Science.gov

Sample records for combustivel tipo mtr

  1. MTR OFFICE WINGS AT WEST SIDE OF MTR HIGH BAY ...

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

    MTR OFFICE WINGS AT WEST SIDE OF MTR HIGH BAY REACTOR BUILDING. CONTEXTUAL VIEW. CAMERA FACING NORTHEAST. FROM LEFT TO RIGHT, TRA-652 (OFFICE WING), TRA-661 (SOUTH WING EXTENSION), SECOND/THIRD FLOOR (BALCONIES) OF MTR-603, MTR HIGH-BAY. AT RIGHT EDGE OF VIEW IS REACTOR SERVICES BUILDING (TRA-635). INL NEGATIVE NO. HD46-44-1. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  2. MTR MAIN FLOOR. MTR TRACTOR IS IN CENTER OF VIEW ...

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

    MTR MAIN FLOOR. MTR TRACTOR IS IN CENTER OF VIEW AMIDST AN ACCUMULATION OF CLUTTER ON THE FLOOR. TRACTOR HAD ATTACHMENTS IN FRONT TO FACILITATE MOVING OF COFFINS. INL NEGATIVE NO. 56-3027. Jack L. Anderson, Photographer, 9/17/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  3. Transportation of spent MTR fuels

    SciTech Connect

    Raisonnier, D.

    1997-08-01

    This paper gives an overview of the various aspects of MTR spent fuel transportation and provides in particular information about the on-going shipment of 4 spent fuel casks to the United States. Transnucleaire is a transport and Engineering Company created in 1963 at the request of the French Atomic Energy Commission. The company followed the growth of the world nuclear industry and has now six subsidiaries and affiliated companies established in countries with major nuclear programs.

  4. Regulation of the MtrC-MtrD-MtrE efflux-pump system modulates the in vivo fitness of Neisseria gonorrhoeae.

    PubMed

    Warner, Douglas M; Folster, Jason P; Shafer, William M; Jerse, Ann E

    2007-12-15

    The Neisseria gonorrhoeae MtrC-MtrD-MtrE multidrug-resistance efflux pump expels macrolide antibiotics, penicillin, and antimicrobial effectors of the innate defense. Mutation of the mtrR locus, which encodes a transcriptional repressor of the mtrCDE operon, increases gonococcal resistance to these agents. Here we report that, in a mouse infection model, an mtrR mutant is more fit than the wild-type bacteria. Consistent with derepression of the mtrCDE operon as the primary reason for the fitness benefit, an mtrR,mtrE double mutant and an mtrE mutant showed no difference in survival phenotype. Gonococcal mutants deficient in MtrA, an activator of the mtrCDE operon, exhibited significantly reduced fitness in vivo, and mtrA mutants with spontaneous compensatory mtrR mutations were selected during infection. These results confirm the importance of the MtrC-MtrD-MtrE efflux-pump system during experimental gonococcal genital-tract infection and also illustrate an antibiotic-resistance mechanism that is accompanied by a fitness benefit rather than a fitness cost. PMID:18190261

  5. MTR BUILDING, TRA603. WEST SIDE OF MTR SECOND/THIRD FLOOR AND ...

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

    MTR BUILDING, TRA-603. WEST SIDE OF MTR SECOND/THIRD FLOOR AND HIGH-BAY REACTOR FLOOR (WITH STAIRWAY FROM ROOF). CAMERA FACING EAST FROM ROOF OF TRA-604. INL NEGATIVE NO. HD46-42-3. Mike Crane, Photographer, April 2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  6. MTR plates modeling with MAIA

    SciTech Connect

    Marelle, V.; Dubois, S.; Ripert, M.; Noirot, J.

    2008-07-15

    MAIA is a thermo-mechanical code dedicated to the modeling of MTR fuel plates. The main physical phenomena modeled in the code are the cladding oxidation, the interaction between fuel and Al-matrix, the swelling due to fission products and the Al/fuel particles interaction. The creeping of the plate can be modeled in the mechanical calculation. MAIA has been validated on U-Mo dispersion fuel experiments such as IRIS 1 and 2 and FUTURE. The results are in rather good agreement with post-irradiation examinations. MAIA can also be used to calculate in-pile behavior of U{sub 3}Si{sub 2} plates as in the SHARE experiment irradiated in the SCK/Mol BR2 reactor. The main outputs given by MAIA throughout the irradiation are temperatures, cladding oxidation thickness, interaction thickness, volume fraction of meat constituents, swelling, displacements, strains and stresses. MAIA is originally a two-dimensional code but a three-dimensional version is currently under development. (author)

  7. MTR, SOUTH FACE OF REACTOR. SPECIAL SUPPLEMENTAL SHIELDING WAS REQUIRED ...

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

    MTR, SOUTH FACE OF REACTOR. SPECIAL SUPPLEMENTAL SHIELDING WAS REQUIRED OUTSIDE OF MTR FOR EXPERIMENTS. THE AIRCRAFT NUCLEAR PROPULSION PROJECT DOMINATED THE USE OF THIS PART OF THE MTR. INL NEGATIVE NO. 7225. Unknown Photographer, 11/28/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. MTR BASEMENT. WORKERS (DON ALVORD AND CYRIL VAN ORDEN OF ...

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

    MTR BASEMENT. WORKERS (DON ALVORD AND CYRIL VAN ORDEN OF PHILLIPS PETROLEUM CO.) POSE FOR GAMMA IRRADIATION EXPERIMENT IN MTR CANAL. CANS OF FOOD WILL BE LOWERED TO CANAL BOTTOM, WHERE SPENT MTR FUEL ELEMENTS EMIT GAMMA RADIATION. INL NEGATIVE NO. 11746. Unknown Photographer, 8/20/1954 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  9. MTR BUILDING, TRA603. DETAILED VIEW OF NORTHWEST CORNERS OF MTR ...

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

    MTR BUILDING, TRA-603. DETAILED VIEW OF NORTHWEST CORNERS OF MTR HIGH-BAY AND SECOND/THIRD STORY SECTIONS. NOTE SHAPE OF PANEL ABOVE WINDOW OVER "TRA-603" BUILDING NUMBERS. THIS IS A "STANDARD PANEL." INL NEGATIVE NUMBER HD46-42-2. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  10. ETR AND MTR COMPLEXES IN CONTEXT. CAMERA FACING NORTHERLY. FROM ...

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

    ETR AND MTR COMPLEXES IN CONTEXT. CAMERA FACING NORTHERLY. FROM BOTTOM TO TOP: ETR COOLING TOWER, ELECTRICAL BUILDING AND LOW-BAY SECTION OF ETR BUILDING, HEAT EXCHANGER BUILDING (WITH U SHAPED YARD), COMPRESSOR BUILDING. MTR REACTOR SERVICES BUILDING IS ATTACHED TO SOUTH WALL OF MTR. WING A IS ATTACHED TO BALCONY FLOOR OF MTR. NEAR UPPER RIGHT CORNER OF VIEW IS MTR PROCESS WATER BUILDING. WING B IS AT FAR WEST END OF COMPLEX. NEAR MAIN GATE IS GAMMA FACILITY, WITH "COLD" BUILDINGS BEYOND: RAW WATER STORAGE TANKS, STEAM PLANT, MTR COOLING TOWER PUMP HOUSE AND COOLING TOWER. INL NEGATIVE NO. 56-4101. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  11. MATERIALS TESTING REACTOR (MTR) BUILDING, TRA603. CONTEXTUAL VIEW OF MTR ...

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

    MATERIALS TESTING REACTOR (MTR) BUILDING, TRA-603. CONTEXTUAL VIEW OF MTR BUILDING SHOWING NORTH SIDES OF THE HIGH-BAY REACTOR BUILDING, ITS SECOND/THIRD FLOOR BALCONY LEVEL, AND THE ATTACHED ONE-STORY OFFICE/LABORATORY BUILDING, TRA-604. CAMERA FACING SOUTHEAST. VERTICAL CONCRETE-SHROUDED BEAMS SUPPORT PRECAST CONCRETE PANELS. CONCRETE PROJECTION FORMED AS A BUNKER AT LEFT OF VIEW IS TRA-657, PLUG STORAGE BUILDING. INL NEGATIVE NO. HD46-42-1. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  12. Analysis of Structural MtrC Models Based on Homology with the Crystal Structure of MtrF

    SciTech Connect

    Edwards, Marcus; Fredrickson, Jim K.; Zachara, John M.; Richardson, David; Clarke, Thomas A.

    2012-12-01

    The outer-membrane decahaem cytochrome MtrC is part of the transmembrane MtrCAB complex required for mineral respiration by Shewanella oneidensis. MtrC has significant sequence similarity to the paralogous decahaem cytochrome MtrF, which has been structurally solved through X-ray crystallography. This now allows for homology-based models of MtrC to be generated. The structure of these MtrC homology models contain ten bis-histidine-co-ordinated c-type haems arranged in a staggered cross through a four-domain structure. This model is consistent with current spectroscopic data and shows that the areas around haem 5 and haem 10, at the termini of an octahaem chain, are likely to have functions similar to those of the corresponding haems in MtrF. The electrostatic surfaces around haem 7, close to the β-barrels, are different in MtrF and MtrC, indicating that these haems may have different potentials and interact with substrates differently.

  13. Mycobacterium tuberculosis MtrB Sensor Kinase Interactions with FtsI and Wag31 Proteins Reveal a Role for MtrB Distinct from That Regulating MtrA Activities

    PubMed Central

    Plocinska, Renata; Martinez, Luis; Gorla, Purushotham; Pandeeti, Emmanuel; Sarva, Krishna; Blaszczyk, Ewelina; Dziadek, Jaroslaw

    2014-01-01

    The septal association of Mycobacterium tuberculosis MtrB, the kinase partner of the MtrAB two-component signal transduction system, is necessary for the optimal expression of the MtrA regulon targets, including ripA, fbpB, and ftsI, which are involved in cell division and cell wall synthesis. Here, we show that MtrB, irrespective of its phosphorylation status, interacts with Wag31, whereas only phosphorylation-competent MtrB interacts with FtsI. We provide evidence that FtsI depletion compromises the MtrB septal assembly and MtrA regulon expression; likewise, the absence of MtrB compromises FtsI localization and, possibly, FtsI activity. We conclude from these results that FtsI and MtrB are codependent for their activities and that FtsI functions as a positive modulator of MtrB activation and MtrA regulon expression. In contrast to FtsI, Wag31 depletion does not affect MtrB septal assembly and MtrA regulon expression, whereas the loss of MtrB increased Wag31 localization and the levels of PknA/PknB (PknA/B) serine-threonine protein kinase-mediated Wag31 phosphorylation. Interestingly, we found that FtsI decreased levels of phosphorylated Wag31 (Wag31∼P) and that MtrB interacted with PknA/B. Overall, our results indicate that MtrB interactions with FtsI, Wag31, and PknA/B are required for its optimal localization, MtrA regulon expression, and phosphorylation of Wag31. Our results emphasize a new role for MtrB in cell division and cell wall synthesis distinct from that regulating the MtrA phosphorylation activities. PMID:25225272

  14. MTR BUILDING AND BALCONY FLOORS. CAMERA FACING EASTERLY. PHOTOGRAPHER DID ...

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

    MTR BUILDING AND BALCONY FLOORS. CAMERA FACING EASTERLY. PHOTOGRAPHER DID NOT EXPLAIN DARK CLOUD. MTR WING WILL ATTACH TO GROUND FLOOR. INL NEGATIVE NO. 1567. Unknown Photographer, 2/28/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  15. REACTIVITY MEASUREMENT FACILITY, UNDER CONSTRUCTION OVER MTR CANAL IN BASEMENT ...

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

    REACTIVITY MEASUREMENT FACILITY, UNDER CONSTRUCTION OVER MTR CANAL IN BASEMENT OF MTR BUILDING, TRA-603. WOOD PLANKS REST ON CANAL WALL OBSERVABLE IN FOREGROUND. INL NEGATIVE NO. 11745. Unknown Photographer, 8/20/1954 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  16. 33 CFR 154.1041 - Specific response information to be maintained on mobile MTR facilities.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... be maintained on mobile MTR facilities. 154.1041 Section 154.1041 Navigation and Navigable Waters... maintained on mobile MTR facilities. (a) Each mobile MTR facility must carry the following information as... respond to a discharge from the mobile MTR facility. (3) List of the appropriate persons and...

  17. CONTEXTUAL AERIAL VIEW OF "EXCLUSION" MTR AREA WITH IDAHO CHEMICAL ...

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

    CONTEXTUAL AERIAL VIEW OF "EXCLUSION" MTR AREA WITH IDAHO CHEMICAL PROCESSING PLANT IN BACKGROUND AT CENTER TOP OF VIEW. CAMERA FACING EAST. EXCLUSION GATE HOUSE AT LEFT OF VIEW. BEYOND MTR BUILDING AND ITS WING, THE PROCESS WATER BUILDING AND WORKING RESERVOIR ARE LEFT-MOST. FAN HOUSE AND STACK ARE TO ITS RIGHT. PLUG STORAGE BUILDING IS RIGHT-MOST STRUCTURE. NOTE FAN LOFT ABOVE MTR BUILDING'S ONE-STORY WING. THIS WAS LATER CONVERTED FOR OFFICES. INL NEGATIVE NO. 3610. Unknown Photographer, 10/30/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  18. MTR BASEMENT. GENERAL ELECTRIC CONTROL CONSOLE FOR AIRCRAFT NUCLEAR PROPULSION ...

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

    MTR BASEMENT. GENERAL ELECTRIC CONTROL CONSOLE FOR AIRCRAFT NUCLEAR PROPULSION EXPERIMENT NO. 1. INL NEGATIVE NO. 6510. Unknown Photographer, 9/29/1959 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  19. TOP OF MTR. CONTROL RODS AND GRID PLATE EMERGE FROM ...

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

    TOP OF MTR. CONTROL RODS AND GRID PLATE EMERGE FROM REACTOR TANK. INL NEGATIVE NO. 6206. R.G. Larsen, Photographer, 6/27/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  20. MTR MAIN FLOOR. MEN DEMONSTRATE INSERTION OF DUMMY PLUG INTO ...

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

    MTR MAIN FLOOR. MEN DEMONSTRATE INSERTION OF DUMMY PLUG INTO AN MTR BEAM HOLE. ONE MAN CHECKS RADIATION LEVEL AT THE END OF THE UNIVERSAL COFFIN, WHILE ANOTHER USES TOOL TO INSERT PLUG INTO HOLE THROUGH COFFIN. MEN WEAR "ANTI-C" (ANTI-CONTAMINATION) CLOTHING. INL NEGATIVE NO. 6198. R.G. Larsen, Photographer, 6/27/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  1. The MATROSHKA experiment: results and comparison from extravehicular activity (MTR-1) and intravehicular activity (MTR-2A/2B) exposure.

    PubMed

    Berger, Thomas; Bilski, Paweł; Hajek, Michael; Puchalska, Monika; Reitz, Günther

    2013-12-01

    Astronauts working and living in space are exposed to considerably higher doses and different qualities of ionizing radiation than people on Earth. The multilateral MATROSHKA (MTR) experiment, coordinated by the German Aerospace Center, represents the most comprehensive effort to date in radiation protection dosimetry in space using an anthropomorphic upper-torso phantom used for radiotherapy treatment planning. The anthropomorphic upper-torso phantom maps the radiation distribution as a simulated human body installed outside (MTR-1) and inside different compartments (MTR-2A: Pirs; MTR-2B: Zvezda) of the Russian Segment of the International Space Station. Thermoluminescence dosimeters arranged in a 2.54 cm orthogonal grid, at the site of vital organs and on the surface of the phantom allow for visualization of the absorbed dose distribution with superior spatial resolution. These results should help improve the estimation of radiation risks for long-term human space exploration and support benchmarking of radiation transport codes. PMID:24252101

  2. 33 CFR 154.1041 - Specific response information to be maintained on mobile MTR facilities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... maintained on mobile MTR facilities. (a) Each mobile MTR facility must carry the following information as... respond to a discharge from the mobile MTR facility. (3) List of the appropriate persons and agencies... National Response Center. (b) The owner or operator of the mobile facility must also retain the...

  3. ELECTRICAL LINES ARRIVE FROM CENTRAL FACILITIES AREA, SOUTH OF MTR. ...

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

    ELECTRICAL LINES ARRIVE FROM CENTRAL FACILITIES AREA, SOUTH OF MTR. EXCAVATION RUBBLE IN FOREGROUND. CONTRACTOR CRAFT SHOPS, CRANES, AND OTHER MATERIALS ON SITE. CAMERA FACES EAST, WITH LITTLE BUTTE AND MIDDLE BUTTE IN DISTANCE. INL NEGATIVE NO. 335. Unknown Photographer, 7/1/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  4. CUTS FOR MTR EXCAVATION ILLUSTRATE SEDIMENTARY MANTLE OF SOIL AND ...

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

    CUTS FOR MTR EXCAVATION ILLUSTRATE SEDIMENTARY MANTLE OF SOIL AND GRAVEL OVERLAYING LAVA ROCK FIFTY FEET BELOW. SAGEBRUSH HAS BEEN SCOURED FROM REST OF SITE. CAMERA PROBABLY FACES SOUTHWEST. INL NEGATIVE NO. 67. Unknown Photographer, 6/4/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  5. REACTIVITY MEASUREMENT FACILITY. CAMERA LOOKS DOWN INTO MTR CANAL. REACTOR ...

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

    REACTIVITY MEASUREMENT FACILITY. CAMERA LOOKS DOWN INTO MTR CANAL. REACTOR IS FUELED AS AN ETR MOCK-UP. LIGHTS DANGLE BELOW WATER LEVEL. CONTROL RODS AND OTHER APPARATUS DESCEND FROM ABOVE WATER LEVEL. INL NEGATIVE NO. 56-900. Jack L. Anderson, Photographer, 3/26/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  6. MTR CONTROL ROOM WITH CONTROL CONSOLE AND STATUS READOUTS ALONG ...

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

    MTR CONTROL ROOM WITH CONTROL CONSOLE AND STATUS READOUTS ALONG WALL. WORKERS MAKE ELECTRICAL AND OTHER CONNECTIONS. INL NEGATIVE NO. 4289. Unknown Photographer, 2/26/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  7. CAMERA IS ON CATWALK ABOVE MTR. CRANE HOOK LOWERS TOP ...

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

    CAMERA IS ON CATWALK ABOVE MTR. CRANE HOOK LOWERS TOP PLUG ONTO REACTOR. NOTE PLANK-LIKE BRIDGE (WALKWAY) TO BALCONY AT UPPER RIGHT. INL NEGATIVE NO. 4502. Unknown Photographer, probable date 3/31/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. CONTROL ROOM ON MARCH 31, 1952, AS THE MTR GOES ...

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

    CONTROL ROOM ON MARCH 31, 1952, AS THE MTR GOES CRITICAL FOR THE FIRST TIME. COMPARE CEILING FIXTURES IN THIS PHOTO AND PHOTO ID-33-G-212 FOR COMMON PERSPECTIVE. INL NEGATIVE NO. 4517. Unknown Photographer, 3/31/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  9. CANAL EMERGES FROM EAST SIDE OF MTR BUILDING. "EXTRA" LENGTH ...

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

    CANAL EMERGES FROM EAST SIDE OF MTR BUILDING. "EXTRA" LENGTH WAS TO STORE SPENT FUEL THAT WOULD ACCUMULATE BEFORE THE CHEMICAL PROCESSING PLANT WAS READY TO PROCESS IT. INL NEGATIVE NO. 1659. Unknown Photographer, 3/9/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  10. Fission yeast mtr1p regulates interphase microtubule cortical dwell-time

    PubMed Central

    Carlier-Grynkorn, Frédérique; Ji, Liang; Fraisier, Vincent; Lombard, Berangère; Dingli, Florent; Loew, Damarys; Paoletti, Anne; Ronot, Xavier; Tran, Phong T.

    2014-01-01

    ABSTRACT The microtubule cytoskeleton plays important roles in cell polarity, motility and division. Microtubules inherently undergo dynamic instability, stochastically switching between phases of growth and shrinkage. In cells, some microtubule-associated proteins (MAPs) and molecular motors can further modulate microtubule dynamics. We present here the fission yeast mtr1+, a new regulator of microtubule dynamics that appears to be not a MAP or a motor. mtr1-deletion (mtr1Δ) primarily results in longer microtubule dwell-time at the cell tip cortex, suggesting that mtr1p acts directly or indirectly as a destabilizer of microtubules. mtr1p is antagonistic to mal3p, the ortholog of mammalian EB1, which stabilizes microtubules. mal3Δ results in short microtubules, but can be partially rescued by mtr1Δ, as the double mutant mal3Δ mtr1Δ exhibits longer microtubules than mal3Δ single mutant. By sequence homology, mtr1p is predicted to be a component of the ribosomal quality control complex. Intriguingly, deletion of a predicted ribosomal gene, rps1801, also resulted in longer microtubule dwell-time similar to mtr1Δ. The double-mutant mal3Δ rps1801Δ also exhibits longer microtubules than mal3Δ single mutant alone. Our study suggests a possible involvement of mtr1p and the ribosome complex in modulating microtubule dynamics. PMID:24928430

  11. Fission yeast mtr1p regulates interphase microtubule cortical dwell-time.

    PubMed

    Carlier-Grynkorn, Frédérique; Ji, Liang; Fraisier, Vincent; Lombard, Berangère; Dingli, Florent; Loew, Damarys; Paoletti, Anne; Ronot, Xavier; Tran, Phong T

    2014-01-01

    The microtubule cytoskeleton plays important roles in cell polarity, motility and division. Microtubules inherently undergo dynamic instability, stochastically switching between phases of growth and shrinkage. In cells, some microtubule-associated proteins (MAPs) and molecular motors can further modulate microtubule dynamics. We present here the fission yeast mtr1(+), a new regulator of microtubule dynamics that appears to be not a MAP or a motor. mtr1-deletion (mtr1Δ) primarily results in longer microtubule dwell-time at the cell tip cortex, suggesting that mtr1p acts directly or indirectly as a destabilizer of microtubules. mtr1p is antagonistic to mal3p, the ortholog of mammalian EB1, which stabilizes microtubules. mal3Δ results in short microtubules, but can be partially rescued by mtr1Δ, as the double mutant mal3Δ mtr1Δ exhibits longer microtubules than mal3Δ single mutant. By sequence homology, mtr1p is predicted to be a component of the ribosomal quality control complex. Intriguingly, deletion of a predicted ribosomal gene, rps1801, also resulted in longer microtubule dwell-time similar to mtr1Δ. The double-mutant mal3Δ rps1801Δ also exhibits longer microtubules than mal3Δ single mutant alone. Our study suggests a possible involvement of mtr1p and the ribosome complex in modulating microtubule dynamics. PMID:24928430

  12. Identification of a cell envelope protein (MtrF) involved in hydrophobic antimicrobial resistance in Neisseria gonorrhoeae.

    PubMed

    Veal, Wendy L; Shafer, William M

    2003-01-01

    The mtrCDE-encoded efflux pump of Neisseria gonorrhoeae provides gonococci with a mechanism to resist structurally diverse antimicrobial hydrophobic agents (HAs). Strains of N. gonorrhoeae that display hypersusceptibility to HAs often contain mutations in the efflux pump genes, mtrCDE. Such strains frequently contain a phenotypically suppressed mutation in mtrR, a gene that encodes a repressor (MtrR) of mtrCDE gene expression, and one that would normally result in HA resistance. We have recently examined HA-hypersusceptible clinical isolates of gonococci that contain such phenotypically suppressed mtrR mutations, in order to determine whether genes other than mtrCDE are involved in HA resistance. These studies led to the discovery of a gene that we have designated mtrF, located downstream of the mtrR gene, that is predicted to encode a 56.1 kDa cytoplasmic membrane protein containing 12 transmembrane domains. Expression of mtrF was enhanced in a strain deficient in MtrR production, indicating that this gene, together with the closely linked mtrCDE operon, is subject to MtrR-dependent transcriptional control. Orthologues of mtrF were identified in a number of diverse bacteria. Except for the AbgT protein of Escherichia coli, their products have been identified as hypothetical proteins with unknown function(s). Genetic evidence is presented that MtrF is important in the expression of high-level detergent resistance by gonococci. We propose that MtrF acts in conjunction with the MtrC-MtrD-MtrE efflux pump, to confer on gonococci high-level resistance to certain HAs. PMID:12493784

  13. MTR MAIN FLOOR. NEUTRON TUNNEL (SPANNED BY STILELIKE STEPS) PROJECTS ...

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

    MTR MAIN FLOOR. NEUTRON TUNNEL (SPANNED BY STILE-LIKE STEPS) PROJECTS FROM THE SOUTHEAST CORNER OF THE MTR TOWARD SOUTHEAST CORNER OF BUILDING, WHERE SHIELDING BLOCKS BEGIN TO SURROUND THE TUNNEL AS IT NEARS DETECTING INSTRUMENTS NEAR THE BUILDING WALL. GEAR RELATED TO CRYSTAL NEUTRON SPECTROMETER IS IN FOREGROUND SURROUNDED BY SHIELDING. DATA CONSOLES ARE AT MID-LEVEL OF EAST FACE. OTHER WORK PROCEEDS ON TOP OF AND ELSEWHERE AROUND REACTOR. NOTE TOOLS HANGING AGAINST SOUTHEAST CORNER, USED TO CHANGE FUEL ELEMENTS AND OTHER REACTOR ITEMS DURING REFUELING CYCLES. INL NEGATIVE NO. 10439. Unknown Photographer, 4/20/1954 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  14. MTR CAISSONS WERE DRILLED INTO BEDROCK. IN CENTER OF VIEW, ...

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

    MTR CAISSONS WERE DRILLED INTO BEDROCK. IN CENTER OF VIEW, CONCRETE FLOWS FROM TRUCK INTO DRUM, WHICH IS LOWERED INTO CAISSON AND RELEASED AT BOTTOM OF HOLE. BEYOND, TRUCK-MOUNTED DRILLING RIG DRILLS HOLE FOR ANOTHER CAISSON NEAR EDGE OF EXCAVATION. MATERIAL REMOVED FROM HOLE IS CARRIED BY CONVEYOR TO WAITING TRUCK. INL NEGATIVE NO. 307. Unknown Photographer, 6/1950. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  15. MTR BASEMENT. DOORWAY TO SOURCE STORAGE VAULT IS AT CENTER ...

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

    MTR BASEMENT. DOORWAY TO SOURCE STORAGE VAULT IS AT CENTER OF VIEW; TO DECONTAMINATION ROOM, AT RIGHT. PART OF MAZE ENTRY IS VISIBLE INSIDE VAULT DOORWAY. INL NEGATIVE NO. 7763. Unknown Photographer, photo was dated as 3/30/1953, but this was probably an error. The more likely date is 3/30/1952. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  16. TOP OF MTR. MAN CLIMBS FRAME ON FOOT LADDER TO ...

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

    TOP OF MTR. MAN CLIMBS FRAME ON FOOT LADDER TO POSITION CRANE HOOK, WHICH WILL LIFT TOP PLUG FROM REACTOR AS A STEP IN REFUELING PROCEDURES. NOTE CRANE OPERATOR AT UPPER LEFT OF VIEW. ENTIRE APPARATUS, INCLUDING FRAME AND DRIVES FOR CONTROL RODS, WILL BE LIFTED. INL NEGATIVE NO. 6199. R.G. Larsen, Photographer, 6/22/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  17. CONTROL CONSOLE FOR MTR FISSION PRODUCT MONITOR, USED TO DETECT ...

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

    CONTROL CONSOLE FOR MTR FISSION PRODUCT MONITOR, USED TO DETECT BREAKS IN CLADDING OF FUEL ELEMENTS. COUNT-RATE METER IN TOP PANEL INDICATES AMOUNT OF RADIOACTIVITY. LOWER PANELS SUPPLY POWER AND AMPLIFICATION OF SIGNALS GENERATED BY SCINTILLATION COUNTER/PHOTOMULTIPLIER TUBE COMBINATION IN RESPONSE TO RADIOACTIVITY IN A SAMPLE OF THE COOLING WATER. INL NEGATIVE NO. 56-771. Jack L. Anderson, Photographer, 3/15/1956. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  18. Mutations in Mtr4 Structural Domains Reveal Their Important Role in Regulating tRNAiMet Turnover in Saccharomyces cerevisiae and Mtr4p Enzymatic Activities In Vitro

    PubMed Central

    Li, Yan; Burclaff, Joseph; Anderson, James T.

    2016-01-01

    RNA processing and turnover play important roles in the maturation, metabolism and quality control of a large variety of RNAs thereby contributing to gene expression and cellular health. The TRAMP complex, composed of Air2p, Trf4p and Mtr4p, stimulates nuclear exosome-dependent RNA processing and degradation in Saccharomyces cerevisiae. The Mtr4 protein structure is composed of a helicase core and a novel so-called arch domain, which protrudes from the core. The helicase core contains highly conserved helicase domains RecA-1 and 2, and two structural domains of unclear functions, winged helix domain (WH) and ratchet domain. How the structural domains (arch, WH and ratchet domain) coordinate with the helicase domains and what roles they are playing in regulating Mtr4p helicase activity are unknown. We created a library of Mtr4p structural domain mutants for the first time and screened for those defective in the turnover of TRAMP and exosome substrate, hypomodified tRNAiMet. We found these domains regulate Mtr4p enzymatic activities differently through characterizing the arch domain mutants K700N and P731S, WH mutant K904N, and ratchet domain mutant R1030G. Arch domain mutants greatly reduced Mtr4p RNA binding, which surprisingly did not lead to significant defects on either in vivo tRNAiMet turnover, or in vitro unwinding activities. WH mutant K904N and Ratchet domain mutant R1030G showed decreased tRNAiMet turnover in vivo, as well as reduced RNA binding, ATPase and unwinding activities of Mtr4p in vitro. Particularly, K904 was found to be very important for steady protein levels in vivo. Overall, we conclude that arch domain plays a role in RNA binding but is largely dispensable for Mtr4p enzymatic activities, however the structural domains in the helicase core significantly contribute to Mtr4p ATPase and unwinding activities. PMID:26820724

  19. Mutations in Mtr4 Structural Domains Reveal Their Important Role in Regulating tRNAiMet Turnover in Saccharomyces cerevisiae and Mtr4p Enzymatic Activities In Vitro.

    PubMed

    Li, Yan; Burclaff, Joseph; Anderson, James T

    2016-01-01

    RNA processing and turnover play important roles in the maturation, metabolism and quality control of a large variety of RNAs thereby contributing to gene expression and cellular health. The TRAMP complex, composed of Air2p, Trf4p and Mtr4p, stimulates nuclear exosome-dependent RNA processing and degradation in Saccharomyces cerevisiae. The Mtr4 protein structure is composed of a helicase core and a novel so-called arch domain, which protrudes from the core. The helicase core contains highly conserved helicase domains RecA-1 and 2, and two structural domains of unclear functions, winged helix domain (WH) and ratchet domain. How the structural domains (arch, WH and ratchet domain) coordinate with the helicase domains and what roles they are playing in regulating Mtr4p helicase activity are unknown. We created a library of Mtr4p structural domain mutants for the first time and screened for those defective in the turnover of TRAMP and exosome substrate, hypomodified tRNAiMet. We found these domains regulate Mtr4p enzymatic activities differently through characterizing the arch domain mutants K700N and P731S, WH mutant K904N, and ratchet domain mutant R1030G. Arch domain mutants greatly reduced Mtr4p RNA binding, which surprisingly did not lead to significant defects on either in vivo tRNAiMet turnover, or in vitro unwinding activities. WH mutant K904N and Ratchet domain mutant R1030G showed decreased tRNAiMet turnover in vivo, as well as reduced RNA binding, ATPase and unwinding activities of Mtr4p in vitro. Particularly, K904 was found to be very important for steady protein levels in vivo. Overall, we conclude that arch domain plays a role in RNA binding but is largely dispensable for Mtr4p enzymatic activities, however the structural domains in the helicase core significantly contribute to Mtr4p ATPase and unwinding activities. PMID:26820724

  20. CONCRETE POURS HAVE PRODUCED A REINFORCED SUPPORT BASE FOR MTR ...

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

    CONCRETE POURS HAVE PRODUCED A REINFORCED SUPPORT BASE FOR MTR REACTOR. PIPE TUNNEL IS UNDER CONSTRUCTION AT CENTER OF VIEW. PIPES WILL CARRY RADIOACTIVE WATER FROM REACTOR TO WATER PROCESS BUILDING. CAMERA LOOKS SOUTH INTO TUNNEL ALONG WEST SIDE OF REACTOR BASE. TWO CAISSONS ARE AT LEFT SIDE OF VIEW. NOTE "WINDOW" IN SOUTH FACE OF REACTOR BASE AND ALSO GROUP OF PENETRATIONS TO ITS LEFT. INL NEGATIVE NO. 733. Unknown Photographer, 10/6/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  1. WORKERS FABRICATE ROOF SLABS FOR MTR BUILDING AT THE CONSTRUCTION ...

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

    WORKERS FABRICATE ROOF SLABS FOR MTR BUILDING AT THE CONSTRUCTION SITE. FORMS WERE MADE OF STEEL. AFTER AN INCH OF CONCRETE HAD BEEN POURED IN THE FORM, A MAT OF REINFORCING STEEL WAS PLACED ON IT. THE REMAINDER OF THE FORM WAS FILLED, AND THE CONCRETE WAS VIBRATED, STRUCK, AND TROWELED. GROOVES AT CORNER WILL HAVE 1/4 INCH RODS WELDED INTO THE EYE OF THE STEEL MAT FOR GROUNDING. INL NEGATIVE NO. 578. Unknown Photographer, 9/1/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  2. TEST REACTOR AREA PLOT PLAN CA. 1968. MTR AND ETR ...

