Science.gov

Sample records for 10-2 cm2 v-1

  1. Nondispersive hole transport in a polyfluorene copolymer with a mobility of 0.01 cm2 V-1 s-1

    NASA Astrophysics Data System (ADS)

    Fong, H. H.; Papadimitratos, Alexios; Malliaras, George G.

    2006-10-01

    The hole mobility in the fluorene copolymer poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)) diphenylamine)] (TFB) was measured using the time-of-flight technique. Transport was found to be nondispersive throughout the temperature range between 220 and 350K, indicating the absence of intrinsic traps in this material. At room temperature, TFB shows a hole mobility of 0.01cm2V-1s-1, with a weak field dependence. The hole mobility is independent of sample thickness in the range between 0.9 and 6.4μm. These results are in agreement with a narrow transport manifold, with a width of 65.9±0.5meV.

  2. Electron Mobility Exceeding 10 cm(2) V(-1) s(-1) and Band-Like Charge Transport in Solution-Processed n-Channel Organic Thin-Film Transistors.

    PubMed

    Xu, Xiaomin; Yao, Yifan; Shan, Bowen; Gu, Xiao; Liu, Danqing; Liu, Jinyu; Xu, Jianbin; Zhao, Ni; Hu, Wenping; Miao, Qian

    2016-07-01

    Solution-processed n-channel organic thin-film transistors (OTFTs) that exhibit a field-effect mobility as high as 11 cm(2) V(-1) s(-1) at room temperature and a band-like temperature dependence of electron mobility are reported. By comparison of solution-processed OTFTs with vacuum-deposited OTFTs of the same organic semiconductor, it is found that grain boundaries are a key factor inhibiting band-like charge transport. PMID:27151777

  3. High Charge-Carrier Mobility of 2.5 cm(2) V(-1) s(-1) from a Water-Borne Colloid of a Polymeric Semiconductor via Smart Surfactant Engineering.

    PubMed

    Cho, Jangwhan; Cheon, Kwang Hee; Ahn, Hyungju; Park, Kwang Hun; Kwon, Soon-Ki; Kim, Yun-Hi; Chung, Dae Sung

    2015-10-01

    Semiconducting polymer nanoparticles dispersed in water are synthesized by a novel method utilizing non-ionic surfactants. By developing a smart surfactant engineering technique involving a selective post-removal process of surfactants, an unprecedentedly high mobility of 2.51 cm(2) V(-1) s(-1) from a water-borne colloid is demonstrated for the first time. PMID:26288123

  4. Growth of ˜5 cm2V-1s-1 mobility, p-type Copper(I) oxide (Cu2O) films by fast atmospheric atomic layer deposition (AALD) at 225°C and below

    NASA Astrophysics Data System (ADS)

    Muñoz-Rojas, D.; Jordan, M.; Yeoh, C.; Marin, A. T.; Kursumovic, A.; Dunlop, L. A.; Iza, D. C.; Chen, A.; Wang, H.; MacManus Driscoll, J. L.

    2012-12-01

    Phase pure, dense Cu2O thin films were grown on glass and polymer substrates at 225°C by rapid atmospheric atomic layer deposition (AALD). Carrier mobilities of 5 cm2V-1s-1 and carrier concentrations of ˜1016 cm-3 were achieved in films of thickness 50 - 120 nm, over a >10 cm2 area. Growth rates were ˜1 nm.min-1 which is two orders of magnitude faster than conventional ALD.. The high mobilities achieved using the atmospheric, low temperature method represent a significant advance for flextronics and flexible solar cells which require growth on plastic substrates.

  5. Mg dopant in Cu2SnSe3: An n-type former and a promoter of electrical mobility up to 387 cm2 V-1 s-1

    NASA Astrophysics Data System (ADS)

    Kuo, Dong-Hau; Wubet, Walelign

    2014-10-01

    Mg-doped Cu2SnSe3 bulk materials with the (Cu2-xMgx)SnSe3 (Mg-x-CTSe) formula at x=0, 0.05, 0.1, 0.15, and 0.2 were prepared at 550 °C for 2 h with soluble sintering aids of Sb2S3 and Te. Defect chemistry was studied by measuring structural and electrical properties of Mg-doped Cu2SnSe3 as a function of dopant concentration. Mg-x-CTSe pellets show p-type at x=0, 0.05 and 0.1 and n-type at x=0.15 and 0.2. The low hole concentration of 3.2×1017 cm-3 and high mobility of 387 cm2 V-1 s-1 were obtained for (Cu2-xMgx)SnSe3 bulks at x=0.1 (5% Mg) as compared to 2.2×1018 cm-3 and 91 cm2 V-1 s-1 for the undoped one. The explanation based upon the Mg-to-Cu antisite donor defect for the changes in electrical property was declared. A high Mg content for Mg-x-CTSe at x≥0.1 can lead to the formation of second phases. The study in bulk Mg-x-CTSe has been based upon defect states and is consistent and supported by the data of structural and electrical properties.

  6. Mg dopant in Cu2ZnSnSe4: An n-type former and a promoter of electrical mobility up to 120 cm2 V-1 s-1

    NASA Astrophysics Data System (ADS)

    Kuo, Dong-Hau; Wubet, Walelign

    2014-07-01

    Mg-doped Cu2ZnSnSe4 (CZTSe) bulk materials with the (Cu2-xMgx)ZnSnSe4 formula at x=0, 0.1, 0.2, 0.3, and 0.4 were prepared at 600 °C for 2 h with soluble sintering aids of Sb2S3 and Te. Defect chemistry was studied by measuring structural and electrical properties of Mg-doped CZTSe as a function of dopant concentration. Except at x=0, all Mg-doped CZTSe pellets showed an n-type behavior. The Mg-doped CZTSe pellets showed an n-type behavior. n-Type Mg-CZTSe pellets at x=0.1 showed the highest electrical conductivity of 24.6 S cm-1 and the net hole mobility of 120 cm2 V-1 s-1, while they were 11.8 S cm-1 and 36.5 cm2 V-1 s-1 for the undoped p-type CZTSe. Mg dopant is a strong promoter of electrical mobility. Mg dopant behaves as a donor defect in CZTSe at a 5% doping content, but is also used as an acceptor at a high content above 5%. Mg doping has further developed CZTSe into a promising semiconductor.

  7. AMR on the CM-2

    NASA Technical Reports Server (NTRS)

    Berger, Marsha J.; Saltzman, Jeff S.

    1992-01-01

    We describe the development of a structured adaptive mesh algorithm (AMR) for the Connection Machine-2 (CM-2). We develop a data layout scheme that preserves locality even for communication between fine and coarse grids. On 8K of a 32K machine we achieve performance slightly less than 1 CPU of the Cray Y-MP. We apply our algorithm to an inviscid compressible flow problem.

  8. Lessons Learned From CM-2 Modal Testing and Analysis

    NASA Technical Reports Server (NTRS)

    McNelis, Mark E.; Goodnight, Thomas W.; Carney, Kelly S.; Otten, Kim D.

    2002-01-01

    The Combustion Module-2 (CM-2) is a space experiment that launches on Shuttle mission STS-107 in the SPACEHAB Double Research Module. The CM-2 flight hardware is installed into SPACEHAB single and double racks. The CM-2 flight hardware was vibration tested in the launch configuration to characterize the structure's modal response. Cross-orthogonality between test and analysis mode shapes were used to assess model correlation. Lessons learned for pre-test planning and model verification are discussed.

  9. Characterization of Luminescent Minerals in CM2 Chondrite (Jbilet Winselwan)

    NASA Astrophysics Data System (ADS)

    Kiku, Y. K.; Ohgo, S. O.; Nishido, H. N.

    2014-09-01

    We have characterized luminescent minerals of forsterite, diopside and spinel in the CM2 chondrite (Jbilet Winselwan) using SEM-CL and to discuss the formation of the luminescent minerals under aqueous conditions.

  10. CM-2 Environmental / Modal Testing of Spacehab Racks

    NASA Technical Reports Server (NTRS)

    McNelis, Mark E.; Goodnight, Thomas W.; Farkas, Michael A.

    2001-01-01

    Combined environmental/modal vibration testing has been implemented at the NASA Glenn Research Center's Structural Dynamics Laboratory. The benefits of combined vibration testing are that it facilitates test article modal characterization and vibration qualification testing. The Combustion Module-2 (CM-2) is a space experiment that launches on Shuttle mission STS 107 in the SPACEHAB Research Double Module. The CM-2 flight hardware is integrated into a SPACEHAB single and double rack. CM-2 rack level combined vibration testing was recently completed on a shaker table to characterize the structure's modal response and verify the random vibration response. Control accelerometers and limit force gauges, located between the fixture and rack interface, were used to verify the input excitation. Results of the testing were used to verify the loads and environments for flight on the Shuttle.

  11. CM-2 Environmental/Modal Testing of SPACEHAB Racks

    NASA Technical Reports Server (NTRS)

    McNelis, Mark E.; Goodnight, Thomas W.

    2001-01-01

    Combined environmental/modal vibration testing has been implemented at the NASA Glenn Research Center's Structural Dynamics Laboratory. The benefits of combined vibration testing are that it facilitates test article modal characterization and vibration qualification testing. The Combustion Module-2 (CM-2) is a space experiment that will launch on shuttle mission STS-107 in the SPACEHAB Research Double Module. The CM-2 flight hardware is integrated into a SPACEHAB single and double rack. CM-2 rack-level combined vibration testing was recently completed on a shaker table to characterize the structure's modal response and verify the random vibration response. Control accelerometers and limit force gauges, located between the fixture and rack interface, were used to verify the input excitation. Results of the testing were used to verify the loads and environments for flight on the shuttles.

  12. Benchmarking and performance analysis of the CM-2. [SIMD computer

    NASA Technical Reports Server (NTRS)

    Myers, David W.; Adams, George B., II

    1988-01-01

    A suite of benchmarking routines testing communication, basic arithmetic operations, and selected kernel algorithms written in LISP and PARIS was developed for the CM-2. Experiment runs are automated via a software framework that sequences individual tests, allowing for unattended overnight operation. Multiple measurements are made and treated statistically to generate well-characterized results from the noisy values given by cm:time. The results obtained provide a comparison with similar, but less extensive, testing done on a CM-1. Tests were chosen to aid the algorithmist in constructing fast, efficient, and correct code on the CM-2, as well as gain insight into what performance criteria are needed when evaluating parallel processing machines.

  13. Microbiological study of the Murchison CM2 meteorite

    NASA Astrophysics Data System (ADS)

    Pikuta, Elena V.; Hoover, Richard B.

    2012-10-01

    In 1864, Louis Pasteur attempted to cultivate living microorganisms from pristine samples of the Orgueil CI1 carbonaceous meteorite. His results were negative and never published, but recorded it in his laboratory notebooks. At that time, only aerobic liquid or agar-based organic reach media were used, as his research on anaerobes had just started. In our laboratory the Murchison CM2 carbonaceous meteorite was selected to expand on these studies for microbiological study by cultivation on anaerobic mineral media. Since the surface could have been more easily contaminated, interior fragments of a sample of the Murchison meteorite were extracted and crushed under sterile conditions. The resulting powder was then mixed in anoxic medium and injected into Hungate tubes containing anaerobic media with various growth substrates at different pH and salinity and incubated at different temperatures. The goal of the experiments was to determine if living cells would grow from the material of freshly fractured interior fragments of the stone. If any growth occurred, work could then be carried out to assess the nature of the environmental contamination by observations of the culture growth (rates of speed and biodiversity); live/dead fluorescent staining to determine contamination level and DNA analysis to establish the microbial species present. In this paper we report the results of that study.

  14. Presolar grains in the CM2 chondrite Sutter's Mill

    NASA Astrophysics Data System (ADS)

    Zhao, Xuchao; Lin, Yangting; Yin, Qing-Zhu; Zhang, Jianchao; Hao, Jialong; Zolensky, Michael; Jenniskens, Peter

    2014-11-01

    The Sutter's Mill (SM) carbonaceous chondrite is a regolith breccia, composed predominantly of CM2 clasts with varying degrees of aqueous alteration and thermal metamorphism. An investigation of presolar grains in four Sutter's Mill sections, SM43, SM51, SM2-4, and SM18, was carried out using NanoSIMS ion mapping technique. A total of 37 C-anomalous grains and one O-anomalous grain have been identified, indicating an abundance of 63 ppm for presolar C-anomalous grains and 2 ppm for presolar oxides. Thirty-one silicon carbide (SiC), five carbonaceous grains, and one Al-oxide (Al2O3) were confirmed based on their elemental compositions determined by C-N-Si and O-Si-Mg-Al isotopic measurements. The overall abundance of SiC grains in Sutter's Mill (55 ppm) is consistent with those in other CM chondrites. The absence of presolar silicates in Sutter's Mill suggests that they were destroyed by aqueous alteration on the parent asteroid. Furthermore, SM2-4 shows heterogeneous distributions of presolar SiC grains (12-54 ppm) in different matrix areas, indicating that the fine-grained matrix clasts come from different sources, with various thermal histories, in the solar nebula.

  15. IEP Prov v.1

    ERIC Educational Resources Information Center

    Steel, Lawrence E.

    2005-01-01

    Perhaps the most time consuming task facing today's busy special educator is keeping up with all the paperwork associated with national, state and local regulations. IEP Pro v.1-a PC and Macintosh compatible CD-ROM program-creates IEP's, then tracks and manages many of the administrative and paperwork tasks associated with running a special…

  16. Development of carbon foils with a thickness of up to 600 μg/cm 2

    NASA Astrophysics Data System (ADS)

    Kindler, Birgit; Hartmann, Willi; Hübner, Annett; Lommel, Bettina; Steiner, Jutta

    2010-02-01

    Carbon foils are applied as stripper for the heavy-ion accelerator as well as targets in different experiments at GSI. Carbon foils in a thickness range 5-100 μg/cm 2 are routinely produced with good homogeneity and excellent durability. Foils thicker than 100 μg/cm 2 used to be purchased. To overcome problems that emerged and intensified in some applications we started to advance our own carbon production towards higher thickness. We describe the production of carbon foils up to a thickness of 600 μg/cm 2, report on first tests as stripper foils and as targets, and discuss our future plans.

  17. Development and characterization of a 280 cm2 vanadium/oxygen fuel cell

    NASA Astrophysics Data System (ADS)

    Noack, Jens; Cremers, Carsten; Bayer, Domnik; Tübke, Jens; Pinkwart, Karsten

    2014-05-01

    A vanadium/oxygen fuel cell with an active area of 280 cm2 has been developed. The cell consisted of two membranes with two half-cells and an intermediate chamber. The maximum achieved power density was 23 mW cm-2 at 0.56 V with lambda air = 3 and a 1.6 M V2+ solution at room temperature. The average discharge power density was 19.6 mW cm-2 at a constant current density of 40 mA cm-2 with an average voltage efficiency of 33%. The fuel based energy density was 18.2% of the theoretical value with 11.8 Wh L-1. In comparison with a similarly constructed 50 cm2 cell, both achieved similar performance levels. An analysis using the half-cell potential profiles and by means of impedance spectroscopy revealed that, as for the 50 cm2 cell, the low rate of oxygen reduction reaction significantly affected the performance of the cell. Thus gives potential for the optimization of the cathode reaction and a reduction in the ohmic resistances potential for higher power densities.

  18. GFDL's CM2 global coupled climate models. Part I: Formulation and simulation characteristics

    USGS Publications Warehouse

    Delworth, T.L.; Broccoli, A.J.; Rosati, A.; Stouffer, R.J.; Balaji, V.; Beesley, J.A.; Cooke, W.F.; Dixon, K.W.; Dunne, J.; Dunne, K.A.; Durachta, J.W.; Findell, K.L.; Ginoux, P.; Gnanadesikan, A.; Gordon, C.T.; Griffies, S.M.; Gudgel, R.; Harrison, M.J.; Held, I.M.; Hemler, R.S.; Horowitz, L.W.; Klein, S.A.; Knutson, T.R.; Kushner, P.J.; Langenhorst, A.R.; Lee, H.-C.; Lin, S.-J.; Lu, J.; Malyshev, S.L.; Milly, P.C.D.; Ramaswamy, V.; Russell, J.; Schwarzkopf, M.D.; Shevliakova, E.; Sirutis, J.J.; Spelman, M.J.; Stern, W.F.; Winton, M.; Wittenberg, A.T.; Wyman, B.; Zeng, F.; Zhang, R.

    2006-01-01

    The formulation and simulation characteristics of two new global coupled climate models developed at NOAA's Geophysical Fluid Dynamics Laboratory (GFDL) are described. The models were designed to simulate atmospheric and oceanic climate and variability from the diurnal time scale through multicentury climate change, given our computational constraints. In particular, an important goal was to use the same model for both experimental seasonal to interannual forecasting and the study of multicentury global climate change, and this goal has been achieved. Tw o versions of the coupled model are described, called CM2.0 and CM2.1. The versions differ primarily in the dynamical core used in the atmospheric component, along with the cloud tuning and some details of the land and ocean components. For both coupled models, the resolution of the land and atmospheric components is 2?? latitude ?? 2.5?? longitude; the atmospheric model has 24 vertical levels. The ocean resolution is 1?? in latitude and longitude, with meridional resolution equatorward of 30?? becoming progressively finer, such that the meridional resolution is 1/3?? at the equator. There are 50 vertical levels in the ocean, with 22 evenly spaced levels within the top 220 m. The ocean component has poles over North America and Eurasia to avoid polar filtering. Neither coupled model employs flux adjustments. The co ntrol simulations have stable, realistic climates when integrated over multiple centuries. Both models have simulations of ENSO that are substantially improved relative to previous GFDL coupled models. The CM2.0 model has been further evaluated as an ENSO forecast model and has good skill (CM2.1 has not been evaluated as an ENSO forecast model). Generally reduced temperature and salinity biases exist in CM2.1 relative to CM2.0. These reductions are associated with 1) improved simulations of surface wind stress in CM2.1 and associated changes in oceanic gyre circulations; 2) changes in cloud tuning and

  19. Aliphatic amines in Antarctic CR2, CM2, and CM1/2 carbonaceous chondrites

    NASA Astrophysics Data System (ADS)

    Aponte, José C.; McLain, Hannah L.; Dworkin, Jason P.; Elsila, Jamie E.

