorse, William C; Shuler, Michael L; Lion, Leonard W

    2009-03-01

    A common form of biocatalysis of Mn(II) oxidation results in the formation of biogenic Mn(III, IV) oxides and is a key reaction in the geochemical cycling of Mn. In this study, we grew the model Mn(II)-oxidizing bacterium Leptothrix discophora SS-1 in media with limited iron (0.1 microM iron/5.8 mM pyruvate) and sufficient iron (0.2 microM iron/5.8 mM pyruvate). The influence of iron on the rate of extracellular Mn(II) oxidation was evaluated. Cultures in which cell growth was limited by iron exhibited reduced abilities to oxidize Mn(II) compared to cultures in medium with sufficient iron. While the extracellular Mn(II)-oxidizing factor (MOF) is thought to be a putative multicopper oxidase, Mn(II) oxidation in the presence of zero added Cu(II) was detected and the decrease in the observed Mn(II) oxidation rate in iron-limited cultures was not relieved when the medium was supplemented with Cu(II). The decline of Mn(II) oxidation under iron-limited conditions was not accompanied by siderophore production and is unlikely to be an artifact of siderophore complex formation with Mn(III). The temporal variations in mofA gene transcript levels under conditions of limited and abundant iron were similar, indicating that iron limitation did not interfere with the transcription of the mofA gene. Our quantitative PCR results provide a step forward in understanding the regulation of Mn(II) oxidation. The mechanistic role of iron in Mn(II) oxidation is uncertain; the data are consistent with a direct requirement for iron as a component of the MOF or an indirect effect of iron resulting from the limitation of one of many cellular functions requiring iron. PMID:19114505

  14. Iron Requirement for Mn(II) Oxidation by Leptothrix discophora SS-1▿

    PubMed Central

    El Gheriany, Iman A.; Bocioaga, Daniela; Hay, Anthony G.; Ghiorse, William C.; Shuler, Michael L.; Lion, Leonard W.

    2009-01-01

    A common form of biocatalysis of Mn(II) oxidation results in the formation of biogenic Mn(III, IV) oxides and is a key reaction in the geochemical cycling of Mn. In this study, we grew the model Mn(II)-oxidizing bacterium Leptothrix discophora SS-1 in media with limited iron (0.1 μM iron/5.8 mM pyruvate) and sufficient iron (0.2 μM iron/5.8 mM pyruvate). The influence of iron on the rate of extracellular Mn(II) oxidation was evaluated. Cultures in which cell growth was limited by iron exhibited reduced abilities to oxidize Mn(II) compared to cultures in medium with sufficient iron. While the extracellular Mn(II)-oxidizing factor (MOF) is thought to be a putative multicopper oxidase, Mn(II) oxidation in the presence of zero added Cu(II) was detected and the decrease in the observed Mn(II) oxidation rate in iron-limited cultures was not relieved when the medium was supplemented with Cu(II). The decline of Mn(II) oxidation under iron-limited conditions was not accompanied by siderophore production and is unlikely to be an artifact of siderophore complex formation with Mn(III). The temporal variations in mofA gene transcript levels under conditions of limited and abundant iron were similar, indicating that iron limitation did not interfere with the transcription of the mofA gene. Our quantitative PCR results provide a step forward in understanding the regulation of Mn(II) oxidation. The mechanistic role of iron in Mn(II) oxidation is uncertain; the data are consistent with a direct requirement for iron as a component of the MOF or an indirect effect of iron resulting from the limitation of one of many cellular functions requiring iron. PMID:19114505