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

    TEST REACTOR AREA PLOT PLAN CA. 1968. MTR AND ETR AREAS SOUTH OF PERCH AVENUE. "COLD" SERVICES NORTH OF PERCH. ADVANCED TEST REACTOR IN NEW SECTION WEST OF COLD SERVICES SECTION. NEW PERIMETER FENCE ENCLOSES BETA RAY SPECTROMETER, TRA-669, AN ATR SUPPORT FACILITY, AND ATR STACK. UTM LOCATORS HAVE BEEN DELETED. IDAHO NUCLEAR CORPORATION, FROM A BLAW-KNOX DRAWING, 3/1968. INL INDEX NO. 530-0100-00-400-011646, REV. 0. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  3. MTR BUILDING INTERIOR, TRA603. BASEMENT. CAMERA IN WEST CORRIDOR FACING ...

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

    MTR BUILDING INTERIOR, TRA-603. BASEMENT. CAMERA IN WEST CORRIDOR FACING SOUTH. FREIGHT ELEVATOR IS AT RIGHT OF VIEW. AT CENTER VIEW IS MTR VAULT NO. 1, USED TO STORE SPECIAL OR FISSIONABLE MATERIALS. INL NEGATIVE NO. HD46-6-3. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  4. MTR, TRA603. SOURCE STORAGE VAULT IN BASEMENT. MAZE ENTRY. SOLID ...

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

    MTR, TRA-603. SOURCE STORAGE VAULT IN BASEMENT. MAZE ENTRY. SOLID CONCRETE WALLS. CONCRETE PLUGS, ONE LINED WITH LEAD, AND LIFT HANDLES. FLOOR WELLS SIX FEET DEEP BELOW FLOOR. IDO MTR-603-IDO-5, 12/1952. INL INDEX NO. 531-0603-00-396-110469, REV. 0. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  5. MTR, TRA603. BASEMENT DECONTAMINATION ROOM DETAILS. WALLS OF SOLID CONCRETE ...

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

    MTR, TRA-603. BASEMENT DECONTAMINATION ROOM DETAILS. WALLS OF SOLID CONCRETE MASONRY. STAINLESS STEEL WORK BENCH, FLOOR COVING AND DRAINS. "WARM" FLOOR DRAIN. OVERHEAD SHOWER WITH CHAIN PULL. IDO MTR-603-IDO-4, 12/1952. INL INDEX NO. 531-0603-00-396-110468, REV. 1. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  6. Crystal structure of the open state of the Neisseria gonorrhoeae MtrE outer membrane channel.

    PubMed

    Lei, Hsiang-Ting; Chou, Tsung-Han; Su, Chih-Chia; Bolla, Jani Reddy; Kumar, Nitin; Radhakrishnan, Abhijith; Long, Feng; Delmar, Jared A; Do, Sylvia V; Rajashankar, Kanagalaghatta R; Shafer, William M; Yu, Edward W

    2014-01-01

    Active efflux of antimicrobial agents is one of the most important strategies used by bacteria to defend against antimicrobial factors present in their environment. Mediating many cases of antibiotic resistance are transmembrane efflux pumps, composed of one or more proteins. The Neisseria gonorrhoeae MtrCDE tripartite multidrug efflux pump, belonging to the hydrophobic and amphiphilic efflux resistance-nodulation-cell division (HAE-RND) family, spans both the inner and outer membranes of N. gonorrhoeae and confers resistance to a variety of antibiotics and toxic compounds. We here describe the crystal structure of N. gonorrhoeae MtrE, the outer membrane component of the MtrCDE tripartite multidrug efflux system. This trimeric MtrE channel forms a vertical tunnel extending down contiguously from the outer membrane surface to the periplasmic end, indicating that our structure of MtrE depicts an open conformational state of this channel. PMID:24901251

  7. CONTEXTUAL AERIAL VIEW OF "COLD" NORTH HALF OF MTR COMPLEX. ...

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

    CONTEXTUAL AERIAL VIEW OF "COLD" NORTH HALF OF MTR COMPLEX. CAMERA FACING EASTERLY. FOREGROUND CORNER CONTAINS OIL STORAGE TANKS. WATER TANKS AND WELL HOUSES ARE BEYOND THEM TO THE LEFT. LARGE LIGHT-COLORED BUILDING IN CENTER OF VIEW IS STEAM PLANT. DEMINERALIZER AND WATER STORAGE TANK ARE BEYOND. SIX-CELL COOLING TOWER AND ITS PUMP HOUSE ARE ABOVE IT IN VIEW. SERVICE BUILDINGS INCLUDING CANTEEN ARE ON NORTH SIDE OF ROAD. "EXCLUSION" AREA IS BEYOND ROAD. COMPARE LOCATION OF EXCLUSION-AREA GATE WITH PHOTO ID-33-G-202. INL NEGATIVE NO. 3608. Unknown Photographer, 10/30/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. ENGINEERING TEST REACTOR, TRA642. CONTEXTUAL VIEW ORIENTATING ETR TO MTR. ...

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

    ENGINEERING TEST REACTOR, TRA-642. CONTEXTUAL VIEW ORIENTATING ETR TO MTR. CAMERA IS ON ROOF OF MTR BUILDING AND FACES DUE SOUTH. MTR SERVICE BUILDING, TRA-635, IN LOWER RIGHT CORNER. STEEL FRAMES SHOW BUILDINGS TO BE ATTACHED TO ETR BUILDING. HIGH-BAY SECTION IN CENTER IS REACTOR BUILDING. TWO-STORY CONTROL ROOM AND OFFICE BUILDING, TRA-647, IS BETWEEN IT AND MTR SERVICE BUILDING. STRUCTURE TO THE LEFT (WITH NO FRAMING YET) IS COMPRESSOR BUILDING, TRA-643, AND BEYOND IT WILL BE HEAT EXCHANGER BUILDING, TRA-644, GREAT SOUTHERN BUTTE ON HORIZON. INL NEGATIVE NO. 56-2382. Jack L. Anderson, Photographer, 6/10/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  9. PUMP HOUSE FOR MTR WELL NO. 1, TRA601. FLOOR PLAN, ...

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

    PUMP HOUSE FOR MTR WELL NO. 1, TRA-601. FLOOR PLAN, ELEVATIONS, SECTION SHOWING WELL CASING, ROOF FRAMING PLAN. AS BUILT. WELL HOUSE FOR WELL NO. 2, TRA-602, WAS IDENTICAL IN ALL PARTICULARS EXCEPT FLOOR DIMENSIONS AND ARRANGEMENT OF PUMP AND ELECTRICAL EQUIPMENT INSIDE. IDAHO OPERATIONS OFFICE MTR-601-IDO-1, 12/1954. INL INDEX NO. 531-0601-00-396-110463, REV. 2. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  10. Mutational and gene expression analysis of mtrDEF, omcA and mtrCAB during arsenate and iron reduction in Shewanella sp. ANA-3

    PubMed Central

    Reyes, Carolina; Murphy, Julie N.; Saltikov, Chad W.

    2011-01-01

    Summary Arsenate respiration and Fe(III) reduction are important processes that influence the fate and transport of arsenic in the environment. The goal of this study was to investigate the impact of arsenate on Fe(III) reduction using arsenate and Fe(III) reduction deficient mutants of Shewanella sp. strain ANA-3. Ferrihydrite reduction in the absence of arsenate was similar for an arsenate reduction mutant (arrA and arsC deletion strain of ANA-3) compared with wild-type ANA-3. However, the presence of arsenate adsorbed onto ferrihydrite impeded Fe(III) reduction for the arsenate reduction mutant but not in the wild-type. In an Fe(III) reduction mutant (mtrDEF, omcA, mtrCAB null mutant of ANA-3), arsenate was reduced similarly to wild-type ANA-3 indicating the Fe(III) reduction pathway is not required for ferrihydrite-associated arsenate reduction. Expression analysis of the mtr/omc gene cluster of ANA-3 showed that omcA and mtrCAB were expressed under soluble Fe(III), ferrihydrite and arsenate growth conditions and not in aerobically grown cells. Expression of arrA was greater with ferrihydrite pre-adsorbed with arsenate relative to ferrihydrite only. Lastly, arrA and mtrA were simultaneously induced in cells shifted to anaerobic conditions and exposed to soluble Fe(III) and arsenate. These observations suggest that, unlike Fe(III), arsenate can co-induce operons (arr and mtr) implicated in arsenic mobilization. PMID:20236164

  11. MtrA of the sodium ion pumping methyltransferase binds cobalamin in a unique mode.

    PubMed

    Wagner, Tristan; Ermler, Ulrich; Shima, Seigo

    2016-01-01

    In the three domains of life, vitamin B12 (cobalamin) is primarily used in methyltransferase and isomerase reactions. The methyltransferase complex MtrA-H of methanogenic archaea has a key function in energy conservation by catalysing the methyl transfer from methyl-tetrahydromethanopterin to coenzyme M and its coupling with sodium-ion translocation. The cobalamin-binding subunit MtrA is not homologous to any known B12-binding proteins and is proposed as the motor of the sodium-ion pump. Here, we present crystal structures of the soluble domain of the membrane-associated MtrA from Methanocaldococcus jannaschii and the cytoplasmic MtrA homologue/cobalamin complex from Methanothermus fervidus. The MtrA fold corresponds to the Rossmann-type α/β fold, which is also found in many cobalamin-containing proteins. Surprisingly, the cobalamin-binding site of MtrA differed greatly from all the other cobalamin-binding sites. Nevertheless, the hydrogen-bond linkage at the lower axial-ligand site of cobalt was equivalently constructed to that found in other methyltransferases and mutases. A distinct polypeptide segment fixed through the hydrogen-bond linkage in the relaxed Co(III) state might be involved in propagating the energy released upon corrinoid demethylation to the sodium-translocation site by a conformational change. PMID:27324530

  12. MtrA of the sodium ion pumping methyltransferase binds cobalamin in a unique mode

    PubMed Central

    Wagner, Tristan; Ermler, Ulrich; Shima, Seigo

    2016-01-01

    In the three domains of life, vitamin B12 (cobalamin) is primarily used in methyltransferase and isomerase reactions. The methyltransferase complex MtrA–H of methanogenic archaea has a key function in energy conservation by catalysing the methyl transfer from methyl-tetrahydromethanopterin to coenzyme M and its coupling with sodium-ion translocation. The cobalamin-binding subunit MtrA is not homologous to any known B12-binding proteins and is proposed as the motor of the sodium-ion pump. Here, we present crystal structures of the soluble domain of the membrane-associated MtrA from Methanocaldococcus jannaschii and the cytoplasmic MtrA homologue/cobalamin complex from Methanothermus fervidus. The MtrA fold corresponds to the Rossmann-type α/β fold, which is also found in many cobalamin-containing proteins. Surprisingly, the cobalamin-binding site of MtrA differed greatly from all the other cobalamin-binding sites. Nevertheless, the hydrogen-bond linkage at the lower axial-ligand site of cobalt was equivalently constructed to that found in other methyltransferases and mutases. A distinct polypeptide segment fixed through the hydrogen-bond linkage in the relaxed Co(III) state might be involved in propagating the energy released upon corrinoid demethylation to the sodium-translocation site by a conformational change. PMID:27324530

  13. The Mtr4 ratchet helix and arch domain both function to promote RNA unwinding.

    PubMed

    Taylor, Lacy L; Jackson, Ryan N; Rexhepaj, Megi; King, Alejandra Klauer; Lott, Lindsey K; van Hoof, Ambro; Johnson, Sean J

    2014-12-16

    Mtr4 is a conserved Ski2-like RNA helicase and a subunit of the TRAMP complex that activates exosome-mediated 3'-5' turnover in nuclear RNA surveillance and processing pathways. Prominent features of the Mtr4 structure include a four-domain ring-like helicase core and a large arch domain that spans the core. The 'ratchet helix' is positioned to interact with RNA substrates as they move through the helicase. However, the contribution of the ratchet helix in Mtr4 activity is poorly understood. Here we show that strict conservation along the ratchet helix is particularly extensive for Ski2-like RNA helicases compared to related helicases. Mutation of residues along the ratchet helix alters in vitro activity in Mtr4 and TRAMP and causes slow growth phenotypes in vivo. We also identify a residue on the ratchet helix that influences Mtr4 affinity for polyadenylated substrates. Previous work indicated that deletion of the arch domain has minimal effect on Mtr4 unwinding activity. We now show that combining the arch deletion with ratchet helix mutations abolishes helicase activity and produces a lethal in vivo phenotype. These studies demonstrate that the ratchet helix modulates helicase activity and suggest that the arch domain plays a previously unrecognized role in unwinding substrates. PMID:25414331

  14. Preliminary developments of MTR plates with uranium nitride

    SciTech Connect

    Durand, J.P.; Laudamy, P.; Richter, K.

    1997-08-01

    In the opinion of CERCA, the total weight of Uranium per MTR plate (without changing the external dimensions) cannot be further increased using U{sub 3}Si{sub 2}. Limits have been reached on plates with a thicker meat or loaded to 6g Ut/cm{sup 3}. The use of a denser fuel like Uranium mononitride could permit an increase in these limits. A collaboration between the Institute for Transuranium Elements (ITU), Joint Research Centre of the European Commission, and CERCA has been set ut. The preliminary studies at the ITU to check compatibility between aluminium and UN proved that there are no metallurgical interactions below 500{degrees}C. Feasibility of the manufacturing, on a laboratory scale at CERCA, of depleted Uranium mononitride plates loaded to 7 g Ut/cm{sup 3} has been demonstrated. The manufacturing process, however, is only one aspect of the development of a new fuel. The experience gained in the case of U{sub 3}Si{sub 2} has shown that the development of a new fuel requires considerable time and financial investment. Such a development certainly represents an effort of about 10 years.

  15. Mtr Extracellular Electron Transfer Pathways in Fe(III)-reducing or Fe(II)-oxidizing Bacteria: A Genomic Perspective

    SciTech Connect

    Shi, Liang; Rosso, Kevin M.; Zachara, John M.; Fredrickson, Jim K.

    2012-12-01

    Originally discovered in the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1 (MR-1), the Mtr (i.e., metal-reducing) pathway exists in all characterized strains of metal-reducing Shewanella. The protein components identified to date for the Mtr pathway of MR-1 include four multi-heme c-type cytochromes (c-Cyts), CymA, MtrA, MtrC and OmcA, and a porin-like, outer membrane protein MtrB. They are strategically positioned along the width of the MR-1 cell envelope to mediate electron transfer from the quinone/quinol pool in the inner-membrane to the Fe(III)-containing minerals external to the bacterial cells. A survey of microbial genomes revealed homologues of the Mtr pathway in other dissimilatory Fe(III)-reducing bacteria, including Aeromonas hydrophila, Ferrimonas balearica and Rhodoferax ferrireducens, and in the Fe(II)-oxidizing bacteria Dechloromonas aromatica RCB, Gallionella capsiferriformans ES-2 and Sideroxydans lithotrophicus ES-1. The widespread distribution of Mtr pathways in Fe(III)-reducing or Fe(II)-oxidizing bacteria emphasizes the importance of this type of extracellular electron transfer pathway in microbial redox transformation of Fe. Their distribution in these two different functional groups of bacteria also emphasizes the bi-directional nature of electron transfer reactions carried out by the Mtr pathways. The characteristics of the Mtr pathways may be shared by other pathways used by microorganisms for exchanging electrons with their extracellular environments.

  16. The Mtr Respiratory Pathway Is Essential for Reducing Flavins and Electrodes in Shewanella oneidensis▿ †

    PubMed Central

    Coursolle, Dan; Baron, Daniel B.; Bond, Daniel R.; Gralnick, Jeffrey A.

    2010-01-01

    The Mtr respiratory pathway of Shewanella oneidensis strain MR-1 is required to effectively respire both soluble and insoluble forms of oxidized iron. Flavins (riboflavin and flavin mononucleotide) recently have been shown to be excreted by MR-1 and facilitate the reduction of insoluble substrates. Other Shewanella species tested accumulated flavins in supernatants to an extent similar to that of MR-1, suggesting that flavin secretion is a general trait of the species. External flavins have been proposed to act as both a soluble electron shuttle and a metal chelator; however, at biologically relevant concentrations, our results suggest that external flavins primarily act as electron shuttles for MR-1. Using deletion mutants lacking various Mtr-associated proteins, we demonstrate that the Mtr extracellular respiratory pathway is essential for the reduction of flavins and that decaheme cytochromes found on the outer surface of the cell (MtrC and OmcA) are required for the majority of this activity. Given the involvement of external flavins in the reduction of electrodes, we monitored current production by Mtr respiratory pathway mutants in three-electrode bioreactors under controlled flavin concentrations. While mutants lacking MtrC were able to reduce flavins at 50% of the rate of the wild type in cell suspension assays, these strains were unable to grow into productive electrode-reducing biofilms. The analysis of mutants lacking OmcA suggests a role for this protein in both electron transfer to electrodes and attachment to surfaces. The parallel phenotypes of Mtr mutants in flavin and electrode reduction blur the distinction between direct contact and the redox shuttling strategies of insoluble substrate reduction by MR-1. PMID:19897659

  17. MTR and In-vivo 1H-MRS studies on mouse brain with parkinson's disease

    NASA Astrophysics Data System (ADS)

    Yoon, Moon-Hyun; Kim, Hyeon-Jin; Chung, Jin-Yeung; Doo, Ah-Reum; Park, Hi-Joon; Kim, Seung-Nam; Choe, Bo-Young

    2012-12-01

    The aim of this study was to investigate whether the changes in the magnetization transfer ratio (MTR) histogram are related to specific characteristics of Parkinson's disease (PD) and to investigate whether the MTR histogram parameters are associated with neurochemical dysfunction by performing in vivo proton magnetic resonance spectroscopy (1H-MRS). MTR and in vivo 1H-MRS studies were performed on control mice (n = 10) and 1-methyl-1,2,3,6-tetrahydropyridine intoxicated mice (n = 10). All the MTR and in vivo 1H-MRS experiments were performed on a 9.4 T MRI/MRS system (Bruker Biospin, Germany) using a standard head coil. The protondensity fast spin echo (FSE) images and the T2-weighted spin echo (SE) images were acquired with no gap. Outer volume suppression (OVS), combined with the ultra-short echo-time stimulated echo acquisition mode (STEAM), was used for the localized in-vivo 1H-MRS. The quantitative analysis of metabolites was performed from the 1H spectra obtained in vivo on the striatum (ST) by using jMRUI (Lyon, France). The peak height of the MTR histograms in the PD model group was significantly lower than that in the control group (p < 0.05). The midbrain MTR values for volume were lower in the PD group than the control group(p < 0.05). The complex peak (Glx: glutamine+glutamate+ GABA)/creatine (Cr) ratio of the right ST in the PD group was significantly increased as compared to that of the control group. The present study revealed that the peak height of the MTR histogram was significantly decreased in the ST and substantia nigra, and a significant increase in the Gl x /Cr ratio was found in the ST of the PD group, as compared with that of the control group. These findings could reflect the early phase of neuronal dysfunction of neurotransmitters.

  18. Shielding analysis of the NAC-LWT cask with MTR fuel using SCALE

    SciTech Connect

    Napolitano, D.G.

    1995-12-31

    NAC International has used the SCALE Code Package extensively for transport and storage cask design. This includes the design of the NAC-STC dual purpose cask, the ENSA-DPT dual purpose cask as well as design modifications to the NAC-LWT cask. The NAC-LWT is a legal weight truck cask that was originally designed to transport one pressurized water reactor (PWR) fuel assembly or two boiling water reactor (BWR) fuel assemblies. Recently, this cask has been modified to transport up to 42 materials test reactor (MTR) fuel elements. This paper discusses the use of the SCALE package in performing a source term analysis of MTR fuel and shielding analysis of the NAC-LWT cask in support of a 10 CFR Part 71 license amendment for MTR fuel contents.

  19. The crystal structure of Mtr4 reveals a novel arch domain required for rRNA processing

    SciTech Connect

    Jackson, R.N.; Robinson, H.; Klauer, A. A.; Hintze, B. J.; van Hoof, A.; Johnson, S. J.

    2010-07-01

    The essential RNA helicase, Mtr4, performs a critical role in RNA processing and degradation as an activator of the nuclear exosome. The molecular basis for this vital function is not understood and detailed analysis is significantly limited by the lack of structural data. In this study, we present the crystal structure of Mtr4. The structure reveals a new arch-like domain that is specific to Mtr4 and Ski2 (the cytosolic homologue of Mtr4). In vivo and in vitro analyses demonstrate that the Mtr4 arch domain is required for proper 5.8S rRNA processing, and suggest that the arch functions independently of canonical helicase activity. In addition, extensive conservation along the face of the putative RNA exit site highlights a potential interface with the exosome. These studies provide a molecular framework for understanding fundamental aspects of helicase function in exosome activation, and more broadly define the molecular architecture of Ski2-like helicases.

  20. MTR WING, TRA604, INTERIOR. BASEMENT. INTERIOR VIEW FROM SAME LOCATION ...

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

    MTR WING, TRA-604, INTERIOR. BASEMENT. INTERIOR VIEW FROM SAME LOCATION IN WEST CORRIDOR AS PHOTO ID-33-G-42 BUT CAMERA FACES SOUTH. SIGN ON DOOR FOR "PIPE TUNNEL" WARNS OF RADIOLOGICAL AND ASBESTOS HAZARDS. DOOR HAS METAL HASPS. SIGN ON OVERHEAD WASTE HEAT RECOVERY PIPES SAYS THEY CONTAIN "ASBESTOS FREE INSULATION." FIRE DOOR AT LEFT LEADS TO STAIRWAY TO FIRST FLOOR. DOOR AT RIGHT LEADS TO ROOM WHICH ONCE CONTAINED MTR LIBRARY. INL NEGATIVE NO. HD46-13-4. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  1. MTR,TRA603. EXPERIMENTERS' SPACE ALLOCATIONS IN BASEMENT AS OF 1963. SHIELDED ...

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

    MTR,TRA-603. EXPERIMENTERS' SPACE ALLOCATIONS IN BASEMENT AS OF 1963. SHIELDED CUBICLES WERE IDENTIFIED BY SPONSORING LABORATORY AND ITS TEST HOLE NUMBER IN THE REACTOR, IE, "KAPL HB-1" SIGNIFIED KNOLLS ATOMIC POWER LABORATORY, HORIZONTAL BEAM NO. 1. "WAPD" WAS WESTINGHOUSE ATOMIC POWER DIVISION. CATCH TANKS AND SAMPLE STATIONS FOR TEST LOOPS WERE ASSOCIATED WITH THESE CUBICLES. NOTE DESKS, STORAGE CABINETS, SWITCH GEAR, INSTRUMENT PANELS. PHILLIPS PETROLEUM COMPANY MTR-E-5205, 4/1963. INL INDEX NO. 531-0603-00-706-009757, REV. 5. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  2. Performance of the MTR core with MOX fuel using the MCNP4C2 code.

    PubMed

    Shaaban, Ismail; Albarhoum, Mohamad

    2016-08-01

    The MCNP4C2 code was used to simulate the MTR-22 MW research reactor and perform the neutronic analysis for a new fuel namely: a MOX (U3O8&PuO2) fuel dispersed in an Al matrix for One Neutronic Trap (ONT) and Three Neutronic Traps (TNTs) in its core. Its new characteristics were compared to its original characteristics based on the U3O8-Al fuel. Experimental data for the neutronic parameters including criticality relative to the MTR-22 MW reactor for the original U3O8-Al fuel at nominal power were used to validate the calculated values and were found acceptable. The achieved results seem to confirm that the use of MOX fuel in the MTR-22 MW will not degrade the safe operational conditions of the reactor. In addition, the use of MOX fuel in the MTR-22 MW core leads to reduce the uranium fuel enrichment with (235)U and the amount of loaded (235)U in the core by about 34.84% and 15.21% for the ONT and TNTs cases, respectively. PMID:27213809

  3. MTR WING A, TRA604, INTERIOR. MAIN FLOOR. DETAIL VIEW INSIDE ...

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

    MTR WING A, TRA-604, INTERIOR. MAIN FLOOR. DETAIL VIEW INSIDE LABORATORY 114. CAMERA FACING NORTH. DISPOSAL OF RADIOACTIVE MATERIALS IS UNDERWAY. INL NEGATIVE NO. HD46-12-4. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  4. MTR, TRA603. INCANAL CONVEYOR TABLE, SAW TABLE, AND STORAGE AREA ...

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

    MTR, TRA-603. IN-CANAL CONVEYOR TABLE, SAW TABLE, AND STORAGE AREA RACKS. DISCHARGE MECHANISM. BLAW-KNOX 3150-579-1, 12/1950. INL INDEX NO. 531-603-40-098-100302, REV. 3. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  5. MTR WING, TRA604. A LABORATORY ROOM WITH ITS CABINETS AND ...

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

    MTR WING, TRA-604. A LABORATORY ROOM WITH ITS CABINETS AND SERVICE STRIP DOWN CENTER OF ROOM. CARD IN LEFT CORNER OF VIEW WAS INSERTED BY INL PHOTOGRAPHER TO COVER AN OBSOLETE SECURITY RESTRICTION PRINTED ON THE ORIGINAL NEGATIVE. INL NEGATIVE NO. 3817. Unknown Photographer, 11/28/1951 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  6. Kinetic Monte Carlo Simulations and Molecular Conductance Measurements of the Bacterial Decaheme Cytochrome MtrF

    SciTech Connect

    Byun, H. S.; Pirbadian, S.; Nakano, Aiichiro; Shi, Liang; El-Naggar, Mohamed Y.

    2014-09-05

    Microorganisms overcome the considerable hurdle of respiring extracellular solid substrates by deploying large multiheme cytochrome complexes that form 20 nanometer conduits to traffic electrons through the periplasm and across the cellular outer membrane. Here we report the first kinetic Monte Carlo simulations and single-molecule scanning tunneling microscopy (STM) measurements of the Shewanella oneidensis MR-1 outer membrane decaheme cytochrome MtrF, which can perform the final electron transfer step from cells to minerals and microbial fuel cell anodes. We find that the calculated electron transport rate through MtrF is consistent with previously reported in vitro measurements of the Shewanella Mtr complex, as well as in vivo respiration rates on electrode surfaces assuming a reasonable (experimentally verified) coverage of cytochromes on the cell surface. The simulations also reveal a rich phase diagram in the overall electron occupation density of the hemes as a function of electron injection and ejection rates. Single molecule tunneling spectroscopy confirms MtrF's ability to mediate electron transport between an STM tip and an underlying Au(111) surface, but at rates higher than expected from previously calculated heme-heme electron transfer rates for solvated molecules.

  7. MTR STACK, TRA71, DETAIL OF PUMICE BLOCK SERVICE BUILDING AT ...

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

    MTR STACK, TRA-71-, DETAIL OF PUMICE BLOCK SERVICE BUILDING AT BASE OF STACK. CAMERA FACING SOUTHEAST. INL NEGATIVE NO. HD52-1-2. Mike Crane, Photographer, 5/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. MTR WING A, TRA604, INTERIOR. MAIN FLOOR. VIEW DOWN CORRIDOR ...

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

    MTR WING A, TRA-604, INTERIOR. MAIN FLOOR. VIEW DOWN CORRIDOR 2 (BETWEEN ROOMS ON WEST WALL AND IN CENTER OF FLOOR). CAMERA FACING SOUTH. PUMICE BLOCK WALLS. INL NEGATIVE NO. HD46-12-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  9. MTR WING, TRA604. FIRST FLOOR PLAN. ENTRY LOBBY, MACHINE SHOP, ...

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

    MTR WING, TRA-604. FIRST FLOOR PLAN. ENTRY LOBBY, MACHINE SHOP, INSTRUMENT SHOP, COUNTING ROOM, HEALTH PHYSICS LAB, LABS AND OFFICES, STORAGE, SHIPPING AND RECEIVING. BLAW-KNOX 3150-4-2, 7/1950. INL INDEX NO. 053-604-00-099-100008, REV. 7. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  10. MTR, TRA603. BASEMENT FLOOR PLAN. REACTOR SHIELDING, CANAL AND RABBIT ...

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

    MTR, TRA-603. BASEMENT FLOOR PLAN. REACTOR SHIELDING, CANAL AND RABBIT CANAL, DEEP WELL STORAGE. DECONTAMINATION ROOM, VAULT, MONITOR ROOM, OFFICE, STAIRWAYS. BLAW-KNOX 3150-803-1, 7/1950. INL INDEX NO. 531-0603-00-098-100560, REV. 6. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  11. MTR COMPRESSOR BUILDING, TRA651. TWO JOY COMPRESSORS ARE INSTALLED. OUT ...

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

    MTR COMPRESSOR BUILDING, TRA-651. TWO JOY COMPRESSORS ARE INSTALLED. OUT OF VIEW ON RIGHT WERE TWO INGERSOLL-RAND COMPRESSORS. NOTE FRAME STRUCTURE OF METAL-SIDING BUILDING. COMPARE WITH ID-33-G-4. INL NEGATIVE NO. 56-1257. Jack L. Anderson, Photographer, 4/20/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  12. MTR BLOWER AND FAN HOUSE, TRA610. FIRST FLOOR, ROOF AND ...

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

    MTR BLOWER AND FAN HOUSE, TRA-610. FIRST FLOOR, ROOF AND FOUNDATION PLANS. DOOR SCHEDULE AND LOCATION OF STRUCTURAL STEEL AND HOLLOW METAL DOORS. BLAW-KNOX 3150-810-1, 1/1951. INL INDEX NO. 531-0610-00-098-100688, REV. 2. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  13. MTR, TRA603. SUBBASEMENT FLOOR PLAN. INLET/OUTLET TUNNELS FOR COOLANT WATER ...

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

    MTR, TRA-603. SUB-BASEMENT FLOOR PLAN. INLET/OUTLET TUNNELS FOR COOLANT WATER (NORTH SIDE) AND AIR (SOUTH SIDE). RABBIT CANAL AND BULKHEADS. SUMPS AND DRAINS. BLAW-KNOX 3150-3-7, 3/1950. INL INDEX NO. 531-0603-00-098-100006, REV. 4. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  14. MTR WING, TRA604, INTERIOR. BASEMENT. WEST CORRIDOR. CAMERA FACES NORTH. ...

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

    MTR WING, TRA-604, INTERIOR. BASEMENT. WEST CORRIDOR. CAMERA FACES NORTH. HVAC AREA IS AT RIGHT OF CORRIDOR. INL NEGATIVE NO. HD46-13-3. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  15. MTR BUILDING INTERIOR, TRA603. BASEMENT. CAMERA IS IN SOUTHWEST QUADRANT ...

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

    MTR BUILDING INTERIOR, TRA-603. BASEMENT. CAMERA IS IN SOUTHWEST QUADRANT OF BASEMENT AND FACING NORTHEAST. PANEL DISPLAYS DATA READOUTS. INL NEGATIVE NO. HD46-6-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  16. MTR BUILDING INTERIOR, TRA603. CAMERA IS AT NORTH END OF ...

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

    MTR BUILDING INTERIOR, TRA-603. CAMERA IS AT NORTH END OF THIRD FLOOR BALCONY LOOKING SOUTHEAST. DETAIL OF REACTOR'S NORTH FACE AND ITS TEST HOLES. MOCK-UP APPARATUS IS BEYOND REACTOR. INL NEGATIVE NO. HD46-5-4. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  17. MTR BUILDING INTERIOR, TRA603. CAMERA IS ON SECOND FLOOR BALCONY ...

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

    MTR BUILDING INTERIOR, TRA-603. CAMERA IS ON SECOND FLOOR BALCONY LOOKING DOWN ON WEST FACE OF REACTOR. SHIELDING BLOCKS IN FOREGROUND ATOP CABINET. INL NEGATIVE NO. HD46-3-4. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  18. MTR BUILDING INTERIOR, TRA603. CAMERA IS AT SOUTH END OF ...

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

    MTR BUILDING INTERIOR, TRA-603. CAMERA IS AT SOUTH END OF THIRD FLOOR BALCONY LOOKING NORTHEAST. BRIDGE BETWEEN BALCONY AND REACTOR TOP AT LEFT OF VIEW. INL NEGATIVE NO. HD46-5-1. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  19. MTR BUILDING INTERIOR, TRA603, REACTOR FLOOR. DETAIL OF REACTOR'S SOUTH ...

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

    MTR BUILDING INTERIOR, TRA-603, REACTOR FLOOR. DETAIL OF REACTOR'S SOUTH FACE. CAMERA FACING NORTHWESTERLY. INL NEGATIVE NO. HD46-1-1. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  20. MTR BUILDING INTERIOR, TRA603, REACTOR FLOOR. CONTEXTUAL VIEW OF SOUTHWEST ...

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

    MTR BUILDING INTERIOR, TRA-603, REACTOR FLOOR. CONTEXTUAL VIEW OF SOUTHWEST CORNER OF REACTOR. WEST FACE IS TOWARD LEFT OF VIEW. CAMERA FACING NORTHEAST. INL NEGATIVE NO. HD46-2-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  1. MTR BUILDING INTERIOR, TRA603. CAMERA IS ON SECOND FLOOR BALCONY ...

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

    MTR BUILDING INTERIOR, TRA-603. CAMERA IS ON SECOND FLOOR BALCONY LOOKING DOWN ON REACTOR FLOOR, FACING NORTHEAST, THE WEST AND SOUTH FACES OF THE REACTOR. MOCK-UP APPARATUS IS AT RIGHT OF VIEW. INL NEGATIVE NO. HD-46-3-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  2. REACTOR SERVICES BUILDING, TRA635. EAST SIDE. CAMERA LOOKING NORTHWEST. MTR ...

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

    REACTOR SERVICES BUILDING, TRA-635. EAST SIDE. CAMERA LOOKING NORTHWEST. MTR BUILDING, TRA-603, AT RIGHT OF VIEW. INL NEGATIVE NO. HD46-41-2. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  3. REACTOR SERVICES BUILDING, TRA635. WEST SIDE. CAMERA LOOKING NORTHEAST. MTR ...

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

    REACTOR SERVICES BUILDING, TRA-635. WEST SIDE. CAMERA LOOKING NORTHEAST. MTR (TRA-603) AT LEFT OF VIEW. INL NEGATIVE NO. HD46-41-2. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  4. MTR BUILDING INTERIOR, TRA603. CAMERA FACING SOUTHEAST CORNER OF REACTOR ...