    2016-09-01

    Meteoritic water-soluble organic compounds provide a unique record of the processes that occurred during the formation of the solar system and the chemistry preceding the origins of life on Earth. We have investigated the molecular distribution, compound-specific δ13C isotopic ratios and enantiomeric compositions of aliphatic monoamines present in the hot acid-water extracts of the carbonaceous chondrites LAP 02342 (CR2), GRA 95229 (CR2), LON 94101 (CM2), LEW 90500 (CM2), and ALH 83100 (CM1/2). Analyses of the concentration of monoamines in these meteorites revealed: (a) the CR2 chondrites studied here contain higher concentrations of monoamines relative to the analyzed CM2 chondrites; (b) the concentration of monoamines decreases with increasing carbon number; and (c) isopropylamine is the most abundant monoamine in these CR2 chondrites, while methylamine is the most abundant amine species in these CM2 and CM1/2 chondrites. The δ13C values of monoamines in CR2 chondrite do not correlate with the number of carbon atoms; however, in CM2 and CM1/2 chondrites, the 13C enrichment decreases with increasing monoamine carbon number. The δ13C values of methylamine in CR2 chondrites ranged from -1 to +10‰, while in CM2 and CM1/2 chondrites the δ13C values of methylamine ranged from +41 to +59‰. We also observed racemic compositions of sec-butylamine, 3-methyl-2-butylamine, and sec-pentylamine in the studied carbonaceous chondrites. Additionally, we compared the abundance and δ13C isotopic composition of monoamines to those of their structurally related amino acids. We found that monoamines are less abundant than amino acids in CR2 chondrites, with the opposite being true in CM2 and CM1/2 chondrites. We used these collective data to evaluate different primordial synthetic pathways for monoamines in carbonaceous chondrites and to understand the potential common origins these molecules may share with meteoritic amino acids.

  20. Searching for HI at NHI~1017 cm-2 around nearby galaxies.

    NASA Astrophysics Data System (ADS)

    Pisano, Daniel J.; Lockman, Felix J.; Wolfe, Spencer A.

    2015-01-01

    One of the outstanding questions in astronomy today is how galaxies obtain the gas that they need to continue forming stars for more than a few billion years. Simulations suggest that for low mass galaxies in low density environments, gas should remain cool while it is accreted along filaments from the intergalactic medium. Unfortunately, to date, observations have identified only about 10% of the needed accretion to sustain star formation. Most of these searches have been limited to searching for neutral hydrogen (HI) at column densities above 1019 cm-2. We have used the Green Bank Telescope (GBT) to search for cold accretion being traced by HI in emission down to NHI~1017 cm-2 around three local galaxies. I will report on the results of our search and the implications for the accretion rate in the local universe.

  1. Molecular Composition of Carbonaceous Globules in the Bells (CM2) Chondrite

    NASA Technical Reports Server (NTRS)

    Clemett, S. J.; Nakamura-Messenger, K.; Thomas-Keprta, K. L.; Robinson, G.-A.; Mckay, D. S.

    2009-01-01

    Some meteorites and IDPs contain micron-size carbonaceous globules that are associated with significant H and/or N isotopic anomalies. This has been interpreted as indicating that such globules may contain at least partial preserved organic species formed in the outer reaches of the proto-solar disk or the presolar cold molecular cloud. Owing to their small sizes, relatively little is known about their chemical compositions. Here we present in situ measurements of aromatic molecular species in organic globules from the Bells (CM2) chondrite by microprobe two-step laser mass spectrometry. This meteorite was chosen for study because we have previously found this meteorite to contain high abundances of globules that often occur in clusters. The Bells (CM2) globules are also noteworthy for having particularly high enrichments in H-2. and N-15. In this study, we identified individual globules and clusters of globules using native UV fluorescence.

  2. The EET87513 clast N: A CM2 fragment in an HED polymict breccia

    NASA Technical Reports Server (NTRS)

    Buchanan, P. C.; Zolensky, M. E.; Reid, A. M.; Barrett, R. A.

    1993-01-01

    Xenoliths of material resembling carbonaceous chondrites have been found in several HED polymict breccias. Most workers concluded that these clasts are related to CM2 meteorites on the basis of texture, bulk composition, and mineralogy. Data on clast N, a carbonaceous chondrite fragment from the howardite EET87513 large enough (approximately 4x5mm on the surface of the slab from which it was separated) to extract bulk samples for INAA and oxygen isotope analysis and to provide a thin section for electron microprobe, SEM, and TEM analysis is reported. Preliminary data for this clast were previously reported. INAA was performed at Oregon State University and bulk oxygen isotopic composition was determined at the University of Chicago. These data confirm that EET87513 clast N is a fragment of CM2 material.

  3. Investigation of Pyridine Carboxylic Acids in CM2 Carbonaceous Chondrites: Potential Precursor Molecules for Ancient Coenzymes

    NASA Technical Reports Server (NTRS)

    Smith, Karen E.; Callahan, Michael P.; Gerakines, Perry A.; Dworkin, Jason P.; House, Christopher H.

    2014-01-01

    The distribution and abundances of pyridine carboxylic acids (including nicotinic acid) in eight CM2 carbonaceous chondrites (ALH 85013, DOM 03183, DOM 08003, EET 96016, LAP 02333, LAP 02336, LEW 85311, and WIS 91600) were investigated by liquid chromatography coupled to UV detection and high resolution Orbitrap mass spectrometry. We find that pyridine monocarboxylic acids are prevalent in CM2-type chondrites and their abundance negatively correlates with the degree of pre-terrestrial aqueous alteration that the meteorite parent body experienced. We lso report the first detection of pyridine dicarboxylic acids in carbonaceous chondrites. Additionally, we carried out laboratory studies of proton-irradiated pyridine in carbon dioxide-rich ices (a 1:1 mixture) to serve as a model of the interstellar ice chemistry that may have led to the synthesis of pyridine carboxylic acids. Analysis of the irradiated ice residue shows that a comparable suite of pyridine mono- and dicarboxylic acids was produced, although aqueous alteration may still play a role in the synthesis (and ultimate yield) of these compounds in carbonaceous meteorites. Nicotinic acid is a precursor to nicotinamide adenine dinucleotide, a likely ancient molecule used in cellular metabolism in all of life, and its common occurrence in CM2 chondrites may indicate that meteorites may have been a source of molecules for the emergence of more complex coenzymes on the early Earth.

  4. Investigation of Pyridine Carboxylic Acids in CM2 Carbonaceous Chondrites: Potential Precursor Molecules for Ancient Coenzymes

    NASA Technical Reports Server (NTRS)

    Smith, Karen E.; Callahan, Michael P.; Gerakines, Perry A.; Dworkin, Jason P.; House, Christopher H.

    2014-01-01

    The distribution and abundances of pyridine carboxylic acids (including nicotinic acid) in eight CM2 carbonaceous chondrites (ALH 85013, DOM 03183, DOM 08003, EET 96016, LAP 02333, LAP 02336, LEW 85311, and WIS 91600) were investigated by liquid chromatography coupled to UV detection and high resolution Orbitrap mass spectrometry. We find that pyridine monocarboxylic acids are prevalent in CM2-type chondrites and their abundance negatively correlates with the degree of pre-terrestrial aqueous alteration that the meteorite parent body experienced. We also report the first detection of pyridine dicarboxylic acids in carbonaceous chondrites. Additionally, we carried out laboratory studies of proton-irradiated pyridine in carbon dioxide-rich ices (a 1:1 mixture) to serve as a model of the interstellar ice chemistry that may have led to the synthesis of pyridine carboxylic acids. Analysis of the irradiated ice residue shows that a comparable suite of pyridine mono- and dicarboxylic acids was produced, although aqueous alteration may still play a role in the synthesis (and ultimate yield) of these compounds in carbonaceous meteorites. Nicotinic acid is a precursor to nicotinamide adenine dinucleotide, a likely ancient molecule used in cellular metabolism in all of life, and its common occurrence in CM2 chondrites may indicate that meteorites may have been a source of molecules for the emergence of more complex coenzymes on the early Earth.

  5. Investigation of pyridine carboxylic acids in CM2 carbonaceous chondrites: Potential precursor molecules for ancient coenzymes

    NASA Astrophysics Data System (ADS)

    Smith, Karen E.; Callahan, Michael P.; Gerakines, Perry A.; Dworkin, Jason P.; House, Christopher H.

    2014-07-01

    The distribution and abundances of pyridine carboxylic acids (including nicotinic acid) in eight CM2 carbonaceous chondrites (ALH 85013, DOM 03183, DOM 08003, EET 96016, LAP 02333, LAP 02336, LEW 85311, and WIS 91600) were investigated by liquid chromatography coupled to UV detection and high resolution Orbitrap mass spectrometry. We find that pyridine monocarboxylic acids are prevalent in CM2-type chondrites and their abundance negatively correlates with the degree of pre-terrestrial aqueous alteration that the meteorite parent body experienced. We also report the first detection of pyridine dicarboxylic acids in carbonaceous chondrites. Additionally, we carried out laboratory studies of proton-irradiated pyridine in carbon dioxide-rich ices (a 1:1 mixture) to serve as a model of the interstellar ice chemistry that may have led to the synthesis of pyridine carboxylic acids. Analysis of the irradiated ice residue shows that a comparable suite of pyridine mono- and dicarboxylic acids was produced, although aqueous alteration may still play a role in the synthesis (and ultimate yield) of these compounds in carbonaceous meteorites. Nicotinic acid is a precursor to nicotinamide adenine dinucleotide, a likely ancient molecule used in cellular metabolism in all of life, and its common occurrence in CM2 chondrites may indicate that meteorites may have been a source of molecules for the emergence of more complex coenzymes on the early Earth.

  6. Experimental investigation of a 1 kA/cm2 sheet beam plasma cathode electron gun

    NASA Astrophysics Data System (ADS)

    Kumar, Niraj; Narayan Pal, Udit; Kumar Pal, Dharmendra; Prajesh, Rahul; Prakash, Ram

    2015-01-01

    In this paper, a cold cathode based sheet-beam plasma cathode electron gun is reported with achieved sheet-beam current density ˜1 kA/cm2 from pseudospark based argon plasma for pulse length of ˜200 ns in a single shot experiment. For the qualitative assessment of the sheet-beam, an arrangement of three isolated metallic-sheets is proposed. The actual shape and size of the sheet-electron-beam are obtained through a non-conventional method by proposing a dielectric charging technique and scanning electron microscope based imaging. As distinct from the earlier developed sheet beam sources, the generated sheet-beam has been propagated more than 190 mm distance in a drift space region maintaining sheet structure without assistance of any external magnetic field.

  7. YBCO film deposition on very large areas up to 20 × 20 cm2

    NASA Astrophysics Data System (ADS)

    Kinder, H.; Berberich, P.; Prusseit, W.; Rieder-Zecha, S.; Semerad, R.; Utz, B.

    1997-08-01

    In the last decade we have developed thermal reactive co-evaporation as a technique to produce high quality YBCO and other oxide films of very large size up to 9 inches in diameter. This was achieved by intermittent deposition and reaction with oxygen using a heater which rotates the substrate in and out of an oxygen pocket. Even larger substrates, e. g. coated conductors, cannot be rotated. Therefore we have recently developed a new setup where the substrate is held fixed, and the oxygen pocket is set in linear reciprocation. This technique allows simultaneous deposition on a square of 20×20 cm 2. Moreover, we have developed an instant refill mechanism for the thermal boats, and stable rate control by atomic absorption spectroscopy (AAS), in order to obtain a continuous process suitable for small scale mass production.

  8. Krylov methods preconditioned with incompletely factored matrices on the CM-2

    NASA Technical Reports Server (NTRS)

    Berryman, Harry; Saltz, Joel; Gropp, William; Mirchandaney, Ravi

    1989-01-01

    The performance is measured of the components of the key interative kernel of a preconditioned Krylov space interative linear system solver. In some sense, these numbers can be regarded as best case timings for these kernels. Sweeps were timed over meshes, sparse triangular solves, and inner products on a large 3-D model problem over a cube shaped domain discretized with a seven point template. The performance of the CM-2 is highly dependent on the use of very specialized programs. These programs mapped a regular problem domain onto the processor topology in a careful manner and used the optimized local NEWS communications network. The rather dramatic deterioration in performance was documented when these ideal conditions no longer apply. A synthetic workload generator was developed to produce and solve a parameterized family of increasingly irregular problems.

  9. Actinic defect counting statistics over 1 cm2 area of EUVL mask blank

    SciTech Connect

    Jeong, Seongtae; Lai, Chih-Wei; Rekawa, Seno; Walton, Chris W.; Bokor, Jeffrey

    2000-02-18

    As a continuation of comparison experiments between EUV inspection and visible inspection of defects on EUVL mask blanks, we report on the result of an experiment where the EUV defect inspection tool is used to perform at-wavelength defect counting over 1 cm{sup 2} of EUVL mask blank. Initial EUV inspection found five defects over the scanned area and the subsequent optical scattering inspection was able to detect all of the five defects. Therefore, if there are any defects that are only detectable by EUV inspection, the density is lower than the order of unity per cm2. An upgrade path to substantially increase the overall throughput of the EUV inspection system is also identified in the manuscript.

  10. Compositions of Partly Altered Olivine and Replacement Serpentine in the CM2 Chondrite QUE93005

    NASA Technical Reports Server (NTRS)

    Velbel, M. A.; Tonui, E. K.; Zolensky, M. E.

    2005-01-01

    Some phyllosilicates in CM carbonaceous chondrites formed by aqueous alteration of anhydrous precursor phases. Although broad trends in the compositions of hydrous phyllosilicates are recognized and believed to be related to trends in degree of aqueous alteration, details of the reactions that formed specific secondary minerals remain obscure. This paper reports compositional relationships between remnants of partially pseudomorphically (or alteromorphically) replaced silicates and their alteration products (serpentine) in the CM2 chondrite QUE93005 and compares it with previously published results for ALH81002. Reactants and products were characterized by optical petrography, backscattered scanning electron microscopy (BSEM), and electron microprobe. By focusing on serpentine formed from known reactants (olivines), and on only those instances in which some of the reactant silicate remains, direct compositional relationships between reactants and products, and the elemental mobility required by the reactions, can be established. Additional information is included in the original extended abstract.

  11. Organic blend semiconductors and transistors with hole mobility exceeding 10 cm2/Vs (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Paterson, Alexandra F.; Anthopoulos, Thomas D.

    2015-10-01

    Plastic electronics that can be manufactured using solution-based methods are the subject of great research interest due to their potential for low-cost, large-area electronic applications. The interest in this field has led to considerable research and subsequent advances in device performance. To this end solution-processed organic thin-film transistors (OTFTs) have shown impressive improvements in recent years through the increasing values of charge carrier mobility. Here we report the development of next generation organic blend materials for OTFTs with hole mobilities of 10 cm2/Vs. These high performance devices have been achieved using a novel semiconducting blend system comprising of an amorphous-like conjugated polymer and a high mobility small molecule. The combination of a highly crystalline small molecule with the polymer binder aids the formation of uniform films as well as enables an element of control over the nucleation and growth of the small molecule. The polymer binders investigated belongs to the family of indacenodithiophene-based copolymers which are renowned for their high carrier mobilities regardless of their apparent structural disorder. The addition of the polymer with carefully chosen small molecules is found to further increase the hole mobility of the resulting blend OTFT to over 10 cm2/Vs. These organic devices provide an interesting insight into this rather complex blend system, highlighting the correlation between the morphology developed following solution processing and device performance, as well as exploring the role of each of the two components in the blend in terms of their contribution to charge transport.

  12. Spectral content of buried Ag foils at 10(16) W/cm(2) laser illumination.

    PubMed

    Huntington, C M; Maddox, B R; Park, H-S; Prisbrey, S; Remington, B A

    2014-11-01

    Sources of 5-12 keV thermal Heα x-rays are readily generated by laser irradiation of mid-Z foils at intensities >10(14) W/cm(2), and are widely used as probes for inertial confinement fusion and high-energy-density experiments. Higher energy 17-50 keV x-ray sources are efficiently produced from "cold" Kα emission using short pulse, petawatt lasers at intensities >10(18) W/cm(2) [H.-S. Park, B. R. Maddox et al., "High-resolution 17-75 keV backlighters for high energy density experiments," Phys. Plasmas 15(7), 072705 (2008); B. R. Maddox, H. S. Park, B. A. Remington et al., "Absolute measurements of x-ray backlighter sources at energies above 10 keV," Phys. Plasmas 18(5), 056709 (2011)]. However, when long pulse (>1 ns) lasers are used with Z > 30 elements, the spectrum contains contributions from both K shell transitions and from ionized atomic states. Here we show that by sandwiching a silver foil between layers of high-density carbon, the ratio of Kα:Heα in the x-ray spectrum is significant increased over directly illuminated Ag foils, with narrower lines from K-shell transitions. Additionally, the emission volume is more localized for the sandwiched target, producing a more planar x-ray sheet. This technique may be useful for generating probes requiring spectral purity and a limited spatial extent, for example, in incoherent x-ray Thomson scattering experiments. PMID:25430207

  13. Spectral content of buried Ag foils at 1016 W/cm2 laser illuminationa)

    NASA Astrophysics Data System (ADS)

    Huntington, C. M.; Maddox, B. R.; Park, H.-S.; Prisbrey, S.; Remington, B. A.

    2014-11-01

    Sources of 5-12 keV thermal Heα x-rays are readily generated by laser irradiation of mid-Z foils at intensities >1014 W/cm2, and are widely used as probes for inertial confinement fusion and high-energy-density experiments. Higher energy 17-50 keV x-ray sources are efficiently produced from "cold" Kα emission using short pulse, petawatt lasers at intensities >1018 W/cm2 [H.-S. Park, B. R. Maddox et al., "High-resolution 17-75 keV backlighters for high energy density experiments," Phys. Plasmas 15(7), 072705 (2008); B. R. Maddox, H. S. Park, B. A. Remington et al., "Absolute measurements of x-ray backlighter sources at energies above 10 keV," Phys. Plasmas 18(5), 056709 (2011)]. However, when long pulse (>1 ns) lasers are used with Z > 30 elements, the spectrum contains contributions from both K shell transitions and from ionized atomic states. Here we show that by sandwiching a silver foil between layers of high-density carbon, the ratio of Kα:Heα in the x-ray spectrum is significant increased over directly illuminated Ag foils, with narrower lines from K-shell transitions. Additionally, the emission volume is more localized for the sandwiched target, producing a more planar x-ray sheet. This technique may be useful for generating probes requiring spectral purity and a limited spatial extent, for example, in incoherent x-ray Thomson scattering experiments.

  14. The amino acid composition of the Sutter's Mill CM2 carbonaceous chondrite

    NASA Astrophysics Data System (ADS)

    Burton, Aaron S.; Glavin, Daniel P.; Elsila, Jamie E.; Dworkin, Jason P.; Jenniskens, Peter; Yin, Qing-Zhu

    2014-11-01

    We determined the abundances and enantiomeric compositions of amino acids in Sutter's Mill fragment #2 (designated SM2) recovered prior to heavy rains that fell April 25-26, 2012, and two other meteorite fragments, SM12 and SM51, that were recovered postrain. We also determined the abundance, enantiomeric, and isotopic compositions of amino acids in soil from the recovery site of fragment SM51. The three meteorite stones experienced terrestrial amino acid contamination, as evidenced by the low D/L ratios of several proteinogenic amino acids. The D/L ratios were higher in SM2 than in SM12 and SM51, consistent with rain introducing additional L-amino acid contaminants to SM12 and SM51. Higher percentages of glycine, β-alanine, and γ-amino-n-butyric acid were observed in free form in SM2 and SM51 compared with the soil, suggesting that these free amino acids may be indigenous. Trace levels of D+L-β-aminoisobutyric acid (β-AIB) observed in all three meteorites are not easily explained as terrestrial contamination, as β-AIB is rare on Earth and was not detected in the soil. Bulk carbon and nitrogen and isotopic ratios of the SM samples and the soil also indicate terrestrial contamination, as does compound-specific isotopic analysis of the amino acids in the soil. The amino acid abundances in SM2, the most pristine SM meteorite analyzed here, are approximately 20-fold lower than in the Murchison CM2 carbonaceous chondrite. This may be due to thermal metamorphism in the Sutter's Mill parent body at temperatures greater than observed for other aqueously altered CM2 meteorites.