  15. COMPUTATIONAL MODELING OF CATHODIC LIMITATIONS ON LOCALIZED CORROSION OF WETTED SS 316L, AT ROOM TEMPERATURE

    SciTech Connect

    F. Cui; F.J. Presuel-Moreno; R.G. Kelly

    2005-10-13

    The ability of a SS316L surface wetted with a thin electrolyte layer to serve as an effective cathode for an active localized corrosion site was studied computationally. The dependence of the total net cathodic current, I{sub net}, supplied at the repassivation potential E{sub rp} (of the anodic crevice) on relevant physical parameters including water layer thickness (WL), chloride concentration ([Cl{sup -}]) and length of cathode (Lc) were investigated using a three-level, full factorial design. The effects of kinetic parameters including the exchange current density (i{sub o,c}) and Tafel slope ({beta}{sub c}) of oxygen reduction, the anodic passive current density (i{sub p}) (on the cathodic surface), and E{sub rp} were studied as well using three-level full factorial designs of [Cl{sup -}] and Lc with a fixed WL of 25 {micro}m. The study found that all the three parameters WL, [Cl{sup -}] and Lc as well as the interactions of Lc x WL and Lc x [Cl{sup -}] had significant impact on I{sub net}. A five-factor regression equation was obtained which fits the computation results reasonably well, but demonstrated that interactions are more complicated than can be explained with a simple linear model. Significant effects on I{sub net} were found upon varying either i{sub o,c}, {beta}{sub c}, or E{sub rp}, whereas i{sub p} in the studied range was found to have little impact. It was observed that I{sub net} asymptotically approached maximum values (I{sub max}) when Lc increased to critical minimum values. I{sub max} can be used to determine the stability of coupled localized corrosion and the critical Lc provides important information for experimental design and corrosion protection.

  16. SS-A/Ro52 promotes apoptosis by regulating Bcl-2 production

    SciTech Connect

    Jauharoh, Siti Nur Aisyah; Saegusa, Jun; Sugimoto, Takeshi; Ardianto, Bambang; Kasagi, Shimpei; Sugiyama, Daisuke; Kurimoto, Chiyo; Tokuno, Osamu; Nakamachi, Yuji; Kumagai, Shunichi; Kawano, Seiji

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Ro52{sup low} HeLa cells are resistant to apoptosis upon various stimulations. Black-Right-Pointing-Pointer Ro52 is upregulated by IFN-{alpha}, etoposide, or IFN-{gamma} and anti-Fas Ab. Black-Right-Pointing-Pointer Ro52-mediated apoptosis is independent of p53. Black-Right-Pointing-Pointer Ro52 selectively regulates Bcl-2 expression. -- Abstract: SS-A/Ro52 (Ro52), an autoantigen in systemic autoimmune diseases such as systemic lupus erythematosus and Sjoegren's syndrome, has E3 ligase activity to ubiquitinate proteins that protect against viral infection. To investigate Ro52's role during stress, we transiently knocked it down in HeLa cells by siRo52 transfection. We found that Ro52{sup low} HeLa cells were significantly more resistant to apoptosis than wild-type HeLa cells when stimulated by H{sub 2}O{sub 2}- or diamide-induced oxidative stress, IFN-{alpha}, IFN-{gamma} and anti-Fas antibody, etoposide, or {gamma}-irradiation. Furthermore, Ro52-mediated apoptosis was not influenced by p53 protein level in HeLa cells. Depleting Ro52 in HeLa cells caused Bcl-2, but not other Bcl-2 family molecules, to be upregulated. Taken together, our data showed that Ro52 is a universal proapoptotic molecule, and that its proapoptotic effect does not depend on p53, but is exerted through negative regulation of the anti-apoptotic protein Bcl-2. These findings shed light on a new physiological role for Ro52 that is important to intracellular immunity.

  17. Canine echinococcosis: genetic diversity of Echinococcus granulosus sensu stricto (s.s.) from definitive hosts.

    PubMed

    Boufana, B; Lett, W; Lahmar, S; Griffiths, A; Jenkins, D J; Buishi, I; Engliez, S A; Alrefadi, M A; Eljaki, A A; Elmestiri, F M; Reyes, M M; Pointing, S; Al-Hindi, A; Torgerson, P R; Okamoto, M; Craig, P S