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

    MTR BUILDING INTERIOR, TRA-603. CAMERA FACING SOUTHEAST CORNER OF REACTOR FLOOR. SUPPLIES AND EQUIPMENT RELATE TO MOCK-UP PROJECT. NOTE PRECAST WALL PANELS SUPPORTED BY VERTICAL COLUMNS OF REINFORCED CONCRETE. INL NEGATIVE NO. HD46-4-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  5. MTR BUILDING INTERIOR, TRA603, REACTOR FLOOR. DETAIL OF REACTOR TEST ...

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

    MTR BUILDING INTERIOR, TRA-603, REACTOR FLOOR. DETAIL OF REACTOR TEST HOLE OPENING IN WEST FACE. CAMERA FACING NORTHEAST. INL NEGATIVE NO. HD46-2-1. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  6. MTR BUILDING INTERIOR, TRA603, REACTOR FLOOR. VIEW DOWN CORRIDOR CREATED ...

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

    MTR BUILDING INTERIOR, TRA-603, REACTOR FLOOR. VIEW DOWN CORRIDOR CREATED BY EAST WALL ON LEFT AND APPARATUS ON RIGHT. CAMERA FACING SOUTH. INL NEGATIVE NO. HD46-1-3. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  7. SOUTH WING, MTR661. INTERIOR DETAIL INSIDE LAB ROOM 131. CAMERA ...

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

    SOUTH WING, MTR-661. INTERIOR DETAIL INSIDE LAB ROOM 131. CAMERA FACING NORTHEAST. NOTE CONCRETE BLOCK WALLS. SAFETY SHOWER AND EYE WASHER AT REAR WALL. INL NEGATIVE NO. HD46-7-2. Mike Crane, Photographer, 2/2005. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. Structure and function of Neisseria gonorrhoeae MtrF illuminates a class of antimetabolite efflux pumps.

    PubMed

    Su, Chih-Chia; Bolla, Jani Reddy; Kumar, Nitin; Radhakrishnan, Abhijith; Long, Feng; Delmar, Jared A; Chou, Tsung-Han; Rajashankar, Kanagalaghatta R; Shafer, William M; Yu, Edward W

    2015-04-01

    Neisseria gonorrhoeae is an obligate human pathogen and the causative agent of the sexually transmitted disease gonorrhea. The control of this disease has been compromised by the increasing proportion of infections due to antibiotic-resistant strains, which are growing at an alarming rate. N. gonorrhoeae MtrF is an integral membrane protein that belongs to the AbgT family of transporters for which no structural information is available. Here, we describe the crystal structure of MtrF, revealing a dimeric molecule with architecture distinct from all other families of transporters. MtrF is a bowl-shaped dimer with a solvent-filled basin extending from the cytoplasm to halfway across the membrane bilayer. Each subunit of the transporter contains nine transmembrane helices and two hairpins, posing a plausible pathway for substrate transport. A combination of the crystal structure and biochemical functional assays suggests that MtrF is an antibiotic efflux pump mediating bacterial resistance to sulfonamide antimetabolite drugs. PMID:25818299

  9. MTR WING A, TRA604. SOUTH SIDE. CAMERA FACING NORTH. THIS ...

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

    MTR WING A, TRA-604. SOUTH SIDE. CAMERA FACING NORTH. THIS VIEW TYPIFIES TENDENCY FOR EXPANSIONS TO TAKE THE FORM OF PROJECTIONS AND INFILL USING AVAILABLE YARD SPACES. INL NEGATIVE NO. HD47-44-3. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  10. MTR BUILDING, TRA603. SOUTH ELEVATION. PRECAST INSULATED PANEL DETAILS. AIR ...

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

    MTR BUILDING, TRA-603. SOUTH ELEVATION. PRECAST INSULATED PANEL DETAILS. AIR DUCT PLENUM CHAMBER. BLAW-KNOX 3150-80-5, 9/1950. INL INDEX NO. 531-0603-00-098-100564, REV. 4. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  11. MTR, TRA603. NORTH ELEVATION. PLUG STORAGE AREA WITH ROLLING STEEL ...

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

    MTR, TRA-603. NORTH ELEVATION. PLUG STORAGE AREA WITH ROLLING STEEL DOOR. PIPE TUNNEL IN SUB-BASEMENT. FIXED SASH WINDOWS IN BALCONY SECTION. DOOR DETAILS. BLAW-KNOX 3150-803-7, 7/1950. INL INDEX NO. 531-0603-00-098-100566, REV. 4. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  12. MTR WING, TRA604. PRECAST CONCRETE PANELS AND DIMENSIONS FOR PANELS ...

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

    MTR WING, TRA-604. PRECAST CONCRETE PANELS AND DIMENSIONS FOR PANELS K THROUGH Q. BLAW-KNOX 3150-804-21, SHEET #2, 11/1950. INL INDEX NO. 531-0604-62-098-100645, REV. 2. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  13. MTR STACK, TRA710, CONTEXTUAL VIEW, CAMERA FACING SOUTH. PERIMETER SECURITY ...

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

    MTR STACK, TRA-710, CONTEXTUAL VIEW, CAMERA FACING SOUTH. PERIMETER SECURITY FENCE AND SECURITY LIGHTING IN VIEW AT LEFT. INL NEGATIVE NO. HD52-1-1. Mike Crane, Photographer, 5/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  14. MTR, TRA603. CONTROL ROOM DETAILS. ACOUSTIC PLASTER CEILING, USHAPED CONSOLE, ...

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

    MTR, TRA-603. CONTROL ROOM DETAILS. ACOUSTIC PLASTER CEILING, U-SHAPED CONSOLE, INSTRUMENT PANELS, GLASS DOOR, ASPHALT TILE FLOOR AND COLORS. BLAW-KNOX 3150-803-11, 10/1950. INL INDEX NO. 531-0603-00-098-100570, REV. 3. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  15. Construction of prokaryotic expression plasmid of mtrC protein of Neisseria gonorrhoeae and its expression in E. coli.

    PubMed

    Chen, Hongxiang; Tu, Yating; Lin, Nengxing; Huang, Changzheng

    2005-01-01

    In order to provide a rational research basis for detection of resistance of Neisseria gonorrhoeae to antimicrobial hydrophobic agents and study on the resistant mechanism of multiple transferable resistance (mtr) efflux system, plasmid pET-28a(+) encoding mtrC gene was constructed and the related target protein was expressed in Escherichia coli (E. coli) DE3. The fragments of mtrC gene of Neisseria gonorrhoeae from the standard strains were amplified and cloned into prokaryotic expression plasmid pET-28a(+) with restriction endonuclease to construct recombinant pET-mtrC which was verified by restriction endonuclease and DNA sequencing. The recombinant was transformed into E. coli DE3 to express the protein mtrC induced by IPTG. The results showed mtrC DNA fragment was proved correct through restriction endonuclease and DNA sequencing. Its sequence was 99.5% homologus to that published on GeneBank (U14993). A 48.5 kD fusion protein which was induced by IPTG was detected by SDS-PAGE. It was concluded that the construction of prokaryotic expression plasmid of mtrC protein of Neisseria gonorrhoeae was correct and the fusion protein was successively expressed in E. coli. PMID:16463681

  16. The exosome-binding factors Rrp6 and Rrp47 form a composite surface for recruiting the Mtr4 helicase

    PubMed Central

    Schuch, Benjamin; Feigenbutz, Monika; Makino, Debora L; Falk, Sebastian; Basquin, Claire; Mitchell, Phil; Conti, Elena

    2014-01-01

    The exosome is a conserved multi-subunit ribonuclease complex that functions in 3′ end processing, turnover and surveillance of nuclear and cytoplasmic RNAs. In the yeast nucleus, the 10-subunit core complex of the exosome (Exo-10) physically and functionally interacts with the Rrp6 exoribonuclease and its associated cofactor Rrp47, the helicase Mtr4 and Mpp6. Here, we show that binding of Mtr4 to Exo-10 in vitro is dependent upon both Rrp6 and Rrp47, whereas Mpp6 binds directly and independently of other cofactors. Crystallographic analyses reveal that the N-terminal domains of Rrp6 and Rrp47 form a highly intertwined structural unit. Rrp6 and Rrp47 synergize to create a composite and conserved surface groove that binds the N-terminus of Mtr4. Mutation of conserved residues within Rrp6 and Mtr4 at the structural interface disrupts their interaction and inhibits growth of strains expressing a C-terminal GFP fusion of Mtr4. These studies provide detailed structural insight into the interaction between the Rrp6–Rrp47 complex and Mtr4, revealing an important link between Mtr4 and the core exosome. PMID:25319414

  17. The exosome-binding factors Rrp6 and Rrp47 form a composite surface for recruiting the Mtr4 helicase.

    PubMed

    Schuch, Benjamin; Feigenbutz, Monika; Makino, Debora L; Falk, Sebastian; Basquin, Claire; Mitchell, Phil; Conti, Elena

    2014-12-01

    The exosome is a conserved multi-subunit ribonuclease complex that functions in 3' end processing, turnover and surveillance of nuclear and cytoplasmic RNAs. In the yeast nucleus, the 10-subunit core complex of the exosome (Exo-10) physically and functionally interacts with the Rrp6 exoribonuclease and its associated cofactor Rrp47, the helicase Mtr4 and Mpp6. Here, we show that binding of Mtr4 to Exo-10 in vitro is dependent upon both Rrp6 and Rrp47, whereas Mpp6 binds directly and independently of other cofactors. Crystallographic analyses reveal that the N-terminal domains of Rrp6 and Rrp47 form a highly intertwined structural unit. Rrp6 and Rrp47 synergize to create a composite and conserved surface groove that binds the N-terminus of Mtr4. Mutation of conserved residues within Rrp6 and Mtr4 at the structural interface disrupts their interaction and inhibits growth of strains expressing a C-terminal GFP fusion of Mtr4. These studies provide detailed structural insight into the interaction between the Rrp6-Rrp47 complex and Mtr4, revealing an important link between Mtr4 and the core exosome. PMID:25319414

  18. Extracellular Reduction of Hexavalent Chromium by Cytochromes MtrC and OmcA of Shewanella oneidensis MR-1 ▿

    PubMed Central

    Belchik, Sara M.; Kennedy, David W.; Dohnalkova, Alice C.; Wang, Yuanmin; Sevinc, Papatya C.; Wu, Hong; Lin, Yuehe; Lu, H. Peter; Fredrickson, James K.; Shi, Liang

    2011-01-01

    To characterize the roles of cytochromes MtrC and OmcA of Shewanella oneidensis MR-1 in Cr(VI) reduction, the effects of deleting the mtrC and/or omcA gene on Cr(VI) reduction and the cellular locations of reduced Cr(III) precipitates were investigated. Compared to the rate of reduction of Cr(VI) by the wild type (wt), the deletion of mtrC decreased the initial rate of Cr(VI) reduction by 43.5%, while the deletion of omcA or both mtrC and omcA lowered the rate by 53.4% and 68.9%, respectively. In wt cells, Cr(III) precipitates were detected by transmission electron microscopy in the extracellular matrix between the cells, in association with the outer membrane, and inside the cytoplasm. No extracellular matrix-associated Cr(III) precipitates, however, were found in the cytochrome mutant cell suspension. In mutant cells without either MtrC or OmcA, most Cr(III) precipitates were found in association with the outer membrane, while in mutant cells lacking both MtrC and OmcA, most Cr(III) precipitates were found inside the cytoplasm. Cr(III) precipitates were also detected by scanning election microscopy on the surfaces of the wt and mutants without MtrC or OmcA but not on the mutant cells lacking both MtrC and OmcA, demonstrating that the deletion of mtrC and omcA diminishes the extracellular formation of Cr(III) precipitates. Furthermore, purified MtrC and OmcA reduced Cr(VI) with apparent kcat values of 1.2 ± 0.2 (mean ± standard deviation) and 10.2 ± 1 s−1 and Km values of 34.1 ± 4.5 and 41.3 ± 7.9 μM, respectively. Together, these results consistently demonstrate that MtrC and OmcA are the terminal reductases used by S. oneidensis MR-1 for extracellular Cr(VI) reduction where OmcA is a predominant Cr(VI) reductase. PMID:21498755

  19. MTR BUILDING, TRA603. EAST SIDE. CAMERA FACING WEST. CORRUGATED IRON ...

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

    MTR BUILDING, TRA-603. EAST SIDE. CAMERA FACING WEST. CORRUGATED IRON BUILDING MARKED WITH "X" IS TRA-651. TRA-626, TO ITS RIGHT, HOUSED COMPRESSOR EQUIPMENT FOR THE AIRCRAFT NUCLEAR PROPULSION PROGRAM. LATER, IT WAS USED FOR STORAGE. INL NEGATIVE NO. HD46-42-4. Mike Crane, Photographer, April 2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  20. MTR BUILDING INTERIOR, TRA603, REACTOR FLOOR. CAMERA IS IN NORTHEAST ...

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

    MTR BUILDING INTERIOR, TRA-603, REACTOR FLOOR. CAMERA IS IN NORTHEAST CORNER FACING SOUTHWEST. NORTH FACE OF REACTOR IS IN LEFT HALF OF VIEW. WEST WALL CONTAINS CONTROL BALCONIES. BRIDGE FROM REACTOR TO SECOND-FLOOR BALCONY IS IN CENTER OF VIEW. INL NEGATIVE NO. HD46-1-4. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  1. MTR BUILDING INTERIOR, TRA603, REACTOR FLOOR. VIEW DOWN CORRIDOR CREATED ...

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

    MTR BUILDING INTERIOR, TRA-603, REACTOR FLOOR. VIEW DOWN CORRIDOR CREATED BY REACTOR (LEFT OF VIEW) AND WEST WALL ON RIGHT. BRIDGE OVERHEAD PROVIDED ACCESS TO TOP OF REACTOR FROM BALCONY. NOTE WIDTH OF BRIDGE. CAMERA FACING SOUTH TOWARDS OPEN DOOR OF REACTOR SERVICE BUILDING, TRA-635. INL NEGATIVE NO. HD46-1-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  2. MTR BUILDING INTERIOR, TRA603, SECOND FLOOR BALCONY. CAMERA FACING NORTH. ...

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

    MTR BUILDING INTERIOR, TRA-603, SECOND FLOOR BALCONY. CAMERA FACING NORTH. ROOMS 204, 203, 202, AND 201 ARE TO LEFT. VIEW TOWARDS REACTOR FLOOR IS SEEN THROUGH BALCONY RAILING. PLATFORM BETWEEN REACTOR AND THIRD FLOOR BALCONY IS SEEN BEYOND SQUARE PILLAR IN FOREGROUND. INL NEGATIVE NO. HD46-3-1. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  3. MTR BUILDING INTERIOR, TRA603. CAMERA IS AT NORTH END OF ...

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

    MTR BUILDING INTERIOR, TRA-603. CAMERA IS AT NORTH END OF SECOND FLOOR BALCONY LOOKING TOWARDS WORK PLATFORMS ON NORTH FACE OF REACTOR. BRIDGE TO THIRD FLOOR BALCONY FROM TOP OF REACTOR IS AT UPPER RIGHT OF VIEW. CAMERA FACING EASTERLY. INL NEGATIVE NO. HD-46-4-1. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  4. MTR BUILDING INTERIOR, TRA603. CAMERA IS ON SECOND FLOOR BALCONY ...

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

    MTR BUILDING INTERIOR, TRA-603. CAMERA IS ON SECOND FLOOR BALCONY LOOKING DOWN ON REACTOR FLOOR, FACING EAST. REACTOR IS AT LEFT OF VIEW. APPARATUS DIRECTLY IN FRONT OF CAMERA IS PART OF A MOCK-UP PROJECT. INL NEGATIVE NO. HD46-3-3. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  5. MTR BUILDING INTERIOR, TRA603. CAMERA IS AT NORTH END OF ...

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

    MTR BUILDING INTERIOR, TRA-603. CAMERA IS AT NORTH END OF THIRD FLOOR BALCONY LOOKING SOUTHEAST AND ACROSS TOP OF REACTOR. MOCK-UP APPARATUS IS BEYOND REACTOR. BRIDGE CONNECTING BALCONY AND REACTOR TOP AT RIGHT OF VIEW. INL NEGATIVE NO. HD46-5-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  6. MTR WING A, TRA604, INTERIOR. BASEMENT. DETAIL OF A19 LAB ...

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

    MTR WING A, TRA-604, INTERIOR. BASEMENT. DETAIL OF A-19 LAB AREA ALONG SOUTH WALL. SIGN ON FLOOR DIRECTS WORKERS TO OBTAIN WHOLE BODY FRISK UPON LEAVING AREA. SIGN ON EQUIPMENT IN CENTER OF VIEW REQUESTS WORKERS TO "NOTIFY HEALTH PHYSICS BEFORE WORKING ON THIS SYSTEM." CAMERA FACING SOUTHWEST. INL NEGATIVE NO. HD46-13-2. Mike Crane, Photographer, 2/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  7. MTR BUILDING, TRA603. SOUTHEAST CORNER, EAST SIDE FACING TOWARD RIGHT ...

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

    MTR BUILDING, TRA-603. SOUTHEAST CORNER, EAST SIDE FACING TOWARD RIGHT OF VIEW. CAMERA FACING NORTHWEST. LIGHT-COLORED PROJECTION AT LEFT IS ENGINEERING SERVICES BUILDING, TRA-635. SMALL CONCRETE BLOCK BUILDING AT CENTER OF VIEW IS FAST CHOPPER DETECTOR HOUSE, TRA-665. INL NEGATIVE NO. HD46-43-3. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. MTR WING, TRA604. PRECAST CONCRETE PANELS AND DIMENSIONS. TYPES A, ...

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

    MTR WING, TRA-604. PRECAST CONCRETE PANELS AND DIMENSIONS. TYPES A, B, C, D, E, AND F; AND HOW THEY ARE CONNECTED. TYPES C AND D ARE ON WEST SIDE WHERE GLASS BLOCKS SURROUND ENTRY DOOR. BLAW-KNOX 3150-804-20, SHEET #1, 11/1950. INL INDEX NO. 531-0604-62-098-100644, REV. 0. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  9. MTR WING, TRA604. ELEVATIONS OF NORTH, WEST AND SOUTH SIDES. ...

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

    MTR WING, TRA-604. ELEVATIONS OF NORTH, WEST AND SOUTH SIDES. EAST SIDE CONNECTS TO TRA-603'S WEST SIDE. REFERENCE TO PANEL TYPES A, B, C, D, E, H. WINDOWS IN BANKS OF FOUR. DETAILS OF ENTRY ON WEST SIDE: CANOPY, GLASS BLOCK. FAN DECK. BLAW-KNOX 3150-804-5, 11/1950. INL INDEX NO. 531-0604-00-098-100630, REV. 5. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  10. Thermodynamics of Electron Flow in the Bacterial Deca-heme Cytochrome MtrF

    SciTech Connect

    Breuer, Marian; Zarzycki, Piotr P.; Blumberger, Jochen; Rosso, Kevin M.

    2012-07-01

    Electron transporting multiheme cytochromes are essential to the metabolism of microbes that inhabit soils and carry out important biogeochemical processes. Recently the first crystal structure of a prototype bacterial deca-heme cytochrome (MtrF) has been resolved and its electrochemistry characterized. However, the molecular details of electron conductance along heme chains in the cytochrome are difficult to access via experiment due to the nearly identical chemical nature of the heme cofactors. Here we employ large-scale molecular dynamics simulations to compute the reduction potentials of the ten hemes of MtrF in aqueous solution. We find that as a whole they fall within a range of about 0.3 V in agreement with experiment. Individual reduction potentials give rise to a free energy profile for electron conduction that is approximately symmetric with respect to the center of the protein. Our calculations indicate that there is no significant potential bias along the orthogonal octa- and tetra-heme chains suggesting that under aqueous conditions MtrF is a nearly reversible two-dimensional conductor.

  11. Targeted protein degradation of outer membrane decaheme cytochrome MtrC metal reductase in Shewanella oneidensis MR-1 measured using biarsenical probe CrAsH-EDT(2).

    PubMed

    Xiong, Yijia; Chen, Baowei; Shi, Liang; Fredrickson, James K; Bigelow, Diana J; Squier, Thomas C

    2011-11-15

    Development of efficient microbial biofuel cells requires an ability to exploit interfacial electron transfer reactions to external electron acceptors, such as metal oxides; such reactions occur in the facultative anaerobic Gram-negative bacterium Shewanella oneidensis MR-1 through the catalytic activity of the outer membrane decaheme c-type cytochrome MtrC. Central to the utility of this pathway to synthetic biology is an understanding of cellular mechanisms that maintain optimal MtrC function, cellular localization, and renewal by degradation and resynthesis. In order to monitor trafficking to the outer membrane, and the environmental sensitivity of MtrC, we have engineered a tetracysteine tag (i.e., CCPGCC) at its C-terminus that permits labeling by the cell impermeable biarsenical fluorophore carboxy-FlAsH (CrAsH) of MtrC at the surface of living Shewanella oneidensis MR-1 cells. In comparison, the cell permeable reagent FlAsH permits labeling of the entire population of MtrC, including proteolytic fragments resulting from incorrect maturation. We demonstrate specific labeling by CrAsH of engineered MtrC (MtrC*) which is dependent on the presence of a functional type 2 secretion system (T2S), as evidenced by T2S system gspD or gspG deletion mutants which are incapable of CrAsH labeling. Under these latter conditions, MtrC* undergoes proteolytic degradation to form a large 35-38 kDa fragment; this degradation product is also resolved during normal turnover of the CrAsH-labeled MtrC protein. No MtrC protein is released into the medium during turnover, suggesting the presence of cellular turnover systems involving MtrC reuptake and degradation. The mature MtrC localized on the outer membrane is a long-lived protein, with a turnover rate of 0.043 h(-1) that is insensitive to O(2) concentration. Maturation of MtrC is relatively inefficient, with substantial rates of turnover of the immature protein prior to export to the outer membrane (i.e., 0.028 h(-1)) that are

  12. Dose Rate Calculations of Spent MTR-HEU Fuel Elements of the IAN-R1 Research Reactor

    NASA Astrophysics Data System (ADS)

    Sarta Fuentes, Jose Antonio

    2005-04-01

    With cooperation of the International Atomic Energy Agency (IAEA) and the Department of Energy (DOE) of the United States, several tasks related to the waste disposal of spent MTR fuel enriched nominally to 93% were carried out for the conversion of the IAN-R1 Research Reactor from MTR-HEU fuel to TRIGA-LEU fuel. In order to remove the spent MTR-HEU fuel of the core and store it safetly, a program was established at the Instituto de Ciencias Nucleares y Energìas Alternativas (INEA). This program included training, acquisition of hardware and sofware, design and construction of a decay pool, transfer of the spent HEU fuel elements into the decay pool and his final transport to Savanah River in United States. In this paper are presented external dose rates which were calculated for a standard spent MTR-HEU fuel element of the IAN-R1 Research Reactor. The calculations take in consideration the activity due to contributions of fission, activation and actinides products for each relevant radionuclide present in a standard spent MTR-HEU fuel. The datas obtained were the base for the respective dosimetric evaluations in the transfering operations of fuel elements into the decay pool and for shielding calculations in designing of the decay pool.

  13. Radionuclide Compositions and Total Activity of Spent MTR-HEU Fuel Elements of the IAN-R1 Research Reactor

    NASA Astrophysics Data System (ADS)

    Sarta, Josè A.; Castiblanco, Luis A.

    2005-05-01

    With cooperation of the International Atomic Energy Agency (IAEA) and the Department of Energy (DOE) of the United States, several calculations and tasks related to the waste disposal of spent MTR fuel enriched nominally to 93% were carried out for the conversion of the IAN-R1 Research Reactor from MTR-HEU fuel to TRIGA-LEU fuel. In order to remove the spent MTR-HEU fuel of the core and store it safely a program was established at the Instituto de Ciencias Nucleares y Energìas Alternativas (INEA). This program included training, acquisition of hardware and software, design and construction of a decay pool, transfer of the spent HEU fuel elements into the decay pool and his final transport to Savannah River in United States. In this paper are presented data of activities calculated for each relevant radionuclide present in spent MTR-HEU fuel elements of the IAN-R1 Research Reactor and the total activity. The total activity calculated takes in consideration contributions of fission, activation and actinides products. The data obtained were the base for shielding calculations for the decay pool concerning the storage of spent MTR-HEU fuel elements and the respective dosimetric evaluations in the transferring operations of fuel elements into the decay pool.

  14. Radionuclide Compositions and Total Activity of Spent MTR-HEU Fuel Elements of the IAN-R1 Research Reactor

    SciTech Connect

    Sarta, Jose A.; Castiblanco, Luis A

    2005-05-24

    With cooperation of the International Atomic Energy Agency (IAEA) and the Department of Energy (DOE) of the United States, several calculations and tasks related to the waste disposal of spent MTR fuel enriched nominally to 93% were carried out for the conversion of the IAN-R1 Research Reactor from MTR-HEU fuel to TRIGA-LEU fuel. In order to remove the spent MTR-HEU fuel of the core and store it safely a program was established at the Instituto de Ciencias Nucleares y Energias Alternativas (INEA). This program included training, acquisition of hardware and software, design and construction of a decay pool, transfer of the spent HEU fuel elements into the decay pool and his final transport to Savannah River in United States. In this paper are presented data of activities calculated for each relevant radionuclide present in spent MTR-HEU fuel elements of the IAN-R1 Research Reactor and the total activity. The total activity calculated takes in consideration contributions of fission, activation and actinides products. The data obtained were the base for shielding calculations for the decay pool concerning the storage of spent MTR-HEU fuel elements and the respective dosimetric evaluations in the transferring operations of fuel elements into the decay pool.

  15. Targeted Protein Degradation of Outer Membrane Decaheme Cytochrome MtrC Metal Reductase in Shewanella oneidensis MR-1 Measured Using Biarsenical Probe CrAsH-EDT2

    SciTech Connect

    Xiong, Yijia; Chen, Baowei; Shi, Liang; Fredrickson, Jim K.; Bigelow, Diana J.; Squier, Thomas C.

    2011-10-14

    Development of efficient microbial biofuel cells requires an ability to exploit interfacial electron transfer reactions to external electron acceptors, such as metal oxides; such reactions occur in the facultative anaerobic gram-negative bacterium Shewanella oneidensis MR-1 through the catalytic activity of the outer membrane decaheme c-type cytochrome MtrC. Central to the utility of this pathway to synthetic biology is an understanding of cellular mechanisms that maintain optimal MtrC function, cellular localization, and renewal by degradation and resynthesis. In order to monitor trafficking to the outer membrane, and the environmental sensitivity of MtrC, we have engineered a tetracysteine tag (i.e., CCPGCC) at its C-terminus that permits labeling by the cell impermeable biarsenical fluorophore, carboxy-FlAsH (CrAsH) of MtrC at the surface of living Shewanella oneidensis MR-1 cells. In comparison, the cell permeable reagent FlAsH permits labeling of the entire population of MtrC, including proteolytic fragments resulting from incorrect maturation. We demonstrate specific labeling by CrAsH of engineered MtrC which is dependent on the presence of a functional type-2 secretion system (T2S), as evidenced by T2S system gspD or gspG deletion mutants which are incapable of CrAsH labeling. Under these latter conditions, MtrC undergoes proteolytic degradation to form a large 35-38 kDa fragment; this degradation product is also resolved during normal turnover of the CrAsH-labeled MtrC protein. No MtrC protein is released into the medium during turnover, suggesting the presence of cellular turnover systems involving MtrC reuptake and degradation. The mature MtrC localized on the outer membrane is a long-lived protein, with a turnover rate of 0.043 hr-1 that is insensitive to O2 concentration. Maturation of MtrC is relatively inefficient, with substantial rates of turnover of the immature protein prior to export to the outer membrane (i.e., 0.028 hr-1) that are consistent

  16. MpeR regulates the mtr efflux locus in Neisseria gonorrhoeae and modulates antimicrobial resistance by an iron-responsive mechanism.

    PubMed

    Mercante, Alexandra Dubon; Jackson, Lydgia; Johnson, Paul J T; Stringer, Virginia A; Dyer, David W; Shafer, William M

    2012-03-01

    Previous studies have shown that the MpeR transcriptional regulator produced by Neisseria gonorrhoeae represses the expression of mtrF, which encodes a putative inner membrane protein (MtrF). MtrF works as an accessory protein with the Mtr efflux pump, helping gonococci to resist high levels of diverse hydrophobic antimicrobials. Regulation of mpeR has been reported to occur by an iron-dependent mechanism involving Fur (ferric uptake regulator). Collectively, these observations suggest the presence of an interconnected regulatory system in gonococci that modulates the expression of efflux pump protein-encoding genes in an iron-responsive manner. Herein, we describe this connection and report that levels of gonococcal resistance to a substrate of the mtrCDE-encoded efflux pump can be modulated by MpeR and the availability of free iron. Using microarray analysis, we found that the mtrR gene, which encodes a direct repressor (MtrR) of mtrCDE, is an MpeR-repressed determinant in the late logarithmic phase of growth when free iron levels would be reduced due to bacterial consumption. This repression was enhanced under conditions of iron limitation and resulted in increased expression of the mtrCDE efflux pump operon. Furthermore, as judged by DNA-binding analysis, MpeR-mediated repression of mtrR was direct. Collectively, our results indicate that both genetic and physiologic parameters (e.g., iron availability) can influence the expression of the mtr efflux system and modulate levels of gonococcal susceptibility to efflux pump substrates. PMID:22214775

  17. Studies of mixed HEU-LEU-MTR cores using 3D models

    SciTech Connect

    Haenggi, P.; Lehmann, E.; Hammer, J.; Christen, R.

    1997-08-01

    Several different core loadings were assembled at the SAPHIR research reactor in Switzerland combining the available types of MTR-type fuel elements, consisting mainly of both HEU and LEU fuel. Bearing in mind the well known problems which can occur in such configurations (especially power peaking), investigations have been carried out for each new loading with a 2D neutron transport code (BOXER). The axial effects were approximated by a global buckling value and therefore the radial effects could be studied in considerably detail. Some of the results were reported at earlier RERTR meetings and were compared to those obtained by other methods and with experimental values. For the explicit study of the third dimension of the core, another code (SILWER), which has been developed in PSI for LWR power plant cores, has been selected. With the help of an adapted model for the MTR-core of SAPHIR, several important questions have been addressed. Among other aspects, the estimation of the axial contribution to the hot channel factors, the influence of the control rod position and of the Xe-poisoning on the power distribution were studied. Special attention was given to a core position where a new element was assumed placed near a empty, water filled position. The comparison of elements of low and high enrichments at this position was made in terms of the induced power peaks, with explicit consideration of axial effects. The program SILWER has proven to be applicable to MTR-cores for the investigation of axial effects. For routine use as for the support of reactor operation, this 3D code is a good supplement to the standard 2D model.

  18. The use of experimental data in an MTR-type nuclear reactor safety analysis

    NASA Astrophysics Data System (ADS)

    Day, Simon E.

    Reactivity initiated accidents (RIAs) are a category of events required for research reactor safety analysis. A subset of this is unprotected RIAs in which mechanical systems or human intervention are not credited in the response of the system. Light-water cooled and moderated MTR-type ( i.e., aluminum-clad uranium plate fuel) reactors are self-limiting up to some reactivity insertion limit beyond which fuel damage occurs. This characteristic was studied in the Borax and Spert reactor tests of the 1950s and 1960s in the USA. This thesis considers the use of this experimental data in generic MTR-type reactor safety analysis. The approach presented herein is based on fundamental phenomenological understanding and uses correlations in the reactor test data with suitable account taken for differences in important system parameters. Specifically, a semi-empirical approach is used to quantify the relationship between the power, energy and temperature rise response of the system as well as parametric dependencies on void coefficient and the degree of subcooling. Secondary effects including the dependence on coolant flow are also examined. A rigorous curve fitting approach and error assessment is used to quantify the trends in the experimental data. In addition to the initial power burst stage of an unprotected transient, the longer term stability of the system is considered with a stylized treatment of characteristic power/temperature oscillations (chugging). A bridge from the HEU-based experimental data to the LEU fuel cycle is assessed and outlined based on existing simulation results presented in the literature. A cell-model based parametric study is included. The results are used to construct a practical safety analysis methodology for determining reactivity insertion safety limits for a light-water moderated and cooled MTR-type core.

  19. MTR, TRA603. FIRST FLOOR PLAN. REACTOR AT CENTER. TWENTYMETER CHOPPER ...

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

    MTR, TRA-603. FIRST FLOOR PLAN. REACTOR AT CENTER. TWENTY-METER CHOPPER HOUSE. COFFIN TURNING ROLLS. REMOVABLE PANEL OVER CANAL ON EAST SIDE. NEW PLUG STORAGE ACCESS. DOOR SCHEDULE INDICATES STEEL (FOR VAULT), WIRE MESH, AND HOLLOW METAL TYPES. STORAGE AND ISSUE ROOM. SAFETY SHOWERS. DOORWAY TO WING, TRA-604. BLAW-KNOX 3150-803-2, 7/1950. INL INDEX NO. 531-0603-00-098-100561, REV. 10. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  20. MTR WING, TRA604. ONE OF THE LABORATORY UNITS ALONG THE ...

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

    MTR WING, TRA-604. ONE OF THE LABORATORY UNITS ALONG THE SOUTH SIDE WALL. NOTE SINK, CABINET, TABLE, AND HOOD UNITS. DUCT ABOVE RECEIVES CONTAMINATED AIR AND SENDS IT TO FAN HOUSE AND STACK. NOTE PARTITION WALL BEHIND WORK UNITS. THE HEALTH PHYSICS LAB WAS SIMILARLY EQUIPPED. WINDOW AT LEFT EDGE OF VIEW. CARD IN LOWER RIGHT WAS INSERTED BY INL PHOTOGRAPHER TO COVER AN OBSOLETE SECURITY RESTRICTION PRINTED ON ORIGINAL NEGATIVE. INL NEGATIVE NO. 4225. Unknown Photographer, 2/13/1952 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  1. MTR, TRA603. LONGITUDINAL SECTION SHOWS EAST/WEST SECTION AND PROJECTION OF ...