  15. Intensity increasing up to 4 MW/cm2 with BALB's via wavelengths coupling

    NASA Astrophysics Data System (ADS)

    Timmermann, Andre; Bartoschewski, Daniel; Schlüter, Stephan; Burke, Colin; Meinschien, Jens

    2009-02-01

    An increase in the performance of micro-optic beam shaping resulted in diode laser modules with more than 400W out of 200 μm fibre based on Broad Area Laser Bars (BALB). The brightness of a 400 W laser module opened the door for new applications in material processing such as temper marking of stainless steel and metal sheet cutting. Further improvements of the light sources and the beam shaping for BALB's have increased the efficiency of the laser modules. Therefore we present an output power of 1200 W out of a 200 μm fibre (0.22 NA). This is achieved by further sophistication of the coupling technique and four wavelength coupling. The beam parameter product is still 22 mm*mrad with a power density of 3800 kW/cm2 if focussed to a 200 μm spot. Furthermore, each of the four wavelength modules are separately exchangeable and checkable. The availability of a top-hat profile out of the fibre proves itself to be advantageous compared to the traditional Gaussian beam profiles of fibre, solid-state and gas lasers. This leads to excellent laser cutting results with extremely small cutting kerfs down to 200 μm and very plane cutting edges. Process speeds rise up to more than 10 m/min i.e. for thin sheet stainless steel or titanium. In the near future, 600 W out of 200 μm based on BALB's with a beam compressor is possible. With wavelength coupling, power levels with up to 2 kW out of 200 μm fibre will be reached. This will result in a power density of more than 6 MW/cm2.

  16. On the Behavior of Phosphorus During the Aqueous Alteration of CM2 Carbonaceous Chondrites

    NASA Technical Reports Server (NTRS)

    Brearley, Adrian J.; Chizmadia, Lysa J.

    2005-01-01

    During the earliest period of solar system formation, water played an important role in the evolution of primitive dust, both after accretion of planetesimals and possible before accretion within the protoplanetary disk. Many chondrites show evidence of variable degrees of aqueous alteration, the CM2 chondrites being among the most studied [1]. This group of chondrites is characterized by mineral assemblages of both primary and secondary alteration phases. Hence, these meteorites retain a particularly important record of the reactions that occurred between primary high temperature nebular phases and water. Studies of these chondrites can provide information on the conditions and environments of aqueous alteration and the mobility of elements during alteration. This latter question is at the core of a debate concerning the location of aqueous alteration, i.e. whether alteration occurred predominantly within a closed system after accretion (parent body alteration) or whether some degree of alteration occurred within the solar nebula or on ephemeral protoplanetary bodies prior to accretion. At the core of the parent body alteration model is the hypothesis that elemental exchange between different components, principally chondrules and matrix, must have occurred. chondrules and matrix, must have occurred. In this study, we focus on the behavior of the minor element, phosphorus. This study was stimulated by observations of the behavior of P during the earliest stages of alteration in glassy mesostasis in type II chondrules in CR chondrites and extends the preliminary observations of on Y791198 to other CM chondrites.

  17. Efficient Monolithic Perovskite/Silicon Tandem Solar Cell with Cell Area >1 cm(2).

    PubMed

    Werner, Jérémie; Weng, Ching-Hsun; Walter, Arnaud; Fesquet, Luc; Seif, Johannes Peter; De Wolf, Stefaan; Niesen, Bjoern; Ballif, Christophe

    2016-01-01

    Monolithic perovskite/crystalline silicon tandem solar cells hold great promise for further performance improvement of well-established silicon photovoltaics; however, monolithic tandem integration is challenging, evidenced by the modest performances and small-area devices reported so far. Here we present first a low-temperature process for semitransparent perovskite solar cells, yielding efficiencies of up to 14.5%. Then, we implement this process to fabricate monolithic perovskite/silicon heterojunction tandem solar cells yielding efficiencies of up to 21.2 and 19.2% for cell areas of 0.17 and 1.22 cm(2), respectively. Both efficiencies are well above those of the involved subcells. These single-junction perovskite and tandem solar cells are hysteresis-free and demonstrate steady performance under maximum power point tracking for several minutes. Finally, we present the effects of varying the intermediate recombination layer and hole transport layer thicknesses on tandem cell photocurrent generation, experimentally and by transfer matrix simulations. PMID:26687850

  18. N-15-Rich Organic Globules in a Cluster IDP and the Bells CM2 Chondrite

    NASA Technical Reports Server (NTRS)

    Messenger, S.; Nakamura-Messenger, K.; Keller, Lindsay P.

    2008-01-01

    Organic matter in primitive meteorites and chondritic porous interplanetary dust particles (CP IDPs) is commonly enriched in D/H and 15N/14N relative to terrestrial values [1-3]. These anomalies are ascribed to the partial preservation of presolar cold molecular cloud material [1]. Some meteorites and IDPs contain m-size inclusions with extreme H and N isotopic anomalies [2-4], possibly due to preserved pristine primordial organic grains. We recently showed that the in the Tagish Lake meteorite, the principle carriers of these anomalies are sub- m, hollow organic globules [5]. The globules likely formed by photochemical processing of organic ices in a cold molecular cloud or the outermost regions of the protosolar disk [5]. We proposed that similar materials should be common among primitive meteorites, IDPs, and comets. Similar objects have been observed in organic extracts of carbonaceous chondrites [6-8], however their N and H isotopic compositions are generally unknown. Bulk H and N isotopic compositions may indicate which meteorites best preserve interstellar organic compounds. Thus, we selected the Bells CM2 carbonaceous chondrites for study based on its large bulk 15N (+335 %) and D (+990 %) [9].

  19. Predictability of El Niño Flavors in GFDL CM2.1 Simulations

    NASA Astrophysics Data System (ADS)

    Chen, C.; Cane, M. A.; Chen, D.; Henderson, N.; Wittenberg, A. T.

    2013-12-01

    This work explores the predictability of El Niño flavors in a 2000-year pre-industrial run of the GFDL CM2.1 coupled GCM, which has a reasonably realistic ENSO simulation. Central Pacific (CP) and Eastern Pacific (EP) flavors are defined in the phase space of the two leading principal components (PCs) of tropical Pacific sea surface temperature anomalies. The predictability of the different El Niño flavors is quite limited due to the intrinsic chaotic property of the climate system. The interference of two leading transient growing modes is shown to contribute to El Niño diversity. The precursors (i.e. optimal initial patterns) of these modes in the simulation are diagnosed using linear inverse modeling and singular vector analysis, which are then applied in a statistical model to forecast the probability, given any initial state, of evolution into each El Niño type. We find that the horizon to distinguish the precursors of flavors in the PC space is ~3 months before a CP El Niño peak or 6 months before an EP El Niño peak. The approach in this work is potentially useful for evaluating coupled GCMs, both as a dynamical diagnostic and as a better baseline for forecast skill than persistence.

  20. Fast-Electron Temperature Measurements in Laser Irradiation at 1014 W/cm2

    NASA Astrophysics Data System (ADS)

    Solodov, A. A.; Yaakobi, B.; Myatt, J. F.; Stoeckl, C.; Froula, D. H.

    2014-10-01

    The temperature T of the fast electrons in planar-target irradiation using 2-ns UV pulses at 1014 W/cm2 was measured on the OMEGA EP laser using the bremsstrahlung radiation [hard x-ray (HXR)] and the Kα radiation from high- Z signature layers. The HXR was measured by a nine-channel filter spectrometer [hard x-ray image plate (HXIP)]. Two types of experiments used the Kα radiation. The first used a thick Mo (or Ag) target and the ratio of Kα emitted toward the front and the back of the target, measured and simulated by a Monte Carlo (MC) code. The ratio decreases with increasing T (since Kα is emitted deeper in the foil and therefore absorbed less on the way back out). The second type used a target composed of five consecutive- Z layers (Nb, Mo, Rh, Pd, Ag) and Kα lines emitted from the back (highest- Z) , measured and simulated by the MC code. For higher temperatures, the Kα energy decreases more slowly with Z. All of these measurements agree with each other. However, a three-channel scintillation photomultiplier system systematically yields higher temperatures. This indicates a higher-energy radiation component that is not detected by the HXIP because of the sharp drop in image plate (IP) sensitivity. Extending the HXIP detection to higher energies (using Kα fluorescence, for which the IP sensitivity is high) is planned. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  1. Methylmercury degradation by Pseudomonas putida V1.

    PubMed

    Cabral, Lucélia; Yu, Ri-Qing; Crane, Sharron; Giovanella, Patricia; Barkay, Tamar; Camargo, Flávio A O

    2016-08-01

    Environmental contamination of mercury (Hg) has caused public health concerns with focuses on the neurotoxic substance methylmercury, due to its bioaccumulation and biomagnification in food chains. The goals of the present study were to examine: (i) the transformation of methylmercury, thimerosal, phenylmercuric acetate and mercuric chloride by cultures of Pseudomonas putida V1, (ii) the presence of the genes merA and merB in P. putida V1, and (iii) the degradation pathways of methylmercury by P. putida V1. Strain V1 cultures readily degraded methylmercury, thimerosal, phenylmercury acetate, and reduced mercuric chloride into gaseous Hg(0). However, the Hg transformation in LB broth by P. putida V1 was influenced by the type of Hg compounds. The merA gene was detected in P. putida V1, on the other hand, the merB gene was not detected. The sequencing of this gene, showed high similarity (100%) to the mercuric reductase gene of other Pseudomonas spp. Furthermore, tests using radioactive (14)C-methylmercury indicated an uncommon release of (14)CO2 concomitant with the production of Hg(0). The results of the present work suggest that P. putida V1 has the potential to remove methylmercury from contaminated sites. More studies are warranted to determine the mechanism of removal of methylmercury by P. putida V1. PMID:27062344

  2. A Comparison Between Silicon Carbide from Indarch (EH4) and CM2 Meteorites

    NASA Astrophysics Data System (ADS)

    Russell, S. S.; Alexander, C. M. O'd.; Ott, U.; Zinner, E. K.; Arden, J. W.; Pillinger, C. T.

    1993-07-01

    A light-element stepped-combustion, noble-gas, ion-probe, and SEM study of interstellar SiC from Indarch has been undertaken in order to compare SiC isolated from enstatite chondrites with SiC from the more extensively studied CM2 carbonaceous chondrites. Eighty-five grams of Indarch were etched in HF/HCl, crushed and treated with 9MHF/1MHCl + 1M HCl, Cr(sub)2O(sub)7^2- in H(sub)2SO(sub)4, and then HClO(sub)4, leaving an acid-resistant residue equivalent to 42 ppm of the whole rock. Carbon, nitrogen, and noble-gas data were acquired by stepped combustion and pyrolysis after precombusting the samples to 600 degrees C to oxidize nanometer-sized diamond. The presence of isotopically anomalous SiC in the Indarch residue is indicated by the isotopically heavy CO2 released at high temperature during stepped combustion, with a maximum delta ^13C value of +1420 per mil (^12C/^13C = 36.2), identical to results obtained for typical CM2 samples [1]. In contrast to CM meteorites, however, the peak release of heavy carbon occurs at 1200 degrees C, some 200 degrees C higher than the peak release temperatures of Murchison and Cold Bokkeveld. A similarly high release temperature was seen in the stepped-combustion analysis of the noble gas in the Indarch residue. This suggests a morphological and/or size difference between the SiC present in the two types of meteorites. The nitrogen stepped-combustion profile of the Indarch residue is dominated by the presence of Si(sub)3N(sub)4 of unremarkable isotopic composition (delta ^15N = -56 per mil) that could not be resolved from nitrogen released from SiC. The abundance of SiC in Indarch is estimated, from the stepped combustion data, to be about 1.4 ppm (or 14 ppm SiC in the matrix, not dissimilar to values obtained for CM2 meteorites). A comparison of the noble-gas data from grain-size fractions of Murchison [2] and the bulk Indarch residue data, particularly the Ne-E/Xe-s ratio, suggests that Indarch is enriched in fine-grained Si

  3. 47 CFR 10.2 - Purpose.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Purpose. 10.2 Section 10.2 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL MOBILE ALERT SYSTEM General Information § 10.2... Mobile Alert System....

  4. 47 CFR 10.2 - Purpose.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Purpose. 10.2 Section 10.2 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL MOBILE ALERT SYSTEM General Information § 10.2... Mobile Alert System....

  5. 47 CFR 10.2 - Purpose.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 1 2012-10-01 2012-10-01 false Purpose. 10.2 Section 10.2 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL COMMERCIAL MOBILE ALERT SYSTEM General Information § 10.2... Mobile Alert System....

  6. 47 CFR 10.2 - Purpose.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 1 2014-10-01 2014-10-01 false Purpose. 10.2 Section 10.2 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL WIRELESS EMERGENCY ALERTS General Information § 10.2 Purpose... Emergency Alerts system....

  7. 47 CFR 10.2 - Purpose.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 1 2013-10-01 2013-10-01 false Purpose. 10.2 Section 10.2 Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL WIRELESS EMERGENCY ALERTS General Information § 10.2 Purpose... Emergency Alerts system....

  8. Formation of spinel-, hibonite-rich inclusions found in CM2 carbonaceous chrondrites

    SciTech Connect

    Simon, S B; Grossman, L; Hutcheon, I D; Phinney, D L; Weber, P K; Fallon, S J

    2005-11-03

    We report petrography, mineral chemistry, bulk chemistry, and bulk isotopic compositions of a suite of 40 spinel-rich inclusions from the Murchison (CM2) carbonaceous chondrite. Seven types of inclusions are identified based on mineralogy: spinel-hibonite-perovskite; spinel-perovskite-pyroxene; spinel-perovskite-melilite; spinel-hibonite-perovskite-melilite; spinel-hibonite; spinel-pyroxene; and spinel-melilite-anorthite. Hibonite-bearing inclusions have Ti-poor spinel compared to the hibonite-free ones, and spinel-hibonite-perovskite inclusions have the highest average bulk TiO{sub 2} contents (7.8 wt%). The bulk CaO/Al{sub 2}O{sub 3} ratios of the inclusions range from 0.005-0.21, well below the solar value of 0.79. Hibonite-, spinel-rich inclusions consist of phases that are not predicted by condensation calculations to coexist; in the equilibrium sequence, hibonite is followed by melilite, which is followed by spinel. Therefore, hibonite-melilite or melilite-spinel inclusions should be dominant instead. One explanation for the 'missing melilite' is that it condensed as expected but was lost due to evaporation of Mg and Ca during heating and melting of spherule precursors. If this theory were correct, melilite-poor spherules would have isotopically heavy Mg and Ca. Except for one inclusion with F{sub Mg} = 4.3 {+-} 2.6{per_thousand}/amu and another with isotopically light Ca (F{sub Ca} = 3.4 {+-} 2.0{per_thousand}/amu), however, all the inclusions we analyzed have normal isotopic compositions within their 2{sigma} uncertainties. Thus, we found no evidence for significant mass-dependent fractionation. Our preferred explanation for the general lack of melilite among hibonite-, spinel-bearing inclusions is kinetic inhibition of melilite condensation relative to spinel. Because of similarities between the crystal structures of hibonite and spinel, it should be easier for spinel to form from hibonite than for melilite to do so.

  9. Fe and O EELS Studies of Ion Irradiated Murchison CM2 Carbonaceous Chondrite Matrix

    NASA Technical Reports Server (NTRS)

    Keller, L. P.; Christofferson, R.; Dukes, C. A.; Baragiola, R. A.; Rahman, Z.

    2015-01-01

    Introduction: The physical and chemical response of hydrated carbonaceous chondrite materials to space weathering processes is poorly understood. Improving this understanding is a key part of establishing how regoliths on primitive carbonaceous asteroids respond to space weathering processes, knowledge that supports future sample return missions (Hayabusa 2 and OSIRISREx) that are targeting objects of this type. We previously reported on He+ irradiation of Murchison matrix and showed that the irradiation resulted in amorphization of the matrix phyllosilicates, loss of OH, and surface vesiculation. Here, we report electron energy-loss spectroscopy (EELS) measurements of the irradiated material with emphasis on the Fe and O speciation. Sample and Methods: A polished thin section of the Murchison CM2 carbonaceous chondrite was irradiated with 4 kilovolts He(+) (normal incidence) to a total dose of 1 x 10(exp 18) He(+) per square centimeter. We extracted thin sections from both irradiated and unirradiated regions in matrix using focused ion beam (FIB) techniques with electron beam deposition for the protective carbon strap to minimize surface damage artifacts from the FIB milling. The FIB sections were analyzed using a JEOL 2500SE scanning and transmission electron microscope (STEM) equipped with a Gatan Tridiem imaging filter. EELS spectra were collected from 50 nanometer diameter regions with an energy resolution of 0.7 electronvolts FWHM at the zero loss. EELS spectra were collected at low electron doses to minimize possible artifacts from electron-beam irradiation damage. Results and Discussion: Fe L (sub 2,3) EELS spectra from matrix phyllosilicates in CM chondrites show mixed Fe(2+)/Fe(3+) oxidation states with Fe(3+)/Sigma Fe approximately 0.5. Fe L(sub 2,3) spectra from the irradiated/ amorphized matrix phyllosilicates show higher Fe(2+)/Fe(3+) ratios compared to spectra obtained from pristine material at depths beyond the implantation/amorphization layer. We

  10. Impact-Induced Chondrule Deformation and Aqueous Alteration of CM2 Murchison

    NASA Technical Reports Server (NTRS)

    Hanna, R. D.; Zolensky, M.; Ketcham, R. A.; Behr, W. M.; Martinez, J. E.