    2015-11-01

    Canids, particularly dogs, constitute the major source of cystic echinococcosis (CE) infection to humans, with the majority of cases being caused by Echinococcus granulosus (G1 genotype). Canine echinococcosis is an asymptomatic disease caused by adult tapeworms of E. granulosus sensu lato (s.l.). Information on the population structure and genetic variation of adult E. granulosus is limited. Using sequenced data of the mitochondrial cytochrome c oxidase subunit 1 (cox1) we examined the genetic diversity and population structure of adult tapeworms of E. granulosus (G1 genotype) from canid definitive hosts originating from various geographical regions and compared it to that reported for the larval metacestode stage from sheep and human hosts. Echinococcus granulosus (s.s) was identified from adult tapeworm isolates from Kenya, Libya, Tunisia, Australia, China, Kazakhstan, United Kingdom and Peru, including the first known molecular confirmation from Gaza and the Falkland Islands. Haplotype analysis showed a star-shaped network with a centrally positioned common haplotype previously described for the metacestode stage from sheep and humans, and the neutrality indices indicated population expansion. Low Fst values suggested that populations of adult E. granulosus were not genetically differentiated. Haplotype and nucleotide diversities for E. granulosus isolates from sheep and human origin were twice as high as those reported from canid hosts. This may be related to self-fertilization of E. granulosus and/or to the longevity of the parasite in the respective intermediate and definitive hosts. Improved nuclear single loci are required to investigate the discrepancies in genetic variation seen in this study.

  18. Chandra Low Energy Transmission Grating Spectrum of SS Cygni in Outburst

    SciTech Connect

    Mauche, C W

    2004-02-20

    We have fitted the Chandra Low Energy Transmission Grating spectrum of SS Cygni in outburst with a single temperature blackbody suffering the photoelectric opacity of a neutral column density and the scattering opacity of an outflowing wind. We find that this simple model is capable of reproducing the essential features of the observed spectrum with the blackbody temperature T{sub bl} {approx} 250{+-}50 kK, hydrogen column density N{sub H} {approx} 5.0{sup +2.9}{sub -1.5}x10{sup 19} cm{sup -2}, fractional emitting area f {approx} 5.6{sup +60}{sub -4.5} x10{sup -3}, boundary layer luminosity Lbl {approx} 5{sup +18}{sub -3} x10{sup 33} erg s{sup -1}, wind velocity v {approx} 2500 km s{sup -1}, wind mass-loss rate w {approx} 1.1x10{sup 16} g s{sup -1}, and arbitrary values of the wind ionization fractions of 20 ions of O, Ne,Mg, Si, S, and Fe. Given that in outburst the accretion disk luminosity L{sub disk} {approx}1x10{sup 35} erg s{sup -1}, L{sub bl}/L{sub disk} {approx} 0.05{sup +0.18}{sub -0.03}, which can be explained if the white dwarf (or an equatorial belt thereon) is rotating with an angular velocity {Omega}{sub wd} {approx} 0.7{sup +0.1}{sub -0.2}Hz, hence V{sub rot}sini {approx} 2300 km s{sup -1}.

  19. Oral delivery of beta-lactamase by Lactococcus lactis subsp. lactis transformed with Plasmid ss80.

    PubMed

    Kaushal, Gagan; Shao, Jun

    2006-04-01

    The objective was to use normal flora to deliver protein/peptide drugs orally. A probiotic bacterium, Lactococcus lactis subsp. lactis (L. lactis) transformed with Plasmid ss80, which made it able to synthesize and secrete beta-lactamase, a 29 kDa protein, was used as the delivery system for beta-lactamase. Oral absorption of beta-lactamase in rats when delivered by this L. lactis system was investigated. The oral bioavailability of beta-lactamase delivered by 3x10(7) of the L. lactis was equivalent to 209 mU of i.v. dose, and the estimated relative bioavailability was 16.7%. When delivered by beta-lactamase free solution form, the relative oral bioavailability was 4.7%, which increased to 6.0% when co-administered with 3x10(7) of the untransformed L. lactis. The results demonstrated that the L. lactis significantly increased the beta-lactamase oral bioavailability by 2-3-folds (p<0.01), the mean residence time (MRT) by 3-4 times (p<0.01), and the mean absorption time (MAT) by 6-14 times (p<0.01), as compared to the free solution form with/without the untransformed L. lactis. In conclusion, the L. lactis is more efficient in delivering beta-lactamase orally compared with the free solution form. It also provides a sustained delivery mechanism for beta-lactamase. Gene-transformed normal flora may be used as an efficient and sustained delivery system for protein drugs through oral route.