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

    MTR, TRA-603. LONGITUDINAL SECTION SHOWS EAST/WEST SECTION AND PROJECTION OF CANAL BEYOND EAST WALL OF BUILDING; PIPE TUNNEL, BULKHEAD LOCATIONS IN CANAL, SWING-OUT ISOLATION GATE, TUNNEL HATCH UNDER ROADWAY; SUB-PILE AND RABBIT CANAL SECTIONS; BALCONY CONTROL AND INSTRUMENT ROOMS; CATWALK, MAIN AND AUXILIARY HOISTS. AIR COMPRESSOR BUILDING (TRA-626) TO THE NORTH. BLAW-KNOX BKC-3150-3-5, 3/1950. INL INDEX NO. 531-0603-00-098-100004, REV. 7. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  2. Comparison of radioiodinated TOC, TOCA and Mtr-TOCA: the effect of carbohydration on the pharmacokinetics.

    PubMed

    Wester, Hans-Jürgen; Schottelius, Margret; Scheidhauer, Klemens; Reubi, Jean-Claude; Wolf, Ingo; Schwaiger, Markus

    2002-01-01

    Although somatostatin-based peptide receptor imaging (sst-PRI) and peptide receptor radiotherapy (sst-PRRT) of human endocrine tumours and their metastases has become a valuable method, the experience with radiohalogenated sst-directed peptides has so far been disappointing. To extend the broad spectrum of radiohalogens with suitable radionuclide properties for sst-PRI and PRRT, new strategies in ligand development are required. The major drawbacks to be overcome include fast hepatic uptake, high abdominal background activity and low tumour uptake. Recently we introduced radiolabelled glycated octreotides as a new series of sst-binding radiotracers with excellent physicochemical characteristics. In this study we compared [(125)I]Tyr(3)-octreotide ([(125)I]TOC, ( 1)), [(125)I]Tyr(3)-octreotate ([(125)I]TOCA, ( 2)) and a carbohydrated octreotide derivative, maltotriose-[(125)I]Tyr(3)-octreotate ([(125)I]Mtr-TOCA, ( 3)) to evaluate the effect of single C-terminal oxidation and simultaneous N-terminal carbohydration. The biodistribution was compared in nude mice bearing AR42J tumour xenografts. Compared with ( 1), activity uptake of ( 2) and ( 3) at 1 h was decreased in intestine [36% ( 2), 72% ( 3)], liver [62% ( 2), 79% ( 3)] and kidney [34% ( 2), 41% ( 3)], respectively. Blood clearance was fast for all compounds investigated. Using ( 1) as reference, tumour uptake of ( 2) and ( 3) was 3.8- and 4.3-fold higher at 1 h p.i. At 1 h the tumour-to-blood ratio of ( 3) was 28.2+/-7.3, and the tumour-to-muscle ratio, 147+/-48. Specificity of tumour uptake was demonstrated in AR42J tumour-bearing mice by pretreatment with 0.8 mg TOC/kg 5 min prior to injection of ( 3). In cells transfected with sst1-sst5, the binding profile of I-Mtr-TOCA revealed a very high affinity and selectivity for sst2. In a first scintigraphic [(123)I]Mtr-TOCA study of a patient with a carcinoid of the small intestine with known peritoneal carcinomatosis and a solitary liver metastasis, all tumour

  3. WATER PROCESS SYSTEM FLOW DIAGRAM FOR MTR, TRA603. SUMMARY OF ...

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

    WATER PROCESS SYSTEM FLOW DIAGRAM FOR MTR, TRA-603. SUMMARY OF COOLANT FLOW FROM WORKING RESERVOIR TO INTERIOR OF REACTOR'S THERMAL SHIELD. NAMES TANK SECTIONS. PIPE AND DRAIN-LINE SIZES. SHOWS DIRECTION OF AIR FLOW THROUGH PEBBLE AND GRAPHITE BLOCK ZONE. NEUTRON CURTAIN AND THERMAL COLUMN DOOR. BLAW-KNOX 3150-92-7, 3/1950. INL INDEX NO. 531-0603-51-098-100036, REV. 6. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  4. MTR4, a putative RNA helicase and exosome co-factor, is required for proper rRNA biogenesis and development in Arabidopsis thaliana.

    PubMed

    Lange, Heike; Sement, François M; Gagliardi, Dominique

    2011-10-01

    The exosome is a conserved protein complex that is responsible for essential 3'→5' RNA degradation in both the nucleus and the cytosol. It is composed of a nine-subunit core complex to which co-factors confer both RNA substrate recognition and ribonucleolytic activities. Very few exosome co-factors have been identified in plants. Here, we have characterized a putative RNA helicase, AtMTR4, that is involved in the degradation of several nucleolar exosome substrates in Arabidopsis thaliana. We show that AtMTR4, rather than its closely related protein HEN2, is required for proper rRNA biogenesis in Arabidopsis. AtMTR4 is mostly localized in the nucleolus, a subcellular compartmentalization that is shared with another exosome co-factor, RRP6L2. AtMTR4 and RRP6L2 cooperate in several steps of rRNA maturation and surveillance, such as processing the 5.8S rRNA and removal of rRNA maturation by-products. Interestingly, degradation of the Arabidopsis 5' external transcribed spacer (5' ETS) requires cooperation of both the 5'→3' and 3'→5' exoribonucleolytic pathways. Accumulating AtMTR4 targets give rise to illegitimate small RNAs; however, these do not affect rRNA metabolism or contribute to the phenotype of mtr4 mutants. Plants lacking AtMTR4 are viable but show several developmental defects, including aberrant vein patterning and pointed first leaves. The mtr4 phenotype resembles that of several ribosomal protein and nucleolin mutants, and may be explained by delayed ribosome biogenesis, as we observed a reduced rate of rRNA accumulation in mtr4 mutants. Taken together, these data link AtMTR4 with rRNA biogenesis and development in Arabidopsis. PMID:21682783

  5. Analysis of MTR and MTRR Polymorphisms for Neural Tube Defects Risk Association

    PubMed Central

    Wang, Yongxin; Liu, Yuan; Ji, Wenyu; Qin, Hu; Wu, Hao; Xu, Danshu; Tukebai, Turtuohut; Wang, Zengliang

    2015-01-01

    Abstract Neural tube defects (NTDs) are the most common congenital defects of the central nervous system among neonates and the folate status during pregnancy was considered as the most important etiopathogenesis of NTDs. Besides, methionine synthase (MTR) gene and methionine synthase reductase (MTRR) gene were folate metabolism involved genes and had been investigated in several previous studies with inconsistent results. Hence, we aimed to explore the association of 4 selected single-nucleotide polymorphisms (SNPs) on MTRR/MTR gene and the susceptibility of NTDs in a Chinese population. Seven SNPs were selected from HapMap databases with Haploview 4.2 software. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to genotype the polymorphisms from blood samples of 165 NTDs patients and 280 healthy controls. The correlation between these SNPs and NTDs risk was tested by Student t test and Chi-square test by STATA 11.0 software. Furthermore, we performed a meta-analysis of relevant studies to investigate the association between the SNPs MTRR 66A>G and MTR 2756A>G and the susceptibility of NTDs. An increased risk of NTDs was verified to be significantly associated with MTRR 66A>G (G allele vs. A allele: OR = 1.36 (1.03–1.80), P = 0.028; GG + AG vs. AA: OR = 1.60 (1.05–2.43), P = 0.027) and MTR 2756A>G (G allele vs. A allele: OR = 1.45 (1.06–1.98), P = 0.021; GG + AG vs. AA: OR = 1.51 (1.02–2.23), P = 0.038) in our study. However, the other SNPs in our analysis showed no significant association with NTDs risk (all P > 0.05). Furthermore, the result of the meta-analysis supported the association between MTRR 66A>G and NTDs risk (G allele vs. A allele: OR = 1.32, 95% CI = 1.09–1.61, GG + GA vs. AA: OR = 1.49, 95% CI = 1.06–2.09, GG vs. AA: OR = 1.61, 95% CI = 1.04–2.49). Our study confirmed that the MTRR 66A>G and MTR 2756A>G were significantly

  6. Mutagenesis of the C1 Oxidation Pathway in Methanosarcina barkeri: New Insights into the Mtr/Mer Bypass Pathway▿

    PubMed Central

    Welander, Paula V.; Metcalf, William W.

    2008-01-01

    A series of Methanosarcina barkeri mutants lacking the genes encoding the enzymes involved in the C1 oxidation/reduction pathway were constructed. Mutants lacking the methyl-tetrahydromethanopterin (H4MPT):coenzyme M (CoM) methyltransferase-encoding operon (Δmtr), the methylene-H4MPT reductase-encoding gene (Δmer), the methylene-H4MPT dehydrogenase-encoding gene (Δmtd), and the formyl-methanofuran:H4MPT formyl-transferase-encoding gene (Δftr) all failed to grow using either methanol or H2/CO2 as a growth substrate, indicating that there is an absolute requirement for the C1 oxidation/reduction pathway for hydrogenotrophic and methylotrophic methanogenesis. The mutants also failed to grow on acetate, and we suggest that this was due to an inability to generate the reducing equivalents needed for biosynthetic reactions. Despite their lack of growth on methanol, the Δmtr and Δmer mutants were capable of producing methane from this substrate, whereas the Δmtd and Δftr mutants were not. Thus, there is an Mtr/Mer bypass pathway that allows oxidation of methanol to the level of methylene-H4MPT in M. barkeri. The data further suggested that formaldehyde may be an intermediate in this bypass; however, no methanol dehydrogenase activity was found in Δmtr cell extracts, nor was there an obligate role for the formaldehyde-activating enzyme (Fae), which has been shown to catalyze the condensation of formaldehyde and H4MPT in vitro. Both the Δmer and Δmtr mutants were able to grow on a combination of methanol plus acetate, but they did so by metabolic pathways that are clearly distinct from each other and from previously characterized methanogenic pathways. PMID:18178739

  7. Isolation of a High-Affinity Functional Protein Complex between OmcA and MtrC: Two Outer Membrane Decaheme c-type Cytochromes of Shewanella oneidensis MR-1

    SciTech Connect

    Shi, Liang; Chen, Baowei; Wang, Zheming; Elias, Dwayne A.; Mayer, M. Uljana; Gorby, Yuri A.; Ni, Shuisong; Lower, Brian H.; Kennedy, David W.; Wunschel, David S.; Mottaz, Heather M.; Marshall, Matthew J.; Hill, Eric A.; Beliaev, Alex S.; Zachara, John M.; Fredrickson, Jim K.; Squier, Thomas C.

    2006-07-01

    SUMMARY Shewanella oneidensis MR-1 is a facultatively anaerobic bacterium that is capable of using insoluble oxidized metals, such as manganese [Mn(III, IV)] and iron [Fe(III)] oxides and oxyhydroxides, as terminal electron acceptors during anaerobic respiration. The ability of S. oneidensis MR-1 to reduce oxidized Mn and/or Fe has previously been linked to OmcA and MtrC: two decaheme c-type cytochromes that are localized to the outer membrane. To investigate how the electron transport proteins OmcA and MtrC are organized, we expressed and purified recombinant OmcA and MtrC from wild type S. oneidensis MR-1 as well as a mutant that lacked OmcA and MtrC (ΔomcA/mtrC). After purification to the nearly electrophoretic homogeneity from the ΔomcA/mtrC mutant, the recombinant OmcA and MtrC exhibited the characteristics of c-type cytochromes, and each of their polypeptides was confirmed to contain 10 hemes. When purified from wild type cells, endogenous MtrC or OmcA was always co-purified with recombinant OmcA or MtrC, respectively. Fluorescence polarization experiment showed that recombinant OmcA bound to the FlAsH-labeled MtrC with a dissociation constant of 7 ×10-7 M. The purified recombinant OmcA or MtrC alone displayed intrinsic ferric reductase activity with NADH used as an electron donor. Ferric reductase specific activity increased by 35 to 41% when nearly equimolar concentrations of OmcA and MtrC were assayed relative to the two proteins assayed independently. These results demonstrate that OmcA and MtrC directly interact with each other to form a stable complex with high ferric reductase activity.

  8. FarR regulates the farAB-encoded efflux pump of Neisseria gonorrhoeae via an MtrR regulatory mechanism.

    PubMed

    Lee, E-H; Rouquette-Loughlin, C; Folster, J P; Shafer, W M

    2003-12-01

    The farAB operon of Neisseria gonorrhoeae encodes an efflux pump which mediates gonococcal resistance to antibacterial fatty acids. It was previously observed that expression of the farAB operon was positively regulated by MtrR, which is a repressor of the mtrCDE-encoded efflux pump system (E.-H. Lee and W. M. Shafer, Mol. Microbiol. 33:839-845, 1999). This regulation was believed to be indirect since MtrR did not bind to the farAB promoter. In this study, computer analysis of the gonococcal genome sequence database, lacZ reporter fusions, and gel mobility shift assays were used to elucidate the regulatory mechanism by which expression of the farAB operon is modulated by MtrR in gonococci. We identified a regulatory protein belonging to the MarR family of transcriptional repressors and found that it negatively controls expression of farAB by directly binding to the farAB promoter. We designated this regulator FarR to signify its role in regulating the farAB operon. We found that MtrR binds to the farR promoter, thereby repressing farR expression. Hence, MtrR regulates farAB in a positive fashion by modulating farR expression. This MtrR regulatory cascade seems to play an important role in adjusting levels of the FarAB and MtrCDE efflux pumps to prevent their excess expression in gonococci. PMID:14645274

  9. Direct Involvement of Type II Secretion System in Extracellular Translocation of Shewanella Oneidensis Outer Membrane Cytochromes MtrC and OmcA

    SciTech Connect

    Shi, Liang; Deng, Shuang; Marshall, Matthew J.; Wang, Zheming; Kennedy, David W.; Dohnalkova, Alice; Mottaz, Heather M.; Hill, Eric A.; Gorby, Yuri A.; Beliaev, Alex S.; Richardson, David J.; Zachara, John M.; Fredrickson, Jim K.

    2008-08-01

    Outer membrane decaheme c-type cytochromes MtrC and OmcA of Shewanella oneidensis MR-1 are extracellular lipoproteins important for dissimilatory reduction of solid metal (hydr)oxides during anaerobic respiration. To investigate the roles of type II secretion system (T2S) in translocation of MtrC and OmcA across outer membrane, we measured the effects of deleting two T2S genes, gspD and gspG, on the secretion of MtrC and OmcA when cells were grown under anaerobic conditions. Deletion of gspD or gspG resulted in slightly yellowish supernatants, different from the pink supernatant of wild type (wt). Comparative proteomic analyses revealed that, although MtrC, OmcA and NrfA, a periplasmic nitrite reductase, were present the supernatants of wt and ΔgspD mutant, their peptides counts were much lower in ΔgspD than in wt. Subsequent analyses with heme-staining and Western blot not only confirmed that deletion of gspD or gspG reduced the abundances of MtrC and OmcA in the supernatants, but also revealed that the deletions consequently increased their abundances inside the cells. Complementation of ΔgspG mutant with functional GspG could reverse the effects of deleting gspG on the colors of the supernatants and the abundances of MtrC and OmcA. In contrast, Western results showed that the abundance of NrfA was reduced in the supernatant and the cells of ΔgspD mutant, suggesting that reduced NrfA in the periplasm, where MtrC and OmcA were accumulated, contributed to its reduction in the supernatant. Thus, our results demonstrate at the first time that T2S facilitates translocation of MtrC and OmcA across outer membrane.

  10. Characterization of Shewanella oneidensis MtrC: a cell-surface decaheme cytochrome involved in respiratory electron transport to extracellular electron acceptors

    SciTech Connect

    Hartshorne, Robert S.; Jepson, Brian N.; Clarke, Thomas A.; Field, Sarah J.; Fredrickson, Jim K.; Zachara, John M.; Shi, Liang; Butt, Julea N.; Richardson, David

    2007-09-04

    Abstract MtrC is a decaheme c-type cytochrome associated with the outer cell membrane of Fe(III)-respiring species of the Shewanella genus. It is proposed to play a role in anaerobic respiration by mediating electron transfer to extracellular mineral oxides that can serve as terminal electron acceptors. The present work presents the first spectropotentiometric and voltammetric characterization of MtrC, using protein purified from Shewanella oneidensis MR-1. Potentiometric titrations, monitored by UV–vis absorption and electron paramagnetic resonance (EPR) spectroscopy, reveal that the hemes within MtrC titrate over a broad potential range spanning between approximately +100 and approximately *500 mV (vs. the standard hydrogen electrode). Across this potential window the UV– vis absorption spectra are characteristic of low-spin c-type hemes and the EPR spectra reveal broad, complex features that suggest the presence of magnetically spin-coupled lowspin c-hemes. Non-catalytic protein film voltammetry of MtrC demonstrates reversible electrochemistry over a potential window similar to that disclosed spectroscopically. The voltammetry also allows definition of kinetic properties of MtrC in direct electron exchange with a solid electrode surface and during reduction of a model Fe(III) substrate. Taken together, the data provide quantitative information on the potential domain in which MtrC can operate.

  11. Structural characterization of the principal mRNA-export factor Mex67–Mtr2 from Chaetomium thermophilum

    SciTech Connect

    Aibara, Shintaro; Valkov, Eugene; Lamers, Meindert H.; Dimitrova, Lyudmila; Hurt, Ed; Stewart, Murray

    2015-06-27

    The crystal structures of the individual domains of the Mex67–Mtr2 complex from C. thermophilum have been determined and their arrangement in solution has been studied by SAXS. Members of the Mex67–Mtr2/NXF–NXT1 family are the principal mediators of the nuclear export of mRNA. Mex67/NXF1 has a modular structure based on four domains (RRM, LRR, NTF2-like and UBA) that are thought to be present across species, although the level of sequence conservation between organisms, especially in lower eukaryotes, is low. Here, the crystal structures of these domains from the thermophilic fungus Chaetomium thermophilum are presented together with small-angle X-ray scattering (SAXS) and in vitro RNA-binding data that indicate that, not withstanding the limited sequence conservation between different NXF family members, the molecules retain similar structural and RNA-binding properties. Moreover, the resolution of crystal structures obtained with the C. thermophilum domains was often higher than that obtained previously and, when combined with solution and biochemical studies, provided insight into the structural organization, self-association and RNA-binding properties of Mex67–Mtr2 that facilitate mRNA nuclear export.

  12. Electrochemical interaction of Shewanella oneidensis MR-1 and its outer membrane cytochromes OmcA and MtrC with hematite electrodes

    SciTech Connect

    Meitl, Leisa A.; Eggleston, Carrick M.; Colberg, Patricia J.; Khare, Nidhi; Reardon, Catherine L.; Shi, Liang

    2009-09-15

    Bacterial metal reduction is an important biogeochemical process in anaerobic environments. An understanding of electron transfer pathways from dissimilatory metal reducing bacteria (DMRB) to solid phase metal (hydr)oxides is important for understanding metal redox cycling in soils and sediments, for utilizing DMRB in bioremedation, and for developing technologies such as microbial fuel cells. Here we hypothesize that the outer membrane cytochromes OmcA and MtrC from Shewanella oneidensis MR-1 are the only terminal reductases capable of direct electron transfer to a hematite working electrode. Cyclic voltammetry (CV) was used to study electron transfer between hematite electrodes and protein films, S. oneidensis MR-1 wild-type cell suspensions, and cytochrome deletion mutants. After controlling for hematite electrode dissolution at negative potential, the midpoint potentials of adsorbed OmcA and MtrC were measured (-201 mV and -163 mV vs. Ag/AgCl, respectively). Cell suspensions of wild-type MR-1, deletion mutants deficient in OmcA (ΔomcA), MtrC (ΔmtrC), and both OmcA and MtrC (ΔmtrC-ΔomcA) were also studied; voltammograms for ΔmtrC-ΔomcA were indistinguishable from the control. When the control was subtracted from the single deletion mutant voltammograms, redox peaks were consistent with the present cytochrome (i.e., ΔomcA consistent with MtrC and ΔmtrC consistent with OmcA). The results indicate that OmcA and MtrC are capable of direct electron exchange with hematite electrodes, consistent with a role as terminal reductases in the S. oneidensis MR-1 anaerobic respiratory pathway involving ferric minerals. There was no evidence for other terminal reductases operating under the conditions investigated. A Marcus-based approach to electron transfer kinetics indicated that the rate constant for electron transfer ket varies from 0.025 s-1 in the absence of a barrier to 63.5 s-1 with a 0.2 eV barrier.

  13. Genetic Variant in MTRR, but Not MTR, Is Associated with Risk of Congenital Heart Disease: An Integrated Meta-Analysis

    PubMed Central

    Zhong, Rong; Zou, Li; Zhu, Beibei; Chen, Wei; Shen, Na; Ke, Juntao; Lou, Jiao; Wang, Zhenling; Sun, Yu; Liu, Lifeng; Song, Ranran

    2014-01-01

    Background Congenital heart disease (CHD) is one of the most common birth defects and the leading cause of deaths among individuals with congenital structural abnormalities worldwide. Both Methionine synthase reductase (MTRR) and Methionine synthase (MTR) are key enzymes involved in the metabolic pathway of homocysteine, which are significant in the earlier period embryogenesis, particularly in the cardiac development. Evidence is mounting for the association between MTRR A66G (rs1801394)/MTR A2756G (rs1805087) and the CHD risk, but results are controversial. Therefore, we conducted a meta-analysis integrating case-control and transmitted disequilibrium test (TDT) studies to obtain more precise estimate of the associations of these two variants with the CHD risk. Methods To combine case-control and TDT studies, we used the Catmap package of R software to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Results A total of 9 reports were included in the final meta-analysis. Eight of them comprised of 914 cases, 964 controls, and 441 families that were germane to MTRR A66G polymorphism; and 4 reports comprised of 250 cases, 205 controls, and 53 families that were relevant to MTR A2756G polymorphism. The pooled OR for the MTRR 66 G allele versus A allele was 1.35 (95% CI = 1.14–1.59, P<0.001, Pheterogeneity = 0.073). For MTR A2756G, the G allele conferred a pooled OR of 1.10 (95% CI = 0.78–1.57, P = 0.597, Pheterogeneity = 0.173) compared with the A allele. Sensitivity analyses were carried out to asses the effects of each individual study on the pooled OR, indicating the stability of the outcome. Moreover, positive results were also obtained in all subgroups stratified by study type and ethnicity except the subgroup of TDT studies in MTRR A66G variant. Conclusions This meta-analysis demonstrated a suggestive result that the A66G variant in MTRR, but not the A2756G in MTR, may be associated with the increase of CHD risks. PMID

  14. Search for polarimetric sensitivity in the first observations with THEMIS spectropolarimetric mode MTR (August 1998 campaign)

    NASA Astrophysics Data System (ADS)

    Bommier, V.; Rayrole, J.

    2002-01-01

    The present paper is devoted to the search for the polarimetric sensitivity level in observations of the Fe I 5576 Å line performed with the THEMIS spectropolarimetric mode MTR on August 23 1998. This line is insensitive to the Zeeman effect and the present work is thus useful to calibration purposes. The upper level of the line is unpolarizable (J=0) and insensitive to the Hanle effect, and the observations have been performed at disk center to avoid any scattering polarization of lower level atomic polarization origin. In the present paper, we describe the steps of a method that is the basis of a data reduction code implemented on systems at the Meudon Observatory for the interpretation of observations where a large number ( ~ 150) of images are averaged, and where the signal is in addition averaged along the slit. First, we describe the numerical methods used to determine the line position in the images, and to perform operations on the profiles by FFT techniques (such as translation, dilation, defocusing, apodization). Then, the preprocessing steps are described: dark current subtraction, destretching and flat-field correction. The polarization analysis is then performed, based on the idea that, as the flat-field images are unpolarized, they can be used to correct spurious polarization occuring in the observations. As a result, the observed line is found to be unpolarized, and a sensitivity of 2-4x 10-4 is found for the polarization degree in the neighboring continuum.

  15. Draft genome sequence of Janthinobacterium lividum strain MTR reveals its mechanism of capnophilic behavior.

    PubMed

    Valdes, Natalia; Soto, Paola; Cottet, Luis; Alarcon, Paula; Gonzalez, Alex; Castillo, Antonio; Corsini, Gino; Tello, Mario

    2015-01-01

    Janthinobacterium lividum is a Gram-negative bacterium able to produce violacein, a pigment with antimicrobial and antitumor properties. Janthinobacterium lividum colonizes the skin of some amphibians and confers protection against fungal pathogens. The mechanisms underlying this association are not well understood. In order to identify the advantages for the bacterium to colonize amphibian skin we sequenced Janthinobacterium lividum strain MTR, a strain isolated from Cajón del Maipo, Chile. The strain has capnophilic behavior, with growth favored by high concentrations (5 %) of carbon dioxide. Its genome is 6,535,606 bp in size, with 5,362 coding sequences and a G + C content of 62.37 %. The presence of genes encoding for products that participate in the carbon fixation pathways (dark CAM pathways), and the entire set of genes encoding for the enzymes of the glyoxylate cycle may explain the capnophilic behavior and allow us to propose that the CO2 secreted by the skin of amphibians is the signal molecule that guides colonization by Janthinobacterium lividum. PMID:26605004

  16. The RNA Helicases AtMTR4 and HEN2 Target Specific Subsets of Nuclear Transcripts for Degradation by the Nuclear Exosome in Arabidopsis thaliana

    PubMed Central

    Lange, Heike; Zuber, Hélène; Sement, François M.; Chicher, Johana; Kuhn, Lauriane; Hammann, Philippe; Brunaud, Véronique; Bérard, Caroline; Bouteiller, Nathalie; Balzergue, Sandrine; Aubourg, Sébastien; Martin-Magniette, Marie-Laure; Vaucheret, Hervé; Gagliardi, Dominique

    2014-01-01

    The RNA exosome is the major 3′-5′ RNA degradation machine of eukaryotic cells and participates in processing, surveillance and turnover of both nuclear and cytoplasmic RNA. In both yeast and human, all nuclear functions of the exosome require the RNA helicase MTR4. We show that the Arabidopsis core exosome can associate with two related RNA helicases, AtMTR4 and HEN2. Reciprocal co-immunoprecipitation shows that each of the RNA helicases co-purifies with the exosome core complex and with distinct sets of specific proteins. While AtMTR4 is a predominantly nucleolar protein, HEN2 is located in the nucleoplasm and appears to be excluded from nucleoli. We have previously shown that the major role of AtMTR4 is the degradation of rRNA precursors and rRNA maturation by-products. Here, we demonstrate that HEN2 is involved in the degradation of a large number of polyadenylated nuclear exosome substrates such as snoRNA and miRNA precursors, incompletely spliced mRNAs, and spurious transcripts produced from pseudogenes and intergenic regions. Only a weak accumulation of these exosome substrate targets is observed in mtr4 mutants, suggesting that MTR4 can contribute, but plays rather a minor role for the degradation of non-ribosomal RNAs and cryptic transcripts in Arabidopsis. Consistently, transgene post-transcriptional gene silencing (PTGS) is marginally affected in mtr4 mutants, but increased in hen2 mutants, suggesting that it is mostly the nucleoplasmic exosome that degrades aberrant transgene RNAs to limit their entry in the PTGS pathway. Interestingly, HEN2 is conserved throughout green algae, mosses and land plants but absent from metazoans and other eukaryotic lineages. Our data indicate that, in contrast to human and yeast, plants have two functionally specialized RNA helicases that assist the exosome in the degradation of specific nucleolar and nucleoplasmic RNA populations, respectively. PMID:25144737

  17. Solution-Based Structural Analysis of the Decaheme Cytochrome, MtrA, by Small-Angle X-ray Scattering and Analytical Ultracentrifugation

    PubMed Central

    2011-01-01

    The potential exploitation of metal-reducing bacteria as a means for environmental cleanup or alternative fuel is an exciting prospect; however, the cellular processes that would allow for these applications need to be better understood. MtrA is a periplasmic decaheme c-type cytochrome from Shewanella oneidensis involved in the reduction of extracellular iron oxides and therefore is a critical element in Shewanella ability to engage in extracellular charge transfer. As a relatively small 333-residue protein, the heme content is surprisingly high. MtrA is believed to obtain electrons from the inner membrane-bound quinol oxidoreductase, CymA, and shuttle them across the outer membrane to MtrC, another decaheme cytochrome that directly interacts with insoluble metal oxides. How MtrA is able to perform this task is a question of interest. Here through the use of two solution-based techniques, small-angle X-ray scattering (SAXS) and analytical ultracentrifugation (AUC), we present the first structural analysis of MtrA. Our results establish that between 0.5 and 4 mg/mL, MtrA exists as a monomeric protein that is shaped like an extended molecular “wire” with a maximum protein dimension (Dmax) of 104 Å and a rod-like aspect ratio of 2.2 to 2.5. This study contributes to a greater understanding of how MtrA fulfills its role in the redox processes that must occur before electrons reach the outside of the cell. PMID:21838277

  18. Tipos de cáncer

    Cancer.gov

    Lista alfabética de todos los tipos de cáncer con enlaces a enfermedades específicas e información general sobre tratamiento, cuidados de apoyo, exámenes de detección, prevención, estudios clínicos y otros temas.

  19. Interaction of MTHFR C677T and A1298C, and MTR A2756G gene polymorphisms in breast cancer risk in a population in Northeast Brazil.

    PubMed

    de Cássia Carvalho Barbosa, Rita; da Costa, Débora Menezes; Cordeiro, Denise Ellen Francelino; Vieira, Ana Patricia Freitas; Rabenhorst, Silvia Helena Barem

    2012-11-01

    Polymorphisms in genes encoding enzymes of folate metabolism are a focus of breast cancer risk studies due of the role of these enzymes in DNA methylation, synthesis, and repair. MTHFR, encoding for 5,10-methylenetetrahydrofolate reductase, is one of the most studied genes in this regard, but findings are controversial, and the majority of studies have analyzed polymorphisms individually. In this case control study, we examined the combination of the polymorphisms MTHFR C677T and A1298C with MTR A2756G, where MTR, methionine synthase, is an important enzyme of the folate cycle in the methylation pathway. One hundred and forty-two patients with breast cancer and controls were included and the genotypes were determined using PCR-RFLP. In the population studied, individuals carrying the polymorphic allele in the heterozygous state for both enzymes, MTHFR C677T and MTR A2756G, had an increased risk [odds ratio, OR=2.77 (95% confidence interval, CI=1.19-6.52)] for disease, compared to those with the wild genotype. In addition, individuals carrying the MTR 2756 genotype AG had an increased risk when this was combined with the MTHFR 1298 genotype CC [OR=5.13 (95% CI=0.87-38.82)]. No significant results were found from the analyses associating the MTHFR C677T and A1298C genotypes. However, when stratifying the patients by age (50 years old as the cut-off), patients over 50 years old had greater risk, with the presence of both MTHFR polymorphisms in the heterozygous state [OR=5.33 (95% CI=1.42-21.03)]. This study points out the importance of the interactions between the MTHFR C677T, MTHFR A1298C and MTR A2756G polymorphisms, and also highlights the relevance of the MTR A2756G polymorphism and age in breast cancer risk. PMID:23155246

  20. Specific Bonds between an Iron Oxide Surface and Outer Membrane Cytochromes MtrC and OmcA from Shewanella oneidensis MR-1

    SciTech Connect

    Lower, Brian H.; Shi, Liang; Yongsunthon, Ruchirej; Droubay, Timothy C.; Mccready, David E.; Lower, Steven

    2007-07-31

    Shewanella oneidensis MR-1 is purported to express outer membrane cytochromes (e.g., MtrC and OmcA) that transfer electrons directly to Fe(III) in a mineral during anaerobic respiration.  A prerequisite for this type of reaction would be the formation of a stable bond between a cytochrome and an iron oxide surface.  Atomic force microscopy (AFM) was used to detect whether a specific bond forms between a hematite (Fe2O3) thin film, created with oxygen plasma assisted molecular beam epitaxy (MBE), and recombinant MtrC or OmcA molecules coupled to gold substrates.  Force spectra displayed a unique force signature indicative of a specific bond between each cytochrome and the hematite surface.  The strength of the OmcA-hematite bond was approximately twice as strong as the MtrC-hematite bond, but direct binding to hematite was twice as favorable for MtrC.  Reversible folding/unfolding reactions were observed for mechanically denatured MtrC molecules bound to hematite.  The force measurements for the hematite-cytochrome pairs were compared to spectra collected between an iron oxide and S. oneidensis under anaerobic conditions.  There is a strong correlation between the whole cell and pure protein force spectra suggesting that the unique binding attributes of each cytochrome complement one another and allow both MtrC and OmcA to play a prominent role in the transfer of electrons to Fe(III) in minerals.  Finally, by comparing the magnitude of binding force for the whole cell vs. pure protein data, we were able to estimate that a single bacterium of S. oneidensis (2 x 0.5 μm) expresses ~104 cytochromes on its outer surface. 

  1. Characterization of Axial and Proximal Histidine Mutations of the Decaheme Cytochrome MtrA from Shewanella sp. Strain ANA-3 and Implications for the Electron Transport System

    PubMed Central

    Qian, Fang; Zhang, Alissa; Bondarev, Sergey; Welch, Angel; Thelen, Michael P.

    2012-01-01

    Extracellular respiration of solid-phase electron acceptors in some microorganisms requires a complex chain of multiheme c-type cytochromes that span the inner and outer membranes. In Shewanella species, MtrA, an ∼35-kDa periplasmic decaheme c-type cytochrome, is an essential component for extracellular respiration of iron(III). The exact mechanism of electron transport has not yet been resolved, but the arrangement of the polypeptide chain may have a strong influence on the capability of the MtrA cytochrome to transport electrons. The iron hemes of MtrA are bound to its polypeptide chain via proximal (CXXCH) and distal histidine residues. In this study, we show the effects of mutating histidine residues of MtrA to arginine on protein expression and extracellular respiration using Shewanella sp. strain ANA-3 as a model organism. Individual mutations to six out of nine proximal histidines in CXXCH of MtrA led to decreased protein expression. However, distal histidine mutations resulted in various degrees of protein expression. In addition, the effects of histidine mutations on extracellular respiration were tested using ferrihydrite and current production in microbial fuel cells. These results show that proximal histidine mutants were unable to reduce ferrihydrite. Mutations to the distal histidine residues resulted in various degrees of ferrihydrite reduction. These findings indicate that mutations to the proximal histidine residues affect MtrA expression, leading to loss of extracellular respiration ability. In contrast, mutations to the distal histidine residues are less detrimental to protein expression, and extracellular respiration can proceed. PMID:22923588

  2. Specific bonds between an iron oxide surface and outer membrane cytochromes MtrC and OmcA from Shewanella oneidensis MR-1.