    2014-01-01

    Deformed chondrules in CM2 Murchison have been found to define a prominent foliation [1,2] and lineation [3] in 3D using X-ray computed tomography (XCT). It has been hypothesized that chondrules in foliated chondrites deform by "squeezing" into surrounding pore space [4,5], a process that also likely removes primary porosity [6]. However, shock stage classification based on olivine extinction in Murchison is consistently low (S1-S2) [4-5,7] implying that significant intracrystalline plastic deformation of olivine has not occurred. One objective of our study is therefore to determine the microstructural mechanisms and phases that are accommodating the impact stress and resulting in relative displacements within the chondrules. Another question regarding impact deformation in Murchison is whether it facilitated aqueous alteration as has been proposed for the CMs which generally show a positive correlation between degree of alteration and petrofabric strength [7,2]. As pointed out by [2], CM Murchison represents a unique counterpoint to this correlation: it has a strong petrofabric but a relatively low degree of aqueous alteration. However, Murchison may not represent an inconsistency to the proposed causal relationship between impact and alteration, if it can be established that the incipient aqueous alteration post-dated chondrule deformation. Methods: Two thin sections from Murchison sample USNM 5487 were cut approximately perpendicular to the foliation and parallel to lineation determined by XCT [1,3] and one section was additionally polished for EBSD. Using a combination of optical petrography, SEM, EDS, and EBSD several chondrules were characterized in detail to: determine phases, find microstructures indicative of strain, document the geometric relationships between grain-scale microstructures and the foliation and lineation direction, and look for textural relationships of alteration minerals (tochilinite and Mg-Fe serpentine) that indicate timing of their

  11. Successful Capture, Extraction and Identification of Hypervelocity CM2 Meteorite Fragments Shot by Light-Gas Gun

    NASA Technical Reports Server (NTRS)

    Snead, C.; Westphal, A. J.; Dominguez, G.; Zolensky, M. E.

    2003-01-01

    Here we report the successful capture, extraction and identification of two fragments of a CM2 meteorite (ALH83100) into lowdensity aerogel. The shot was carried out at the AVGR at NASAARC. A mixture of powdered ALH83100 and borosilicate glass microspheres was shot at 4.55.0 km/sec into 50 mg cm silicate aerogel.

  12. 5 CFR 10.2 - Accountability systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 1 2011-01-01 2011-01-01 false Accountability systems. 10.2 Section 10.2 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES AGENCY ACCOUNTABILITY SYSTEMS; OPM AUTHORITY TO REVIEW PERSONNEL MANAGEMENT PROGRAMS (RULE X) § 10.2 Accountability systems. The Director...

  13. 15 CFR 10.2 - Funding.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 15 Commerce and Foreign Trade 1 2012-01-01 2012-01-01 false Funding. 10.2 Section 10.2 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR THE DEVELOPMENT OF VOLUNTARY PRODUCT STANDARDS § 10.2 Funding. Groups who represent producers, distributors, consumers or users,...

  14. 15 CFR 10.2 - Funding.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 15 Commerce and Foreign Trade 1 2013-01-01 2013-01-01 false Funding. 10.2 Section 10.2 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR THE DEVELOPMENT OF VOLUNTARY PRODUCT STANDARDS § 10.2 Funding. Groups who represent producers, distributors, consumers or users,...

  15. 15 CFR 10.2 - Funding.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Funding. 10.2 Section 10.2 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR THE DEVELOPMENT OF VOLUNTARY PRODUCT STANDARDS § 10.2 Funding. Groups who represent producers, distributors, consumers or users,...

  16. 15 CFR 10.2 - Funding.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 1 2014-01-01 2014-01-01 false Funding. 10.2 Section 10.2 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR THE DEVELOPMENT OF VOLUNTARY PRODUCT STANDARDS § 10.2 Funding. Groups who represent producers, distributors, consumers or users,...

  17. 15 CFR 10.2 - Funding.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Funding. 10.2 Section 10.2 Commerce and Foreign Trade Office of the Secretary of Commerce PROCEDURES FOR THE DEVELOPMENT OF VOLUNTARY PRODUCT STANDARDS § 10.2 Funding. Groups who represent producers, distributors, consumers or users,...

  18. 36 CFR 10.2 - Charges.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Charges. 10.2 Section 10.2 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR DISPOSAL OF CERTAIN WILD ANIMALS § 10.2 Charges. No charge will be made for the animals, but the receiver will...

  19. 5 CFR 10.2 - Accountability systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Accountability systems. 10.2 Section 10.2 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES AGENCY ACCOUNTABILITY SYSTEMS; OPM AUTHORITY TO REVIEW PERSONNEL MANAGEMENT PROGRAMS (RULE X) § 10.2 Accountability systems. The Director...

  20. Charge collection studies on custom silicon detectors irradiated up to 1.6·1017 neq/cm-2

    NASA Astrophysics Data System (ADS)

    Kramberger, G.; Cindro, V.; Mandić, I.; Mikuž, M.; Zavrtanik, M.

    2013-08-01

    Silicon n+-p diodes with special design of the implant — so called ``spaghetti diodes'' — were used to study the impact of implantation process on charge multiplication after irradiations to extremely large 1 MeV neutron equivalent fluences of reactor neutrons up to 1.6·1017 cm-2. Silicon remains functional even at these unprecedented levels of irradiation. Above 1015 cm-2 collected charge (Q) grows linearly with bias voltage, with the Q-V slope exhibiting a power law dependence on fluence. Different implantation processes were implemented on samples to study the impact of implantation on charge multiplication. ``Spaghetti'' diodes of different thicknesses were also compared to conventional strip and pad detectors in order to determine the impact of different electric and weighting field on the collected charge.

  1. 24 CFR 10.2 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 1 2012-04-01 2012-04-01 false Definitions. 10.2 Section 10.2 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development... Departmental statement of general or particular applicability and future effect designed to: (1)...

  2. 24 CFR 10.2 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 1 2014-04-01 2014-04-01 false Definitions. 10.2 Section 10.2 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development... Departmental statement of general or particular applicability and future effect designed to: (1)...

  3. 24 CFR 10.2 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 1 2013-04-01 2013-04-01 false Definitions. 10.2 Section 10.2 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development... Departmental statement of general or particular applicability and future effect designed to: (1)...

  4. 24 CFR 10.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Definitions. 10.2 Section 10.2 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development... Departmental statement of general or particular applicability and future effect designed to: (1)...

  5. 24 CFR 10.2 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Definitions. 10.2 Section 10.2 Housing and Urban Development Office of the Secretary, Department of Housing and Urban Development... Departmental statement of general or particular applicability and future effect designed to: (1)...

  6. 12 CFR 10.2 - Filing requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Filing requirements. 10.2 Section 10.2 Banks....2 Filing requirements. (a) A national bank shall use Form MSD-4 (Uniform Application for Municipal...) Forms MSD-4 and MSD-5, with instructions, may be obtained by contacting the OCC at 250 E Street,...

  7. TOUGH+ v1.5 Core Code

    2015-08-27

    TOUGH+ v1.5 is a numerical code for the simulation of multi-phase, multi-component flow and transport of mass and heat through porous and fractured media, and represents the third update of the code since its first release [Moridis et al., 2008]. TOUGH+ is a successor to the TOUGH2 [Pruess et al., 1991; 2012] family of codes for multi-component, multiphase fluid and heat flow developed at the Lawrence Berkeley National Laboratory. It is written in standard FORTRANmore » 95/2003, and can be run on any computational platform (workstations, PC, Macintosh). TOUGH+ v1.5 employs dynamic memory allocation, thus minimizing storage requirements. It has a completely modular structure, follows the tenets of Object-Oriented Programming (OOP), and involves the advanced features of FORTRAN 95/2003, i.e., modules, derived data types, the use of pointers, lists and trees, data encapsulation, defined operators and assignments, operator extension and overloading, use of generic procedures, and maximum use of the powerful intrinsic vector and matrix processing operations. TOUGH+ v1.5 is the core code for its family of applications, i.e., the part of the code that is common to all its applications. It provides a description of the underlying physics and thermodynamics of non-isothermal flow, of the mathematical and numerical approaches, as well as a detailed explanation of the general (common to all applications) input requirements, options, capabilities and output specifications. The core code cannot run by itself: it needs to be coupled with the code for the specific TOUGH+ application option that describes a particular type of problem. The additional input requirements specific to a particular TOUGH+ application options and related illustrative examples can be found in the corresponding User’s Manual.« less

  8. TOUGH+ v1.5 Core Code

    SciTech Connect

    Moridis, George J.

    2015-08-27

    TOUGH+ v1.5 is a numerical code for the simulation of multi-phase, multi-component flow and transport of mass and heat through porous and fractured media, and represents the third update of the code since its first release [Moridis et al., 2008]. TOUGH+ is a successor to the TOUGH2 [Pruess et al., 1991; 2012] family of codes for multi-component, multiphase fluid and heat flow developed at the Lawrence Berkeley National Laboratory. It is written in standard FORTRAN 95/2003, and can be run on any computational platform (workstations, PC, Macintosh). TOUGH+ v1.5 employs dynamic memory allocation, thus minimizing storage requirements. It has a completely modular structure, follows the tenets of Object-Oriented Programming (OOP), and involves the advanced features of FORTRAN 95/2003, i.e., modules, derived data types, the use of pointers, lists and trees, data encapsulation, defined operators and assignments, operator extension and overloading, use of generic procedures, and maximum use of the powerful intrinsic vector and matrix processing operations. TOUGH+ v1.5 is the core code for its family of applications, i.e., the part of the code that is common to all its applications. It provides a description of the underlying physics and thermodynamics of non-isothermal flow, of the mathematical and numerical approaches, as well as a detailed explanation of the general (common to all applications) input requirements, options, capabilities and output specifications. The core code cannot run by itself: it needs to be coupled with the code for the specific TOUGH+ application option that describes a particular type of problem. The additional input requirements specific to a particular TOUGH+ application options and related illustrative examples can be found in the corresponding User’s Manual.

  9. Generation and diagnostics of pulsed intense ion beams with an energy density of 10 J/cm2

    NASA Astrophysics Data System (ADS)

    Isakova, Yu.; Pushkarev, A.; Khailov, I.; Zhong, H.

    2015-07-01

    The paper presents the results of a study on transportation and focusing of a pulsed ion beam at gigawatt power level, generated by a diode with explosive-emission cathode. The experiments were carried out with the TEMP-4M accelerator operating in double-pulse mode: the first pulse is of negative polarity (500 ns, 100-150 kV), and this is followed by a second pulse of positive polarity (120 ns, 200-250 kV). To reduce the beam divergence, we modified the construction of the diode. The width of the anode was increased compared to that of the cathode. We studied different configurations of planar and focusing strip diodes. It was found that the divergence of the ion beam formed by a planar strip diode, after construction modification, does not exceed 3° (half-angle). Modification to the construction of a focusing diode made it possible to reduce the beam divergence from 8° to 4°-5°, as well as to increase the energy density at the focus up to 10-12 J/cm2, and decrease the shot to shot variation in the energy density from 10%-15% to 5%-6%. When measuring the ion beam energy density above the ablation threshold of the target material (3.5-4 J/cm2), we used a metal mesh with 50% transparency to lower the energy density. The influence of the metal mesh on beam transport has been studied.

  10. Coulomb-Boltzmann-Shifted distribution in laser-generated plasmas from 1010 up to 1019 W/cm2 intensities

    NASA Astrophysics Data System (ADS)

    Torrisi, L.

    2016-02-01

    The charge production from laser-generated plasmas generates not isotropically ion acceleration in vacuum and with mean kinetic energy proportional to the ion charge state. The ion velocity depends on many factors of which the most important are the plasma temperature, the adiabatic gas expansion in vacuum and the Coulomb acceleration. The ion energy distributions of the emitted ions from the plasma can be well explained by the Coulomb-Boltzmann-Shifted function, with a cut-off limitation at high energy for a wide range of laser intensities. It can be applied for intensities of 1010 W/cm2, when plasma is produced only in the backward direction from thick targets (backward plasma acceleration regime), as well as at intensities of the order of 1019 W/cm2, when plasma is produced in the forward direction from thin targets in target-normal sheath acceleration regime. It loses of validity in radiation pressure acceleration regime, at which ions are emitted near mono-energetically.

  11. 36 CFR 10.2 - Charges.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... services of a veterinarian for testing, vaccinating, and treating the animals at the park for communicable... CERTAIN WILD ANIMALS § 10.2 Charges. No charge will be made for the animals, but the receiver will...

  12. RealGasBrine v1.0 option of TOUGH+ v1.5

    SciTech Connect

    Moridis, George

    2015-02-27

    RealGasBrine v1.0 is a numerical code that for the simulation of the behavior of gas-bearing porous and/fractured geologic media. It is an option of TOUGH+ v1.5 [Moridis, 2014], a successor to the TOUGH2 [Pruess et al., 1999; 2012] family of codes for multi-component, multiphase ?uid and heat ?ow developed at the Lawrence Berkeley National Laboratory. RealGasBrine v1.0 needs the TOUGH+ v1.5 core code in order to compile and execute. It is written in standard FORTRAN 95/2003, and can be run on any computational platform (workstation, PC, Macintosh) for which such compilers are available. RealGasBrine v1.0 describes the non-isothermal two- (for pure water) or three-phase (for brine) flow of an aqueous phase and a real gas mixture in a gas-bearing medium, with a particular focus in ultra-tight (such as tight-sand and shale gas) systems. Up to 12 individual real gases can be tracked, and salt can precipitate as solid halite. The capabilities of the code include coupled flow and thermal effects, real gas behavior, Darcy and non-Darcy flow, several isotherm options of gas sorption onto the grains of the porous media, complex fracture descriptions, gas solubility into water, and geomechanical effects on flow properties. RealGasBrine v1.0 allows the study of flow and transport of fluids and heat over a wide range of time frames and spatial scales not only in gas reservoirs, but also in any problem involving the flow of gases in geologic media, including the geologic storage of greenhouse gas mixtures, the behavior of geothermal reservoirs with multi-component condensable (H2O and CO2) and non-condensable gas mixtures, the transport of water and released H2 in nuclear waste storage applications, etc.

  13. Chondrules in the Murray CM2 meteorite and compositional differences between CM-CO and ordinary chondrite chondrules

    NASA Astrophysics Data System (ADS)

    Rubin, A. E.; Wasson, J. T.

    1986-02-01

    Thirteen of the least aqueously altered chondrules in Murray (CM2) were analyzed for bulk compositions, by means of a broad beam electron microprobe, to explore the compositional differences between the CM-CO, and the ordinary chondrite OC chondrules. The CO chondrules are richer in refractory lithophiles and poorer in Cr, Mn, and volatile lithophiles than the OC chondrules; much lower refractory lithophile abundances in CM chondrules resulted from aqueous alteration. Evidence is found for two important lithophile precursor components of CM-CO chondrite chondrules: (1) pyroxene- and refractory-rich, FeO-poor, and (2) olivine-rich, refractoryand FeO-poor. It is suggested that the pyroxene- and refractory-rich, FeO-poor lithophile precursor component has formed by an incomplete evaporation of presolar silicates that brought these materials into the enstatite stability field.

  14. Design and fabrication of prototype 6×6 cm2 microchannel plate photodetector with bialkali photocathode for fast timing applications

    NASA Astrophysics Data System (ADS)

    Xie, Junqi; Byrum, Karen; Demarteau, Marcel; Gregar, Joseph; May, Edward; Virgo, Mathew; Wagner, Robert; Walters, Dean; Wang, Jingbo; Xia, Lei; Zhao, Huyue

    2015-06-01

    Planar microchannel plate-based photodetectors with a bialkali photocathode are able to achieve photon detection with very good time and position resolution. A 6×6 cm2 photodetector production facility was designed and built at Argonne National Laboratory. Small form-factor MCP-based photodetectors completely constructed out of glass were designed and prototypes were successfully fabricated. Knudsen effusion cells were incorporated in the photocathode growth chamber to achieve uniform and high quantum efficiency photocathodes. The thin film uniformity was simulated and measured for an antimony film deposition, showing uniformity of better than 10%. Several prototype devices with bialkali photocathodes have been fabricated with the described system and their characteristics were evaluated in the large signal (multi-PE) limit. A typical prototype device exhibits time-of-flight resolution of ~27 psec and differential time resolution of ~9 psec, corresponding to spatial resolution of ~0.65 mm.

  15. Backward-going MeV electrons and gamma rays from 1018 W/cm2 laser interactions with water

    NASA Astrophysics Data System (ADS)

    Feister, Scott; Morrison, John T.; Frische, Kyle D.; Orban, Chris; Ovchinnikov, Vladimir M.; Nees, John A.; Austin, Drake R.; Chowdhury, Enam A.; Freeman, Richard R.; Roquemore, W. Melvyn

    2015-05-01

    Gamma rays with ~1 MeV energy are measured following the relativistic interaction of a 3 mJ, 1018 W/cm2 short pulse laser with a 30 μm diameter flowing water column. Contrary to expectations, radiation emission is peaked in the direction opposite to the normally-incident laser propagation (specular direction). Experimental measurements and particle-in-cell (PIC) simulations of laser-plasma interaction show a pre-formed-plasma-dependent, backward-going, beam-like primary electron source. The MeV component of the electron and gamma ray spectrum, which is more than five times the ponderomotive energy scale of the laser, is highly sensitive to the presence of a nanosecond-timescale laser pre-pulse. This research was sponsored by the Quantum and Non-Equilibrium Processes Division of the Air Force Office of Scientific Research, under the management of Dr. Enrique Parra, Program Manager.

  16. Xenoliths in the CM2 Carbonaceous Chondrite LON 94101: Implications for Complex Mixing on the Asteroidal Parent Body

    NASA Technical Reports Server (NTRS)

    Lindgren, P.; Lee, M. R.; Sofe, M.; Zolensky, M. E.

    2011-01-01

    Xenoliths are foreign clasts that oc-cur in various classes of meteorites, e.g. [1,2,3]. A re-cent study reveals the presence of several distinct classes of xenoliths in regolith-bearing meteorites, in-cluding in over 20 different carbonaceous chondrites [4]. The most common types of xenoliths are fine-grained hydrous clasts, often referred to as C1 or CI clasts in the literature, although their mineralogy is actually more similar to hydrous micrometeorites [5,6]. Xenoliths in meteorites present an opportunity to study material not yet classified or available as separate meteorites, and can provide additional information on processes in the dynamic early history of the Solar Sys-tem. Here we have performed chemical and mineralogi-cal analyses of xenoliths in the CM2 carbonaceous chondrite LON 94101, using scanning electron micro-scopy (SEM) and transmission electron microscopy (TEM).

  17. Volumetric cone-beam CT system based on a 41x41 cm2 flat-panel imager

    NASA Astrophysics Data System (ADS)

    Jaffray, David A.; Siewerdsen, Jeffrey H.

    2001-06-01

    Cone-beam computed tomography (CBCT) based upon large-area flat-panel imager (FPI) technology is a flexible and adaptable technology that offers large field-of-view (FOV), high spatial resolution, and soft-tissue imaging. The imaging performance of FPI-based cone-beam CT has been evaluated on a computer-controlled bench-top system using an early prototype FPI with a small FOV (20.5 X 20.5 cm2). These investigations demonstrate the potential of this exciting technology. In this report, imaging performance is evaluated using a production grade large-area FPI (41 X 41 cm2) for which the manufacturer has achieved a significant reduction in additive noise. This reduction in additive noise results in a substantial improvement in detective quantum efficiency (DQE) at low exposures. The spatial resolution over the increased FOV of the cone-beam CT system is evaluated by imaging a fine steel wire placed at various locations within the volume of reconstruction. The measured modulation transfer function (MTF) of the system demonstrates spatial frequency pass beyond 1 mm-1 (10% modulation) with a slight degradation at points off the source plane. In addition to investigations of imaging performance, progress has also been made in the integration of this technology with a medical linear accelerator for on-line image-guided radiation therapy. Unlike the bench-top system, this implementation must contend with significant geometric non-idealities caused by gravity-induced flex of the x-ray tube and FPI support assemblies. A method of characterizing and correcting these non-idealities has been developed. Images of an anthropomorphic head phantom qualitatively demonstrate the excellent spatial resolution and large FOV achievable with the cone-beam approach in the clinical implementation.