  20. Evaluation of fluorimetric pH sensors for bioprocess monitoring at low pH.

    PubMed

    Janzen, Nils H; Schmidt, Michael; Krause, Christian; Weuster-Botz, Dirk

    2015-09-01

    Optical chemical sensors are the standard for pH monitoring in small-scale bioreactors such as microtiter plates, shaking flasks or other single-use bioreactors. The dynamic pH range of the so far commercially available fluorescent pH sensors applied in small-scale bioreactors is restricted to pH monitoring around neutral pH, although many fermentation processes are performed at pH < 6 on industrial scale. Thus, two new prototype acidic fluorescence pH sensors immobilized in single-use stirred-tank bioreactors, one with excitation at 470 nm and emission at 550 nm (sensor 470/550) and the other with excitation at 505 nm and emission at 600 nm (sensor 505/600), were characterized with respect to dynamic ranges and operational stability in representative fermentation media. Best resolution and dynamic range was observed with pH sensor 505/600 in mineral medium (dynamic range of 3.9 < pH < 7.2). Applying the same pH sensors to complex medium results in a drastic reduction of resolution and dynamic ranges. Yeast extract in complex medium was found to cause background fluorescence at the sensors' operating wavelength combinations. Optical isolation of the sensor by adding a black colored polymer layer above the sensor spot and fixing an aperture made of adhesive photoresistant foil between the fluorescence reader and the transparent bottom of the polystyrene reactors enabled full re-establishment of the sensor's characteristics. Reliability and operational stability of sensor 505/600 was shown by online pH monitoring (4.5 < pH < 5.8) of parallel anaerobic batch fermentations of Clostridium acetobutylicum for the production of acetone, butanol and ethanol (ABE) with offline pH measurements with a standard glass electrode as reference. PMID:25969385

  1. Monitoring fetal pH by telemetry

    NASA Technical Reports Server (NTRS)

    Blum, A.; Donahoe, T.; Jhabvala, M. D.; Ryan, W.

    1980-01-01

    Telemetry unit has been developed for possible use in measuring scalp-tissue pH and heart rate of unborn infant. Unit radius data to receiver as much as 50 ft. away. Application exists during hours just prior to childbirth to give warning of problems that might require cesarean delivery.

  2. Optoelectronic pH Meter: Further Details

    NASA Technical Reports Server (NTRS)

    Jeevarajan, Antony S.; Anderson, Mejody M.; Macatangay, Ariel V.

    2009-01-01

    A collection of documents provides further detailed information about an optoelectronic instrument that measures the pH of an aqueous cell-culture medium to within 0.1 unit in the range from 6.5 to 7.5. The instrument at an earlier stage of development was reported in Optoelectronic Instrument Monitors pH in a Culture Medium (MSC-23107), NASA Tech Briefs, Vol. 28, No. 9 (September 2004), page 4a. To recapitulate: The instrument includes a quartz cuvette through which the medium flows as it is circulated through a bioreactor. The medium contains some phenol red, which is an organic pH-indicator dye. The cuvette sits between a light source and a photodetector. [The light source in the earlier version comprised red (625 nm) and green (558 nm) light-emitting diodes (LEDs); the light source in the present version comprises a single green- (560 nm)-or-red (623 nm) LED.] The red and green are repeatedly flashed in alternation. The responses of the photodiode to the green and red are processed electronically to obtain the ratio between the amounts of green and red light transmitted through the medium. The optical absorbance of the phenol red in the green light varies as a known function of pH. Hence, the pH of the medium can be calculated from the aforesaid ratio.

  3. pH & Rate of Enzymatic Reactions.

    ERIC Educational Resources Information Center

    Clariana, Roy B.