    PubMed

    Lower, Brian H; Shi, Liang; Yongsunthon, Ruchirej; Droubay, Timothy C; McCready, David E; Lower, Steven K

    2007-07-01

    Shewanella oneidensis MR-1 is purported to express outer membrane cytochromes (e.g., MtrC and OmcA) that transfer electrons directly to Fe(III) in a mineral during anaerobic respiration. A prerequisite for this type of reaction would be the formation of a stable bond between a cytochrome and an iron oxide surface. Atomic force microscopy (AFM) was used to detect whether a specific bond forms between a hematite (Fe(2)O(3)) thin film, created with oxygen plasma-assisted molecular beam epitaxy, and recombinant MtrC or OmcA molecules coupled to gold substrates. Force spectra displayed a unique force signature indicative of a specific bond between each cytochrome and the hematite surface. The strength of the OmcA-hematite bond was approximately twice that of the MtrC-hematite bond, but direct binding to hematite was twice as favorable for MtrC. Reversible folding/unfolding reactions were observed for mechanically denatured MtrC molecules bound to hematite. The force measurements for the hematite-cytochrome pairs were compared to spectra collected for an iron oxide and S. oneidensis under anaerobic conditions. There is a strong correlation between the whole-cell and pure-protein force spectra, suggesting that the unique binding attributes of each cytochrome complement one another and allow both MtrC and OmcA to play a prominent role in the transfer of electrons to Fe(III) in minerals. Finally, by comparing the magnitudes of binding force for the whole-cell versus pure-protein data, we were able to estimate that a single bacterium of S. oneidensis (2 by 0.5 microm) expresses approximately 10(4) cytochromes on its outer surface. PMID:17468239

  3. Specific Bonds between an Iron Oxide Surface and Outer Membrane Cytochromes MtrC and OmcA from Shewanella oneidensis MR-1▿

    PubMed Central

    Lower, Brian H.; Shi, Liang; Yongsunthon, Ruchirej; Droubay, Timothy C.; McCready, David E.; Lower, Steven K.

    2007-01-01

    Shewanella oneidensis MR-1 is purported to express outer membrane cytochromes (e.g., MtrC and OmcA) that transfer electrons directly to Fe(III) in a mineral during anaerobic respiration. A prerequisite for this type of reaction would be the formation of a stable bond between a cytochrome and an iron oxide surface. Atomic force microscopy (AFM) was used to detect whether a specific bond forms between a hematite (Fe2O3) thin film, created with oxygen plasma-assisted molecular beam epitaxy, and recombinant MtrC or OmcA molecules coupled to gold substrates. Force spectra displayed a unique force signature indicative of a specific bond between each cytochrome and the hematite surface. The strength of the OmcA-hematite bond was approximately twice that of the MtrC-hematite bond, but direct binding to hematite was twice as favorable for MtrC. Reversible folding/unfolding reactions were observed for mechanically denatured MtrC molecules bound to hematite. The force measurements for the hematite-cytochrome pairs were compared to spectra collected for an iron oxide and S. oneidensis under anaerobic conditions. There is a strong correlation between the whole-cell and pure-protein force spectra, suggesting that the unique binding attributes of each cytochrome complement one another and allow both MtrC and OmcA to play a prominent role in the transfer of electrons to Fe(III) in minerals. Finally, by comparing the magnitudes of binding force for the whole-cell versus pure-protein data, we were able to estimate that a single bacterium of S. oneidensis (2 by 0.5 μm) expresses ∼104 cytochromes on its outer surface. PMID:17468239

  4. Deletion of mtrC in Haemophilus ducreyi Increases Sensitivity to Human Antimicrobial Peptides and Activates the CpxRA Regulon ▿

    PubMed Central

    Rinker, Sherri D.; Trombley, Michael P.; Gu, Xiaoping; Fortney, Kate R.; Bauer, Margaret E.

    2011-01-01

    Haemophilus ducreyi resists killing by antimicrobial peptides encountered during human infection, including cathelicidin LL-37, α-defensins, and β-defensins. In this study, we examined the role of the proton motive force-dependent multiple transferable resistance (MTR) transporter in antimicrobial peptide resistance in H. ducreyi. We found a proton motive force-dependent effect on H. ducreyi's resistance to LL-37 and β-defensin HBD-3, but not α-defensin HNP-2. Deletion of the membrane fusion protein MtrC rendered H. ducreyi more sensitive to LL-37 and human β-defensins but had relatively little effect on α-defensin resistance. The mtrC mutant 35000HPmtrC exhibited phenotypic changes in outer membrane protein profiles, colony morphology, and serum sensitivity, which were restored to wild type by trans-complementation with mtrC. Similar phenotypes were reported in a cpxA mutant; activation of the two-component CpxRA regulator was confirmed by showing transcriptional effects on CpxRA-regulated genes in 35000HPmtrC. A cpxR mutant had wild-type levels of antimicrobial peptide resistance; a cpxA mutation had little effect on defensin resistance but led to increased sensitivity to LL-37. 35000HPmtrC was more sensitive than the cpxA mutant to LL-37, indicating that MTR contributed to LL-37 resistance independent of the CpxRA regulon. The CpxRA regulon did not affect proton motive force-dependent antimicrobial peptide resistance; however, 35000HPmtrC had lost proton motive force-dependent peptide resistance, suggesting that the MTR transporter promotes proton motive force-dependent resistance to LL-37 and human β-defensins. This is the first report of a β-defensin resistance mechanism in H. ducreyi and shows that LL-37 resistance in H. ducreyi is multifactorial. PMID:21444663

  5. In Vivo Identification of the Outer Membrane Protein OmcA-MtrC Interaction Network in Shewanella oneidensis MR-1 Cells Using Novel Hydrophobic Chemical Cross-Linkers

    SciTech Connect

    Zhang, Haizhen; Tang, Xiaoting; Munske, Gerhard R.; Zakharova, Natalia L.; Yang, Li; Zheng, Chunxiang; Wolff, Meagan A.; Tolic, Nikola; Anderson, Gordon A.; Shi, Liang; Marshall, Matthew J.; Fredrickson, Jim K.; Bruce, James E.

    2008-04-01

    Outer membrane (OM) cytochromes OmcA (SO1779) and MtrC (SO1778) are the integral components of electron transfer used by Shewanella oneidensis for anaerobic respiration of metal (hydr)oxides. Here the OmcA-MtrC interaction was identified in vivo using a novel hydrophobic chemical cross-linker (MRN) combined with immunoprecipitation techniques. In addition, identification of other OM proteins from the cross-linked complexes allows first visualization of the OmcA-MtrC interaction network. Further experiments on omcA and mtrC mutant cells showed OmcA plays a central role in the network interaction. For comparison, two commercial cross-linkers were also used in parallel and both resulted in fewer OM protein identifications, indicating the superior properties of MRN for identification of membrane protein interactions. Finally, comparison experiments of in vivo cross-linking and cell lysate cross-linking resulted in significantly different protein interaction data, demonstrating the importance of in vivo cross-linking for study of protein-protein interactions in cells.

  6. Role of Outer-Membrane Cytochromes MtrC and OmcA in the Biomineralization of Ferrihydrite by Shewanella oneidensis MR-1.

    SciTech Connect

    Reardon, Catherine L.; Dohnalkova, Alice; Nachimuthu, Ponnusamy; Kennedy, David W.; Saffarini, Daad; Arey, Bruce W.; Shi, Liang; Wang, Zheming; Moore, Dean A.; Mclean, Jeffrey S.; Moyles, Dianne M.; Marshall, Matthew J.; Zachara, John M.; Fredrickson, Jim K.; Beliaev, Alex S.

    2010-01-01

    In an effort to improve the understanding of electron transfer mechanisms at the microbe-mineral interface, Shewanella oneidensis MR-1 mutants with in-frame deletions of outer membrane cytochrome genes mtrC, omcA, or both, were characterized for the ability to reduce metal oxides using a suite of microscopic, spectroscopic, and biochemicalr techniques. The results indicate that neither MtrC nor OmcA are essential for the reduction of soluble, complexed Fe(III)-citrate or Fe(III)-NTA; however, at least one of these outer membrane cytochromes is required for the reduction of Fe(III)- and Mn(III/IV)- oxides. In vitro analysis of purified, recombinant protein demonstrated that both cytochromes transfer electrons directly to metal-oxides; however, MtrC transfers electrons at a faster rate than OmcA. Immunolocalization of MtrC and OmcA reveal that both cytochromes are surface-exposed on the cell outer-membrane and co-localize with insoluble iron precipitates when respiring ferrihydrite or cultured aerobically with Fe(III)-citrate. Additionally, during prolonged incubation, wild-type cells promoted biotransformation of ferrihydrite to vivianite [Fe3(PO4)2•8H2O] while the double cytochrome mutant was unable to form any secondary mineral phases. Collectively, our results support a role for direct electron transfer from OMCs to metal oxides by establishing their in vitro electron transfer activities, confirming the requirement of either MtrC or OmcA for in vivo reductive biomineralization of ferrihydrite, and localizing the cytochromes to the cell exterior where they can directly contact mineral substrates.

  7. The MTR 2756A>G polymorphism and maternal risk of birth of a child with Down syndrome: a case-control study and a meta-analysis.

    PubMed

    Coppedè, Fabio; Bosco, Paolo; Lorenzoni, Valentina; Migheli, Francesca; Barone, Concetta; Antonucci, Ivana; Stuppia, Liborio; Romano, Corrado; Migliore, Lucia

    2013-12-01

    Methionine synthase (MTR) is required for the conversion of homocysteine (hcy) to methionine in the one-carbon metabolic pathway. Previous studies investigating a common MTR 2756A>G polymorphism as a maternal risk factor for the birth of a child with Down syndrome (DS) are conflicting and limited by small case-control cohorts, and its contribution to circulating hcy levels is still debated. We performed a large case-control study and a meta-analysis of the literature to further address the role of MTR 2756A>G as a maternal risk factor for the birth of a child with DS. 286 mothers of a DS child (MDS) and 305 control mothers of Italian origin were included in the case-control study. Genotyping was performed by means of PCR/RFLP technique. Data on circulating levels of hcy, folates, and vitamin B12 were available for 189 MDS and 194 control mothers. The meta analysis of previous and present data involved a total of 8 studies (1,171 MDS and 1,402 control mothers). Both the case-control study and the meta-analysis showed no association of MTR 2756A>G with the maternal risk of birth of a child with DS (OR = 1.15; 95 % CI 0.85-1.55, and OR = 1.08; 95 % CI 0.93-1.25, respectively), even after stratification of the overall data available for the meta-analysis into ethnic groups. No association of the studied polymorphism with circulating levels of hcy, folates, and vitamin B12 was observed. Present data do not support a role for MTR 2756A>G as independent maternal risk factor for a DS birth. PMID:24150725

  8. Molecular Structure and Free Energy Landscape for Electron Transport in the Deca-Heme Cytochrome MtrF

    SciTech Connect

    Breuer, Marian; Zarzycki, Piotr P.; Shi, Liang; Clarke, Thomas; Edwards, Marcus; Butt, Julea N.; Richardson, David J.; Fredrickson, Jim K.; Zachara, John M.; Blumberger, Jochen; Rosso, Kevin M.

    2012-12-01

    The free energy profile for electron flow through the bacterial deca-heme cytochrome MtrF has been computed using thermodynamic integration and classical molecular dynamics. The extensive calculations on two versions of the structure help validate the method and results, because differences in the profiles can be related to differences in the charged amino acids local to specific heme groups. First estimates of reorganization free energies λ yield a range consistent with expectations for partially solvent exposed cofactors, and reveal an activation energy range surmountable for electron flow. Future work will aim at increasing the accuracy of λ with polarizable force field dynamics and quantum chemical energy gap calculations, as well as quantum chemical computation of electronic coupling matrix elements.

  9. Role of MTHFR C677T and MTR A2756G polymorphisms in thyroid and breast cancer development.

    PubMed

    Zara-Lopes, T; Gimenez-Martins, A P A; Nascimento-Filho, C H V; Castanhole-Nunes, M M U; Galbiatti-Dias, A L S; Padovani-Júnior, J A; Maniglia, J V; Francisco, J L E; Pavarino, E C; Goloni-Bertollo, E M

    2016-01-01

    Folate metabolism is essential for DNA synthesis and repair. Alterations in genes that participate in folate metabolism can be associated with several types of malignant neoplasms, including thyroid and breast cancer. In the present case-control study, we examined the association between methylenetetrahydrofolate reductase (MTHFR C677T, rs1801133) and methionine synthase (MTR A2756G, rs1805087) polymorphisms and risk for thyroid and breast cancer. Polymerase chain reaction-restriction fragment length technique was used to determine the specific genotypes in the genes of interest. Statistical analysis was performed by multiple logistic regression test. We found an association between MTHFR C677T polymorphism and risks to both thyroid (OR = 2.50; 95%CI = 1.15-5.46; P = 0.02) and breast cancer (OR = 2.53; 95%CI = 1.08-5.93; P = 0.03). Tobacco consumption and high body mass index were also associated with thyroid cancer. In addition, increased age (≥50 years) and alcohol consumption were found to be associated with breast cancer. Our results indicated that MTHFR C677T is significantly associated with thyroid and breast cancer risks. Thus, these factors may be used as potential prognostic markers for thyroid and breast cancers. PMID:27173331

  10. Association study of folate-related enzymes (MTHFR, MTR, MTRR) genetic variants with non-obstructive male infertility in a Polish population.

    PubMed

    Kurzawski, Mateusz; Wajda, Anna; Malinowski, Damian; Kazienko, Anna; Kurzawa, Rafal; Drozdzik, Marek

    2015-03-01

    Spermatogenesis is a process where an important contribution of genes involved in folate-mediated one-carbon metabolism is observed. The aim of the present study was to investigate the association between male infertility and the MTHFR (677C > T; 1298A > C), MTR (2756A > G) and MTRR (66A > G) polymorphisms in a Polish population. No significant differences in genotype or allele frequencies were detected between the groups of 284 infertile men and of 352 fertile controls. These results demonstrate that common polymorphisms in folate pathway genes are not major risk factors for non-obstructive male infertility in the Polish population. PMID:25983623

  11. Homocysteine Metabolism Gene Polymorphisms (MTHFR C677T, MTHFR A1298C, MTR A2756G and MTRR A66G) Jointly Elevate the Risk of Folate Deficiency

    PubMed Central

    Li, Wen-Xing; Dai, Shao-Xing; Zheng, Jun-Juan; Liu, Jia-Qian; Huang, Jing-Fei

    2015-01-01

    Folate deficiency is strongly associated with cardiovascular disease. We aimed to explore the joint effect of the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, methionine synthase (MTR) A2756G, and methionine synthase reductase (MTRR) A66G polymorphisms on folate deficiency in a Chinese hypertensive population. A total of 480 subjects aged 28–75 were enrolled in this study from September 2005–December 2005 from six hospitals in different Chinese regions. Known genotypes were detected by PCR-RFLP methods and serum folate was measured by chemiluminescence immunoassay. Our results showed that MTHFR 677TT and MTR 2756AG + GG were independently associated with a higher risk of folate deficiency (TT vs. CC + CT, p < 0.001 and AG + GG vs. AA p = 0.030, respectively). However, the MTHFR A1298C mutation may confer protection by elevating the serum folate level (p = 0.025). Furthermore, patients carrying two or more risk genotypes showed higher odds of folate deficiency than null risk genotype carriers, especially those carrying four risk genotypes. These findings were verified by generalized multifactor dimensionality reduction (p = 0.0107) and a cumulative effects model (p = 0.001). The results of this study have shown that interactions among homocysteine metabolism gene polymorphisms lead to dramatic elevations in the folate deficiency risk. PMID:26266420

  12. Homocysteine Metabolism Gene Polymorphisms (MTHFR C677T, MTHFR A1298C, MTR A2756G and MTRR A66G) Jointly Elevate the Risk of Folate Deficiency.

    PubMed

    Li, Wen-Xing; Dai, Shao-Xing; Zheng, Jun-Juan; Liu, Jia-Qian; Huang, Jing-Fei

    2015-08-01

    Folate deficiency is strongly associated with cardiovascular disease. We aimed to explore the joint effect of the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, methionine synthase (MTR) A2756G, and methionine synthase reductase (MTRR) A66G polymorphisms on folate deficiency in a Chinese hypertensive population. A total of 480 subjects aged 28-75 were enrolled in this study from September 2005-December 2005 from six hospitals in different Chinese regions. Known genotypes were detected by PCR-RFLP methods and serum folate was measured by chemiluminescence immunoassay. Our results showed that MTHFR 677TT and MTR 2756AG + GG were independently associated with a higher risk of folate deficiency (TT vs. CC + CT, p < 0.001 and AG + GG vs. AA p = 0.030, respectively). However, the MTHFR A1298C mutation may confer protection by elevating the serum folate level (p = 0.025). Furthermore, patients carrying two or more risk genotypes showed higher odds of folate deficiency than null risk genotype carriers, especially those carrying four risk genotypes. These findings were verified by generalized multifactor dimensionality reduction (p = 0.0107) and a cumulative effects model (p = 0.001). The results of this study have shown that interactions among homocysteine metabolism gene polymorphisms lead to dramatic elevations in the folate deficiency risk. PMID:26266420

  13. Role of outer membrane c-type cytochromes MtrC and OmcA in Shewanella oneidensis MR-1 cell production, accumulation and detachment during respiration on hematite

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The iron-reducing bacterium Shewanella oneidensis MR-1 has the capacity to contribute to iron cycling over the long term by respiring on crystalline iron oxides such as hematite when poorly crystalline phases are depleted. The ability of outer membrane cytochromes OmcA and MtrC of MR-1 to bind to an...

  14. Effects of Bio-Au Nanoparticles on Electrochemical Activity of Shewanella oneidensis Wild Type and ΔomcA/mtrC Mutant

    NASA Astrophysics Data System (ADS)

    Wu, Ranran; Cui, Li; Chen, Lixiang; Wang, Chao; Cao, Changli; Sheng, Guoping; Yu, Hanqing; Zhao, Feng

    2013-11-01

    Both Shewanella oneidensis MR-1 wild type and its mutant ΔomcA/mtrC are capable of transforming AuIII into Au nanoparticles (AuNPs). Cyclic voltammetry reveals a decrease in redox current after the wild type is exposed to AuIII but an increase in oxidation current for the mutant. The peak current of the wild type is much higher than that of the mutant before the exposure of AuIII, but lower than that of the mutant after the formation of AuNPs. This suggests that damage to the electron transfer chain in the mutant could be repaired by AuNPs to a certain extent. Spectroscopy and SDS-PAGE analysis indicate a decrease in cell protein content after the formation of AuNPs, which provides a convenient way to detect intracellular information on cells.

  15. Effects of Bio-Au Nanoparticles on Electrochemical Activity of Shewanella oneidensis Wild Type and ΔomcA/mtrC Mutant

    PubMed Central

    Wu, Ranran; Cui, Li; Chen, Lixiang; Wang, Chao; Cao, Changli; Sheng, Guoping; Yu, Hanqing; Zhao, Feng

    2013-01-01

    Both Shewanella oneidensis MR-1 wild type and its mutant ΔomcA/mtrC are capable of transforming AuIII into Au nanoparticles (AuNPs). Cyclic voltammetry reveals a decrease in redox current after the wild type is exposed to AuIII but an increase in oxidation current for the mutant. The peak current of the wild type is much higher than that of the mutant before the exposure of AuIII, but lower than that of the mutant after the formation of AuNPs. This suggests that damage to the electron transfer chain in the mutant could be repaired by AuNPs to a certain extent. Spectroscopy and SDS-PAGE analysis indicate a decrease in cell protein content after the formation of AuNPs, which provides a convenient way to detect intracellular information on cells. PMID:24264440

  16. Homocysteine Level and Mechanisms of Injury in Parkinson's Disease as Related to MTHFR, MTR, and MTHFD1 Genes Polymorphisms and L-Dopa Treatment

    PubMed Central

    Rozycka, Agata; Jagodzinski, Pawel P.; Kozubski, Wojciech; Lianeri, Margarita; Dorszewska, Jolanta

    2013-01-01

    An elevated concentration of total homocysteine (tHcy) in plasma and cerebrospinal fluid is considered to be a risk factor for Alzheimer's disease (AD) and Parkinson's disease (PD). Homocysteine (Hcy) levels are influenced by folate concentrations and numerous genetic factors through the folate cycle, however, their role in the pathogenesis of PD remains controversial. Hcy exerts a neurotoxic action and may participate in the mechanisms of neurodegeneration, such as excitotoxicity, oxidative stress, calcium accumulation, and apoptosis. Elevated Hcy levels can lead to prooxidative activity, most probably through direct interaction with N-methyl-D-aspartate (NMDA) receptors and sensitization of dopaminergic neurons to age-related dysfunction and death. Several studies have shown that higher concentration of Hcy in PD is related to long-term administration of levodopa (L-dopa). An elevation of plasma tHcy levels can also reflect deficiencies of cofactors in remethylation of Hcy to methionine (Met) (folates and vitamin B12) and in its transsulfuration to cysteine (Cys) (vitamin B6). It is believed that the increase in the concentration of Hcy in PD can affect genetic polymorphisms of the folate metabolic pathway genes, such as MTHFR (C677T, A1298C and G1793A), MTR (A2756G), and MTHFD1 (G1958A), whose frequencies tend to increase in PD patients, as well as the reduced concentration of B vitamins. In PD, increased levels of Hcy may lead to dementia, depression and progression of the disease. PMID:24532985

  17. Role of Outer Membrane C-Type Cytochromes MtrC and OmcA in Shewanella Oneidensis MR-1 Cell Production, Accumulation, and Detachment During Respiration on Hematite

    SciTech Connect

    Mitchell, Andrew C.; Peterson, L.; Reardon, Catherine L.; Reed, Samantha B.; Culley, David E.; Romine, Margaret F.; Geesey, Gill G.

    2012-07-01

    Solid phase iron oxides are considered to be important terminal electron acceptors for microbial respiration in many anoxic environments. Besides the knowledge that cells attach to and reduce these substrates, other aspects of surface-associated cell behavior and the related cell surface components that influence cell-mineral interactions are not well understood. In the present study, wild-type cells of the dissimilatory iron-reducing bacterium Shewanella oneidensis MR-1 formed thin biofilms one-to-two cell layers in thickness when respiring on natural specular hematite under flow conditions similar to those which exist in aquatic sediments and subsurface environments. The distribution of cells within the biofilm indicated that direct contact was not required for electron transfer from cells to the mineral surface. Detached biomass in the form of single cells represented >99% of the surface-associated wild-type cell production from respiration on hematite over the biofilm life cycle. A mutant deficient in the outer membrane c35 type cytochrome OmcA, while still able to respire and replicate on hematite, established a lower steady-state cell density on the mineral surface than that of the wild-type strain. A mutant deficient in MtrC, another outer membrane c-type cytochrome, and a mutant deficient in both cytochromes were unable to reduce sufficient amounts of hematite to support detectable growth on the mineral surface. When considered in the context of previous work, the results support a growing body of evidence that the relative importance of OmcA and MtrC to cell respiration and replication depends on the form of iron oxide available as terminal electron acceptor.

  18. Qué tipos hay de estudios clínicos

    Cancer.gov

    Información sobre los diversos tipos de estudios clínicos de cáncer, como son los estudios de tratamiento, de prevención, de exámenes selectivos de detección, de cuidados médicos de apoyo y de cuidados paliativos.

  19. Neisseria gonorrhoeae antimicrobial susceptibility in Barcelona: penA, ponA, mtrR, and porB mutations and NG-MAST sequence types associated with decreased susceptibility to cephalosporins.

    PubMed

    Serra-Pladevall, J; Barberá, M J; Rodriguez, S; Bartolomé-Comas, R; Roig, G; Juvé, R; Andreu, A

    2016-09-01

    The aims of this study were to determine the antimicrobial susceptibility of Neisseria gonorrhoeae (NG) in our area, to analyze the molecular mechanisms involved in cephalosporins resistance, and to undertake molecular typing of our NG strains. Antimicrobial susceptibility was determined using the Etest. The genes penA, mtrR, penB, and ponA were studied. Molecular typing was performed by N. gonorrhoeae multiantigen sequence typing. Of 329 strains analyzed in 2013, none showed high-level cephalosporin resistance, but 8.2 % had resistance to cefixime [minimum inhibitory concentration (MIC) > 0.125 μg/mL] and 0.6 % to ceftriaxone (MIC > 0.125 μg/mL). Azithromycin resistance was documented in 4.3 % and ciprofloxacin resistance in 49.2 %. Among 48 strains with an MIC ≥ 0.125 μg/mL to cefixime, 58.3 % showed the penA mosaic pattern XXXIV, 98 % a Leu → Pro substitution at position 421 of the ponA gene, 100 % amino acid changes at positions 101 and 102 of the PorB1b porin, and 87.5 % of strains an adenine deletion in the promoter region of the MtrC-D-E efflux pump. A significant difference between strains with and without decreased cephalosporin susceptibility (MIC ≥ 0.125 μg/mL) was observed for these four genes. Of the 48 strains with an MIC ≥ 0.125 μg/mL to cefixime, 43.8 % belonged to the genogroup G1407 and 27.1 % belonged to the genogroup G2400. A significant association of G1407 with decreased susceptibility (MIC ≥ 0.125 μg/mL) and G2992 with susceptibility was found, and also between G1407 and mosaic pattern XXXIV and between G2400 and A501T substitution in penA. The NG resistance rate in our area is higher than the median of Europe. We have detected the emergence of G2400, which may be a source of antimicrobial resistance. PMID:27255221

  20. Protótipo do primeiro interferômetro brasileiro - BDA

    NASA Astrophysics Data System (ADS)

    Cecatto, J. R.; Fernandes, F. C. R.; Neri, J. A. C. F.; Bethi, N.; Felipini, N. S.; Madsen, F. R. H.; Andrade, M. C.; Soares, A. C.; Alonso, E. M. B., Sawant, H. S.

    2004-04-01

    A interferometria é uma poderosa ferramenta usada para investigar estruturas espaciais de fontes astrofísicas fornecendo uma riqueza de detalhes inatingível pelas técnicas convencionais de imageamento. Em particular, a interferometria com ondas de rádio abre o horizonte de conhecimento do Universo nesta ampla banda do espectro eletromagnético, que vai de cerca de 20 kHz até centenas de GHz já próximo ao infravermelho, e que está acessível a partir de instrumentos instalados em solo. Neste trabalho, apresentamos o interferômetro designado por Arranjo Decimétrico Brasileiro (BDA). Trata-se do primeiro interferômetro a ser desenvolvido no Brasil e América Latina que já está em operação na fase de protótipo. Apresentamos o desenvolvimento realizado até o momento, o sítio de instalação do instrumento, o protótipo e os principais resultados dos testes de sua operação, as perspectivas futuras e a ciência a ser desenvolvida com o instrumento nas fases II e III. Neste trabalho é dada ênfase ao desenvolvimento, testes de operação e principais resultados do protótipo. É discutida brevemente a ciência que pode ser feita com o instrumento. Tanto os detalhes técnicos quanto os principais parâmetros estimados para o instrumento nas próximas fases de desenvolvimento e o desempenho do protótipo serão publicados em breve.

  1. Local structure of spin Peierls compound TiPO4: 47/49Ti and 31P NMR study

    NASA Astrophysics Data System (ADS)

    Stern, Raivo; Heinmaa, Ivo; Leitmäe, Alexander; Joon, Enno; Tsirlin, Alexander; Kremer, Reinhard; Glaum, Robert

    TiPO4 structure is made of slightly corrugated TiO2 ribbon chains of edge-sharing TiO6 octahedra. The almost perfect 1D spin 1/2 Ti3 + chains are well separated by PO4 tetrahedra. By magnetic susceptibility and MAS-NMR measurements [1] it was shown that TiPO4 has nonmagnetic singlet ground state with remarkably high Spin-Peierls (SP) transition temperature. The high-T magnetic susceptibility of TiPO4 follows well that of a S =1/2 Heisenberg chain with very strong nearest-neighbor AF spin-exchange coupling constant of J =965K. On cooling TiPO4 shows two successive phase transitions at 111K and 74K, with incommensurate (IC) SP phase between them. We studied local structure and dynamics in TiPO4 single crystal using 47/49Ti and 31P NMR in the temperature range 40K to 300K, and determined the principal values and orientation of the magnetic shift tensors for 31P and 47,49Ti nuclei. Since 47,49Ti (S =5/2 and S =7/2, respectively) have quadrupolar moments, we also found the principal axis values and orientations of the electric field gradient (efg) tensor in SP phase and at 295K. In SP phase the structure contains 2 magnetically inequivalent P sites and only one Ti site. From the T-dependence of the relaxation rate of 31P and 47Ti nuclei we determined activation energy Ea = 550 K for spin excitations in SP phase. J. Law et al ., PRB 83, 180414(R) (2011).

  2. Estudo de soluções locais e cosmológicas em teorias do tipo tensor-escalar

    NASA Astrophysics Data System (ADS)

    Silva E Costa, S.

    2003-08-01

    Teorias do tipo tensor-escalar são a mais simples extensão possí vel da Relatividade Geral. Nessas teorias, cujo modelo padrão é a teoria de Brans-Dicke, a curvatura do espaço-tempo, descrita por componentes tensoriais, aparece acoplada a um campo escalar que, de certo modo, representa uma variação na constante de acoplamento da gravitação. Tais teorias apresentam soluções locais e cosmológicas que, em determinados limites, recaem nas apresentadas pela Relatividade Geral, mas que em outros limites trazem novidades, tais como conseqüências observacionais da evolução de flutuações primordiais distintas daquelas previstas pela Relatividade Geral (ver, por ex., Nagata et al., PRD 66, p. 103510 (2002)). Graças a esta possibilidade de trazer à luz novidades em relação à gravitação, teorias do tipo tensor-escalar podem ser vistas como um interessante campo alternativo de pesquisas para soluções dos problemas de massa faltante (ou escura) e/ou energia escura. Seguindo tal linha, este trabalho, ainda em sua fase inicial, apresenta soluções gerais de teorias do tipo tensor-escalar para diversas situações, verificando-se em que consiste a divergência dessas soluções dos casos tradicionais possí veis na Relatividade Geral. Como exemplos das soluções aqui apresentadas pode-se destacar uma expressão geral para diferentes soluções cosmológicas englobando diferentes tipos de matéria (representados por diferentes equações de estado), e a expressão para uma solução local representando um buraco negro com rotação, similar à solução de Kerr da Relatividade Geral. Por fim, é importante ressaltar que, embora aqui apresentem-se poucos resultados novos, na literatura sobre o assunto a maior parte das soluções apresentadas limita-se a uns poucos casos especí ficos, tal como soluções cosmológicas apenas com curvatura nula, e que mesmo as soluções disponí veis são, em geral, pouco divulgadas e, portanto, pouco conhecidas, e

  3. Análise Temporal de Estruturas Morfológicas na Cauda do Tipo I do Cometa P/Halley

    NASA Astrophysics Data System (ADS)

    Voelzke, M. R.; Matsuura, O. T.

    1996-08-01

    Com base em (Brandt et al, 1992), centenas de imagens do cometa P/Halley foram visualmente analisadas, objetivando examinar possíveis perturbações magnetohidrodinâmicas ao longo da cauda do tipo I. Do total de 1439 imagens, abrangendo o período entre 16 de outubro de 1982 e 12 de fevereiro de 1991, foram escolhidas 531 do período entre 17 de setembro de 1985 e 06 de julho de 1986 por mostrarem cauda bem desenvolvida e rica de estruturas morfológicas. Nelas constatou-se a existência de 124 estruturas ondulatórias (trens de onda) ao longo da cauda principal, 27 ao longo de caudas secundárias, 109 ondas solitárias (sólitons) ao longo da cauda principal, 36 ao longo de caudas secundárias, 12 caudas do tipo Swan, 47 eventos de desconexão e 23 regiões de adensamento ("knots"). Foi examinada a correlação temporal entre esses diferentes tipos de eventos. Os de desconexão foram analisados isoladamente. Seus movimentos próprios foram calculados, bem como os seus instantes iniciais, o que nos permitiu inferir a passagem do cometa pela fronteira entre setores magnéticos distintos. A velocidade do plasma cometário desconectado foi corrigida dos efeitos de projeção e correlacionada com a distância heliocêntrica do cometa. Também foi investigada a periodicidade de ocorrência das desconexães, e constatado que sua distribuição é bimodal. Por fim, a possibilidade dos modos de propagação de ondas MHD "sausage" e "kink" superficiais ou volumétricas, é discutida no contexto das descontinuidades magnéticas tangenciais. - Brandt, J.C., Niedner Jr., M.B., Rahe, J.: The International Halley Watch Atlas of Large-Scale Phenomena. Impresso por: Johnson Printing Co, Boulder, CO. University of Colorado-Boulder, 1992.

  4. Composição química, evolução e cinemática de estrelas de tipo solar

    NASA Astrophysics Data System (ADS)

    Silva, R. O.; Porto de Mello, G. F.; Milone, A. C.

    2003-08-01

    A composição química das estrelas de tipo solar é um diagnóstico extremamente valioso da evolução química do disco da Galáxia. Existe alguma evidência de que tal evolução tem sido heterogênea no espaço e ao longo do tempo e que a composição química do Sol pode não ser um padrão representativo de abundâncias. Neste trabalho, foram obtidas as abundâncias dos elementos químicos C, N, Na, Mg, Si, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd e Sm em uma amostra de estrelas de tipo solar na vizinhança solar (distâncias £ 25 pc). A técnica empregada foi a análise espectroscópica diferencial em relação ao Sol, baseando-se em dados de alta resolução (R ~ 46.000) e alta razão sinal/ruído (S/R > 300), obtidos com o espectrógrafo échelle de bancada do telescópio de 1,5 m do CTIO. Adicionalmente, abundâncias de C e N foram obtidas através de síntese de bandas moleculares dos Sistemas Eletrônicos Swan do C2 e Vermelho do CN utilizando-se um programa de síntese espectral. Os parâmetros atmosféricos foram estabelecidos usando cores fotométricas, o equilíbrio de excitação e ionização de linhas do Fe e a análise da temperatura e da luminosidade estelares no diagrama HR. Os resultados de abundâncias químicas obtidos proporcionam uma melhor compreensão da relação das abundâncias conhecidas para o Sol com a das estrelas anãs de tipo G da população local, uma vez que as razões de abundâncias de diversos elementos (em relação ao ferro) obtidas para estrelas de metalicidade semelhante à solar diferem daquelas obtidas para o Sol. Tais resultados também contribuem para um melhor entendimento do processo de evolução química da vizinhança solar e do enriquecimento nucleossintético do disco galáctico.