  18. HYDRATE v1.5 OPTION OF TOUGH+ v1.5

    2015-08-27

    HYDRATE v1.5 is a numerical code that for the simulation of the behavior of hydrate-bearing geologic systems, and represents the third update of the code since its first release [Moridis et al., 2008]. It is an option of TOUGH+ v1.5 [Moridis and Pruess, 2014], a successor to the TOUGH2 [Pruess et al., 1999, 2012] family of codes for multi-component, multiphase fluid and heat flow developed at the Lawrence Berkeley National Laboratory. HYDRATE v1.5 needs themore » TOUGH+ v1.5 core code in order to compile and execute. It is written in standard FORTRAN 95/2003, and can be run on any computational platform (workstation, PC, Macintosh) for which such compilers are available. By solving the coupled equations of mass and heat balance, the fully operational TOUGH+HYDRATE code can model the non-isothermal gas release, phase behavior and flow of fluids and heat under conditions typical of common natural CH4-hydrate deposits (i.e., in the permafrost and in deep ocean sediments) in complex geological media at any scale (from laboratory to reservoir) at which Darcy’s law is valid. TOUGH+HYDRATE v1.5 includes both an equilibrium and a kinetic model of hydrate formation and dissociation. The model accounts for heat and up to four mass components, i.e., water, CH4, hydrate, and water-soluble inhibitors such as salts or alcohols. These are partitioned among four possible phases (gas phase, liquid phase, ice phase and hydrate phase). Hydrate dissociation or formation, phase changes and the corresponding thermal effects are fully described, as are the effects of inhibitors. The model can describe all possible hydrate dissociation mechanisms, i.e., depressurization, thermal stimulation, salting-out effects and inhibitor-induced effects.« less

  19. HYDRATE v1.5 OPTION OF TOUGH+ v1.5

    SciTech Connect

    Moridis, George

    2015-08-27

    HYDRATE v1.5 is a numerical code that for the simulation of the behavior of hydrate-bearing geologic systems, and represents the third update of the code since its first release [Moridis et al., 2008]. It is an option of TOUGH+ v1.5 [Moridis and Pruess, 2014], a successor to the TOUGH2 [Pruess et al., 1999, 2012] family of codes for multi-component, multiphase fluid and heat flow developed at the Lawrence Berkeley National Laboratory. HYDRATE v1.5 needs the TOUGH+ v1.5 core code in order to compile and execute. It is written in standard FORTRAN 95/2003, and can be run on any computational platform (workstation, PC, Macintosh) for which such compilers are available. By solving the coupled equations of mass and heat balance, the fully operational TOUGH+HYDRATE code can model the non-isothermal gas release, phase behavior and flow of fluids and heat under conditions typical of common natural CH4-hydrate deposits (i.e., in the permafrost and in deep ocean sediments) in complex geological media at any scale (from laboratory to reservoir) at which Darcy’s law is valid. TOUGH+HYDRATE v1.5 includes both an equilibrium and a kinetic model of hydrate formation and dissociation. The model accounts for heat and up to four mass components, i.e., water, CH4, hydrate, and water-soluble inhibitors such as salts or alcohols. These are partitioned among four possible phases (gas phase, liquid phase, ice phase and hydrate phase). Hydrate dissociation or formation, phase changes and the corresponding thermal effects are fully described, as are the effects of inhibitors. The model can describe all possible hydrate dissociation mechanisms, i.e., depressurization, thermal stimulation, salting-out effects and inhibitor-induced effects.

  20. 31 CFR 10.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... includes an amended tax return and a claim for refund. (7) Service means the Internal Revenue Service. (b... SERVICE Rules Governing Authority to Practice § 10.2 Definitions. (a) As used in this part, except where... Commissioner of Internal Revenue. (4) Practice before the Internal Revenue Service comprehends all...

  1. 39 CFR 10.2 - Advisory service.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., including 5 CFR part 2638. (b) A Governor may obtain advice and guidance on questions of conflicts of... regulations contained in 5 CFR parts 2635 and 7001, or conduct which creates the appearance of such a... POSTAL SERVICE GOVERNORS (ARTICLE X) § 10.2 Advisory service. (a) The General Counsel is the...

  2. 5 CFR 10.2 - Accountability systems.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES AGENCY ACCOUNTABILITY SYSTEMS; OPM AUTHORITY TO REVIEW PERSONNEL MANAGEMENT PROGRAMS (RULE X) § 10.2 Accountability systems. The Director of the Office of Personnel Management may require an agency to establish and maintain a system...

  3. 5 CFR 10.2 - Accountability systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES AGENCY ACCOUNTABILITY SYSTEMS; OPM AUTHORITY TO REVIEW PERSONNEL MANAGEMENT PROGRAMS (RULE X) § 10.2 Accountability systems. The Director of the Office of Personnel Management may require an agency to establish and maintain a system...

  4. 5 CFR 10.2 - Accountability systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE RULES AGENCY ACCOUNTABILITY SYSTEMS; OPM AUTHORITY TO REVIEW PERSONNEL MANAGEMENT PROGRAMS (RULE X) § 10.2 Accountability systems. The Director of the Office of Personnel Management may require an agency to establish and maintain a system...

  5. RealGasBrine v1.0 option of TOUGH+ v1.5

    2015-02-27

    RealGasBrine v1.0 is a numerical code that for the simulation of the behavior of gas-bearing porous and/fractured geologic media. It is an option of TOUGH+ v1.5 [Moridis, 2014], a successor to the TOUGH2 [Pruess et al., 1999; 2012] family of codes for multi-component, multiphase ?uid and heat ?ow developed at the Lawrence Berkeley National Laboratory. RealGasBrine v1.0 needs the TOUGH+ v1.5 core code in order to compile and execute. It is written in standard FORTRANmore » 95/2003, and can be run on any computational platform (workstation, PC, Macintosh) for which such compilers are available. RealGasBrine v1.0 describes the non-isothermal two- (for pure water) or three-phase (for brine) flow of an aqueous phase and a real gas mixture in a gas-bearing medium, with a particular focus in ultra-tight (such as tight-sand and shale gas) systems. Up to 12 individual real gases can be tracked, and salt can precipitate as solid halite. The capabilities of the code include coupled flow and thermal effects, real gas behavior, Darcy and non-Darcy flow, several isotherm options of gas sorption onto the grains of the porous media, complex fracture descriptions, gas solubility into water, and geomechanical effects on flow properties. RealGasBrine v1.0 allows the study of flow and transport of fluids and heat over a wide range of time frames and spatial scales not only in gas reservoirs, but also in any problem involving the flow of gases in geologic media, including the geologic storage of greenhouse gas mixtures, the behavior of geothermal reservoirs with multi-component condensable (H2O and CO2) and non-condensable gas mixtures, the transport of water and released H2 in nuclear waste storage applications, etc.« less

  6. Gas-Phase Oxidation of Cm+ and Cm2+ -- Thermodynamics of neutral and ionized CmO

    SciTech Connect

    Gibson, John K; Haire, Richard G.; Santos, Marta; Pires de Matos, Antonio; Marcalo, Joaquim

    2008-12-08

    Fourier transform ion cyclotron resonance mass spectrometry was employed to study the products and kinetics of gas-phase reactions of Cm+ and Cm2+; parallel studies were carried out with La+/2+, Gd+/2+ and Lu+/2+. Reactions with oxygen-donor molecules provided estimates for the bond dissociation energies, D[M+-O](M = Cm, Gd, Lu). The first ionization energy, IE[CmO], was obtained from the reactivity of CmO+ with dienes, and the second ionization energies, IE[MO+](M = Cm, La, Gd, Lu), from the rates of electron-transfer reactions from neutrals to the MO2+ ions. The following thermodynamic quantities for curium oxide molecules were obtained: IE[CmO]= 6.4+-0.2 eV; IE[CmO+]= 15.8+-0.4 eV; D[Cm-O]= 710+-45 kJ mol-1; D[Cm+-O]= 670+-40 kJ mol-1; and D[Cm2+-O]= 342+-55 kJ mol-1. Estimates for the M2+-O bond energies for M = Cm, La, Gd and Lu are all intermediate between D[N2-O]and D[OC-O]--i.e., 167 kJ mol-1< D[M2+-O]< 532 kJ mol-1 -- such that the four MO2+ ions fulfill the thermodynamic requirement for catalytic O-atom transport from N2O to CO. It was demonstrated that the kinetics are also favorable and that the CmO2+, LaO2+, GdO2+ and LuO2+ dipositive ions each catalyze the gas-phase oxidation of CO to CO2 by N2O. The CmO2+ ion appeared during the reaction of Cm+ with O2 when the intermediate, CmO+, was not collisionally cooled -- although its formation is kinetically and/or thermodynamically unfavorable, CmO2+ is a stable species.

  7. Backward-propagating MeV electrons from 1018 W/cm2 laser interactions with water

    NASA Astrophysics Data System (ADS)

    Morrison, J. T.; Chowdhury, E. A.; Frische, K. D.; Feister, S.; Ovchinnikov, V. M.; Nees, J. A.; Orban, C.; Freeman, R. R.; Roquemore, W. M.

    2015-04-01

    We present an experimental study of the generation of ˜MeV electrons opposite to the direction of laser propagation following the relativistic interaction at normal incidence of a ˜3 mJ, 1018 W/cm2 short pulse laser with a flowing 30 μm diameter water column target. Faraday cup measurements record hundreds of pC charge accelerated to energies exceeding 120 keV, and energy-resolved measurements of secondary x-ray emissions reveal an x-ray spectrum peaking above 800 keV, which is significantly higher energy than previous studies with similar experimental conditions and more than five times the ˜110 keV ponderomotive energy scale for the laser. We show that the energetic x-rays generated in the experiment result from backward-going, high-energy electrons interacting with the focusing optic, and vacuum chamber walls with only a small component of x-ray emission emerging from the target itself. We also demonstrate that the high energy radiation can be suppressed through the attenuation of the nanosecond-scale pre-pulse. These results are supported by 2D particle-in-cell simulations of the laser-plasma interaction, which exhibit beam-like backward-propagating MeV electrons.

  8. Spin-Hall-Effect-Assisted Electroresistance in Antiferromagnets via 105 A/cm2 dc Current

    PubMed Central

    Han, Jiahao; Wang, Yuyan; Pan, Feng; Song, Cheng

    2016-01-01

    Antiferromagnet (AFM) spintronics with reduced electrical current is greatly expected to process information with high integration and low power consumption. In Pt/FeMn and Ta/FeMn hybrids, we observe significant resistance variation (up to 7% of the total resistance) manipulated by 105 A/cm2 dc current. We have excluded the contribution of isotropic structural effects, and confirmed the critical role of the spin Hall injection from Pt (or Ta) to FeMn. This electrical current-manipulated resistance (i.e. electroresistance) is proposed to be attributed to the spin-Hall-effect-induced spin-orbit torque in FeMn. Similar results have also been detected in plain IrMn films, where the charge current generates spin current via the spin Hall effect with the existence of Ir atoms. All the measurements are free from external magnetic fields and ferromagnets. Our findings present an interesting step towards high-efficiency spintronic devices. PMID:27546199

  9. Clasts in the CM2 carbonaceous chondrite Lonewolf Nunataks 94101: Evidence for aqueous alteration prior to complex mixing

    NASA Astrophysics Data System (ADS)

    Lindgren, Paula; Lee, Martin R.; Sofe, Mahmood R.; Zolensky, Michael E.

    2013-06-01

    Clasts in the CM2 carbonaceous chondrite Lonewolf Nunataks (LON) 94101 have been characterized using scanning and transmission electron microscopy and electron microprobe analysis to determine their degrees of aqueous alteration, and the timing of alteration relative to incorporation of clasts into the host. The provenance of the clasts, and the mechanism by which they were incorporated and mixed with their host material are also considered. Results show that at least five distinct types of clasts occur in LON 94101, of which four have been aqueously altered to various degrees and one is largely anhydrous. The fact that they have had different alteration histories implies that the main part of aqueous activity occurred prior to the mixing and assimilation of the clasts with their host. Further, the presence of such a variety of clasts suggests complex mixing in a dynamic environment involving material from various sources. Two of the clasts, one containing approximately 46 vol% carbonate and the other featuring crystals of pyrrhotite up to approximately 1 mm in size, are examples of unusual lithologies and indicate concentration of chemical elements in discrete areas of the parent body(ies), possibly by flow of aqueous solutions.

  10. Pulse-laser irradiation experiments of Murchison CM2 chondrite for reproducing space weathering on C-type asteroids

    NASA Astrophysics Data System (ADS)

    Matsuoka, Moe; Nakamura, Tomoki; Kimura, Yuki; Hiroi, Takahiro; Nakamura, Ryosuke; Okumura, Satoshi; Sasaki, Sho

    2015-07-01

    We performed pulse-laser irradiation experiments of a primitive meteorite to simulate space weathering by micrometeorite bombardments on C-type asteroids. Pellets of powdered Murchison CM2 chondrite were set in vacuum and exposed to pulse laser with a diameter of 0.5 mm and delivered energies of 5, 10, and 15 mJ. We measured reflectance spectra of unirradiated and irradiated surfaces of the pellets. During analysis the pellet was heated to approximately 100 °C and purged in N2 gas in order to reduce absorption of ambient water. The spectra become darker and bluer with increasing laser energies. Their UV reflectance increases and 0.7- and 3-μm band depths decrease from 0 to 15 mJ. The spectral bluing observed in our experiments reproduces the bluing occurred during space weathering of C-type asteroids. High-resolution observation by a transmission electron microscope showed that the laser heating causes preferential melting and evaporation in FeS-rich fine-grained portions, which results in dispersion and deposition of numerous FeS-rich amorphous silicate particles 20-1000 nm in size on the surface of the pellet. In addition, at the laser-irradiated but unmelted areas, heat-induced amorphization and decomposition of serpentine occur. These mineralogical changes make the reflectance spectra of the Murchison CM chondrite darker and bluer.

  11. Spin-Hall-Effect-Assisted Electroresistance in Antiferromagnets via 10(5) A/cm(2) dc Current.

    PubMed

    Han, Jiahao; Wang, Yuyan; Pan, Feng; Song, Cheng

    2016-01-01

    Antiferromagnet (AFM) spintronics with reduced electrical current is greatly expected to process information with high integration and low power consumption. In Pt/FeMn and Ta/FeMn hybrids, we observe significant resistance variation (up to 7% of the total resistance) manipulated by 10(5) A/cm(2) dc current. We have excluded the contribution of isotropic structural effects, and confirmed the critical role of the spin Hall injection from Pt (or Ta) to FeMn. This electrical current-manipulated resistance (i.e. electroresistance) is proposed to be attributed to the spin-Hall-effect-induced spin-orbit torque in FeMn. Similar results have also been detected in plain IrMn films, where the charge current generates spin current via the spin Hall effect with the existence of Ir atoms. All the measurements are free from external magnetic fields and ferromagnets. Our findings present an interesting step towards high-efficiency spintronic devices. PMID:27546199

  12. Thorny devil nanotextured fibers: the way to cooling rates on the order of 1 kW/cm2.

    PubMed

    Sinha-Ray, S; Zhang, Y; Yarin, A L

    2011-01-01

    In the present work high-heat-flux surfaces, which should serve at temperatures of up to 200 °C, were covered by electrospun polymer nanofiber mats with thicknesses of about 30 μm. Then, four different metals were electroplated on separate polymer mats, namely, copper, silver, nickel, and gold. As a result, copper-plated nanofiber mats took on an appearance resembling that of a small Australian thorny devil lizard (i.e., they became very rough on the nanoscale) and acquired a high thermal diffusivity. Silver-plated nanofiber mats also became very rough because of the dendritelike and cactuslike nanostructures on their surfaces. However, nickel-plated nanofibers were only partially rough and their mats incorporated large domains of smooth nickel-plated fibers, and gold-plated nanofibers were practically smooth. Drop impacts on the hot surfaces coated with copper-plated and silver-plated nanofibers revealed tremendously high values of heat removal rates of up to 0.6 kW/cm(2). Such high values of heat flux are more than an order of magnitude higher that the currently available ones and probably can be increased even more using the same technique. They open some intriguing perspectives for the cooling of high-heat-flux microelectronics and optoelectronics and for further miniaturization of such devices, especially for such applications as UAVs and UGVs. PMID:21126096

  13. Structural Basis for Capping Protein Sequestration by Myotrophin (V-1)*

    PubMed Central

    Zwolak, Adam; Fujiwara, Ikuko; Hammer, John A.; Tjandra, Nico

    2010-01-01

    Capping protein (CP) is a ubiquitously expressed, heterodimeric 62-kDa protein that binds the barbed end of the actin filament with high affinity to block further filament elongation. Myotrophin (V-1) is a 13-kDa ankyrin repeat-containing protein that binds CP tightly, sequestering it in a totally inactive complex in vitro. Here, we elucidate the molecular interaction between CP and V-1 by NMR. Specifically, chemical shift mapping and intermolecular paramagnetic relaxation enhancement experiments reveal that the ankyrin loops of V-1, which are essential for V-1/CP interaction, bind the basic patch near the joint of the α tentacle of CP shown previously to drive most of the association of CP with and affinity for the barbed end. Consistently, site-directed mutagenesis of CP shows that V-1 and the strong electrostatic binding site for CP on the barbed end compete for this basic patch on CP. These results can explain how V-1 inactivates barbed end capping by CP and why V-1 is incapable of uncapping CP-capped actin filaments, the two signature biochemical activities of V-1. PMID:20538588

  14. A 100-kV, 100-A/cm2 Electron Optical System for the EB-X3 X-Ray Mask Writer

    NASA Astrophysics Data System (ADS)

    Saito, Kenichi; Kato, Junichi; Matsuda, Tadahito; Nakayama, Yoshinori

    2000-12-01

    In order to increase the throughput of the EB-X3 variably shaped electron beam writing system, a method of increasing the current density with a zoom lens was introduced into the electron optical system. The electron optical characteristics were measured at current densities of 50 and 100 A/cm2 under various zoom-lens conditions, and the results show that this method can increase the current density to 100 A/cm2 without any change in the major electron optical characteristics. At this current density, the patterning resolution was estimated to be 55 nm, and no melting of the first shaping aperture and no microdischarges in the 100-kV electron gun were observed. This confirms that the current density of the EB-X3 can in fact be extended to 100 A/cm2 for the fabrication of X-ray masks with a minimum feature size of 100 nm and below.