    1991-01-01

    A quantitative and inexpensive way to measure the rate of enzymatic reaction is provided. The effects of different pH levels on the reaction rate of an enzyme from yeast are investigated and the results graphed. Background information, a list of needed materials, directions for preparing solutions, procedure, and results and discussion are…

  4. Development of sulfonamide AKT PH domain inhibitors

    PubMed Central

    Ahad, Ali Md.; Zuohe, Song; Du-Cuny, Lei; Moses, Sylvestor A.; Zhou, Li Li; Zhang, Shuxing; Powis, Garth; Meuillet, Emmanuelle J.; Mash, Eugene A.

    2011-01-01

    Disruption of the phosphatidylinositol 3-kinase/AKT signaling pathway can lead to apoptosis in cancer cells. Previously we identified a lead sulfonamide that selectively bound to the pleckstrin homology (PH) domain of AKT and induced apoptosis when present at low micromolar concentrations. To examine the effects of structural modification, a set of sulfonamides related to the lead compound was designed, synthesized, and tested for binding to the expressed PH domain of AKT using a surface plasmon resonance-based competitive binding assay. Cellular activity was determined by means of an assay for pAKT production and a cell killing assay using BxPC3 cells. The most active compounds in the set are lipophilic and possess an aliphatic chain of the proper length. Results were interpreted with the aid of computational modeling. This paper represents the first structure-activity relationship (SAR) study of a large family of AKT PH domain inhibitors. Information obtained will be used in the design of the next generation of inhibitors of AKT PH domain function. PMID:21353784

  5. Ph.D.'s and the Marketplace.

    ERIC Educational Resources Information Center

    Harvey, James

    Throughout the last decade, Ph.D. recipients were accustomed to a job market in which demand for their services far exceeded supply. During the same period, manpower experts predicted this situation would continue in the foreseeable future. However, when the 60's ended, the employment illusion had been rudely dispelled by frantic reports of a…

  6. Teaching Physics Using PhET Simulations

    ERIC Educational Resources Information Center

    Wieman, C. E.; Adams, W. K.; Loeblein, P.; Perkins, K. K.

    2010-01-01

    PhET Interactive Simulations (sims) are now being widely used in teaching physics and chemistry. Sims can be used in many different educational settings, including lecture, individual or small group inquiry activities, homework, and lab. Here we will highlight a few ways to use them in teaching, based on our research and experiences using them in…

  7. What My Ph.D. Taught Me

    ERIC Educational Resources Information Center

    Levenstein, Jessica

    2013-01-01

    The author started in the Ph.D. program in comparative literature at Princeton in 1992, a year after she graduated from college. She fell in love with mythology and the classical traditions and find herself teaching literature. In the remainder of her time at Princeton, she precepted for four or five more classes, got the chance to join the…

  8. The Economic Contribution of PhDs

    ERIC Educational Resources Information Center

    Casey, Bernard H.

    2009-01-01

    This paper looks at what the value of a doctorate is, both to employers in particular and to society and the economy at large. Given the emphasis many universities and funding agencies/governments are putting upon the development of PhD programmes, this is an issue deserving attention. The paper tries to show how two separate but interrelated…

  9. The Ph.D. Value Proposition

    ERIC Educational Resources Information Center

    Cooper, Kenneth J.

    2012-01-01

    Atlanta University launched its doctor of arts in humanities (DAH) programs almost 40 years ago, and, since the 1988 merger with Clark College, Clark Atlanta University has continued to award the degrees. This fall, for the first time, its students will be able to earn Ph.D.s in humanities instead. In DAH programs around the country, there's been…

  10. Discovery of the double Doppler-shifted emission-line systems in the X-ray spectrum of SS 433

    NASA Technical Reports Server (NTRS)

    Kotani, Taro; Kawai, Nobuyuki; Aoki, Takashi; Doty, John; Matsuoka, Masaru; Mitsuda, Kazuhisa; Nagase, Fumiaki; Ricker, George; White, Nick E.