  5. Evaluation of the use of nodal methods for MTR neutronic analysis

    SciTech Connect

    Reitsma, F.; Mueller, E.Z.

    1997-08-01

    Although modern nodal methods are used extensively in the nuclear power industry, their use for research reactor analysis has been very limited. The suitability of nodal methods for material testing reactor analysis is investigated with the emphasis on the modelling of the core region (fuel assemblies). The nodal approach`s performance is compared with that of the traditional finite-difference fine mesh approach. The advantages of using nodal methods coupled with integrated cross section generation systems are highlighted, especially with respect to data preparation, simplicity of use and the possibility of performing a great variety of reactor calculations subject to strict time limitations such as are required for the RERTR program.

  6. Code System for the Analysis of Material Test Reactor (MTR) Cores.

    Energy Science and Technology Software Center (ESTSC)

    1995-03-24

    Version 00 The RETRAC code uses a set of coupled neutron point-kinetics equations and thermal-hydraulic conservation laws to simulate nuclear reactor core behavior under transient or accident conditions. The reactor core is represented by a single equivalent unit cell composed of three regions: fuel, clad, and moderator (coolant).

  7. Health and safety plan for characterization sampling of ETR and MTR facilities

    SciTech Connect

    Baxter, D.E.

    1994-10-01

    This health and safety plan establishes the procedures and requirements that will be used to minimize health and safety risks to persons performing Engineering Test Reactor and Materials Test Reactor characterization sampling activities, as required by the Occupational Safety and Health Administration standard, 29 CFR 1910.120. It contains information about the hazards involved in performing the tasks, and the specific actions and equipment that will be used to protect persons working at the site.

  8. Program Guide for Basic Precision Machining 8754000 (IN48.052300) and Precision Machining MTR0470 (IN48.050300).

    ERIC Educational Resources Information Center

    University of South Florida, Tampa. Dept. of Adult and Vocational Education.

    This competency-based program guide provides course content information and procedures for secondary schools, postsecondary vocational schools, and community colleges in Florida that conduct programs in basic precision machining and precision machining. The first section is on legal authority, which applies to all vocational education programs in…

  9. Evidence for the Assembly of a Bacterial Tripartite Multidrug Pump with a Stoichiometry of 3:6:3*

    PubMed Central

    Janganan, Thamarai K.; Bavro, Vassiliy N.; Zhang, Li; Matak-Vinkovic, Dijana; Barrera, Nelson P.; Venien-Bryan, Catherine; Robinson, Carol V.; Borges-Walmsley, Maria Inês; Walmsley, Adrian R.

    2011-01-01

    The multiple transferable resistance (mTR) pump from Neisseria gonorrhoeae MtrCDE multidrug pump is assembled from the inner and outer membrane proteins MtrD and MtrE and the periplasmic membrane fusion protein MtrC. Previously we established that while there is a weak interaction of MtrD and MtrE, MtrC binds with relatively high affinity to both MtrD and MtrE. MtrD conferred antibiotic resistance only when it was expressed with MtrE and MtrC, suggesting that these proteins form a functional tripartite complex in which MtrC bridges MtrD and MtrE. Furthermore, we demonstrated that MtrC interacts with an intraprotomer groove on the surface of MtrE, inducing channel opening. However, a second groove is apparent at the interface of the MtrE subunits, which might also be capable of engaging MtrC. We have now established that MtrC can be cross-linked to cysteines placed in this interprotomer groove and that mutation of residues in the groove impair the ability of the pump to confer antibiotic resistance by locking MtrE in the closed channel conformation. Moreover, MtrE K390C forms an intermolecular disulfide bond with MtrC E149C locking MtrE in the open channel conformation, suggesting that a functional salt bridge forms between these residues during the transition from closed to open channel conformations. MtrC forms dimers that assemble into hexamers, and electron microscopy studies of single particles revealed that these hexamers are arranged into ring-like structures with an internal aperture sufficiently large to accommodate the MtrE trimer. Cross-linking of single cysteine mutants of MtrC to stabilize the dimer interface in the presence of MtrE, trapped an MtrC-MtrE complex with a molecular mass consistent with a stoichiometry of 3:6 (MtrE3MtrC6), suggesting that dimers of MtrC interact with MtrE, presumably by binding to the two grooves. As both MtrE and MtrD are trimeric, our studies suggest that the functional pump is assembled with a stoichiometry of 3

  10. Isolation and characterization of Saccharomyces cerevisiae mRNA transport-defective (mtr) mutants [published erratum appears in J Cell Biol 1994 Sep;126(6):1627

    PubMed Central

    1994-01-01

    To understand the mechanisms of mRNA transport in eukaryotes, we have isolated Saccharomyces cerevisiae temperature-sensitive (ts) mutants which accumulate poly(A)+ RNA in the nucleus at the restrictive temperature. A total of 21 recessive mutants were isolated and classified into 16 complementation groups. Backcrossed mRNA transport- defective strains from each complementation group have been analyzed. A strain which is ts for heat shock transcription factor was also analyzed since it also shows nuclear accumulation of poly(A)+ RNA at 37 degrees C. At 37 degrees C the mRNA of each mutant is characterized by atypically long polyA tails. Unlike ts pre-mRNA splicing mutants, these strains do not interrupt splicing of pre-mRNA at 37 degrees C; however four strains accumulate oversized RNA polymerase II transcripts. Some show inhibition of rRNA processing and a further subset of these strains is also characterized by inhibition of tRNA maturation. Several strains accumulate nuclear proteins in the cytoplasm when incubated at semipermissive temperature. Remarkably, many strains exhibit nucleolar fragmentation or enlargement at the restrictive temperature. Most strains show dramatic ultrastructural alterations of the nucleoplasm or nuclear membrane. Distinct mutants accumulate poly(A)+ RNA in characteristic patterns in the nucleus. PMID:8045930

  11. HWMA/RCRA Closure Plan for the TRA/MTR Warm Waste System Voluntary Consent Order SITE-TANK-005 Tank System TRA-007

    SciTech Connect

    K. Winterholler

    2007-01-30

    This Hazardous Waste Management Act/Resource Conservation and Recovery Act Closure Plan was developed for portions of the Test Reactor Area/Materials Test Reactor Warm Waste System located in the Materials Test Reactor Building (TRA-603) at the Reactor Technology Complex, Idaho National Laboratory Site, to meet a further milestone established under Voluntary Consent Order Action Plan SITE-TANK-005 for the Tank System TRA-007. The reactor drain tank and canal sump to be closed are included in the Test Reactor Area/Materials Test Reactor Warm Waste System. The reactor drain tank and the canal sump will be closed in accordance with the interim status requirements of the Hazardous Waste Management Act/Resource Conservation and Recovery Act as implemented by the Idaho Administrative Procedures Act 58.01.05.009 and Code of Federal Regulations 265. This closure plan presents the closure performance standards and methods for achieving those standards.

  12. New Dosimetric Interpretation of the DV50 Vessel-Steel Experiment Irradiated in the OSIRIS MTR Reactor Using the Monte-Carlo Code TRIPOLI-4®

    NASA Astrophysics Data System (ADS)

    Malouch, Fadhel

    2016-02-01

    An irradiation program DV50 was carried out from 2002 to 2006 in the OSIRIS material testing reactor (CEA-Saclay center) to assess the pressure vessel steel toughness curve for a fast neutron fluence (E > 1 MeV) equivalent to a French 900-MWe PWR lifetime of 50 years. This program allowed the irradiation of 120 specimens out of vessel steel, subdivided in two successive irradiations DV50 n∘1 and DV50 n∘2. To measure the fast neutron fluence (E > 1 MeV) received by specimens after each irradiation, sample holders were equipped with activation foils that were withdrawn at the end of irradiation for activity counting and processing. The fast effective cross-sections used in the dosimeter processing were determined with a specific calculation scheme based on the Monte-Carlo code TRIPOLI-3 (and the nuclear data ENDF/B-VI and IRDF-90). In order to put vessel-steel experiments at the same standard, a new dosimetric interpretation of the DV50 experiment has been performed by using the Monte-Carlo code TRIPOLI-4 and more recent nuclear data (JEFF3.1.1 and IRDF-2002). This paper presents a comparison of previous and recent calculations performed for the DV50 vessel-steel experiment to assess the impact on the dosimetric interpretation.

  13. Characterization of an electron conduit between bacteria and the extracellular environment

    SciTech Connect

    Hartshorne, R. S.; Reardon, C. L.; Ross, D.; Nuester, J.; Clarke, T. A.; Gates, A. J.; Mills, P. C.; Fredrickson, J. K.; Zachara, J. M.; Shi, L.; Beliaev, A. S.; Marshall, M. J.; Tien, M.; Brantley, S.; Butt, J. N.; Richardson, D. J.

    2009-12-17

    A number of species of Gram-negative bacteria can use insoluble minerals of Fe(III) and Mn(IV) as extracellular respiratory electron acceptors. In some species of Shewanella, deca-heme electron transfer proteins lie at the extracellular face of the outer membrane (OM), where they can interact with insoluble substrates. To reduce extracellular substrates, these redox proteins must be charged by the inner membrane/periplasmic electron transfer system. Here, we present a spectro-potentiometric characterization of a trans-OM icosa-heme complex, MtrCAB, and demonstrate its capacity to move electrons across a lipid bilayer after incorporation into proteoliposomes. We also show that a stable MtrAB subcomplex can assemble in the absence of MtrC; an MtrBC subcomplex is not assembled in the absence of MtrA; and MtrA is only associated to the membrane in cells when MtrB is present. We propose a model for the modular organization of the MtrCAB complex in which MtrC is an extracellular element that mediates electron transfer to extracellular substrates and MtrB is a trans-OM spanning β-barrel protein that serves as a sheath, within which MtrA and MtrC exchange electrons. Finally, we have identified the MtrAB module in a range of bacterial phyla, suggesting that it is widely used in electron exchange with the extracellular environment.

  14. Analytical Method of Correction of B 1 Errors in Mapping of Magnetization Transfer Ratio in Highfield Magnetic Resonance Tomography

    NASA Astrophysics Data System (ADS)

    Yarnykh, V. L.; Khodanovich, M. Yu.

    2015-04-01

    Magnetization Transfer Ratio (MTR) is a widely used parameter for quantitative estimation of tissues in magnetic resonance tomography (MRT). At the same time, MTR is rather sensitive to errors caused by the nonideal characteristics of magnetic resonance tomographs. In particular, MTR depends strongly on the local inhomogeneities of the radio-frequency field B 1 that limits the MTR application for high magnetic field strengths. In the present research, a simple analytical model of the MTR dependence on B 1 is derived. Based on this model, a correction algorithm is developed using a set of parameters independent of tissue. This algorithm is tested for MTR mapping of the human brain in the field with induction of 3 T. The MTR correction demonstrates high accuracy for a wide range of B 1 inhomogeneities. Combination of the analytical algorithm with fast B 1 mapping enables high-precision MTR brain mapping for neuroimaging applications and analysis of histograms on high-field scanners.

  15. Materials Data on Ti(PO3)4 (SG:60) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  16. Materials Data on Ti(PO3)3 (SG:9) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  17. Materials Data on Li2TiPO4F (SG:1) by Materials Project

    DOE Data Explorer

    Kristin Persson

    2016-02-10

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  18. Materials Data on Ti(PO3)4 (SG:15) by Materials Project

    SciTech Connect

    Kristin Persson

    2014-07-09

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  19. Matroshka DOSTEL measurements onboard the International Space Station (ISS)

    NASA Astrophysics Data System (ADS)

    Labrenz, Johannes; Burmeister, Soenke; Berger, Thomas; Heber, Bernd; Reitz, Guenther

    2015-12-01

    This paper presents the absorbed dose and dose equivalent rate measurements achieved with the DOSimetry TElescope (DOSTEL) during the two Matroshka (MTR) experiment campaigns in 2004/2005 (MTR-1) and 2007/2008 (MTR-2B). The comparison between the inside (MTR-2B) and outside (MTR-1) mission has shown that the shielding thickness provided by the International Space Station (ISS) spacecraft hull has a minor effect on the radiation exposure caused by Galactic Cosmic Rays (GCR). The exposure varies with the solar modulation of the GCR, too. Particles from Earth's radiation belts are effectively shielded by the spacecraft hull, and thus the contribution to the radiation exposure is lower for the inside measurement during MTR-2B. While the MTR-DOSTEL absorbed dose rate shows a good agreement with passive detectors of the MTR experiment for the MTR-2B mission phase, the MTR-1 absorbed dose rates from MTR-DOSTEL measurements are much lower than those obtained by a nearby passive detector. Observed discrepancies between the MTR-DOSTEL measurements and the passive detectors located nearby could be explained by the additional exposure to an enhanced flux of electrons trapped between L-parameter 2.5 and 3.5 caused by solar storms in July 2004.

  20. TRA Closure Plan REV 0-9-20-06 HWMA/RCRA Closure Plan for the TRA/MTR Warm Waste System Voluntary Consent Order SITE-TANK-005 Tank System TRA-007

    SciTech Connect

    Winterholler, K.

    2007-01-31

    This Hazardous Waste Management Act/Resource Conservation and Recovery Act closure plan was developed for portions of the Test Reactor Area/Materials Test Reactor Warm Waste System located in the Materials Test Reactor Building (TRA-603) at the Reactor Technology Complex, Idaho National Laboratory Site, to meet a further milestone established under Voluntary Consent Order Action Plan SITE-TANK-005 for Tank System TRA-007. The reactor drain tank and canal sump to be closed are included in the Test Reactor Area/Materials Test Reactor Warm Waste System. The reactor drain tank and the canal sump were characterized as having managed hazardous waste. The reactor drain tank and canal sump will be closed in accordance with the interim status requirements of the Hazardous Waste Management Act/Resource Conservation and Recovery Act as implemented by the Idaho Administrative Procedures Act 58.01.05.009 and 40 Code of Federal Regulations 265. This closure plan presents the closure performance standards and methods for achieving those standards.

  1. Intermediates in the recycling of 5-methylthioribose to methionine in fruits.

    PubMed

    Kushad, M M; Richardson, D G; Ferro, A J

    1983-10-01

    The recycling of 5-methylthioribose (MTR) to methionine in avocado (Persea americana Mill, cv Hass) and tomato (Lycopersicum esculentum Mill, cv unknown) was examined. [(14)CH(3)]MTR was not metabolized in cell free extract from avocado fruit. Either [(14)CH(3)]MTR plus ATP or [(14)CH(3)]5-methylthioribose-1-phosphate (MTR-1-P) alone, however, were metabolized to two new products by these extracts. MTR kinase activity has previously been detected in these fruit extracts. These data indicate that MTR must be converted to MTR-1-P by MTR kinase before further metabolism can occur. The products of MTR-1-P metabolism were tentatively identified as alpha-keto-gamma-methylthiobutyric acid (alpha-KMB) and alpha-hydroxy-gamma-methylthiobutyric acid (alpha-HMB) by chromatography in several solvent systems. [(35)S]alpha-KMB was found to be further metabolized to methionine and alpha-HMB by these extracts, whereas alpha-HMB was not. However, alpha-HMB inhibited the conversion of alpha-KMB to methionine. Both [U-(14)C]alpha-KMB and [U-(14)C]methionine, but not [U-(14)C]alpha-HMB, were converted to ethylene in tomato pericarp tissue. In addition, aminoethoxyvinylglycine inhibited the conversion of alpha-KMB to ethylene. These data suggest that the recycling pathway leading to ethylene is MTR --> MTR-1-P --> alpha-KMB --> methionine --> S-adenosylmethionine --> 1-aminocyclopropane-1-carboxylic acid --> ethylene. PMID:16663204

  2. Myofascial trigger points and innervation zone locations in upper trapezius muscles

    PubMed Central

    2013-01-01

    Background Myofascial trigger points (MTrPs) are hyperirritable spots located in taut bands of muscle fibres. Electrophysiological studies indicate that abnormal electrical activity is detectable near MTrPs. This phenomenon has been described as endplate noise and it has been purported to be associated MTrP pathophysiology. Thus, it is suggested that MTrPs will be overlap the innervation zone (IZ). The purpose of this work was to describe the location of MTrPs and the IZ in the right upper trapezius. Methods We screened 71 individuals and eventually enrolled 24 subjects with neck pain and active MTrPs and 24 neck pain-free subjects with latent MTrPs. Surface electromyography (sEMG) signals were detected using an electrode matrix during isometric contraction of the upper trapezius. A physiotherapist subsequently examined the subject’s trapezius to confirm the presence of MTrPs and establish their location. IZ locations were identified by visual analysis of sEMG signals. IZ and MTrPs locations were described using an anatomical coordinate system (ACS), with the skin area covered by the matrix divided into four quadrants. Results No significant difference was observed between active and latent MTrPs locations (P = 0.6). Forty-five MTrPs were in the third quadrant of the ACS, and 3 were included in second quadrant. IZs were located approximately midway between the seventh cervical vertebrae and the acromial angle in a limited area in the second and third quadrants. The mean distance between MTrP and IZ was 10.4 ± 5.8 mm. Conclusions According to the acquired results, we conclude that IZ and MTrPs are located in well-defined areas in upper trapezius muscle. Moreover, MTrPs in upper trapezius are proximally located to the IZ but not overlapped. PMID:23758854

  3. Structure of Arabidopsis thaliana 5-methylthioribose Kinase Reveals a More Occluded Active Site Than its Bacterial Homolog

    SciTech Connect

    Ku,S.; Cornell, K.; Howell, P.

    2007-01-01

    Metabolic variations exist between the methionine salvage pathway of humans and a number of plants and microbial pathogens. 5-Methylthioribose (MTR) kinase is a key enzyme required for methionine salvage in plants and many bacteria. The absence of a mammalian homolog suggests that MTR kinase is a good target for the design of specific herbicides or antibiotics. The structure of Arabidopsis thaliana MTR kinase co-crystallized with ATP?S and MTR has been determined at 1.9 Angstroms resolution. The structure is similar to B. subtilis MTR kinase and has the same protein kinase fold observed in other evolutionarily related protein kinase-like phosphotransferases. The active site is comparable between the two enzymes with the DXE-motif coordinating the nucleotide-Mg, the D238 of the HGD catalytic loop polarizing the MTR O1 oxygen, and the RR-motif interacting with the substrate MTR. Unlike its bacterial homolog, however, the Gly-rich loop (G-loop) of A. thaliana MTR kinase has an extended conformation, which shields most of the active site from solvent, a feature that resembles eukaryotic protein kinases more than the bacterial enzyme. The G- and W-loops of A. thaliana and B. subtilis MTR kinase adopt different conformations despite high sequence similarity. The ATP?S analog was hydrolyzed during the co-crystallization procedure, resulting in ADP in the active site. This suggests that the A. thaliana enzyme, like its bacterial homolog, may have significant ATPase activity in the absence of MTR. The structure of A. thaliana MTR kinase provides a template for structure-based design of agrochemicals, particularly herbicides whose effectiveness could be regulated by nutrient levels. Features of the MTR binding site offer an opportunity for a simple organic salt of an MTR analog to specifically inhibit MTR kinase.

  4. Experienced versus Inexperienced Interexaminer Reliability on Location and Classification of Myofascial Trigger Point Palpation to Diagnose Lateral Epicondylalgia: An Observational Cross-Sectional Study.

    PubMed

    Mora-Relucio, Raquel; Núñez-Nagy, Susana; Gallego-Izquierdo, Tomás; Rus, Alma; Plaza-Manzano, Gustavo; Romero-Franco, Natalia; Ferragut-Garcías, Alejandro; Pecos-Martín, Daniel

    2016-01-01

    The purpose was to evaluate the interexaminer reliability of experienced and inexperienced examiners on location and classification of myofascial trigger points (MTrPs) in two epicondylar muscles and the association between the MTrP found and the diagnosis of lateral epicondylalgia (LE). Fifty-two pianists (some suffered LE) voluntarily participated in the study. Three physiotherapists (one inexperienced in myofascial pain) examined, located, and marked MTrPs in the extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC) muscles. Forearms were photographed and analyzed to establish the degree of agreement on MTrPs diagnosis. Data showed 81.73% and 77.88% of agreement on MTrP classification and 85.58% and 72.12% on MTrP location between the expert evaluators for ECRB and EDC, respectively. The agreement on MTrP classification between experienced and inexperienced examiners was 54.81% and 51.92% for ECRB and 50.00% and 55.77% for EDC. Also, agreement on MTrP location was 54.81% and 60.58% for ECRB and 48.08% and 48.08% for EDC. A strong association was found between presence of relevant MTrPs, LE diagnosis, and forearm pain when the examiners were experts. The analysis of location and classification of MTrPs in the epicondylar muscles through physical examination by experienced evaluators is reliable, reproducible, and suitable for diagnosing LE. PMID:26881005

  5. Rapid electron exchange between surface-exposed bacterial cytochromes and Fe(III) minerals

    NASA Astrophysics Data System (ADS)

    White, Gaye F.; Shi, Zhi; Shi, Liang; Wang, Zheming; Dohnalkova, Alice C.; Marshall, Matthew J.; Fredrickson, James K.; Zachara, John M.; Butt, Julea N.; Richardson, David J.; Clarke, Thomas A.

    2013-04-01

    The mineral-respiring bacterium Shewanella oneidensis uses a protein complex, MtrCAB, composed of two decaheme cytochromes, MtrC and MtrA, brought together inside a transmembrane porin, MtrB, to transport electrons across the outer membrane to a variety of mineral-based electron acceptors. A proteoliposome system containing a pool of internalized electron carriers was used to investigate how the topology of the MtrCAB complex relates to its ability to transport electrons across a lipid bilayer to externally located Fe(III) oxides. With MtrA facing the interior and MtrC exposed on the outer surface of the phospholipid bilayer, the established in vivo orientation, electron transfer from the interior electron carrier pool through MtrCAB to solid-phase Fe(III) oxides was demonstrated. The rates were 103 times higher than those reported for reduction of goethite, hematite, and lepidocrocite by S. oneidensis, and the order of the reaction rates was consistent with those observed in S. oneidensis cultures. In contrast, established rates for single turnover reactions between purified MtrC and Fe(III) oxides were 103 times lower. By providing a continuous flow of electrons, the proteoliposome experiments demonstrate that conduction through MtrCAB directly to Fe(III) oxides is sufficient to support in vivo, anaerobic, solid-phase iron respiration.

  6. Rapid electron exchange between surface-exposed bacterial cytochromes and Fe(III) minerals

    PubMed Central

    White, Gaye F.; Shi, Zhi; Shi, Liang; Wang, Zheming; Dohnalkova, Alice C.; Marshall, Matthew J.; Fredrickson, James K.; Zachara, John M.; Butt, Julea N.; Richardson, David J.; Clarke, Thomas A.

    2013-01-01

    The mineral-respiring bacterium Shewanella oneidensis uses a protein complex, MtrCAB, composed of two decaheme cytochromes, MtrC and MtrA, brought together inside a transmembrane porin, MtrB, to transport electrons across the outer membrane to a variety of mineral-based electron acceptors. A proteoliposome system containing a pool of internalized electron carriers was used to investigate how the topology of the MtrCAB complex relates to its ability to transport electrons across a lipid bilayer to externally located Fe(III) oxides. With MtrA facing the interior and MtrC exposed on the outer surface of the phospholipid bilayer, the established in vivo orientation, electron transfer from the interior electron carrier pool through MtrCAB to solid-phase Fe(III) oxides was demonstrated. The rates were 103 times higher than those reported for reduction of goethite, hematite, and lepidocrocite by S. oneidensis, and the order of the reaction rates was consistent with those observed in S. oneidensis cultures. In contrast, established rates for single turnover reactions between purified MtrC and Fe(III) oxides were 103 times lower. By providing a continuous flow of electrons, the proteoliposome experiments demonstrate that conduction through MtrCAB directly to Fe(III) oxides is sufficient to support in vivo, anaerobic, solid-phase iron respiration. PMID:23538304

  7. Long-Lasting Gene Conversion Shapes the Convergent Evolution of the Critical Methanogenesis Genes

    PubMed Central

    Wang, Sishuo; Chen, Youhua; Cao, Qinhong; Lou, Huiqiang

    2015-01-01

    Methanogenesis and its key small-molecule methyltransferase Mtr complex are poorly understood despite their pivotal role in Earth’s global carbon cycle. Mtr complex is encoded by a conserved mtrEDCBAFGH operon in most methanogens. Here we report that two discrete lineages, Methanococcales and Methanomicrobiales, have a noncanonical mtr operon carrying two copies of mtrA resulting from an ancient duplication. Compared to mtrA-1, mtrA-2 acquires a distinct transmembrane domain through domain shuffling and gene fusion. However, the nontransmembrane domains (MtrA domain) of mtrA-1 and mtrA-2 are homogenized by gene conversion events lasting throughout the long history of these extant methanogens (over 2410 million years). Furthermore, we identified a possible recruitment of ancient nonmethanogenic methyltransferase genes to establish the methanogenesis pathway. These results not only provide novel evolutionary insight into the methanogenesis pathway and methyltransferase superfamily but also suggest an unanticipated long-lasting effect of gene conversion on gene evolution in a convergent pattern. PMID:26384370

  8. Experienced versus Inexperienced Interexaminer Reliability on Location and Classification of Myofascial Trigger Point Palpation to Diagnose Lateral Epicondylalgia: An Observational Cross-Sectional Study

    PubMed Central

    Mora-Relucio, Raquel; Núñez-Nagy, Susana; Gallego-Izquierdo, Tomás; Rus, Alma; Plaza-Manzano, Gustavo; Romero-Franco, Natalia; Ferragut-Garcías, Alejandro; Pecos-Martín, Daniel

    2016-01-01

    The purpose was to evaluate the interexaminer reliability of experienced and inexperienced examiners on location and classification of myofascial trigger points (MTrPs) in two epicondylar muscles and the association between the MTrP found and the diagnosis of lateral epicondylalgia (LE). Fifty-two pianists (some suffered LE) voluntarily participated in the study. Three physiotherapists (one inexperienced in myofascial pain) examined, located, and marked MTrPs in the extensor carpi radialis brevis (ECRB) and extensor digitorum communis (EDC) muscles. Forearms were photographed and analyzed to establish the degree of agreement on MTrPs diagnosis. Data showed 81.73% and 77.88% of agreement on MTrP classification and 85.58% and 72.12% on MTrP location between the expert evaluators for ECRB and EDC, respectively. The agreement on MTrP classification between experienced and inexperienced examiners was 54.81% and 51.92% for ECRB and 50.00% and 55.77% for EDC. Also, agreement on MTrP location was 54.81% and 60.58% for ECRB and 48.08% and 48.08% for EDC. A strong association was found between presence of relevant MTrPs, LE diagnosis, and forearm pain when the examiners were experts. The analysis of location and classification of MTrPs in the epicondylar muscles through physical examination by experienced evaluators is reliable, reproducible, and suitable for diagnosing LE. PMID:26881005

  9. Molecular Underpinnings of Fe(III) Oxide Reduction by Shewanella Oneidensis MR-1

    PubMed Central

    Shi, Liang; Rosso, Kevin M.; Clarke, Tomas A.; Richardson, David J.; Zachara, John M.; Fredrickson, James K.

    2012-01-01

    In the absence of O2 and other electron acceptors, the Gram-negative bacterium Shewanella oneidensis MR-1 can use ferric [Fe(III)] (oxy)(hydr)oxide minerals as the terminal electron acceptors for anaerobic respiration. At circumneutral pH and in the absence of strong complexing ligands, Fe(III) oxides are relatively insoluble and thus are external to the bacterial cells. S. oneidensis MR-1 and related strains of metal-reducing Shewanella have evolved machinery (i.e., metal-reducing or Mtr pathway) for transferring electrons from the inner-membrane, through the periplasm and across the outer-membrane to the surface of extracellular Fe(III) oxides. The protein components identified to date for the Mtr pathway include CymA, MtrA, MtrB, MtrC, and OmcA. CymA is an inner-membrane tetraheme c-type cytochrome (c-Cyt) that belongs to the NapC/NrfH family of quinol dehydrogenases. It is proposed that CymA oxidizes the quinol in the inner-membrane and transfers the released electrons to MtrA either directly or indirectly through other periplasmic proteins. A decaheme c-Cyt, MtrA is thought to be embedded in the trans outer-membrane and porin-like protein MtrB. Together, MtrAB deliver the electrons through the outer-membrane to the MtrC and OmcA on the outmost bacterial surface. MtrC and OmcA are the outer-membrane decaheme c-Cyts that are translocated across the outer-membrane by the bacterial type II secretion system. Functioning as terminal reductases, MtrC and OmcA can bind the surface of Fe(III) oxides and transfer electrons directly to these minerals via their solvent-exposed hemes. To increase their reaction rates, MtrC and OmcA can use the flavins secreted by S. oneidensis MR-1 cells as diffusible co-factors for reduction of Fe(III) oxides. Because of their extracellular location and broad redox potentials, MtrC and OmcA can also serve as the terminal reductases for soluble forms of Fe(III). In addition to Fe(III) oxides, Mtr pathway is also involved in reduction of

  10. Candidate Assembly Statistical Evaluation

    Energy Science and Technology Software Center (ESTSC)

    1998-07-15

    The Savannah River Site (SRS) receives aluminum clad spent Material Test Reactor (MTR) fuel from all over the world for storage and eventual reprocessing. There are hundreds of different kinds of MTR fuels and these fuels will continue to be received at SRS for approximately ten more years. SRS''s current criticality evaluation methodology requires the modeling of all MTR fuels utilizing Monte Carlo codes, which is extremely time consuming and resource intensive. Now that amore » significant number of MTR calculations have been conducted it is feasible to consider building statistical models that will provide reasonable estimations of MTR behavior. These statistical models can be incorporated into a standardized model homogenization spreadsheet package to provide analysts with a means of performing routine MTR fuel analyses with a minimal commitment of time and resources. This became the purpose for development of the Candidate Assembly Statistical Evaluation (CASE) program at SRS.« less

  11. Cinemática y masas de agujeros negros en galaxias activas del tipo "Narrow Line Seyfert 1"

    NASA Astrophysics Data System (ADS)

    Oío, G.; Schmidt, E.; Vega Neme, L. R.

    We apply a spectral synthesis method to Narrow Line Seyfert 1 active galax- ies with public spectra available. Our goal will be to obtain the stellar ve- locity dispersions, and then the central black hole masses via the Tremaine relation. We comment several problems we found in fitting this type of objects and the possibility of obtaining masses through the emission lines. FULL TEXT IN SPANISH

  12. Relaciones fundamentales de la población de galaxias de tipo temprano del cúmulo de Antlia

    NASA Astrophysics Data System (ADS)

    Calderón, J. P.; Bassino, L. P.; Cellone, S. A.; Smith Castelli, A. V.; Caso, J. P.

    We present the results of a study of more than 100 early-type galaxies in Antlia Cluster, that span from giant ellipticals to dwarf ellipticals, covering a magnitude range of 11 magnitudes (M_{V_T} = -22 to -11). We perform surface photometry of these galaxies, and their total magnitudes, surface brightnesses and radii are determined on the basis of the Sérsic law fits. Finally, the fundamental relations between them are analyzed. FULL TEXT IN SPANISH

  13. Home-Type Activities at the Day Care Center. (Tipos De Actividades Del Hogar En El Centro De Cuidado Diario.)

    ERIC Educational Resources Information Center

    Aaronson, May; Moberg, Patricia E.

    This paper argues that home activities comprise a valuable unplanned curriculum and that many of these activities can be transferred to the day care center. It is suggested that these activities foster a closer relationship between child and caregiver and bridge the gap between familiar home environment and novel day care setting. Home activities…

  14. Charge carrier transport in polycrystalline organic thin film based field effect transistors

    NASA Astrophysics Data System (ADS)

    Rani, Varsha; Sharma, Akanksha; Ghosh, Subhasis

    2016-05-01

    The charge carrier transport mechanism in polycrystalline thin film based organic field effect transistors (OFETs) has been explained using two competing models, multiple trapping and releases (MTR) model and percolation model. It has been shown that MTR model is most suitable for explaining charge carrier transport in grainy polycrystalline organic thin films. The energetic distribution of traps determined independently using Mayer-Neldel rule (MNR) is in excellent agreement with the values obtained by MTR model for copper phthalocyanine and pentacene based OFETs.

  15. A decahaem cytochrome as an electron conduit in protein-enzyme redox processes.

    PubMed

    Lee, Chong-Yong; Reuillard, Bertrand; Sokol, Katarzyna P; Laftsoglou, Theodoros; Lockwood, Colin W J; Rowe, Sam F; Hwang, Ee Taek; Fontecilla-Camps, Juan C; Jeuken, Lars J C; Butt, Julea N; Reisner, Erwin

    2016-05-31

    The decahaem cytochrome MtrC from Shewanella oneidensis MR-1 was employed as a protein electron conduit between a porous indium tin oxide electrode and redox enzymes. Using a hydrogenase and a fumarate reductase, MtrC was shown as a suitable and efficient diode to shuttle electrons to and from the electrode with the MtrC redox activity regulating the direction of the enzymatic reactions. PMID:27193068

  16. The NASA modern technology rotors program

    NASA Technical Reports Server (NTRS)

    Watts, M. E.; Cross, J. L.