  15. Extremely high current density over 1000 A/cm2 operation in M-GaN LEDs on bulk GaN substrates with low-efficiency droop

    NASA Astrophysics Data System (ADS)

    Yokogawa, Toshiya; Inoue, Akira

    2014-02-01

    A high current density over 1000 A/cm2 operation in small chip size m-plane GaN-LED has been successfully demonstrated. The LED with chip size 450 × 450 μm2 has emitted 1353 mW in light output power and 39.2% in external quantum efficiency (EQE) at 1000 A/cm2 (1134 mA). The m-plane GaN-LED has showed asymmetric radiation characteristics. The radiation patterns are controlled by the surface of LED package, the height of LED chip, and striped texture on top m-plane surface.

  16. Schottky barrier diodes of corundum-structured gallium oxide showing on-resistance of 0.1 mΩ·cm2 grown by MIST EPITAXY®

    NASA Astrophysics Data System (ADS)

    Oda, Masaya; Tokuda, Rie; Kambara, Hitoshi; Tanikawa, Tomochika; Sasaki, Takahiro; Hitora, Toshimi

    2016-02-01

    Thin-film corundum-structured gallium oxide (α-Ga2O3) Schottky barrier diodes (SBDs) were fabricated by growing α-Ga2O3 layers on sapphire substrates by the safe, low-cost, and energy-saving MIST EPITAXY® technique, followed by lifting off the α-Ga2O3 layers from the substrates. The SBDs exhibited on-resistance and breakdown voltage of 0.1 mΩ·cm2 and 531 V (SBD1) or 0.4 mΩ·cm2 and 855 V (SBD2), respectively. These results will encourage the future evolution of low-cost and high-performance SBDs with α-Ga2O3.

  17. Is H2O present on Io? The detection of a new strong band near 3590/cm (2.79 microns)

    NASA Astrophysics Data System (ADS)

    Salama, F.; Allamandola, L. J.; Sandford, S. A.; Bregman, J. D.; Witteborn, F. C.; Cruikshank, D. P.

    1994-02-01

    A strong absorption band at 3590 +/- 20/cm (2.790 +/- 0.015 microns) has been discovered in the spectrum of Io using the Kuiper Airborne Observatory (KAO). The 2nu1 + nu3 combination mode of solid SO2 falls at this position. Since SO2 is abundant on Io it must contribute to the new band. However, a band due to H2O was predicted near this frequency in Io's spectrum based on laboratory experiments of H2O:SO2 mixed Io ice analogs which were used to assign the two weak, variable features at 3370 and 3170/cm (2.97 and 3.15 microns) to trace amounts of H2O frozen in solid SO2 on Io. The new band probably originates from both SO2 and H2O. Unfortunately, the spectral resolution of the data is insufficient to settle the issue of whether there are two resolvable components.

  18. New narrow infrared absorption features in the spectrum of Io between 3600 and 3100 cm (2.8-3.2 micrometers)

    NASA Technical Reports Server (NTRS)

    Sandford, Scott A.; Geballe, Thomas R.; Salama, Farid; Goorvitch, David

    1994-01-01

    We report the discovery of a series of infrared absorption bands between 3600 and 3100/cm (2.8-3.2 micrometers) in the spectrum of Io. Individual narrow bands are detected at 3553, 3514.5, 3438, 3423, 3411.5, and 3401/cm (2.815, 2.845, 2.909, 2.921, 2.931, and 2.940 micrometers, respectively). The positions and relative strengths of these bands, and the difference of their absolute strengths between the leading and trailing faces of Io, indicate that they are due to SO2. The band at 3438/cm (2.909 micrometers) could potentially have a contribution from an additional molecular species. The existence of these bands in the spectrum of Io indicates that a substantial fraction of the SO2 on Io must reside in transparent ices having relatively large crystal sizes. The decrease in the continuum observed at the high frequency ends of the spectra is probably due to the low frequency side of the recently detected, strong 3590/cm (2.79 micrometer) feature. This band is likely due to the combination of a moderately strong SO2 band and an additional absorption from another molecular species, perhaps H2O isolated in SO2 at low concentrations. A broad (FWHM approximately = 40-60/cm), weak band is seen near 3160/cm (3.16 micrometers) and is consistent with the presence of small quantities of H2O isolated in SO2-rich ices. There is no evidence in the spectra for the presence of H2O vapor on Io. Thus, the spectra presented here neither provide unequivocal evidence for the presence of H2O on Io nor preclude it at the low concentrations suggested by past studies.

  19. 26 CFR 36.3121(l)(10)-2 - Identification.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 15 2011-04-01 2011-04-01 false Identification. 36.3121(l)(10)-2 Section 36.3121(l)(10)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SUBSIDIARIES § 36.3121(l)(10)-2 Identification. (a) Domestic corporation. A domestic corporation which...

  20. 26 CFR 36.3121(l)(10)-2 - Identification.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 15 2012-04-01 2012-04-01 false Identification. 36.3121(l)(10)-2 Section 36.3121(l)(10)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SUBSIDIARIES § 36.3121(l)(10)-2 Identification. (a) Domestic corporation. A domestic corporation which...

  1. 26 CFR 36.3121(l)(10)-2 - Identification.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 15 2013-04-01 2013-04-01 false Identification. 36.3121(l)(10)-2 Section 36.3121(l)(10)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SUBSIDIARIES § 36.3121(l)(10)-2 Identification. (a) Domestic corporation. A domestic corporation which...

  2. 26 CFR 36.3121(l)(10)-2 - Identification.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 15 2010-04-01 2010-04-01 false Identification. 36.3121(l)(10)-2 Section 36.3121(l)(10)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SUBSIDIARIES § 36.3121(l)(10)-2 Identification. (a) Domestic corporation. A domestic corporation which...

  3. 26 CFR 36.3121(l)(10)-2 - Identification.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 15 2014-04-01 2014-04-01 false Identification. 36.3121(l)(10)-2 Section 36.3121(l)(10)-2 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED... SUBSIDIARIES § 36.3121(l)(10)-2 Identification. (a) Domestic corporation. A domestic corporation which...

  4. Neuronal Projections from V1 to V2 in Amblyopia

    PubMed Central

    Sincich, Lawrence C.; Jocson, Cristina M.; Horton, Jonathan C.

    2012-01-01

    The mechanism of amblyopia in children with congenital cataract is not understood fully, but studies in macaques have shown that geniculate synapses are lost in striate cortex (V1). To search for other projection abnormalities in amblyopia, the pathway from V1 to V2 was examined using a triple-label technique in 3 animals raised with monocular suture. [3H]proline was injected into one eye to label the ocular dominance columns. Cholera toxin B-gold (CTB-Au) was injected in V2 to label V1 projection neurons. Alternate sections were processed for cytochrome oxidase (CO) and CTB-Au, or dipped for autoradiography. Eight fields of CTB-Au-labeled cells in V1 opposite injection sites were plotted in layers 2/3 or 4B. After thin stripe injection, labeled cells were concentrated in CO patches. Despite column shrinkage, cells in deprived and normal columns were equal in size and density, in both layer 2/3 and 4B. After pale or thick stripe injection, labeled cells were concentrated in interpatches. Only 23% of projection neurons originated from deprived columns. This reduction exceeded the degree of column shrinkage, a result explained by the fact that column shrinkage causes disproportionate loss of interpatch territory. These data indicate that early monocular form deprivation does not alter the segregation of patch and interpatch pathways to V2 stripes, or cause selective loss or atrophy of V1 projection neurons. The effect of shrinkage of geniculocortical afferents in layer 4C following visual deprivation is not amplified further by attenuation of the amblyopic eye’s projections from V1 to V2. PMID:22357849

  5. Efficient Receptive Field Tiling in Primate V1.

    PubMed

    Nauhaus, Ian; Nielsen, Kristina J; Callaway, Edward M

    2016-08-17

    The primary visual cortex (V1) encodes a diverse set of visual features, including orientation, ocular dominance (OD), and spatial frequency (SF), whose joint organization must be precisely structured to optimize coverage within the retinotopic map. Prior experiments have only identified efficient coverage based on orthogonal maps. Here we used two-photon calcium imaging to reveal an alternative arrangement for OD and SF maps in macaque V1; their gradients run parallel but with unique spatial periods, whereby low-SF regions coincide with monocular regions. Next we mapped receptive fields and found surprisingly precise micro-retinotopy that yields a smaller point-image and requires more efficient inter-map geometry, thus underscoring the significance of map relationships. While smooth retinotopy is constraining, studies suggest that it improves both wiring economy and the V1 population code read downstream. Altogether, these data indicate that connectivity within V1 is finely tuned and precise at the level of individual neurons. PMID:27499086

  6. Critical currents up to 71 000 A cm -2 at 77 K in melt textured YBCO doped with BaSnO 3

    NASA Astrophysics Data System (ADS)

    Lepropre, M.; Monot, I.; Delamare, M. P.; Hervieu, M.; Simon, Ch; Provost, J.; Desgardin, G.; Raveau, B.; Barbur, J. M.; Bourgault, D.; Braithwaite, D.

    We have performed crtical current density measurements on melt textured YBa 2Cu 3O 7 doped with BaSnO 3, which exhibits transport values at 77 K as high as 7.1 × 10 4 A cm -2 in zero field and 1.1 × 10 4 A cm -2 at 20 T. A systematic study of this ceramic has been carried out using SEM and HREM observations in correlation with Jc measurements. A textured microstructure is observed, characterized by rather regular striation corresponding to platelet-like 123 grain. Large 211 (green phase) inclusions of ≈ 10 μm diameter are also observed, as well as smaller inclusions which correspond to BaSnO 3 (< 10 μm) at the grain boundaries of the platelets or wrapped in the matrix. It has been found that transport Jc data are distributed over a very wide range (2.5 × 10 3-7.1 × 10 4 A cm -2). Nevertheless, magnetic Jc measurements suggest that cracks of the order of micrometres may appear in some regions of the material leading to a drramatic decrease in c for the corresponding sample. On the other hand, HREM observations demonstrate that extended defects such as intergrowth or disordering, as well as twin boundaries, cannot be considered to be the major factors for vortex pinning in the textured 123 material. The presence or obsence of inhomogeneity on the nanoscale does not seem to influence the critical current density. Finally, it has been determined that pinning is more probably due to microstructure.

  7. Dynamics of cell and tissue growth acquired by means of 25 mm2 to 10 cm2 lens-free imaging

    NASA Astrophysics Data System (ADS)

    Momey, F.; Coutard, J.-G.; Bordy, T.; Navarro, F.; Menneteau, M.; Dinten, J.-M.; Allier, C.

    2015-03-01

    In this paper, we discuss a new methodology based on lens-free imaging to perform wound healing assay with unprecedented statistics. Our video lens-free microscopy setup is a simple optical system featuring only a CMOS sensor and a semi coherent illumination system. Yet it is a powerful means for the real-time monitoring of cultivated cells. It presents several key advantages, e.g., integration into standard incubator, compatibility with standard cell culture protocol, simplicity and ease of use. It can perform the follow-up in a large field of view (25 mm2) of several crucial parameters during the culture of cells i.e. their motility, their proliferation rate or their death. Consequently the setup can gather large statistics both in space and time. But in the case of tissue growth experiments, the field of view of 25 mm2 remains not sufficient and results can be biased depending on the position of the device with respect to the recipient of the cell culture. Hence, to conduct exhaustive wound healing assay, here we propose to enlarge the field of view up to 10 cm2 through two different approaches. The first method consists in performing a scan of the cell culture by moving the source/sensor couple and then stitch the stack of images. The second is to make an acquisition by scanning with a line scan camera. The two approaches are compared in term of resolution, complexity and acquisition time. Next we have performed acquisitions of wound healing assay (keratinocytes HaCaT) both in real-time (25 mm2) and in final point (10 cm2) to assess the combination of these two complementary modalities. In the future, we aim at combining directly super wide field of view acquisitions (>10 cm2) with real time ability inside the incubator.

  8. MgZnO/ZnO heterostructures with electron mobility exceeding 1 × 106 cm2/Vs

    PubMed Central

    Falson, Joseph; Kozuka, Yusuke; Uchida, Masaki; Smet, Jurgen H.; Arima, Taka-hisa; Tsukazaki, Atsushi; Kawasaki, Masashi

    2016-01-01

    The inherently complex chemical and crystallographic nature of oxide materials has suppressed the purities achievable in laboratory environments, obscuring the rich physical degrees of freedom these systems host. In this manuscript we provide a systematic approach to defect identification and management in oxide molecular beam epitaxy grown MgZnO/ZnO heterostructures which host two-dimensional electron systems. We achieve samples displaying electron mobilities in excess of 1 × 106 cm2/Vs. This data set for the MgZnO/ZnO system firmly establishes that the crystalline quality has become comparable to traditional semiconductor materials. PMID:27229479

  9. In Situ Location and Characterization of Carbon-bearing Phases in Carbonaceous Chondrites: Insights from Yamato 791198, a Weakly-altered CM2 Chondrite

    NASA Technical Reports Server (NTRS)

    Brearley, Adrian J.

    2004-01-01

    Intense studies of carbonaceous chondrites have provided remarkable insights into the behavior of carbon during the earliest stages of our solar system. This research has demonstrated that carbonaceous meteorites contain a diverse array of organic compounds, whose origins are probably the result of multiple processes that occurred in different locations including interstellar space, the solar nebula and asteroidal parent bodies [1-3]. The most abundant organic carbon component in CI1 and CM2 carbonaceous chondrites is so-called macromolecular carbon, a high molecular weight material that has some affinities to terrestrial kerogen and constitutes approximately 60-70% of the organic material in these meteorites. Although recent studies e.g. [3] have radically improved our understanding of the structural and compositional characteristics of this material, a number of key questions remain to be addressed. In particular, our knowledge of where this macromolecular material is distributed at the fine-scale within carbonaceous chondrites is scant. [4] have shown that organic material is associated with phyllosilicate-rich matrix in CM chondrites, but the detailed mineralogical associations are not well-known. Over the past 2 years, we have begun to address this question by using energy filtered transmission electron microscopy (EFTEM) to locate carbon-bearing materials in situ, focusing specifically on the CM2s. To date we have reported data on the Murchison CM2 chondrite [5], a meteorite that has experienced a modest degree of aqueous alteration. To extend our observations to other CM2 chondrites, we have examined the occurrence of carbon-bearing phases in Yamato 791198. Our recent studies [5] have shown that Y-791198 is among the most weakly-altered CM chondrite currently known and hence is likely to preserve a quite primitive distribution of carbonaceous material. In this study, we present initial observations on the distribution of these materials in one fine

  10. CONTROL OF LASER RADIATION PARAMETERS: Direct amplification of picosecond pulses in neodymium glass with a power density above 100 GW cm-2

    NASA Astrophysics Data System (ADS)

    Ivanov, Vladimir V.; Kutsenko, A. V.; Matsveiko, A. A.; Mikhailov, Yu A.; Popov, A. I.; Sklizkov, G. V.; Starodub, Aleksandr N.; Chekmarev, Alexander M.

    2003-09-01

    A scheme for amplification of ultrashort laser pulses is studied, which is used in experiments on symmetrisation of ablation pressure with the help of a prepulse upon acceleration of foils by laser radiation of high brightness. The possibility of direct amplification of short pulses before their expansion in order to increase the energy contrast is considered. In experiments performed on the PICO facility, the amplification of a 10-ps pulse with a power density exceeding 100 GW cm-2 is demonstrated with the gain equal to 1.2 and the inversion drop above 30 %.

  11. MgZnO/ZnO heterostructures with electron mobility exceeding 1 × 10(6) cm(2)/Vs.

    PubMed

    Falson, Joseph; Kozuka, Yusuke; Uchida, Masaki; Smet, Jurgen H; Arima, Taka-Hisa; Tsukazaki, Atsushi; Kawasaki, Masashi

    2016-01-01

    The inherently complex chemical and crystallographic nature of oxide materials has suppressed the purities achievable in laboratory environments, obscuring the rich physical degrees of freedom these systems host. In this manuscript we provide a systematic approach to defect identification and management in oxide molecular beam epitaxy grown MgZnO/ZnO heterostructures which host two-dimensional electron systems. We achieve samples displaying electron mobilities in excess of 1 × 10(6) cm(2)/Vs. This data set for the MgZnO/ZnO system firmly establishes that the crystalline quality has become comparable to traditional semiconductor materials. PMID:27229479

  12. Reflectance Spectra of CM2 Chondrite Mighei Irradiated with Pulsed Laser and Implications for Low-Albedo Asteroids and Martian Moons

    NASA Technical Reports Server (NTRS)

    Moroz, L. V.; Hiroi, T.; Shingareva, T. V.; Basilevsky, A. T.; Fisenko, A. V.; Semjonova, L. F.; Pieters, C. M.

    2004-01-01

    Micrometeoritic bombardment is an important space weathering process modifying surface optical properties of airless solar system bodies. We have used irradiation with a microsecond pulsed laser as an experimental method to simulate such a process on various targets. The experiment discussed here was performed on a powdered sample of CM2 carbonaceous chondrite Mighei. Shingareva et al. report the details of experimental procedure as well as the results of mineralogical and chemical studies of the irradiated material. Here we present reflectance spectra of irradiated Mighei samples and discuss their spectral properties compared to those of non-irradiated meteorite and low-albedo small solar system bodies.

  13. MgZnO/ZnO heterostructures with electron mobility exceeding 1 × 106 cm2/Vs

    NASA Astrophysics Data System (ADS)

    Falson, Joseph; Kozuka, Yusuke; Uchida, Masaki; Smet, Jurgen H.; Arima, Taka-Hisa; Tsukazaki, Atsushi; Kawasaki, Masashi

    2016-05-01

    The inherently complex chemical and crystallographic nature of oxide materials has suppressed the purities achievable in laboratory environments, obscuring the rich physical degrees of freedom these systems host. In this manuscript we provide a systematic approach to defect identification and management in oxide molecular beam epitaxy grown MgZnO/ZnO heterostructures which host two-dimensional electron systems. We achieve samples displaying electron mobilities in excess of 1 × 106 cm2/Vs. This data set for the MgZnO/ZnO system firmly establishes that the crystalline quality has become comparable to traditional semiconductor materials.

  14. Current density and catalyst-coated membrane resistance distribution of hydro-formed metallic bipolar plate fuel cell short stack with 250 cm2 active area

    NASA Astrophysics Data System (ADS)

    Haase, S.; Moser, M.; Hirschfeld, J. A.; Jozwiak, K.

    2016-01-01

    An automotive fuel cell with an active area of 250 cm2 is investigated in a 4-cell short stack with a current and temperature distribution device next to the bipolar plate with 560 current and 140 temperature segments. The electrical conductivities of the bipolar plate and gas diffusion layer assembly are determined ex-situ with this current scan shunt module. The applied fuel cell consists of bipolar plates constructed of 75-μm-thick, welded stainless-steel foils and a graphitic coating. The electrical conductivities of the bipolar plate and gas diffusion layer assembly are determined ex-situ with this module with a 6% deviation in in-plane conductivity. The current density distribution is evaluated up to 2.4 A cm-2. The entire cell's investigated volumetric power density is 4.7 kW l-1, and its gravimetric power density is 4.3 kW kg-1 at an average cell voltage of 0.5 V. The current density distribution is determined without influencing the operating cell. In addition, the current density distribution in the catalyst-coated membrane and its effective resistivity distribution with a finite volume discretisation of Ohm's law are evaluated. The deviation between the current density distributions in the catalyst-coated membrane and the bipolar plate is determined.