    1994-01-01

    We have used the CCD X-ray spectrometers on ASCA and resolved the X-ray emission line from the jet of SS 433 both into Doppler-shifted components with two distinct velocities, and into emission from different ionization states of iron, i.e., Fe XXV and Fe XXVI. This is the first direct detection of the two Doppler shifted beams in the X-ray spectra of SS 433 and allows the radial velocity of the jet along the line of sight to be determined with an accuracy comparable to the optical spectroscopy. We also found pairs of emission lines from other atomic species, such as ionized silicon and sulfur, with the Doppler shifts consistent with each other. This confirms the origin of the X-ray emission in the high temperature plasma in the jets.

  11. Effect of exposure time on corrosion resistance of prepassivated UNS S31603 SS in the Gulf of Mexico

    SciTech Connect

    Acuiia, N.; Herniindet-Duque, G.

    1998-12-31

    The effect of exposure time, in the Gulf of Mexico, on the UNS S3 1603 stainless steel (SS) pitting corrosion resistance (PCR), was studied for 30 days using both open circuit potential (OCP) and potentiodynamic polarization (PP) techniques. Biofilm formation and corrosion attack were subsequently observed using scanning electron microscope (SEM) and atomic force microscopy (AFM). It was found that microorganisms colonizing the steel specimen`s surface during the first three days of testing, modified the OCP towards electropositive values, increasing the risk of pitting corrosion. It was also observed, that the SS specimens were most sensitive to pitting corrosion within the first fifteen days of exposure in seawater, decreasing this sensitivity during the last week, probably due to a decay in the biological activity and better behavior of the passive film.

  12. Small Punch Creep Studies for Optimization of Nitrogen Content in 316LN SS for Enhanced Creep Resistance

    NASA Astrophysics Data System (ADS)

    Mathew, M. D.; Ganesh Kumar, J.; Ganesan, V.; Laha, K.

    2014-02-01

    Small punch creep (SPC) studies have been carried out to evaluate the creep properties of 316LN stainless steel (SS) at 923 K (650 °C) at various stress levels. The results have been compared with uniaxial creep rupture data obtained from conventional creep tests. The minimum deflection rate was found to obey Norton power law. SPC rupture life was correlated with uniaxial creep rupture life. The influence of nitrogen content on the creep rupture properties of 316LN SS was investigated in the range of 0.07 to 0.14 wt pct. SPC rupture life increased and the minimum deflection rate decreased with the increase in nitrogen content. The trends were found to be in agreement with the results obtained from uniaxial creep rupture tests. These studies have established that SPC is a fast and reliable technique to screen creep properties of different experimental heats of materials for optimizing the chemical composition for developing creep-resistant materials.

  13. Scale Model Acoustic Test Validation of IOP-SS Water Prediction using Loci-STREAM-VoF

    NASA Technical Reports Server (NTRS)

    Nielsen, Tanner; West, Jeff

    2015-01-01

    The Scale Model Acoustic Test (SMAT) is a 5% scale test of the Space Launch System (SLS), which is currently being designed at Marshall Space Flight Center (MSFC). SMAT consists of a 5% scale representation of the ignition overpressure sound-suppression system (IOP-SS) that is being tested to quantify the water flow and induced air entrainment in and around the mobile launcher exhaust hole. This data will be compared with computational fluid dynamics (CFD) simulations using the newly developed Loci-STREAM Volume of Fluid (VoF) methods. Compressible and incompressible VoF methods have been formulated, and are currently being used to simulate the water flow of SMAT IOP-SS. The test data will be used to qualitatively and quantitatively assess and validate the VoF methods.

  14. Shared salinity tolerance invalidates a test for the malaria vector Anopheles farauti s.s. on Guadalcanal, Solomon Islands.