    1986-01-01

    Existing data bases regarding helicopters are based on work conducted on 'old-technology' rotor systems. The Modern Technology Rotors (MTR) Program is to provide extensive data bases on rotor systems using present and emerging technology. The MTR is concerned with modern, four-bladed, rotor systems presently being manufactured or under development. Aspects of MTR philosophy are considered along with instrumentation, the MTR test program, the BV 360 Rotor, and the UH-60 Black Hawk. The program phases include computer modelling, shake test, model-scale test, minimally instrumented flight test, extensively pressure-instrumented-blade flight test, and full-scale wind tunnel test.

  17. Current studies on myofascial pain syndrome.

    PubMed

    Kuan, Ta-Shen

    2009-10-01

    Recent studies have clarified the nature of myofascial trigger points (MTrPs). In an MTrP region, multiple hyperirritable loci can be found. The sensory components of the MTrP locus are sensitized nociceptors that are responsible for pain, referred pain, and local twitch responses. The motor components are dysfunctional endplates that are responsible for taut band formation as a result of excessive acetylcholine (ACh) leakage. The concentrations of pain- and inflammation-related substances are increased in the MTrP region. It has been hypothesized that excessive ACh release, sarcomere shortening, and release of sensitizing substances are three essential features that relate to one another in a positive feedback cycle. This MTrP circuit is the connection among spinal sensory (dorsal horn) neurons responsible for the MTrP phenomena. Recent studies suggest that measurement of biochemicals associated with pain and inflammation in the MTrP region, the sonographic study of MTrPs, and the magnetic resonance elastography for taut band image are potential tools for the diagnosis of MTrPs. Many methods have been used to treat myofascial pain, including laser therapy, shockwave therapy, and botulinum toxin type A injection. PMID:19728962

  18. Export of detritus and invertebrate from headwater streams: linking mountaintop removal and valley fill coal mining to downstream receiving waters

    EPA Science Inventory

    Mountaintop removal and valley fill (MTR/VF) coal mining has resulted in large scale alteration of the topography, reduced forest productivity, and burial of headwater streams in the U.S. Central Appalachians. Although MTR/VF coal mining has occurred for several decades and the ...

  19. Molecular characterization of methanogenic N(5)-methyl-tetrahydromethanopterin: Coenzyme M methyltransferase.

    PubMed

    Upadhyay, Vikrant; Ceh, Katharina; Tumulka, Franz; Abele, Rupert; Hoffmann, Jan; Langer, Julian; Shima, Seigo; Ermler, Ulrich

    2016-09-01

    Methanogenic archaea share one ion gradient forming reaction in their energy metabolism catalyzed by the membrane-spanning multisubunit complex N(5)-methyl-tetrahydromethanopterin: coenzyme M methyltransferase (MtrABCDEFGH or simply Mtr). In this reaction the methyl group transfer from methyl-tetrahydromethanopterin to coenzyme M mediated by cobalamin is coupled with the vectorial translocation of Na(+) across the cytoplasmic membrane. No detailed structural and mechanistic data are reported about this process. In the present work we describe a procedure to provide a highly pure and homogenous Mtr complex on the basis of a selective removal of the only soluble subunit MtrH with the membrane perturbing agent dimethyl maleic anhydride and a subsequent two-step chromatographic purification. A molecular mass determination of the Mtr complex by laser induced liquid bead ion desorption mass spectrometry (LILBID-MS) and size exclusion chromatography coupled with multi-angle light scattering (SEC-MALS) resulted in a (MtrABCDEFG)3 heterotrimeric complex of ca. 430kDa with both techniques. Taking into account that the membrane protein complex contains various firmly bound small molecules, predominantly detergent molecules, the stoichiometry of the subunits is most likely 1:1. A schematic model for the subunit arrangement within the MtrABCDEFG protomer was deduced from the mass of Mtr subcomplexes obtained by harsh IR-laser LILBID-MS. PMID:27342374

  20. Serial Magnetization Transfer Imaging in Acute Optic Neuritis

    ERIC Educational Resources Information Center

    Hickman, S. J.; Toosy, A. T.; Jones, S. J.; Altmann, D. R.; Miszkiel, K. A.; MacManus, D. G.; Barker, G. J.; Plant, G. T.; Thompson, A. J.; Miller, D.H.

    2004-01-01

    In serial studies of multiple sclerosis lesions, reductions in magnetization transfer ratio (MTR) are thought to be due to demyelination and axonal loss, with later rises due to remyelination. This study followed serial changes in MTR in acute optic neuritis in combination with clinical and electrophysiological measurements to determine if the MTR…

  1. FAST CHOPPER BUILDING, TRA665. CONTEXTUAL VIEW: CHOPPER BUILDING IN CENTER. ...

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

    FAST CHOPPER BUILDING, TRA-665. CONTEXTUAL VIEW: CHOPPER BUILDING IN CENTER. MTR REACTOR SERVICES BUILDING,TRA-635, TO LEFT; MTR BUILDING TO RIGHT. CAMERA FACING WEST. INL NEGATIVE NO. HD42-1. Mike Crane, Photographer, 3/2004 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  2. 33 CFR 154.1015 - Applicability.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... transferring oil to or from a vessel with a capacity of 250 barrels or more and deepwater ports; (2) Mobile MTR facilities used or intended to be used to transfer oil to or from a vessel with a capacity of 250 barrels or... ports, and fixed MTR onshore facilities capable of transferring oil to or from a vessel with a...

  3. 33 CFR 154.1015 - Applicability.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... transferring oil to or from a vessel with a capacity of 250 barrels or more and deepwater ports; (2) Mobile MTR facilities used or intended to be used to transfer oil to or from a vessel with a capacity of 250 barrels or... ports, and fixed MTR onshore facilities capable of transferring oil to or from a vessel with a...

  4. 33 CFR 154.1015 - Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... transferring oil to or from a vessel with a capacity of 250 barrels or more and deepwater ports; (2) Mobile MTR facilities used or intended to be used to transfer oil to or from a vessel with a capacity of 250 barrels or... ports, and fixed MTR onshore facilities capable of transferring oil to or from a vessel with a...

  5. Structural and functional characteristics of natural and constructed channels draining a reclaimed mountaintop removal and valley fill coal mine

    EPA Science Inventory

    Mountaintop removal and valley fill (MTR/VF) coal mining has altered the landscape of the Central Appalachian region in the United States. The goals of this study were to 1) compare the structure and function of natural and constructed stream channels in forested and MTR/VF catch...

  6. A Decaheme Cytochrome as a Molecular Electron Conduit in Dye-Sensitized Photoanodes

    PubMed Central

    Hwang, Ee Taek; Sheikh, Khizar; Orchard, Katherine L; Hojo, Daisuke; Radu, Valentin; Lee, Chong-Yong; Ainsworth, Emma; Lockwood, Colin; Gross, Manuela A; Adschiri, Tadafumi; Reisner, Erwin; Butt, Julea N; Jeuken, Lars J C

    2015-01-01

    In nature, charge recombination in light-harvesting reaction centers is minimized by efficient charge separation. Here, it is aimed to mimic this by coupling dye-sensitized TiO2 nanocrystals to a decaheme protein, MtrC from Shewanella oneidensis MR-1, where the 10 hemes of MtrC form a ≈7-nm-long molecular wire between the TiO2 and the underlying electrode. The system is assembled by forming a densely packed MtrC film on an ultra-flat gold electrode, followed by the adsorption of approximately 7 nm TiO2 nanocrystals that are modified with a phosphonated bipyridine Ru(II) dye (RuP). The step-by-step construction of the MtrC/TiO2 system is monitored with (photo)electrochemistry, quartz-crystal microbalance with dissipation (QCM-D), and atomic force microscopy (AFM). Photocurrents are dependent on the redox state of the MtrC, confirming that electrons are transferred from the TiO2 nanocrystals to the surface via the MtrC conduit. In other words, in these TiO2/MtrC hybrid photodiodes, MtrC traps the conduction-band electrons from TiO2 before transferring them to the electrode, creating a photobioelectrochemical system in which a redox protein is used to mimic the efficient charge separation found in biological photosystems. PMID:26180522

  7. SOUTH WING, TRA661. WEST SIDE. CAMERA FACING EAST. COVERED STAIRWAY ...

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

    SOUTH WING, TRA-661. WEST SIDE. CAMERA FACING EAST. COVERED STAIRWAY AND BUILDING END AT LEFT OF VIEW IS TRA-652, ANOTHER MTR OFFICE WING. WEST SIDE OF MTR HIGH BAY BEYOND. INL NEGATIVE NO. HD46-45-2. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. Preliminary Observations on Sensitivity and Specificity of Magnetization Transfer Asymmetry for Imaging Myelin of Rat Brain at High Field

    PubMed Central

    Kim, Jae-Woong; Choi, Jiye; Cho, Janggeun; Lee, Chulhyun; Jeon, Daejong; Park, Sung-Hong

    2015-01-01

    Magnetization transfer ratio (MTR) has been often used for imaging myelination. Despite its high sensitivity, the specificity of MTR to myelination is not high because tissues with no myelin such as muscle can also show high MTR. In this study, we propose a new magnetization transfer (MT) indicator, MT asymmetry (MTA), as a new method of myelin imaging. The experiments were performed on rat brain at 9.4 T. MTA revealed high signals in white matter and significantly low signals in gray matter and muscle, indicating that MTA has higher specificity than MTR. Demyelination and remyelination studies demonstrated that the sensitivity of MTA to myelination was as high as that of MTR. These experimental results indicate that MTA can be a good biomarker for imaging myelination. In addition, MTA images can be efficiently acquired with an interslice MTA method, which may accelerate clinical application of myelin imaging. PMID:26413534

  9. Age-effects in white matter using associated diffusion tensor imaging and magnetization transfer ratio during late childhood and early adolescence.

    PubMed

    Moura, Luciana Monteiro; Kempton, Matthew; Barker, Gareth; Salum, Giovanni; Gadelha, Ary; Pan, Pedro Mario; Hoexter, Marcelo; Del Aquilla, Marco Antonio Gomes; Picon, Felipe Almeida; Anés, Mauricio; Otaduy, Maria Concepcion Garcia; Amaro, Edson; Rohde, Luis Augusto; McGuire, Philip; Bressan, Rodrigo Affonseca; Sato, João Ricardo; Jackowski, Andrea Parolin

    2016-05-01

    In the last decade, several studies have described the typical brain white matter maturation in children and adolescents. Diffusion tensor imaging (DTI) is the most frequent MRI technique used to investigate the structural changes across development. However, few previous studies have used the magnetization transfer ratio (MTR), which gives a closer measure of myelin content. Here, we employed both techniques for the same sample of 176 typically developing children from 7 to 14years of age. We investigated the associations between DTI parameters and MTR measure, to assess the myelination in the brain in development. Secondly, we investigated age-effects on DTI parameters (fractional anisotropy, axial, radial and mean diffusivities) and MTR. No significant correlations between MTR and DTI parameters were observed. In addition, a significant age-effect was detected for DTI data but was not visible for MTR data. Thereby, changes in white matter at this age might be primarily correlated with microstructural changes. PMID:26708037

  10. Regional patterns of grey matter atrophy and magnetisation transfer ratio abnormalities in multiple sclerosis clinical subgroups: A voxel-based analysis study

    PubMed Central

    Muhlert, Nils; Samson, Rebecca S; Sethi, Varun; Wheeler-Kingshott, Claudia AM; Miller, David H; Chard, Declan T

    2015-01-01

    Background: In multiple sclerosis (MS), demyelination and neuro-axonal loss occur in the brain grey matter (GM). We used magnetic resonance imaging (MRI) measures of GM magnetisation transfer ratio (MTR) and volume to assess the regional localisation of reduced MTR (reflecting demyelination) and atrophy (reflecting neuro-axonal loss) in relapsing–remitting MS (RRMS), secondary progressive MS (SPMS) and primary progressive MS (PPMS). Methods: A total of 98 people with MS (51 RRMS, 28 SPMS, 19 PPMS) and 29 controls had T1-weighted volumetric and magnetisation transfer scans. SPM8 was used to undertake voxel-based analysis (VBA) of GM tissue volumes and MTR. MS subgroups were compared with controls, adjusting for age and gender. A voxel-by-voxel basis correlation analysis between MTR and volume within each subject group was performed, using biological parametric mapping. Results: MTR reduction was more extensive than atrophy. RRMS and SPMS patients showed proportionately more atrophy in the deep GM. SPMS and PPMS patients showed proportionately greater cortical MTR reduction. RRMS patients demonstrated the most correlation of MTR reduction and atrophy in deep GM. In SPMS and PPMS patients, there was less extensive correlation. Conclusions: These results suggest that in the deep GM of RRMS patients, demyelination and neuro-axonal loss may be linked, while in SPMS and PPMS patients, neuro-axonal loss and demyelination may occur mostly independently. PMID:25145689

  11. Metabolism of 5-methylthioribose to methionine

    SciTech Connect

    Miyazaki, J.H.; Yang, S.F.

    1987-06-01

    During ethylene biosynthesis, the H/sub 3/CS-group of S-adenosylmethionine is released as 5'-methylthioadenosine, which is recycled to methionine via 5-methylthioribose (MTR). In mungbean hypocotyls and cell-free extracts of avocado, (/sup 14/C)MTR was converted into labeled methionine via 2-keto-4-methylthiobutyric acid (KMB) and 2-hydroxy-4-methylthiobutyric acid (HMB), as intermediates. Incubation of (ribose-U-/sup 14/C)MTR with avocado extract resulted in the production of (/sup 14/C)formate, indicating the conversion of MTR to KMB involves a loss of formate, presumably from C-1 of MTR. Tracer studies showed that KMB was converted readily in vivo and in vitro to methionine, while HMB was converted much more slowly. The conversion of KMB to methionine by dialyzed avocado extract requires an amino donor. Among several potential donors examined, L-glutamine was the most efficient. Anaerobiosis inhibited only partially the oxidation of MTR to formate, KMB/HMB, and methionine by avocado extract. The role of O/sub 2/ in the conversion of MTR to methionine is discussed.

  12. Overexpression of Mycothiol Disulfide Reductase Enhances Corynebacterium glutamicum Robustness by Modulating Cellular Redox Homeostasis and Antioxidant Proteins under Oxidative Stress.

    PubMed

    Si, Meiru; Zhao, Chao; Zhang, Bing; Wei, Dawei; Chen, Keqi; Yang, Xu; Xiao, He; Shen, Xihui

    2016-01-01

    Mycothiol (MSH) is the dominant low-molecular-weight thiol (LMWT) unique to high-(G+C)-content Gram-positive Actinobacteria, such as Corynebacterium glutamicum, and is oxidised into its disulfide form mycothiol disulfide (MSSM) under oxidative conditions. Mycothiol disulfide reductase (Mtr), an NADPH-dependent enzyme, reduces MSSM to MSH, thus maintaining intracellular redox homeostasis. In this study, a recombinant plasmid was constructed to overexpress Mtr in C. glutamicum using the expression vector pXMJ19-His6. Mtr-overexpressing C. glutamicum cells showed increased tolerance to ROS induced by oxidants, bactericidal antibiotics, alkylating agents, and heavy metals. The physiological roles of Mtr in resistance to oxidative stresses were corroborated by decreased ROS levels, reduced carbonylation damage, decreased loss of reduced protein thiols, and a massive increase in the levels of reversible protein thiols in Mtr-overexpressing cells exposed to stressful conditions. Moreover, overexpression of Mtr caused a marked increase in the ratio of reduced to oxidised mycothiol (MSH:MSSM), and significantly enhanced the activities of a variety of antioxidant enzymes, including mycothiol peroxidase (MPx), mycoredoxin 1 (Mrx1), thioredoxin 1 (Trx1), and methionine sulfoxide reductase A (MsrA). Taken together, these results indicate that the Mtr protein functions in C. glutamicum by protecting cells against oxidative stress. PMID:27383057

  13. Overexpression of Mycothiol Disulfide Reductase Enhances Corynebacterium glutamicum Robustness by Modulating Cellular Redox Homeostasis and Antioxidant Proteins under Oxidative Stress

    PubMed Central

    Si, Meiru; Zhao, Chao; Zhang, Bing; Wei, Dawei; Chen, Keqi; Yang, Xu; Xiao, He; Shen, Xihui

    2016-01-01

    Mycothiol (MSH) is the dominant low-molecular-weight thiol (LMWT) unique to high-(G+C)-content Gram-positive Actinobacteria, such as Corynebacterium glutamicum, and is oxidised into its disulfide form mycothiol disulfide (MSSM) under oxidative conditions. Mycothiol disulfide reductase (Mtr), an NADPH-dependent enzyme, reduces MSSM to MSH, thus maintaining intracellular redox homeostasis. In this study, a recombinant plasmid was constructed to overexpress Mtr in C. glutamicum using the expression vector pXMJ19-His6. Mtr-overexpressing C. glutamicum cells showed increased tolerance to ROS induced by oxidants, bactericidal antibiotics, alkylating agents, and heavy metals. The physiological roles of Mtr in resistance to oxidative stresses were corroborated by decreased ROS levels, reduced carbonylation damage, decreased loss of reduced protein thiols, and a massive increase in the levels of reversible protein thiols in Mtr-overexpressing cells exposed to stressful conditions. Moreover, overexpression of Mtr caused a marked increase in the ratio of reduced to oxidised mycothiol (MSH:MSSM), and significantly enhanced the activities of a variety of antioxidant enzymes, including mycothiol peroxidase (MPx), mycoredoxin 1 (Mrx1), thioredoxin 1 (Trx1), and methionine sulfoxide reductase A (MsrA). Taken together, these results indicate that the Mtr protein functions in C. glutamicum by protecting cells against oxidative stress. PMID:27383057

  14. Porin-mediated antibiotic resistance in Neisseria gonorrhoeae: ion, solute, and antibiotic permeation through PIB proteins with penB mutations.

    PubMed

    Olesky, Melanie; Zhao, Shuqing; Rosenberg, Robert L; Nicholas, Robert A

    2006-04-01

    Neisseria gonorrhoeae has two porins, PIA and PIB, whose genes (porA and porB, respectively) are alleles of a single por locus. We recently demonstrated that penB mutations at positions 120 and 121 in PIB, which are presumed to reside in loop 3 that forms the pore constriction zone, confer intermediate-level resistance to penicillin and tetracycline (M. Olesky, M. Hobbs, and R. A. Nicholas, Antimicrob. Agents Chemother. 46:2811-2820, 2002). In the present study, we investigated the electrophysiological properties as well as solute and antibiotic permeation rates of recombinant PIB proteins containing penB mutations (G120K, G120D/A121D, G120P/A121P, and G120R/A121H). In planar lipid bilayers, the predominant conducting state of each porin variant was 30 to 40% of the wild type, even though the anion selectivity and maximum channel conductance of each PIB variant was similar to that of the wild type. Liposome-swelling experiments revealed no significant differences in the permeation of sugars or beta-lactam antibiotics through the wild type or PIB variants. Although these results are seemingly contradictory with the ability of these variants to increase antibiotic resistance, they are consistent with MIC data showing that these porin mutations confer resistance only in strains containing an mtrR mutation, which increases expression of the MtrC-MtrD-MtrE efflux pump. Moreover, both the mtrR and penB mutations were required to decrease in vivo permeation rates below those observed in the parental strain containing either mtrR or porin mutations alone. Thus, these data demonstrate a novel mechanism of porin-mediated resistance in which mutations in PIB have no affect on antibiotic permeation alone but instead act synergistically with the MtrC-MtrD-MtrE efflux pump in the development of antibiotic resistance in gonococci. PMID:16547016

  15. Proximal nerve magnetization transfer MRI relates to disability in Charcot-Marie-Tooth diseases

    PubMed Central

    Dethrage, Lindsey M.; Gore, John C.; Smith, Seth A.; Li, Jun

    2014-01-01

    Objective: The objectives of this study were (1) to develop a novel magnetization transfer ratio (MTR) MRI assay of the proximal sciatic nerve (SN), which is inaccessible via current tools for assessing peripheral nerves, and (2) to evaluate the resulting MTR values as a potential biomarker of myelin content changes in patients with Charcot-Marie-Tooth (CMT) diseases. Methods: MTR was measured in the SN of patients with CMT type 1A (CMT1A, n = 10), CMT type 2A (CMT2A, n = 3), hereditary neuropathy with liability to pressure palsies (n = 3), and healthy controls (n = 21). Additional patients without a genetically confirmed subtype (n = 4), but whose family histories and electrophysiologic tests were consistent with CMT, were also included. The relationship between MTR and clinical neuropathy scores was assessed, and the interscan and inter-rater reliability of MTR was estimated. Results: Mean volumetric MTR values were significantly decreased in the SN of patients with CMT1A (33.8 ± 3.3 percent units) and CMT2A (31.5 ± 1.9 percent units) relative to controls (37.2 ± 2.3 percent units). A significant relationship between MTR and disability scores was also detected (p = 0.01 for genetically confirmed patients only, p = 0.04 for all patients). From interscan and inter-rater reliability analyses, proximal nerve MTR values were repeatable at the slicewise and mean volumetric levels. Conclusions: MTR measurements may be a viable biomarker of proximal nerve pathology in patients with CMT. PMID:25253751

  16. Añadir quimioterapia después de la radioterapia mejora la supervivencia de adultos con un tipo de tu

    Cancer.gov

    Adultos con gliomas de grado bajo, una forma de tumor cerebral, que recibieron tratamiento con quimioterapia después de la radioterapia vivieron más tiempo que pacientes que recibieron solo radioterapia, según los resultados de seguimiento a largo plazo d

  17. Stay at a Healthy Weight. Tips for Kids with Type 2 Diabetes = Mantente en un Peso Saludable. Consejos Para Muchachos con Diabetes Tipo 2

    ERIC Educational Resources Information Center

    US Department of Health and Human Services, 2005

    2005-01-01

    A healthy weight means you are not too fat or too thin. Your doctor may have said that you should not gain more weight or that you need to lose a few pounds. If you have diabetes and are overweight, you are not alone. The steps you take to manage your weight will help you feel better and may improve your blood sugar or glucose (GLOO-kos) levels.…

  18. Análisis y determinación de parámetros físicos de estrellas de tipo FU Orionis

    NASA Astrophysics Data System (ADS)

    Gramajo, L.; Gómez, M.; Whitney, B.

    FU Orionis stars (FUORs) are pre-main sequence objects that periodically incur in a steeply increase of brightness (outburst) of DeltaV~ 6 mag in a period of ~ 10 yr, followed by a gradual descent to the original magnitude in an interval of time of ~100 yr. In this contribution we present initial results on the modeling of the spectral energy distributions (SEDs) of a group of 7 FU Orionis stars: FU Ori, V1515 Cyg, V1057 Cyg, Z CMa, BBW 76, V1735 Cyg, and V883 Ori. We initially used the grid of SEDs calculated by Robitaille et al. (2006). This solution was refined applying the code developed by Whitney et al. (2003). We derived physical and geometrical parameters for the disks of these FUORs. We compared these properties with those of ''canonical'' T Tauri disks. FULL TEXT IN SPANISH

  19. Importance of multidrug efflux pumps in the antimicrobial resistance property of clinical multidrug-resistant isolates of Neisseria gonorrhoeae.

    PubMed

    Golparian, Daniel; Shafer, William M; Ohnishi, Makoto; Unemo, Magnus

    2014-06-01

    The contribution of drug efflux pumps in clinical isolates of Neisseria gonorrhoeae that express extensively drug-resistant or multidrug-resistant phenotypes has heretofore not been examined. Accordingly, we assessed the effect on antimicrobial resistance of loss of the three gonococcal efflux pumps associated with a known capacity to export antimicrobials (MtrC-MtrD-MtrE, MacA-MacB, and NorM) in such clinical isolates. We report that the MIC of several antimicrobials, including seven previously and currently recommended for treatment was significantly impacted. PMID:24733458

  20. Sediment and epilithon metabolism and hydrolytic activity in streams affected by mountaintop removal coal mining, West Virginia, U.S.A.

    EPA Science Inventory

    Mountaintop removal and valley filling (MTR/VF) is a method of coal mining used in the Central Appalachians. Despite regulations requiring that potential mpacts to stream function be considered in determining compensatory mitigation associated with permitted fill activities, asse...

  1. Estimating benthic secondary production from aquatic insect emergence in streams affected by mountaintop removal coal mining, West Virginia USA

    EPA Science Inventory

    Mountaintop removal and valley fill (MTR/VF) coal mining recountours the Appalachian landscape, buries headwater stream channels, and degrades downstream water quality. The goal of this study was to compare benthic community production estimates, based on seasonal insect emergen...

  2. 33 CFR 154.100 - Applicability.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... piping are gas free. (c) Upon a determination by the COTP under § 154.1016 that an MTR facility, as... Operations Manual: Procedures for examination. (10) Section 154.500 Hose assemblies. Paragraphs (a), (b),...

  3. Molecular Underpinnings of Fe(III) Oxide Reduction by Shewanella oneidensis MR-1

    SciTech Connect

    Shi, Liang; Rosso, Kevin M.; Clarke, Thomas A.; Richardson, David J.; Zachara, John M.; Fredrickson, Jim K.

    2012-02-15

    In the absence of O2 and other electron acceptors, the Gram-negative bacterium Shewanella oneidensis MR-1 can use ferric [Fe(III)] (oxy)(hydr)oxide minerals as the terminal electron acceptors for anaerobic respiration. At circumneutral pH and in the absence of strong complexing ligands, Fe(III) oxides are relatively insoluble and thus are external to the bacterial cells. S. oneidensis MR-1 and related strains of metal-reducing Shewanella have evolved the machinery (i.e., metal-reducing or Mtr pathway) for transferring electrons from the inner-membrane, through the periplasm and across the outer-membrane to the surface of extracellular Fe(III) oxides. The protein components identified to date for the Mtr pathway include CymA, MtrA, MtrB, MtrC and OmcA. CymA is an inner-membrane tetraheme c-type cytochrome (c-Cyt) that belongs to the NapC/NrfH family of quinol dehydrogenases. It is proposed that CymA oxidizes the quinol in the inner-membrane and transfers the released electrons to redox proteins in the periplasm. Although the periplasmic proteins receiving electrons from CymA during Fe(III) oxidation have not been identified, they are believed to relay the electrons in the periplasm to MtrA. A decaheme c-Cyt, MtrA is thought to be embedded in the trans outer-membrane and porin-like protein MtrB. Together, MtrAB deliver the electrons through the outer-membrane to the MtrC and OmcA on the outmost bacterial surface. MtrC and OmcA are the outer-membrane decaheme c-Cyts that are translocated across the outer-membrane by the bacterial type II secretion system. Functioning as terminal reductases, MtrC and OmcA can bind the surface of Fe(III) oxides and transfer electrons directly to these minerals via their solvent-exposed hemes. To increase their reaction rates, MtrC and OmcA can use the flavins secreted by S. oneidensis MR-1 cells as diffusible co-factors for reduction of Fe(III) oxides. Because of their extracellular location and broad redox potentials, MtrC and OmcA can

  4. Grey and White Matter Magnetisation Transfer Ratio Measurements in the Lumbosacral Enlargement: A Pilot In Vivo Study at 3T

    PubMed Central

    Ugorji, Chinyere O.; Samson, Rebecca S.; Liechti, Martina D.; Panicker, Jalesh N.; Miller, David H.; Wheeler-Kingshott, Claudia A. M.; Yiannakas, Marios C.

    2015-01-01

    Magnetisation transfer (MT) imaging of the central nervous system has provided further insight into the pathophysiology of neurological disease. However, the use of this method to study the lower spinal cord has been technically challenging, despite the important role of this region, not only for motor control of the lower limbs, but also for the neural control of lower urinary tract, sexual and bowel functions. In this study, the feasibility of obtaining reliable grey matter (GM) and white matter (WM) magnetisation transfer ratio (MTR) measurements within the lumbosacral enlargement (LSE) was investigated in ten healthy volunteers using a clinical 3T MRI system. The mean cross-sectional area of the LSE (LSE-CSA) and the mean GM area (LSE-GM-CSA) were first obtained by means of image segmentation and tissue-specific (i.e. WM and GM) MTR measurements within the LSE were subsequently obtained. The reproducibility of the segmentation method and MTR measurements was assessed from repeated measurements and their % coefficient of variation (%COV). Mean (± SD) LSE-CSA across 10 healthy subjects was 59.3 (± 8.4) mm2 and LSE-GM-CSA was 17.0 (± 3.1) mm2. The mean intra- and inter-rater % COV for measuring the LSE-CSA were 0.8% and 2.3%, respectively and for the LSE-GM-CSA were 3.8% and 5.4%, respectively. Mean (± SD) WM-MTR was 43.2 (± 4.4) and GM-MTR was 40.9 (± 4.3). The mean scan-rescan % COV for measuring WM-MTR was 4.6% and for GM-MTR was 3.8%. Using a paired t-test, a statistically significant difference was identified between WM-MTR and GM-MTR in the LSE (p<0.0001). This pilot study has shown that it is possible to obtain reliable tissue-specific MTR measurements within the LSE using a clinical MR system at 3T. The MTR acquisition and analysis protocol presented in this study can be used in future investigations of intrinsic spinal cord diseases that affect the LSE. PMID:26230729

  5. Structures of 5-Methylthioribose Kinase Reveal Substrate Specificity and Unusual Mode of Nucleotide Binding

    SciTech Connect

    Ku,S.; Yip, P.; Cornell, K.; Riscoe, M.; Behr, J.; Guillerm, G.; Howell, P.

    2007-01-01

    The methionine salvage pathway is ubiquitous in all organisms, but metabolic variations exist between bacteria and mammals. 5-Methylthioribose (MTR) kinase is a key enzyme in methionine salvage in bacteria and the absence of a mammalian homolog suggests that it is a good target for the design of novel antibiotics. The structures of the apo-form of Bacillus subtilis MTR kinase, as well as its ADP, ADP-PO4, AMPPCP, and AMPPCP-MTR complexes have been determined. MTR kinase has a bilobal eukaryotic protein kinase fold but exhibits a number of unique features. The protein lacks the DFG motif typically found at the beginning of the activation loop and instead coordinates magnesium via a DXE motif (Asp{sup 250}-Glu{sup 252}). In addition, the glycine-rich loop of the protein, analogous to the 'Gly triad' in protein kinases, does not interact extensively with the nucleotide. The MTR substrate-binding site consists of Asp{sup 233} of the catalytic HGD motif, a novel twin arginine motif (Arg{sup 340}/Arg{sup 341}), and a semi-conserved W-loop, which appears to regulate MTR binding specificity. No lobe closure is observed for MTR kinase upon substrate binding. This is probably because the enzyme lacks the lobe closure/inducing interactions between the C-lobe of the protein and the ribosyl moiety of the nucleotide that are typically responsible for lobe closure in protein kinases. The current structures suggest that MTR kinase has a dissociative mechanism.

  6. REACTOR SERVICE BUILDING, TRA635, INTERIOR. CAMERA FACES NORTHWEST TOWARDS INTERIOR ...

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

    REACTOR SERVICE BUILDING, TRA-635, INTERIOR. CAMERA FACES NORTHWEST TOWARDS INTERIOR WALL ENCLOSING STORAGE AND OFFICE SPACE ALONG THE WEST SIDE. AT RIGHT EDGE IS DOOR TO MTR BUILDING. FROM RIGHT TO LEFT, SPACE WAS PLANNED FOR A LOCKER ROOM, MTR ISSUE ROOM, AND STORAGE AREAS AND RELATED OFFICES. NOTE SECOND "MEZZANINE" FLOOR ABOVE. INL NEGATIVE NO. 10227. Unknown Photographer, 3/23/1954 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  7. FAST CHOPPER BUILDING, TRA665. CAMERA FACING NORTH. NOTE BRICKEDIN WINDOW ...

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

    FAST CHOPPER BUILDING, TRA-665. CAMERA FACING NORTH. NOTE BRICKED-IN WINDOW ON RIGHT SIDE (BELOW PAINTED NUMERALS "665"). SLIDING METAL DOOR ON COVERED RAIL AT UPPER LEVEL. SHELTERED ENTRANCE TO STEEL SHIELDING DOOR. DOOR INTO MTR SERVICE BUILDING, TRA-635, STANDS OPEN. MTR BEHIND CHOPPER BUILDING. INL NEGATIVE NO. HD42-1. Mike Crane, Photographer, 3/2004 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  8. ETR COMPLEX. CAMERA FACING SOUTH. FROM BOTTOM OF VIEW TO ...

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

    ETR COMPLEX. CAMERA FACING SOUTH. FROM BOTTOM OF VIEW TO TOP: MTR, MTR SERVICE BUILDING, ETR CRITICAL FACILITY, ETR CONTROL BUILDING (ATTACHED TO ETR), ETR BUILDING (HIGH-BAY), COMPRESSOR BUILDING (ATTACHED AT LEFT OF ETR), HEAT EXCHANGER BUILDING (JUST BEYOND COMPRESSOR BUILDING), COOLING TOWER PUMP HOUSE, COOLING TOWER. OTHER BUILDINGS ARE CONTRACTORS' CONSTRUCTION BUILDINGS. INL NEGATIVE NO. 56-4105. Unknown Photographer, ca. 1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  9. Development and aging of superficial white matter myelin from young adulthood to old age: Mapping by vertex-based surface statistics (VBSS).