  15. Low-frequency (<100 kHz), low-intensity (<100 mW/cm(2)) ultrasound to treat venous ulcers: a human study and in vitro experiments.

    PubMed

    Samuels, Joshua A; Weingarten, Michael S; Margolis, David J; Zubkov, Leonid; Sunny, Youhan; Bawiec, Christopher R; Conover, Dolores; Lewin, Peter A

    2013-08-01

    The purpose of this study was to examine whether low frequency (<100 kHz), low intensity (<100 mW/cm(2), spatial peak temporal peak) ultrasound can be an effective treatment of venous stasis ulcers, which affect 500 000 patients annually costing over $1 billion per year. Twenty subjects were treated with either 20 or 100 kHz ultrasound for between 15 and 45 min per session for a maximum of four treatments. Healing was monitored by changes in wound area. Additionally, two in vitro studies were conducted using fibroblasts exposed to 20 kHz ultrasound to confirm the ultrasound's effects on proliferation and cellular metabolism. Subjects receiving 20 kHz ultrasound for 15 min showed statistically faster (p < 0.03) rate of wound closure. All five of these subjects fully healed by the fourth treatment session. The in vitro results indicated that 20 kHz ultrasound at 100 mW/cm(2) caused an average of 32% increased metabolism (p < 0.05) and 40% increased cell proliferation (p < 0.01) after 24 h when compared to the control, non-treated cells. Although statistically limited, this work supports the notion that low-intensity, low-frequency ultrasound is beneficial for treating venous ulcers. PMID:23927194

  16. A thienoisoindigo-naphthalene polymer with ultrahigh mobility of 14.4 cm(2)/V·s that substantially exceeds benchmark values for amorphous silicon semiconductors.

    PubMed

    Kim, Gyoungsik; Kang, Seok-Ju; Dutta, Gitish K; Han, Young-Kyu; Shin, Tae Joo; Noh, Yong-Young; Yang, Changduk

    2014-07-01

    By considering the qualitative benefits associated with solution rheology and mechanical properties of polymer semiconductors, it is expected that polymer-based electronic devices will soon enter our daily lives as indispensable elements in a myriad of flexible and ultra low-cost flat panel displays. Despite more than a decade of research focused on designing and synthesizing state-of-the-art polymer semiconductors for improving charge transport characteristics, the current mobility values are still not sufficient for many practical applications. The confident mobility in excess of ∼10 cm(2)/V·s is the most important requirement for enabling the realization of the aforementioned near-future products. We report on an easily attainable donor-acceptor (D-A) polymer semiconductor: poly(thienoisoindigo-alt-naphthalene) (PTIIG-Np). An unprecedented mobility of 14.4 cm(2)/V·s, by using PTIIG-Np with a high-k gate dielectric poly(vinylidenefluoride-trifluoroethylene) (P(VDF-TrFE)), is achieved from a simple coating processing, which is of a magnitude that is very difficult to obtain with conventional TFTs by means of molecular engineering. This work, therefore, represents a major step toward truly viable plastic electronics. PMID:24915140

  17. 5 × 5 cm2 silicon photonic crystal slabs on glass and plastic foil exhibiting broadband absorption and high-intensity near-fields

    PubMed Central

    Becker, C.; Wyss, P.; Eisenhauer, D.; Probst, J.; Preidel, V.; Hammerschmidt, M.; Burger, S.

    2014-01-01

    Crystalline silicon photonic crystal slabs are widely used in various photonics applications. So far, the commercial success of such structures is still limited owing to the lack of cost-effective fabrication processes enabling large nanopatterned areas (≫ 1 cm2). We present a simple method for producing crystalline silicon nanohole arrays of up to 5 × 5 cm2 size with lattice pitches between 600 and 1000 nm on glass and flexible plastic substrates. Exclusively up-scalable, fast fabrication processes are applied such as nanoimprint-lithography and silicon evaporation. The broadband light trapping efficiency of the arrays is among the best values reported for large-area experimental crystalline silicon nanostructures. Further, measured photonic crystal resonance modes are in good accordance with light scattering simulations predicting strong near-field intensity enhancements greater than 500. Hence, the large-area silicon nanohole arrays might become a promising platform for ultrathin solar cells on lightweight substrates, high-sensitive optical biosensors, and nonlinear optics. PMID:25073935

  18. AMINO ACID ANALYSES OF THE ANTARCTIC CM2 METEORITES ALH 83100 AND LEW 90500 USING LIQUID CHROMATOGRAPHY-TIME OF FLIGHT-MASS SPECTROMETRY

    NASA Technical Reports Server (NTRS)

    Glavin, D. P.; Dworkin, J. P.; Aubrey, A.; Botta, O.; Doty, J. H., III; Bada, J. L.

    2001-01-01

    The investigation of organic compounds in primitive carbonaceous meteorites provides a record of the chemical processes that occurred in the early solar system. In particular, amino acids have been shown to be potential indicators in tracing the nature of carbonaceous chondrite parent bodies [ 13. The delivery of amino acids by carbonaceous chondrites to the early Earth could have been any important source of the Earth's prebiotic organic inventory [2]. Over 80 different amino acids have been detected in the Murchison CM2 meteorite, most of them completely non-existent in the terrestrial biosphere [3]. We have optimized a new liquid chromatography-time-of-flight-mass spectrometry (LC-ToF-MS) technique coupled with OPAMAC derivatization in order to detect amino acids in meteorite extracts by UV fluorescence and exact mass simultaneously. The detection limit of the LC-ToF-MS instrument for amino acids is at least 3 orders of magnitude lower than traditional GC-MS techniques. Here we report on the first analyses of amino acids and their enantiomeric abundances in the CM2 carbonaceous meteorites ALH 83100, LEW 90500, and Murchison using this new LC-ToF-MS instrument configuration. Amino acid analyses of any kind for the CM meteorite ALH 83100 have not previously been reported.

  19. Exploring V1 by modeling the perceptual quality of images.

    PubMed

    Zhang, Fan; Jiang, Wenfei; Autrusseau, Florent; Lin, Weisi

    2014-01-01

    We propose an image quality model based on phase and amplitude differences between a reference and a distorted image. The proposed model is motivated by the fact that polar representations can separate visual information in a more independent and efficient manner than Cartesian representations in the primary visual cortex (V1). We subsequently estimate the model parameters from a large subjective data set using maximum likelihood methods. By comparing the various model hypotheses on the functional form about the phase and amplitude, we find that: (a) discrimination of visual orientation is important for quality assessment and yet a coarse level of such discrimination seems sufficient; and (b) a product-based amplitude-phase combination before pooling is effective, suggesting an interesting viewpoint about the functional structure of the simple cells and complex cells in V1. PMID:24464165

  20. Environmental Impact Assessment (EIA) Process of V1 NPP Decommissioning

    SciTech Connect

    Matejovic, Igor; Polak, Vincent

    2007-07-01

    Through the adoption of Governmental Resolution No. 801/99 the Slovak Republic undertook a commitment to shutdown units 1 and 2 of Jaslovske Bohunice V 1 NPP (WWER 230 reactor type) in 2006 and 2008 respectively. Therefore the more intensive preparation of a decommissioning documentation has been commenced. Namely, the VI NPP Conceptual Decommissioning Plan and subsequently the Environmental Impact Assessment Report of VI NPP Decommissioning were developed. Thus, the standard environmental impact assessment process was performed and the most suitable alternative of V1 NPP decommissioning was selected as a basis for development of further decommissioning documents. The status and main results of the environmental impact assessment process and EIA report are discussed in more detail in this paper. (authors)

  1. High-resolution eye tracking using V1 neuron activity

    PubMed Central

    McFarland, James M.; Bondy, Adrian G.; Cumming, Bruce G.; Butts, Daniel A.

    2014-01-01

    Studies of high-acuity visual cortical processing have been limited by the inability to track eye position with sufficient accuracy to precisely reconstruct the visual stimulus on the retina. As a result, studies on primary visual cortex (V1) have been performed almost entirely on neurons outside the high-resolution central portion of the visual field (the fovea). Here we describe a procedure for inferring eye position using multi-electrode array recordings from V1 coupled with nonlinear stimulus processing models. We show that this method can be used to infer eye position with one arc-minute accuracy – significantly better than conventional techniques. This allows for analysis of foveal stimulus processing, and provides a means to correct for eye-movement induced biases present even outside the fovea. This method could thus reveal critical insights into the role of eye movements in cortical coding, as well as their contribution to measures of cortical variability. PMID:25197783

  2. Ongoing Slow Fluctuations in V1 Impact on Visual Perception.

    PubMed

    Wohlschläger, Afra M; Glim, Sarah; Shao, Junming; Draheim, Johanna; Köhler, Lina; Lourenço, Susana; Riedl, Valentin; Sorg, Christian

    2016-01-01

    The human brain's ongoing activity is characterized by intrinsic networks of coherent fluctuations, measured for example with correlated functional magnetic resonance imaging signals. So far, however, the brain processes underlying this ongoing blood oxygenation level dependent (BOLD) signal orchestration and their direct relevance for human behavior are not sufficiently understood. In this study, we address the question of whether and how ongoing BOLD activity within intrinsic occipital networks impacts on conscious visual perception. To this end, backwardly masked targets were presented in participants' left visual field only, leaving the ipsi-lateral occipital areas entirely free from direct effects of task throughout the experiment. Signal time courses of ipsi-lateral BOLD fluctuations in visual areas V1 and V2 were then used as proxies for the ongoing contra-lateral BOLD activity within the bilateral networks. Magnitude and phase of these fluctuations were compared in trials with and without conscious visual perception, operationalized by means of subjective confidence ratings. Our results show that ipsi-lateral BOLD magnitudes in V1 were significantly higher at times of peak response when the target was perceived consciously. A significant difference between conscious and non-conscious perception with regard to the pre-target phase of an intrinsic-frequency regime suggests that ongoing V1 fluctuations exert a decisive impact on the access to consciousness already before stimulation. Both effects were absent in V2. These results thus support the notion that ongoing slow BOLD activity within intrinsic networks covering V1 represents localized processes that modulate the degree of readiness for the emergence of visual consciousness. PMID:27601986

  3. Ongoing Slow Fluctuations in V1 Impact on Visual Perception

    PubMed Central

    Wohlschläger, Afra M.; Glim, Sarah; Shao, Junming; Draheim, Johanna; Köhler, Lina; Lourenço, Susana; Riedl, Valentin; Sorg, Christian

    2016-01-01

    The human brain’s ongoing activity is characterized by intrinsic networks of coherent fluctuations, measured for example with correlated functional magnetic resonance imaging signals. So far, however, the brain processes underlying this ongoing blood oxygenation level dependent (BOLD) signal orchestration and their direct relevance for human behavior are not sufficiently understood. In this study, we address the question of whether and how ongoing BOLD activity within intrinsic occipital networks impacts on conscious visual perception. To this end, backwardly masked targets were presented in participants’ left visual field only, leaving the ipsi-lateral occipital areas entirely free from direct effects of task throughout the experiment. Signal time courses of ipsi-lateral BOLD fluctuations in visual areas V1 and V2 were then used as proxies for the ongoing contra-lateral BOLD activity within the bilateral networks. Magnitude and phase of these fluctuations were compared in trials with and without conscious visual perception, operationalized by means of subjective confidence ratings. Our results show that ipsi-lateral BOLD magnitudes in V1 were significantly higher at times of peak response when the target was perceived consciously. A significant difference between conscious and non-conscious perception with regard to the pre-target phase of an intrinsic-frequency regime suggests that ongoing V1 fluctuations exert a decisive impact on the access to consciousness already before stimulation. Both effects were absent in V2. These results thus support the notion that ongoing slow BOLD activity within intrinsic networks covering V1 represents localized processes that modulate the degree of readiness for the emergence of visual consciousness. PMID:27601986

  4. 20 CFR 10.2 - What do these regulations contain?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 1 2011-04-01 2011-04-01 false What do these regulations contain? 10.2 Section 10.2 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR FEDERAL EMPLOYEES' COMPENSATION ACT CLAIMS FOR COMPENSATION UNDER THE FEDERAL EMPLOYEES' COMPENSATION ACT,...

  5. 20 CFR 10.2 - What do these regulations contain?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 1 2013-04-01 2012-04-01 true What do these regulations contain? 10.2 Section 10.2 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR FEDERAL EMPLOYEES' COMPENSATION ACT CLAIMS FOR COMPENSATION UNDER THE FEDERAL EMPLOYEES' COMPENSATION ACT,...

  6. 20 CFR 10.2 - What do these regulations contain?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Subpart D. The rules governing emergency and routine medical care, second opinion and referee medical... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false What do these regulations contain? 10.2 Section 10.2 Employees' Benefits OFFICE OF WORKERS' COMPENSATION PROGRAMS, DEPARTMENT OF LABOR...

  7. 28 CFR 10.2 - Language of registration statement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Language of registration statement. 10.2... ON ACTIVITIES WITHIN THE UNITED STATES Registration Statement § 10.2 Language of registration statement. Registration statements must be in English if possible. If in a foreign language they must...

  8. 1 CFR 10.2 - Scope and sources.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 1 General Provisions 1 2012-01-01 2012-01-01 false Scope and sources. 10.2 Section 10.2 General... transcripts or text issued by the Office of the White House Press Secretary, including— (1) Communications to... ancillary form, from the following groups of documents, when issued by the Press Office. (1)...

  9. 1 CFR 10.2 - Scope and sources.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 1 General Provisions 1 2014-01-01 2012-01-01 true Scope and sources. 10.2 Section 10.2 General... transcripts or text issued by the Office of the White House Press Secretary, including— (1) Communications to... ancillary form, from the following groups of documents, when issued by the Press Office. (1)...

  10. 1 CFR 10.2 - Scope and sources.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 1 General Provisions 1 2013-01-01 2012-01-01 true Scope and sources. 10.2 Section 10.2 General... transcripts or text issued by the Office of the White House Press Secretary, including— (1) Communications to... ancillary form, from the following groups of documents, when issued by the Press Office. (1)...

  11. 1 CFR 10.2 - Scope and sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 1 General Provisions 1 2010-01-01 2010-01-01 false Scope and sources. 10.2 Section 10.2 General... transcripts or text issued by the Office of the White House Press Secretary, including— (1) Communications to... ancillary form, from the following groups of documents, when issued by the Press Office. (1)...

  12. 1 CFR 10.2 - Scope and sources.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 1 General Provisions 1 2011-01-01 2011-01-01 false Scope and sources. 10.2 Section 10.2 General... transcripts or text issued by the Office of the White House Press Secretary, including— (1) Communications to... ancillary form, from the following groups of documents, when issued by the Press Office. (1)...

  13. Vasopressin V1a, but not V1b, receptors within the PVN of lactating rats mediate maternal care and anxiety-related behaviour.

    PubMed

    Bayerl, Doris S; Hönig, Jennifer N; Bosch, Oliver J

    2016-05-15

    The brain neuropeptide arginine-vasopressin (AVP) mediates a wide range of social behaviours via its V1a (V1aR) but also its V1b receptor (V1bR). With respect to maternal behaviour, V1bR are still less investigated, whereas V1aR have been shown repeatedly to trigger maternal behaviour, depending on the brain region. Here, we aimed to study the role of both V1aR and V1bR within the hypothalamic paraventricular nucleus (PVN), a major source of AVP, in maternal care (lactation day (LD) 1), maternal motivation in the pup retrieval test (LD 3) and anxiety-related behaviour on the elevated plus maze (EPM; LD 5) by acute local infusion of receptor subtype-specific antagonists for V1aR (d(CH2)5Tyr(Me)(2)AVP) or V1bR (SSR149415). Furthermore, we compared V1bR expression in the PVN of virgin versus lactating rats (LD 4). Our results demonstrate that within the PVN neither V1bR mRNA (qPCR) nor protein (Western Blot) content differed between virgin and lactating rats. Regarding behaviour, acute antagonism of V1aR, but not of V1bR, decreased the occurrence of nursing as well as anxiety-related behaviour as reflected by higher percentage of time spent on and of entries into the open arms of the EPM. Maternal motivation was not affected by any treatment. In summary, we demonstrate subtype-specific involvement of V1 receptors within the PVN in mediating various maternal behaviours. The lack of effects after V1bR blockade reveals that AVP acts mainly via V1aR in the PVN, at least in lactating rats, to mediate maternal care and anxiety. PMID:26909846

  14. The oxygen isotope evolution of parent body aqueous solutions as recorded by multiple carbonate generations in the Lonewolf Nunataks 94101 CM2 carbonaceous chondrite

    NASA Astrophysics Data System (ADS)

    Lee, M. R.; Sofe, M. R.; Lindgren, P.; Starkey, N. A.; Franchi, I. A.

    2013-11-01

    The CM2 carbonaceous chondrite LON 94101 contains aragonite and two generations of calcite that provide snapshots of the chemical and isotopic evolution of aqueous solutions during parent body alteration. Aragonite was the first carbonate to crystallize. It is rare, heterogeneously distributed within the meteorite matrix, and its mean oxygen isotope values are δ18O 39.9 ± 0.6‰, Δ17O -0.3 ± 1.0‰ (1σ). Calcite precipitated soon afterwards, and following a fall in solution Mg/Ca ratios, to produce small equant grains with a mean oxygen isotope value of δ18O 37.5 ± 0.7‰, Δ17O 1.4 ± 1.1‰ (1σ). These grains were partially or completely replaced by serpentine and tochilinite prior to precipitation of the second generation of calcite, which occluded an open fracture to form a millimetre-sized vein, and replaced anhydrous silicates within chondrules and the matrix. The vein calcite has a mean composition of δ18O 18.4 ± 0.3‰, Δ17O -0.5 ± 0.5‰ (1σ). Petrographic and isotopic results therefore reveal two discrete episodes of mineralisation that produced calcite generations with contrasting δ18O, and mean Δ17O values. The aragonite and equant calcite crystallized over a relatively brief period early in the aqueous alteration history of the parent body, and from static fluids that were evolving chemically in response to mineral dissolution and precipitation. The second calcite generation crystallized from solutions of a lower Δ17O, and a lower δ18O and/or higher temperature. As two generations of calcite whose petrographic characteristics and oxygen isotopic compositions are similar to those in LON 94101 occur in at least one other CM2, multiphase carbonate mineralisation could be the typical outcome of the sequence of chemical reactions during parent body aqueous alteration. It is equally possible however that the second generation of calcite formed in response to an event such as impact fracturing and concomitant fluid mobilisation that affected

  15. Three-dimensional nanostructured bilayer solid oxide fuel cell with 1.3 W/cm(2) at 450 °C.

    PubMed

    An, Jihwan; Kim, Young-Beom; Park, Joonsuk; Gür, Turgut M; Prinz, Fritz B

    2013-09-11

    Obtaining high power density at low operating temperatures has been an ongoing challenge in solid oxide fuel cells (SOFC), which are efficient engines to generate electrical energy from fuels. Here we report successful demonstration of a thin-film three-dimensional (3-D) SOFC architecture achieving a peak power density of 1.3 W/cm(2) obtained at 450 °C. This is made possible by nanostructuring of the ultrathin (60 nm) electrolyte interposed with a nanogranular catalytic interlayer at the cathode/electrolyte interface. We attribute the superior cell performance to significant reduction in both the ohmic and the polarization losses due to the combined effects of employing an ultrathin film electrolyte, enhancement of effective area by 3-D architecture, and superior catalytic activity by the ceria-based interlayer at the cathode. These insights will help design high-efficiency SOFCs that operate at low temperatures with power densities that are of practical significance. PMID:23977845

  16. Compositions of Partly Altered Olivine and Replacement Serpentine in the CM2 Chondrites QUE93005 and Nogoya: Implications for Scales of Elemental Redistribution During Aqueous Alteration

    NASA Technical Reports Server (NTRS)

    Velbel, M. A.; Tonui, E. K.; Zolensky, M. E.