    PubMed

    Foley, D H; Bryan, J H

    2000-03-01

    Among the Punctulatus Group of Anopheles mosquitoes (Diptera: Culicidae), first-instar larvae of the medically unimportant freshwater Anopheles farauti species No. 7 survives a seawater tolerance test (SST) that was previously thought to be diagnostic for the saltwater-tolerant malaria vector species, An. farauti Laveran s.s. Salt tolerance in these two closely related isomorphic species appears to be a shared derived character within the Farauti Complex. Failure to differentiate An. farauti s.s. from An. farauti No. 7 will overestimate potential malaria vector numbers and waste limited larval control resources. Use of the SST should therefore be discontinued on Guadalcanal and other techniques such as allozyme electrophoresis used instead. PMID:10759320

  15. Shared salinity tolerance invalidates a test for the malaria vector Anopheles farauti s.s. on Guadalcanal, Solomon Islands [corrected].

    PubMed

    Foley, D H; Bryan, J H

    2000-12-01

    Among the Punctulatus Group of Anopheles mosquitoes (Diptera: Culicidae), first-instar larvae of the medically unimportant freshwater Anopheles farauti species No. 7 survives a seawater tolerance test (STT) that was previously thought to be diagnostic for the saltwater-tolerant malaria vector species, An. farauti Laveran s.s. Salt tolerance in these two closely related isomorphic species appears to be a shared derived character within the Farauti Complex. Failure to differentiate An. farauti s.s. from An. farauti No.7 will overestimate potential malaria vector numbers and waste limited larval control resources. Use of the STT should therefore be discontinued on Guadalcanal and other techniques such as allozyme electrophoresis used instead [corrected]. PMID:11129712

  16. Hold your horSSEs: controlling structure-selective endonucleases MUS81 and Yen1/GEN1

    PubMed Central

    Blanco, Miguel G.; Matos, Joao

    2015-01-01

    Repair of DNA lesions through homologous recombination promotes the establishment of stable chromosomal interactions. Multiple helicases, topoisomerases and structure-selective endonucleases (SSEs) act upon recombining joint molecules (JMs) to disengage chromosomal connections and safeguard chromosome segregation. Recent studies on two conserved SSEs – MUS81 and Yen1/GEN1– uncovered multiple layers of regulation that operate to carefully tailor JM-processing according to specific cellular needs. Temporal restriction of SSE function imposes a hierarchy in pathway usage that ensures efficient JM-processing while minimizing reciprocal exchanges between the recombining DNAs. Whereas a conserved strategy of fine-tuning SSE functions exists in different model systems, the precise molecular mechanisms to implement it appear to be significantly different. Here, we summarize the current knowledge on the cellular switches that are in place to control MUS81 and Yen1/GEN1 functions. PMID:26284109

  17. Hydrothermal carbonization of sewage sludge: The effect of feed-water pH on fate and risk of heavy metals in hydrochars.

    PubMed

    Zhai, Yunbo; Liu, Xiangmin; Zhu, Yun; Peng, Chuan; Wang, Tengfei; Zhu, Luo; Li, Caiting; Zeng, Guangming

    2016-10-01

    In this study, the effect of feed-water pH (pH=2-12) on fate and risk of heavy metals (HMs) in hydrochars (HCs) was investigated. Hydrothermal carbonization (HTC) of sewage sludge (SS) was carried out with different feed-water pH at 270°C. The research results showed that changing feed-water pH had a positive effect on accumulating Pb, Ni, Cd and Zn in HCs. Chemical forms of Cu and Cr converted from an unstable state to stable in the alkaline environment while in the acidic condition was opposite. The effect of feed-water pH on the chemical forms of HMs was variable but not significant. Risk assessments of Igeo, Er(i), RAC and RI were applied to evaluate the accumulation levels of individual metal, the potential ecological risks, the bio-availabilities and the comprehensive toxicity and sensitivity of HMs, respectively. The lowest pollution level of HMs was obtained at 270°C with pH=11. PMID:27367814

  18. Hydrothermal carbonization of sewage sludge: The effect of feed-water pH on fate and risk of heavy metals in hydrochars.