    PubMed

    Wu, Minjie; Kumar, Anand; Yang, Shaolin

    2016-05-01

    Superficial white matter (SWM) lies immediately beneath cortical gray matter and consists primarily of short association fibers. The characteristics of SWM and its development and aging were seldom examined in the literature and warrant further investigation. Magnetization transfer imaging is sensitive to myelin changes in the white matter. Using an innovative multimodal imaging analysis approach, vertex-based surface statistics (VBSS), the current study vertexwise mapped age-related changes of magnetization transfer ratio (MTR) in SWM from young adulthood to old age (30-85 years, N = 66). Results demonstrated regionally selective and temporally heterochronologic changes of SWM MTR with age, including (1) inverted U-shaped trajectories of SWM MTR in the rostral middle frontal, medial temporal, and temporoparietal regions, suggesting continuing myelination and protracted maturation till age 40-50 years and accelerating demyelination at age 60 and beyond, (2) linear decline of SWM MTR in the middle and superior temporal, and pericalcarine areas, indicating early maturation and less acceleration in age-related degeneration, and (3) no significant changes of SWM MTR in the primary motor, somatosensory and auditory regions, suggesting resistance to age-related deterioration. We did not observe similar patterns of changes in cortical thickness in our sample, suggesting the observed SWM MTR changes are not due to cortical atrophy. Hum Brain Mapp 37:1759-1769, 2016. © 2016 Wiley Periodicals, Inc. PMID:26955787

  10. Probable Mechanisms of Needling Therapies for Myofascial Pain Control

    PubMed Central

    Chou, Li-Wei; Kao, Mu-Jung; Lin, Jaung-Geng

    2012-01-01

    Myofascial pain syndrome (MPS) has been defined as a regional pain syndrome characterized by muscle pain caused by myofascial trigger points (MTrPs) clinically. MTrP is defined as the hyperirritable spot in a palpable taut band of skeletal muscle fibers. Appropriate treatment to MTrPs can effectively relieve the clinical pain of MPS. Needling therapies, such as MTrP injection, dry needling, or acupuncture (AcP) can effectively eliminate pain immediately. AcP is probably the first reported technique in treating MPS patients with dry needling based on the Traditional Chinese Medicine (TCM) theory. The possible mechanism of AcP analgesia were studied and published in recent decades. The analgesic effect of AcP is hypothesized to be related to immune, hormonal, and nervous systems. Compared to slow-acting hormonal system, nervous system acts in a faster manner. Given these complexities, AcP analgesia cannot be explained by any single mechanism. There are several principles for selection of acupoints based on the TCM principles: “Ah-Shi” point, proximal or remote acupoints on the meridian, and extra-meridian acupoints. Correlations between acupoints and MTrPs are discussed. Some clinical and animal studies of remote AcP for MTrPs and the possible mechanisms of remote effectiveness are reviewed and discussed. PMID:23346211

  11. A chimeric light-regulated amino acid transport system allows the isolation of blue light regulator (blr) mutants of Neurospora crassa.

    PubMed Central

    Carattoli, A; Kato, E; Rodriguez-Franco, M; Stuart, W D; Macino, G

    1995-01-01

    We have developed a system for the isolation of Neurospora crassa mutants that shows altered responses to blue light. To this end we have used the light-regulated promoter of the albino-3 gene fused to the neutral amino acid permease gene mtr. The product of the mtr gene is required for the uptake of neutral aliphatic and aromatic amino acids, as well as toxic analogs such as p-flurophenylalanine or 4-methyltryptophan. mtr trp-2-carrying cells were transformed with the al-3 promoter-mtr wild-type gene (al-3p-mtr+) to obtain a strain with a light-regulated tryptophan uptake. This strain is sensitive to p-fluorophenylalanine when grown under illumination and resistant when grown in the dark. UV mutagenesis of the al-3p-mtr(+)-carrying strain allowed us to isolate two mutant strains, BLR-1 and BLR-2 (blue light regulator), that are light-resistant to p-fluorophenylalanine and have lost the ability to grow on tryptophan. These two strains have a pale-orange phenotype and show down-regulation of all the photoregulated genes tested (al-3, al-1, con-8, and con-10). Mutations in the BLR strains are not allelic with white collar 1 or white collar 2, regulatory genes that are also involved in the response to blue light. Images Fig. 2 Fig. 3 Fig. 4 PMID:7604041

  12. The Effect of Monochromatic Infrared Photo Energy on the Irritability of Myofascial Trigger Spot of Rabbit Skeletal Muscle

    PubMed Central

    Kuan, Ta-Shen; Lin, Yu-Ching; Lien, Wei-Chih; Hsieh, Pei-Chun; Chung, Yu-Ting; Lin, Sheng-Hsiang; Chou, Li-Wei

    2015-01-01

    Objective. To determine whether the vasodilatation effect of monochromatic infrared photo energy (MIRE) had the potential for the treatment of myofascial trigger spot (MTrS) in rabbits. Design. A randomized-controlled animal study. Subjects. Twelve adult New Zealand rabbits. Methods. For each rabbit, a MTrS (equivalent to a myofascial trigger point in humans) in one side of the biceps femoris muscle was randomly selected for MIRE treatment (experimental side), while another MTrS in the other side (control side) received a sham treatment. The intervention consisted of a daily 40 minutes treatment, three times per week for 2 weeks. The prevalence of endplate noise (EPN) loci in the MTrS was assessed before, immediately after, and one week after the completion of the 2-week treatment. Results. MIRE could suppress the prevalence of EPN in the MTrS. The degree of reduction in EPN prevalence in the MTrS between the experimental side and the control side was significantly different immediately after MIRE treatment, but not significantly different one week after MIRE treatment. Conclusion. Our study suggests that MIRE may be a useful therapeutic option for the management of the myofascial trigger point in humans. PMID:26442122

  13. Remote Subcutaneous Needling to Suppress the Irritability of Myofascial Trigger Spots: An Experimental Study in Rabbits

    PubMed Central

    Fu, Zhonghua; Hsieh, Yueh-Ling; Hong, Chang-Zern; Kao, Mu-Jung; Lin, Jaung-Geng; Chou, Li-Wei

    2012-01-01

    Objective. To obtain electrophysiological effects of Fu's subcutaneous needling (FSN) on needling distance by assessment of endplate noise (EPN) recorded from the myofascial trigger spots (MTrSs) in rabbit skeletal muscle. Method. Eighteen New Zealand rabbits weighing 2.5–3.0 kg were randomly divided into two groups as follows: proximal needling (PN) group and distal needling (DN) group. The needling procedure followed the instructions described by the inventor of FSN, including needling insertion and swaying movement. The amplitudes of EPN on the MTrS region of BF muscle were recorded as an index of MTrS irritability. Random sampling of EPN tracings were taken for further analyses before, during, and after FSN treatment. Results. In PN and DN groups, the trends of EPN amplitude alterations were similar at conditions before, during, and after FSN treatment. The degree of reduction in the EPN amplitude in PN group was significantly higher than that in DN group. There were no significant changes in EPN amplitudes in the MTrS of contralateral BF without FSN intervention either in DN or PN group. Conclusion. The irritability of proximal MTrSs could be modulated after ipsilateral FSNs. The placement of FSN may affect the effectiveness of suppression of irritability of MTrSs. PMID:23346200

  14. Measurement of photon flux with a miniature gas ionization chamber in a Material Testing Reactor

    NASA Astrophysics Data System (ADS)

    Fourmentel, D.; Filliatre, P.; Villard, J. F.; Lyoussi, A.; Reynard-Carette, C.; Carcreff, H.

    2013-10-01

    Nuclear heating measurements in Material Testing Reactors (MTR) are crucial for the design of the experimental devices and the prediction of the temperature of the hosted samples. Nuclear heating in MTR materials (except fuel) is mainly due to the energy deposition by the photon flux. Therefore, the photon flux is a key input parameter for the computer codes which simulate nuclear heating and temperature reached by samples/devices under irradiation. In the Jules Horowitz MTR under construction at the CEA Cadarache, the maximal expected nuclear heating levels will be about 15 to 18 W g-1 and it will be necessary to assess this parameter with the best accuracy. An experiment was performed at the OSIRIS reactor to combine neutron flux, photon flux and nuclear heating measurements to improve the knowledge of the nuclear heating in MTR. There are few appropriate sensors for selective measurement of the photon flux in MTR even if studies and developments are ongoing. An experiment, called CARMEN-1, was conducted at the OSIRIS MTR and we used in particular a gas ionization chamber based on miniature fission chamber design to measure the photon flux. In this paper, we detail Monte-Carlo simulations to analyze the photon fluxes with ionization chamber measurements and we compare the photon flux calculations to the nuclear heating measurements. These results show a good accordance between photon flux measurements and nuclear heating measurement and allow improving the knowledge of these parameters.

  15. Modified pectic polysaccharide from turmeric (Curcuma longa): A potent dietary component against gastric ulcer.

    PubMed

    Harsha, Mysore R; Chandra Prakash, Serkad V; Dharmesh, Shylaja M

    2016-03-15

    Native, intact (TrPP) and modified, low-molecular-weight (MTrPP) forms of pectic polysaccharides isolated from turmeric were evaluated for ulcer-preventive potentials in in vitro and in vivo models. Data indicated that MTrPP possessed significantly better ulcer-preventive property than TrPP; inhibiting ulcer scores up to 85%. Results were substantiated by effective muco-protection, H(+),K(+)-ATPase down-regulation, inhibition of H. pylori growth/adherence, higher antioxidant/cytoprotective mechanisms. Structural data indicated TrPP and MTrPP differ in their molecular weights and structural characteristics with different sugar compositions and side chain ratios. MTrPP was rich in galacturonic acid (687mg/g; TrPP-544mg/g) and galactose (52.9%; TrPP-21.7%). Results were substantiated by NMR/FTIR data indicating the presence of homogalacturonan and rhamnogalacturonam-I containing galactans. By virtue of binding to inflammatory marker (galectin-3), galactans may reduce inflammation induced ulcerations. The low molecular weight of MTrPP (155kDa; TrPP-13kDa) may increase its bioavailability than TrPP, thus MTrPP may possess higher antiulcer potential. PMID:26794747

  16. Diversity and origins of Indian multi-triazole resistant strains of Aspergillus fumigatus.

    PubMed

    Chang, Howard; Ashu, Eta; Sharma, Cheshta; Kathuria, Shallu; Chowdhary, Anuradha; Xu, Jianping

    2016-07-01

    Aspergillus fumigatus is a widespread opportunistic fungal pathogen causing an alarmingly high mortality rate in immunocompromised patients. Nosocomial infections by drug-resistant A. fumigatus strains are of particular concern, and there is a pressing need to understand the origin, dispersal and long-term evolution of drug resistance in this organism. The objective of this study was to investigate the diversity and putative origins of triazole resistance of A. fumigatus from India. Eighty-nine isolates, including 51 multiple triazole resistant (MTR) isolates and 38 azole-susceptible isolates, were genotyped using multilocus sequence typing (MLST), mating typing and PCR fingerprinting. MLST resolved the 51 MTR isolates into three genotypes, two of which have susceptible counterparts, suggesting that MTR isolates originated multiple times in India. The multiple-origin hypothesis was further supported by the diversity of sequences at the triazole target gene CYP51A among the MTR isolates, and by PCR fingerprints. Interestingly, there is abundant evidence for mating and recombination in natural population of A. fumigatus in India, suggesting that sexual spread of TR34 /L98H, the dominant MTR allele, is possible. Our results call for greater attention to MTR in A. fumigatus and for better management of antifungal drug use. PMID:26931802

  17. Moderate treadmill running exercise prior to tendon injury enhances wound healing in aging rats

    PubMed Central

    Zhang, Jianying; Yuan, Ting; Wang, James H-C.

    2016-01-01

    The effect of exercise on wound healing in aging tendon was tested using a rat moderate treadmill running (MTR) model. The rats were divided into an MTR group that ran on a treadmill for 4 weeks and a control group that remained in cages. After MTR, a window defect was created in the patellar tendons of all rats and wound healing was analyzed. We found that MTR accelerated wound healing by promoting quicker closure of wounds, improving the organization of collagen fibers, and decreasing senescent cells in the wounded tendons when compared to the cage control. MTR also lowered vascularization, increased the numbers of tendon stem/progenitor cells (TSCs) and TSC proliferation than the control. Besides, MTR significantly increased the expression of stem cell markers, OCT-4 and Nanog, and tenocyte genes, Collagen I, Collagen III and tenomodulin, and down-regulated PPAR-γ, Collagen II and Runx-2 (non-tenocyte genes). These findings indicated that moderate exercise enhances healing of injuries in aging tendons through TSC based mechanisms, through which exercise regulates beneficial effects in tendons. This study reveals that appropriate exercise may be used in clinics to enhance tendon healing in aging patients. PMID:26885754

  18. Rapid electron exchange between surface-exposed bacterial cytochromes and Fe(III) minerals

    SciTech Connect

    White, Gaye F.; Shi, Zhi; Shi, Liang; Wang, Zheming; Dohnalkova, Alice; Marshall, Matthew J.; Fredrickson, Jim K.; Zachara, John M.; Butt, Julea N.; Richardson, David; Clarke, Thomas A.

    2013-04-16

    The mineral respiring bacterium Shewanella oneidensis uses a protein complex, MtrCAB, composed of two decaheme cytochromes brought together inside a transmembrane porin to transport electrons across the outer membrane to a variety of mineral-based electron acceptors. A proteoliposome system that contains methyl viologen as an internalised electron carrier has been used to investigate how the topology of the MtrCAB complex relates to its ability to transport electrons across a lipid bilayer to externally-located Fe(III) oxides. With MtrA facing the interior and MtrC exposed on the outer surface of the phospholipid bilayer, direct electron transfer from the interior through MtrCAB to solid-phase Fe(III) oxides was demonstrated. The observed rates of conduction through the protein complex were 2 to 3 orders of magnitude higher than that observed in whole cells, demonstrating that direct electron exchange between MtrCAB and Fe(III) oxides is efficient enough to support in-vivo, anaerobic, solid phase iron respiration.

  19. A Cajal body-independent pathway for telomerase trafficking in mice

    SciTech Connect

    Tomlinson, Rebecca L.; Li, Jian; Culp, Bradley R.; Terns, Rebecca M. Terns, Michael P.

    2010-10-15

    The intranuclear trafficking of human telomerase involves a dynamic interplay between multiple nuclear sites, most notably Cajal bodies and telomeres. Cajal bodies are proposed to serve as sites of telomerase maturation, storage, and assembly, as well as to function in the cell cycle-regulated delivery of telomerase to telomeres in human cells. Here, we find that telomerase RNA does not localize to Cajal bodies in mouse cells, and instead resides in separate nuclear foci throughout much of the cell cycle. However, as in humans, mouse telomerase RNA (mTR) localizes to subsets of telomeres specifically during S phase. The localization of mTR to telomeres in mouse cells does not require coilin-containing Cajal bodies, as mTR is found at telomeres at similar frequencies in cells from wild-type and coilin knockout mice. At the same time, we find that human TR localizes to Cajal bodies (as well as telomeres) in mouse cells, indicating that the distinct trafficking of mTR is attributable to an intrinsic property of the RNA (rather than a difference in the mouse cell environment such as the properties of mouse Cajal bodies). We also find that during S phase, mTR foci coalesce into short chains, with at least one of the conjoined mTR foci co-localizing with a telomere. These findings point to a novel, Cajal body-independent pathway for telomerase biogenesis and trafficking in mice.

  20. Voxel-based analysis of grey matter magnetization transfer ratio maps in early relapsing remitting multiple sclerosis.

    PubMed

    Audoin, B; Davies, G; Rashid, W; Fisniku, L; Thompson, A J; Miller, D H

    2007-05-01

    Previous studies using magnetization transfer ratio (MTR) histogram analysis have demonstrated the existence of global grey matter (GM) abnormalities in patients with early relapsing-remitting multiple sclerosis (RRMS). However, MTR histogram analysis does not provide any information on the localization of the morphological changes within the GM. The aim of this study was to investigate the localization of GM injury in early RRMS, performing voxel-based analysis of GM MTR maps. Statistical mapping analysis of GM MTR maps was performed in a group of 38 patients with early RRMS and 45 healthy controls. Between-group comparisons (P<0.05, corrected for multiple comparisons) demonstrated significant GM MTR decrease in patients located in the bilateral lenticular nuclei, the bilateral insula, the left posterior cingulate cortex, and the right orbitofrontal cortex. To limit the potential confounding effect of regional GM atrophy, the percentages of GM were assessed in the regions showing significant MTR decrease, and no GM atrophy was evidenced in these regions. This study demonstrates that several GM regions are commonly affected in patients with early RRMS. Predominant involvement of these structures may be partly related to their vulnerability to anterograde or retrograde degeneration from transected axons in the white matter and/or to the predominant localization of GM demyelinating lesions in such regions. PMID:17463071

  1. Dry Needling Alters Trigger Points in the Upper Trapezius Muscle and Reduces Pain in Subjects with Chronic Myofascial Pain

    PubMed Central

    Gerber, Lynn H.; Shah, Jay; Rosenberger, William; Armstrong, Kathryn; Turo, Diego; Otto, Paul; Heimur, Juliana; Thaker, Nikki; Sikdar, Siddhartha

    2015-01-01

    Objective To determine whether dry needling of an active myofascial trigger point (MTrP) reduces pain and alters the status of the trigger point to either a non-spontaneously tender nodule or its resolution. Design A prospective, non-randomized, controlled interventional clinical study Setting University campus Participants Fifty-six subjects with neck or shoulder girdle pain > 3 months duration and active MTrPs were recruited from a campus-wide, volunteer sample. Fifty-two completed the study (23 male/33 female) with mean age of 35.8 years. Interventions Three weekly dry needling treatments of a single active MTrP Main Outcome Measures Primary Outcomes: Baseline and post treatment evaluations of pain using the verbal analogue scale, the Brief Pain Inventory and the status of the MTrP as determined by digital palpation. Trigger points were rated: active (spontaneously painful), latent (requiring palpation to reproduce the characteristic pain) and resolved (no palpable nodule). Secondary Outcomes: Profile of Mood States, Oswestry Disability Index, Short Form 36, Cervical Range of Motion. Results Primary outcomes: 41 subjects had a change in trigger point status from active to latent or resolved; and 11 had no change (p < .001). Reduction in all pain scores was significant (p<.001). Secondary outcomes: significant improvement in post-treatment cervical rotational asymmetry in subjects with unilateral/bilateral MTrPs (p=.001, p=21, respectively); in pain pressure threshold in subjects with unilateral/bilateral MTrPs, (p=.006, p=.012), respectively; improvement in the SF-36 mental health and physical functioning subscales (p=.019, p=.03) respectively; decrease in the Oswestry disability scale (p=.003). Conclusions Dry needling reduces pain and changes MTrP status. Change in trigger point status is associated with a statistically and clinically significant reduction in pain. Reduction in pain is associated with improved mood, function and level of disability. PMID

  2. A Longitudinal Magnetization Transfer Imaging Evaluation of Brain Injury in a Macaque Model of NeuroAIDS

    PubMed Central

    Li, Chun-Xia; Herndon, James G.; Novembre, Francis J.

    2015-01-01

    Abstract Magnetization transfer (MT) imaging has been explored in prior studies of HIV patients and showed the potential capacity to assess brain injury after HIV infection. In the present study, adult pig-tailed macaques were infected with a highly neuropathogenic virus SIVsmmFGb. MT imaging was exploited to examine the monkey brains before simian immunodeficiency virus (SIV) inoculation and 2, 4, 8, 12, 16, and 20 weeks post-SIV inoculation. Blood samples were collected from each animal for monitoring CD4+ and CD8+ T cells before each MRI scan. The MT ratios (MTR) in several brain regions of interest were evaluated longitudinally. Significant reductions of MTR were observed in whole brain and selected regions of interest (genu, splenium, thalamus, caudate, centrum semiovale, frontal white matter, frontal gray matter, and putamen) in the SIV-infected monkeys, consistent with those reported previously in HIV patients. In particular, the longitudinal results indicate that abnormal MTR reduction can be detected as early as in 2 weeks and MTR may be more sensitive to the brain injury in cortical regions than in subcortical regions during acute SIV infection. In addition, MTR reduction in genu, centrum semiovale, and thalamus significantly correlated with the CD4+ T cell percentage decrease. Also, the MTR reduction in thalamus correlated with the CD8+ T cell percentage elevation. Taken together, this study reported the longitudinal evolution of MTR in different brain regions during SIV infection and further validates previous findings in HIV patients. The preliminary results suggest that MT imaging could be a robust and sensitive approach to characterize the neurodegeneration after SIV or HIV infection. PMID:25376011

  3. Intra-rater reliability of an experienced physiotherapist in locating myofascial trigger points in upper trapezius muscle

    PubMed Central

    Barbero, Marco; Bertoli, Paolo; Cescon, Corrado; Macmillan, Fiona; Coutts, Fiona; Gatti, Roberto

    2012-01-01

    Objectives: Myofascial trigger points (MTrPs) are considered the principal clinical feature of myofascial pain syndrome (MPS). An MTrP consists of spot tenderness within a taut band of muscle fibers and its stimulation can produce both local and referred pain. The clinical diagnosis of MPS depends on correct history taking and a physical examination aimed at identifying the presence of MTrP. The purpose of this study was to investigate the intra-rater reliability of a palpation protocol used for locating an MTrP in the upper trapezius muscle. Methods: Twenty-four subjects with MTrP in the upper trapezius muscle were examined by an experienced physiotherapist. During each of eight experimental sessions, subjects were examined twice in randomized order using a palpation protocol. An anatomical landmark system was defined and the MTrP location established using X and Y values. Results: The intraclass correlation coefficient ICC(1,1) values were 0.62 (95% CI: 0.30–0.81) for X and 0.81 (95% CI: 0.61–0.91) for Y. The Bland–Altman plots for X and Y showed a mean of difference of 0.04 and −0.2 mm, respectively. Limits of agreement for X ranged from −26.3 to 26.2 mm and for Y from −27 to 26.4 mm. Discussion: The ICC(1,1) for the observed values revealed a moderate to high correlation and the Bland–Altman analysis showed means of difference very close to zero with narrow limits of agreement. An experienced physiotherapist can reliably identify MTrP locations in upper trapezius muscle using a palpation protocol. PMID:24179324

  4. Anticancer drug mithramycin interacts with core histones: An additional mode of action of the DNA groove binder

    PubMed Central

    Banerjee, Amrita; Sanyal, Sulagna; Kulkarni, Kirti K.; Jana, Kuladip; Roy, Siddhartha; Das, Chandrima; Dasgupta, Dipak

    2014-01-01

    Mithramycin (MTR) is a clinically approved DNA-binding antitumor antibiotic currently in Phase 2 clinical trials at National Institutes of Health for treatment of osteosarcoma. In view of the resurgence in the studies of this generic antibiotic as a human medicine, we have examined the binding properties of MTR with the integral component of chromatin – histone proteins – as a part of our broad objective to classify DNA-binding molecules in terms of their ability to bind chromosomal DNA alone (single binding mode) or both histones and chromosomal DNA (dual binding mode). The present report shows that besides DNA, MTR also binds to core histones present in chromatin and thus possesses the property of dual binding in the chromatin context. In contrast to the MTR–DNA interaction, association of MTR with histones does not require obligatory presence of bivalent metal ion like Mg2+. As a consequence of its ability to interact with core histones, MTR inhibits histone H3 acetylation at lysine 18, an important signature of active chromatin, in vitro and ex vivo. Reanalysis of microarray data of Ewing sarcoma cell lines shows that upon MTR treatment there is a significant down regulation of genes, possibly implicating a repression of H3K18Ac-enriched genes apart from DNA-binding transcription factors. Association of MTR with core histones and its ability to alter post-translational modification of histone H3 clearly indicates an additional mode of action of this anticancer drug that could be implicated in novel therapeutic strategies. PMID:25473595

  5. Myofascial Trigger Points Then and Now: A Historical and Scientific Perspective

    PubMed Central

    Shah, Jay P.; Thaker, Nikki; Heimur, Juliana; Aredo, Jacqueline V.; Sikdar, Siddhartha; Gerber, Lynn H.

    2015-01-01

    The intent of this paper is to discuss the evolving role of the myofascial trigger point (MTrP) in myofascial pain syndrome (MPS) from both a historical and scientific perspective. MTrPs are hard, discrete, palpable nodules in a taut band of skeletal muscle that may be spontaneously painful (i.e. active), or painful only on compression (i.e. latent). MPS is a term used to describe a pain condition which can be acute or, more commonly, chronic and involves the muscle and its surrounding connective tissue (e.g. fascia). According to Travell and Simons, MTrPs are central to the syndrome—but are they necessary? Although the clinical study of muscle pain and MTrPs has proliferated over the past two centuries, the scientific literature often seems disjointed and confusing. Unfortunately, much of the terminology, theories, concepts, and diagnostic criteria are inconsistent, incomplete, or controversial. In order to address these deficiencies, investigators have recently applied clinical, imaging (of skeletal muscle and brain), and biochemical analyses to systematically and objectively study the MTrP and its role in MPS. Data suggest that the soft tissue milieu around the MTrP, neurogenic inflammation, sensitization, and limbic system dysfunction may all play a role in the initiation, amplification, and perpetuation of MPS. The authors will chronicle the advances that have led to the current understanding of MTrP pathophysiology and its relationship to MPS, and review the contributions of clinicians and researchers who have influenced and expanded our contemporary level of clinical knowledge and practice. PMID:25724849

  6. Meta-Analysis of Studies Comparing Single and Multi-Tablet Fixed Dose Combination HIV Treatment Regimens

    PubMed Central

    Clay, P.G.; Nag, S.; Graham, C.M.; Narayanan, S.

    2015-01-01

    Abstract Availability of a single source review of once-daily fixed-dose single tablet regimen (STR) and multiple tablet fixed-dose regimen (MTR) would optimally inform healthcare providers and policy makers involved in the management of population with human immunodeficiency virus (HIV). We conducted a meta-analysis of published literature to compare patient adherence, clinical, and cost outcomes of STR to MTR. Published literature in English between 2005 and 2014 was searched using Embase, PubMed (Medline in-process), and ClinicalTrials.Gov databases. Two-level screening was undertaken by 2 independent researchers to finalize articles for evidence synthesis. Adherence, efficacy, safety, tolerability, healthcare resource use (HRU), and costs were assessed comparing STR to MTR. A random-effects meta-analysis was performed and heterogeneity examined using meta-regression. Thirty-five articles were identified for qualitative evidence synthesis, of which 9 had quantifiable data for meta-analysis (4 randomized controlled trials and 5 observational studies). Patients on STR were significantly more adherent when compared to patients on MTR of any frequency (odds ratio [OR]: 2.37 [95% CI: 1.68, 3.35], P < 0.001; 4 studies), twice-daily MTR (OR: 2.53 [95% CI: 1.13, 5.66], P = 0.02; 2 studies), and once-daily MTR (OR: 1.81 [95% CI: 1.15, 2.84], P = 0.01; 2 studies). The relative risk (RR) for viral load suppression at 48 weeks was higher (RR: 1.09 [95% CI: 1.04, 1.15], P = .0003; 3 studies) while RR of grade 3 to 4 laboratory abnormalities was lower among patients on STR (RR: 0.68 [95% CI: 0.49, 0.94], P = 0.02; 2 studies). Changes in CD4 count at 48 weeks, any severe adverse events (SAEs), grade 3 to 4 AEs, mortality, and tolerability were found comparable between STR and MTR. Several studies reported significant reduction in HRU and costs among STR group versus MTR. Study depicted comparable tolerability, safety (All-SAE and Grade 3–4 AE), and

  7. Effect of Treatment with Interferon Beta-1a on Changes in Voxel-Wise Magnetization Transfer Ratio in Normal Appearing Brain Tissue and Lesions of Patients with Relapsing–Remitting Multiple Sclerosis: A 24-Week, Controlled Pilot Study

    PubMed Central

    Zivadinov, Robert; Dwyer, Michael G.; Markovic-Plese, Silva; Kennedy, Cheryl; Bergsland, Niels; Ramasamy, Deepa P.; Durfee, Jacqueline; Hojnacki, David; Hayward, Brooke; Dangond, Fernando; Weinstock-Guttman, Bianca

    2014-01-01

    Background This pilot study investigated changes in remyelinating and demyelinating activity in normal appearing brain tissue (NABT) and lesions, by using voxel-wise magnetization transfer ratio (VW-MTR), in patients with relapsing–remitting multiple sclerosis (RRMS) receiving interferon beta-1a 44 mcg subcutaneously (IFN β-1a SC) three times weekly versus healthy controls (HCs) (NCT01085318). Methods Increasing (suggestive of remyelination) and decreasing (suggestive of demyelination) VW-MTR changes in NABT and in T2, T1 and gadolinium (Gd)-enhancing lesion volume were measured over 24 weeks in 23 patients treated with IFN β-1a SC and in 15 HCs (where applicable). VW-MTR changes were tested using the Wilcoxon signed–rank or Wilcoxon rank–sum test. Results A trend for greater volume of NABT with increasing VW-MTR at 24 weeks was observed for patients versus HCs (median [range] 1206 [0–15278]; 342 [0–951] mm3; p = 0.061). NABT volume with increasing VW-MTR at 12 weeks was significantly greater in patients than in HCs (852 [6–11577]; 360 [0–1755] mm3; p = 0.028). Similar findings were detected for lesion volumes. Two patients with notably high numbers of Gd-enhancing lesions at baseline had a markedly greater volume of tissue with increasing VW-MTR compared with other patients. Volume of NABT tissue with decreasing VW-MTR was significantly greater in patients versus HCs at 24 weeks (942 [0–6141]; 297 [0–852] mm3; p<0.001). Conclusions The significant change in NABT volume with increasing VW-MTR at 12 weeks suggests that active remyelination in patients with RRMS may occur during treatment with IFN β-1a SC. Findings from two patients with the highest number of Gd-enhancing lesions at baseline suggest that extensive remyelination in NABT may occur in patients with high disease activity. Tissue volume with decreasing VW-MTR was greater in patients than in HCs, despite treatment, validating the sensitivity of this technique for detecting MS

  8. Meta-Analysis of Studies Comparing Single and Multi-Tablet Fixed Dose Combination HIV Treatment Regimens.

    PubMed

    Clay, P G; Nag, S; Graham, C M; Narayanan, S

    2015-10-01

    Availability of a single source review of once-daily fixed-dose single tablet regimen (STR) and multiple tablet fixed-dose regimen (MTR) would optimally inform healthcare providers and policy makers involved in the management of population with human immunodeficiency virus (HIV).We conducted a meta-analysis of published literature to compare patient adherence, clinical, and cost outcomes of STR to MTR.Published literature in English between 2005 and 2014 was searched using Embase, PubMed (Medline in-process), and ClinicalTrials.Gov databases. Two-level screening was undertaken by 2 independent researchers to finalize articles for evidence synthesis. Adherence, efficacy, safety, tolerability, healthcare resource use (HRU), and costs were assessed comparing STR to MTR. A random-effects meta-analysis was performed and heterogeneity examined using meta-regression.Thirty-five articles were identified for qualitative evidence synthesis, of which 9 had quantifiable data for meta-analysis (4 randomized controlled trials and 5 observational studies). Patients on STR were significantly more adherent when compared to patients on MTR of any frequency (odds ratio [OR]: 2.37 [95% CI: 1.68, 3.35], P < 0.001; 4 studies), twice-daily MTR (OR: 2.53 [95% CI: 1.13, 5.66], P = 0.02; 2 studies), and once-daily MTR (OR: 1.81 [95% CI: 1.15, 2.84], P = 0.01; 2 studies). The relative risk (RR) for viral load suppression at 48 weeks was higher (RR: 1.09 [95% CI: 1.04, 1.15], P = .0003; 3 studies) while RR of grade 3 to 4 laboratory abnormalities was lower among patients on STR (RR: 0.68 [95% CI: 0.49, 0.94], P = 0.02; 2 studies). Changes in CD4 count at 48 weeks, any severe adverse events (SAEs), grade 3 to 4 AEs, mortality, and tolerability were found comparable between STR and MTR. Several studies reported significant reduction in HRU and costs among STR group versus MTR.Study depicted comparable tolerability, safety (All-SAE and Grade 3-4 AE), and mortality and fewer Grade 3 to 4 lab

  9. Efficacy of Myofascial Trigger Point Dry Needling in the Prevention of Pain after Total Knee Arthroplasty: A Randomized, Double-Blinded, Placebo-Controlled Trial

    PubMed Central

    Mayoral, Orlando; Salvat, Isabel; Martín, María Teresa; Martín, Stella; Santiago, Jesús; Cotarelo, José; Rodríguez, Constantino

    2013-01-01

    The aim of this study was to determine whether the dry needling of myofascial trigger points (MTrPs) is superior to placebo in the prevention of pain after total knee arthroplasty. Forty subjects were randomised to a true dry needling group (T) or to a sham group (S). All were examined for MTrPs by an experienced physical therapist 4–5 hours before surgery. Immediately following anesthesiology and before surgery started, subjects in the T group were dry needled in all previously diagnosed MTrPs, while the S group received no treatment in their MTrPs. Subjects were blinded to group allocation as well as the examiner in presurgical and follow-up examinations performed 1, 3, and 6 months after arthroplasty. Subjects in the T group had less pain after intervention, with statistically significant differences in the variation rate of the visual analogue scale (VAS) measurements 1 month after intervention and in the need for immediate postsurgery analgesics. Differences were not significant at 3- and 6-month follow-up examinations. In conclusion, a single dry needling treatment of MTrP under anaesthesia reduced pain in the first month after knee arthroplasty, when pain was the most severe. Results show a superiority of dry needling versus placebo. An interesting novel placebo methodology for dry needling, with a real blinding procedure, is presented. PMID:23606888

  10. Characterization of microcrystalline cellulose and silicified microcrystalline cellulose wet masses using a powder rheometer.

    PubMed

    Luukkonen, P; Schaefer, T; Podczeck, F; Newton, M; Hellén, L; Yliruusi, J

    2001-05-01

    A powder rheometer has been used to study the properties of wet powder masses and the results have been compared to the mixer torque rheometer (MTR). Two different microcrystalline cellulose (MCC) grades (Avicel and Emcocel) and silicified microcrystalline cellulose (SMCC, Prosolv) were used as model powders. The wet massing behaviour of one material (Prosolv) was studied by the powder rheometer using liquid addition experiments, while the rheological properties of wet granules were studied using both the powder rheometer and the MTR. In water addition measurements the torque behaved in a similar way to MTR measurements and the maximum value of ZTL (zero torque limit) was achieved at the capillary state of wet mass. The wet granules exhibited different behaviour in the powder rheometer and the MTR experiments, which indicates that these rheometers involve different shear forces or they measure different properties of the wet granules. Emcocel wet masses achieved the capillary state at lower liquid amount than Avicel and Prosolv masses, which indicates that Emcocel is not able to hold as much water in the internal structure as Avicel and Prosolv. The powder rheometer proved to be a sensitive piece of equipment, which can be used to study both dry and wet powder masses. It was able to distinguish wet granules from wet powder masses after liquid addition, whereas the MTR could not. However, before the powder rheometer can be properly utilised in wet powder mass studies, the problem of torque overload requires resolution. PMID:11297898