    PubMed

    Zhai, Yunbo; Liu, Xiangmin; Zhu, Yun; Peng, Chuan; Wang, Tengfei; Zhu, Luo; Li, Caiting; Zeng, Guangming

    2016-10-01

    In this study, the effect of feed-water pH (pH=2-12) on fate and risk of heavy metals (HMs) in hydrochars (HCs) was investigated. Hydrothermal carbonization (HTC) of sewage sludge (SS) was carried out with different feed-water pH at 270°C. The research results showed that changing feed-water pH had a positive effect on accumulating Pb, Ni, Cd and Zn in HCs. Chemical forms of Cu and Cr converted from an unstable state to stable in the alkaline environment while in the acidic condition was opposite. The effect of feed-water pH on the chemical forms of HMs was variable but not significant. Risk assessments of Igeo, Er(i), RAC and RI were applied to evaluate the accumulation levels of individual metal, the potential ecological risks, the bio-availabilities and the comprehensive toxicity and sensitivity of HMs, respectively. The lowest pollution level of HMs was obtained at 270°C with pH=11.

  19. The KiSS-1/GPR54 system: putative target for endocrine disruption of reproduction at hypothalamic-pituitary unit?

    PubMed

    Navarro, Victor M; Tena-Sempere, Manuel

    2008-04-01

    The hypothalamic-pituitary (HP) unit, key element in the control of development and function of the reproductive axis, is highly sensitive to the organizing and activational effects of endogenous and exogenous compounds with sex steroid activity. Thus, inappropriate sex steroid input during early critical periods of their maturation can induce immediate or delayed defects in the neuroendocrine systems governing reproduction, which might eventually lead to alterations in the timing of puberty onset and/or infertility. Similarly, later inadequate exposures can cause dysfunctions of the gonadotropic axis. In recent years, kisspeptins (the products of KiSS-1 gene that operate through the G protein-coupled receptor 54) have emerged as fundamental regulators of puberty onset and gonadotropin secretion, and neurons in the hypothalamus expressing KiSS-1 have been demonstrated as essential conduits for the dynamic control of the gonadotropic axis by a number of hormonal factors. In this context, the hypothalamic KiSS-1 system has been proven sensitive to the early organizing effects, as well as to the acute regulatory actions, of gonadal steroids: phenomena which are likely to play fundamental roles in the sexual differentiation of gonadotropin secretion, and its feedback regulation by androgen and oestrogen. These observations raise the question on whether the hypothalamic KiSS-1 system might constitute a potential target for endocrine disruption of puberty onset and reproductive function at the HP unit by compounds with oestrogenic, androgenic or anti-androgenic activity. We review herein the physiological basis and initial, albeit so far scarce, experimental evidence supporting such possibility.

  20. Adaptive Dimensionality Reduction with Semi-Supervision (AdDReSS): Classifying Multi-Attribute Biomedical Data

    PubMed Central

    Romo Bucheli, David Edmundo; Madabhushi, Anant

    2016-01-01

    Medical diagnostics is often a multi-attribute problem, necessitating sophisticated tools for analyzing high-dimensional biomedical data. Mining this data often results in two crucial bottlenecks: 1) high dimensionality of features used to represent rich biological data and 2) small amounts of labelled training data due to the expense of consulting highly specific medical expertise necessary to assess each study. Currently, no approach that we are aware of has attempted to use active learning in the context of dimensionality reduction approaches for improving the construction of low dimensional representations. We present our novel methodology, AdDReSS (Adaptive Dimensionality Reduction with Semi-Supervision), to demonstrate that fewer labeled instances identified via AL in embedding space are needed for creating a more discriminative embedding representation compared to randomly selected instances. We tested our methodology on a wide variety of domains ranging from prostate gene expression, ovarian proteomic spectra, brain magnetic resonance imaging, and breast histopathology. Across these various high dimensional biomedical datasets with 100+ observations each and all parameters considered, the median classification accuracy across all experiments showed AdDReSS (88.7%) to outperform SSAGE, a SSDR method using random sampling (85.5%), and Graph Embedding (81.5%). Furthermore, we found that embeddings generated via AdDReSS achieved a mean 35.95% improvement in Raghavan efficiency, a measure of learning rate, over SSAGE. Our results demonstrate the value of AdDReSS to provide low dimensional representations of high dimensional biomedical data while achieving higher classification rates with fewer labelled examples as compared to without active learning. PMID:27421116