    2003-01-01

    Some phyllosilicates in CM carbonaceous chondrites formed by aqueous alteration of anhydrous precursor phases. Although broad trends in the compositions of hydrous phyllosilicates are recognized and believed to be related to trends in degree of aqueous alteration, details of the reactions that formed specific secondary minerals remain obscure. This paper reports compositional relationships between remnants of partially pseudomorphically replaced silicates and their alteration products (serpentine) in the CM2 chondrites QUE93005 and Nogoya and compares both with previously published results for Allan Hills 81002. By focusing on serpentine formed from known reactants (olivines), and on only those instances in which some of the reactant silicate remains, direct compositional relationships between reactants and products, and the elemental mobility required by the reactions, can be established.

  17. Orientation Maps in V1 and Non-Euclidean Geometry.

    PubMed

    Afgoustidis, Alexandre

    2015-12-01

    In the primary visual cortex, the processing of information uses the distribution of orientations in the visual input: neurons react to some orientations in the stimulus more than to others. In many species, orientation preference is mapped in a remarkable way on the cortical surface, and this organization of the neural population seems to be important for visual processing. Now, existing models for the geometry and development of orientation preference maps in higher mammals make a crucial use of symmetry considerations. In this paper, we consider probabilistic models for V1 maps from the point of view of group theory; we focus on Gaussian random fields with symmetry properties and review the probabilistic arguments that allow one to estimate pinwheel densities and predict the observed value of π. Then, in order to test the relevance of general symmetry arguments and to introduce methods which could be of use in modeling curved regions, we reconsider this model in the light of group representation theory, the canonical mathematics of symmetry. We show that through the Plancherel decomposition of the space of complex-valued maps on the Euclidean plane, each infinite-dimensional irreducible unitary representation of the special Euclidean group yields a unique V1-like map, and we use representation theory as a symmetry-based toolbox to build orientation maps adapted to the most famous non-Euclidean geometries, viz. spherical and hyperbolic geometry. We find that most of the dominant traits of V1 maps are preserved in these; we also study the link between symmetry and the statistics of singularities in orientation maps, and show what the striking quantitative characteristics observed in animals become in our curved models. PMID:26082007

  18. MEG studies of human vision: Retinotopic organization of V1

    SciTech Connect

    Aine, C.; George, J.; Ranken, D.; Best, E.; Tiee, W.; Vigil, V.; Flynn, E.; Wood, C.; Supek, S.

    1993-12-31

    A primary goal of noninvasive studies of human vision is to identify and characterize multiple visual areas in the human brain analogous to those identified in studies of nonhuman primates. By combining functional MEG measurements with images of individual anatomy derived from MRI, the authors hope to determine the location and arrangement of multiple visual areas in human cortex and to probe their functional significance. The authors have identified several different visual areas thus far which appear to be topographically organized. This paper focuses on the retinotopic characterization of the primary visual area (V1) in humans.

  19. Speculations on a relativistic strong focusing self-collider with very high luminosity (≥10 40 cm -2s -1): Macroproduction of antinuclei and other micro cross section events and formation of ambiplasma

    NASA Astrophysics Data System (ADS)

    Maglich, Bogdan C.

    1988-08-01

    The luminosity of the weak focusing self-collider (ESCOL) is intrinsically 10 8-10 10 times greater than that of conventional colliding beams, due to the product of the solid angle factor, ˜10 6, and the neutralization factor, ˜10 2 -10 4. We extrapolate to 10-GeV protons the parameters of a recent low energy experiment demonstrating that a 1-MeV deuteron beam, stored in ESCOL as migma, can be neutralized bo oscillating electrons and operate an order of magnitude above the space charge limit without instabilities. With the number density achieved in ESCOL, n = 3.2 × 10 9 ions cm -3, such a relativistic strong focusing self-collider (XYDER) would have a luminosity L ˜ 10 38 cm -2 s -1 for 10-GeV-on-10-GeV protons (equivalent to 250 GeV beam-on-target). At the diamagnetic "limit" density, which for 10 tesla is n = 10 12 ions cm -3, l ˜ 10 43 cm -2 s -1; this would produce 4 × 10 16 antiprotons/s (2 gram of overlinep/year). Other particles, rare nuclei, and rare effects produced with micro- (10 -16), nano- (10 -9 b), and picoscopic (10 -12 b) cross sections will be macro-produced in XYDER. A newly proposed annular magnet would provide a large volume of stored, V = 10 9 cm 3, as well as automatic ejection along the +z and -z axes of the overlinep's and other particles whose momentum is lower than that of the primary proton migma. Antiprotons, being produced with low rapidity, will have energies below 1 GeV in COM, and thus are suitable for beaming, extraction, cooling, abd slowing down to be either stored for space propulsion or used as a source for acceleration. If the magnetic field strength is adjusted for the antiprotons to be confined, an unusual plasma will be formed, consisting of the protons, antiprotons, electrons, and positrons (from pion-muon-electron decays), and similar to Alfvèns "ambiplasman". Its plasmic beta will be unity already at low densities (˜10 11 cm -3 where ωpi/ ωci ≤ 1); the ion-to-electron "temperature" ratio will never achieve

  20. Columnar organization of orientation domains in V1

    NASA Astrophysics Data System (ADS)

    Liedtke, Joscha; Wolf, Fred

    In the primary visual cortex (V1) of primates and carnivores, the functional architecture of basic stimulus selectivities appears similar across cortical layers (Hubel & Wiesel, 1962) justifying the use of two-dimensional cortical models and disregarding organization in the third dimension. Here we show theoretically that already small deviations from an exact columnar organization lead to non-trivial three-dimensional functional structures. We extend two-dimensional random field models (Schnabel et al., 2007) to a three-dimensional cortex by keeping a typical scale in each layer and introducing a correlation length in the third, columnar dimension. We examine in detail the three-dimensional functional architecture for different cortical geometries with different columnar correlation lengths. We find that (i) topological defect lines are generally curved and (ii) for large cortical curvatures closed loops and reconnecting topological defect lines appear. This theory extends the class of random field models by introducing a columnar dimension and provides a systematic statistical assessment of the three-dimensional functional architecture of V1 (see also (Tanaka et al., 2011)).

  1. AREST-CT V1.0 software verification

    SciTech Connect

    Chen, Y.; Engel, D.W.; McGrail, B.P.; Lessor, K.S.

    1995-07-01

    The Analyzer for Radionuclide Source-Term with Chemical Transport (AREST-CT) is a scientific computer code designed for performance assessments of engineered barrier system (EBS) concepts for the underground storage of nuclear waste, including high-level, intermediate, and low-level wastes. The AREST-CT code has features for analyzing the degradation of and release of radionuclides from the waste form, chemical reactions that depend on time and space, and transport of the waste and other products through the EBS. This document provides a description of the verification testing that has been performed on the initial version of ARESTCT (V1.0). Software verification is the process of confirming that the models and algorithms have been correctly implemented into a computer code. Software verification for V1.0 consisted of testing the individual modules (unit tests) and a test of the fully-coupled model (integration testing). The integration test was done by comparing the results from AREST-CT with the results from the reactive transport code CIRF.A. The test problem consisted of a 1-D analysis of the release, transport, and precipitation of {sup 99}{Tc} in an idealized LLW disposal system. All verification tests showed that AREST-CT works properly and in accordance with design specifications.

  2. Hydrogen File Capture v1.0.DLL

    2006-03-28

    Postprocessor for the use with GoldSim commercial software. The program is intended as a DLL for use with a GoldSim model simulation to copy input/output files created during the simulation to a central location on a local LAN. The software is used as part of a modeling package that consists of GoldSim.exe and other external codes linked and executed during a GoldSim model simulation. The FileCapture_v1.0.DLL is used to run Monte Carlo analyses with amore » GoldSim simulation that is executed using the distributed processing module. When distributed processing (i.e., multi-processor run) is used for a GoldSim Model simulation that is comprised of one or more codes linked with the GoldSim.exe, it is sometimes necessary to capture the default input and/or output files generated by the external codes linked with the GoldSim.exe program. Using the input file "FileCapture.In' to list the filenames and path, FileCapture_v1.0.DLL copies the files listed in 'FileCapture.in' from each node on the LAN to a folder called 'FCAP Files' created in the location gie as the path. The DLL will execute for each realization and append 00xxx a number indication which realization the file was generated from.« less

  3. Gain Modulation by Nicotine in Macaque V1

    PubMed Central

    Disney, Anita A.; Aoki, Chiye; Hawken, Michael J.

    2010-01-01

    SUMMARY Acetylcholine is a ubiquitous cortical neuromodulator implicated in cognition. In order to understand the potential for acetylcholine to play a role in visual attention, we studied nicotinic acetylcholine receptor (nAChR) localization and function in area V1 of the macaque. We found nAChRs presynaptically at thalamic synapses onto excitatory, but not inhibitory, neurons in the primary thalamorecipient layer 4c. Furthermore, consistent with the release enhancement suggested by this localization, we discovered that nicotine increases responsiveness and lowers contrast threshold in layer 4c neurons. We also found that nAChRs are expressed by GABAergic interneurons in V1 but rarely by pyramidal neurons, and that nicotine suppresses visual responses outside layer 4c. All sensory systems incorporate gain control mechanisms, or processes which dynamically alter input/output relationships. We demonstrate that at the site of thalamic input to visual cortex, the effect of this nAChR-mediated gain is an enhancement of the detection of visual stimuli. PMID:18031686

  4. Modified MBE hardware and techniques and role of gallium purity for attainment of two dimensional electron gas mobility >35×106 cm2/V s in AlGaAs/GaAs quantum wells grown by MBE

    NASA Astrophysics Data System (ADS)

    Gardner, Geoffrey C.; Fallahi, Saeed; Watson, John D.; Manfra, Michael J.

    2016-05-01

    We provide evidence that gallium purity is the primary impediment to attainment of ultra-high mobility in a two-dimensional electron gas (2DEG) in AlGaAs/GaAs heterostructures grown by molecular beam epitaxy (MBE). The purity of gallium can be enhanced dramatically by in-situ high temperature outgassing within an operating MBE. Based on analysis of data from an initial growth campaign in a new MBE system and modifications employed for a 2nd growth campaign, we have produced 2DEGs with low temperature mobility μ in excess of 35×106 cm2/V s at density n=3.0×1011/cm2 and μ=18×106 cm2/V s at n=1.1×1011/cm2. Our 2nd campaign data indicate that gallium purity remains the factor currently limiting μ<40×106 cm2/V s. We describe strategies to overcome this limitation.

  5. Effects of viewing geometry, aggregation state, and particle size on reflectance spectra of the Murchison CM2 chondrite deconvolved to Dawn FC band passes

    NASA Astrophysics Data System (ADS)

    Izawa, Matthew R. M.; Schäfer, Tanja; Pietrasz, Valerie B.; Cloutis, Edward A.; Mann, Paul; Nathues, Andreas; Mengel, Kurt; Schäfer, Michael; Thangjam, Guneshwar; Hoffmann, Martin; Tait, Kimberly T.; Applin, Daniel M.

    2016-03-01

    Several current and soon-to-launch missions will investigate 'dark' asteroids, whose spectra have few weak or no distinct spectral features. Some carbonaceous chondrites, particularly the CI and CM groups, are reasonable material analogues for many dark asteroid surfaces. In addition to compositional variations, many non-compositional effects, including viewing geometry, surface particle size and particle sorting, can influence reflectance spectra, potentially complicating mineralogical interpretation of such data from remote surfaces. We have carried out an investigation of the effects of phase angle, particle size, aggregation state, and intra-sample heterogeneity on the reflectance spectra (0.4-1.0 μm) of the Murchison CM2 carbonaceous chondrite, deconvolved to Dawn Framing Camera (FC) band passes. This study was motivated by the desire to derive information about the surface of Ceres from Dawn FC data. Key spectral parameters derived from the FC multispectral data include various two-band reflectance ratios as well as three-band ratios that have been derived for mineralogical analysis. Phase angle effects include increased visible slope with increasing phase angle, a trend that may reverse at very high phase angles. Fine-grained particles exert a strong influence on spectral properties relative to their volumetric proportion. Grain size variation effects include a decrease in spectral contrast and increased visible spectral slope with decreasing grain size. Intra-sample heterogeneity, while spectrally detectable, is of relatively limited magnitude.

  6. Heterostructure design and growth conditions necessary for electron mobility exceeding 30x106 cm2/Vs in GaAs quantum wells

    NASA Astrophysics Data System (ADS)

    Fallahi, Saeed; Gardner, Geoffrey; Watson, John; Manfra, Michael

    2015-03-01

    Ultra-high purity GaAs/AlGaAs heterostructures remain the preeminent semiconductor platform for the study of strong correlations in low dimensions. In particular, the study of fragile fractional quantum Hall states such as ν = 5/2 and ν = 12/5 in the 2nd Landau level requires low disorder samples. While low temperature mobility is often specified as a parameter quantifying sample quality, it does not encode all information necessary to quantify disorder relevant to the fractional quantum Hall effect. Here we describe the heterostructure design considerations and molecular-beam-epitaxy growth conditions needed to achieve an electron mobility >30x106cm2/Vs. In particular, we report on the impact of several modulation doping schemes on mobility and the quality of transport in the 2nd Landau level. We also detail constraints on starting source material purity for the achievement of high mobility. In our work high mobility has been achieved primarily through improvements in starting source materials and heterostructure design rather than improvements in vacuum quality.

  7. Performance of a 64-channel, 3.2×3.2 cm2 SiPM tile for TOF-PET application

    NASA Astrophysics Data System (ADS)

    Ferri, Alessandro; Acerbi, Fabio; Gola, Alberto; Piemonte, Claudio; Paternoster, Giovanni; Zorzi, Nicola

    2016-07-01

    In this work, we present a new 3.2×3.2 cm2 detector tile, composed of 8×8 single SiPMs, having a regular 4 mm pitch in both the X and Y directions. The tile fill factor is 85%. We produced two versions of the tile with different SiPM technologies: RGB-HD and NUV. The first one features square micro-cells with 25 μm pitch, a PDE peaked at 550 nm and a DCR of 300 kHz/mm2, at 20 °C and at maximum detection efficiency. The second one features micro-cells with 40 μm pitch and a PDE peaked in the blue part of the spectrum. The dark count rate at 20 °C and at maximum PDE is 100 kHz/mm2. In this work, we show the energy and timing resolution measurements at 511 keV obtained coupling the two tiles to an 8×8 LYSO array with a pixel size of 4×4×22 mm3, perfectly matching the photo-detector array.

  8. Extracting the distribution of laser damage precursors on fused silica surfaces for 351 nm, 3 ns laser pulses at high fluences (20-150 J/cm2).

    PubMed

    Laurence, Ted A; Bude, Jeff D; Ly, Sonny; Shen, Nan; Feit, Michael D

    2012-05-01

    Surface laser damage limits the lifetime of optics for systems guiding high fluence pulses, particularly damage in silica optics used for inertial confinement fusion-class lasers (nanosecond-scale high energy pulses at 355 nm/3.5 eV). The density of damage precursors at low fluence has been measured using large beams (1-3 cm); higher fluences cannot be measured easily since the high density of resulting damage initiation sites results in clustering. We developed automated experiments and analysis that allow us to damage test thousands of sites with small beams (10-30 µm), and automatically image the test sites to determine if laser damage occurred. We developed an analysis method that provides a rigorous connection between these small beam damage test results of damage probability versus laser pulse energy and the large beam damage results of damage precursor densities versus fluence. We find that for uncoated and coated fused silica samples, the distribution of precursors nearly flattens at very high fluences, up to 150 J/cm2, providing important constraints on the physical distribution and nature of these precursors. PMID:22565775

  9. Aging characteristics of blue InGaN micro-light emitting diodes at an extremely high current density of 3.5 kA cm-2

    NASA Astrophysics Data System (ADS)

    Tian, Pengfei; Althumali, Ahmad; Gu, Erdan; Watson, Ian M.; Dawson, Martin D.; Liu, Ran

    2016-04-01

    The aging characteristics of blue InGaN micro-light emitting diodes (micro-LEDs) with different sizes have been studied at an extremely high current density 3.5 kA cm-2 for emerging micro-LED applications including visible light communication (VLC), micro-LED pumped organic lasers and optogenetics. The light output power of micro-LEDs first increases and then decreases due to the competition of Mg activation in p-GaN layer and defect generation in the active region. The smaller micro-LEDs show less light output power degradation compared with larger micro-LEDs, which is attributed to the lower junction temperature of smaller micro-LEDs. It is found that the high current density without additional junction temperature cannot induce significant micro-LED degradation at room temperature but the combination of the high current density and high junction temperature leads to strong degradation. Furthermore, the cluster LEDs, composed of a micro-LED array, have been developed with both high light output power and less light output degradation for micro-LED applications in solid state lighting and VLC.

  10. NIMS Radiance Point Spectra of Gaspra V1.0

    NASA Astrophysics Data System (ADS)

    Granahan, J. C.

    2014-10-01

    This data volume contains radiometrically corrected point spectra of asteroid 951 as acquired by the Galileo spacecraft Near Infrared Mapping Spectrometer (NIMS) on October 29, 1991. They record the spectra collected as the Galileo spacecraft approached the target asteroid. These data are products of the calibration of the raw data number files gap015tn.qub, gap035tn.qub, gap036tn.qub, gap037tn.qub, and gap038tn.qub (DATA SET ID ='GO-A-NIMS-3 TUBE-V1.0') with calibration factors acquired during the first Earth/Moon encounter of the Galileo mission. These raw data .qub files are archived in the Imaging Node of the NASA Planetary Data System (PDS). The calibrated spectra consist of radiance measurements for wavelengths between 0.7 - 5.2 micrometers.

  11. CSPAD upgrades and CSPAD V1.5 at LCLS

    NASA Astrophysics Data System (ADS)

    Herrmann, S.; Hart, P.; Dragone, A.; Freytag, D.; Herbst, R.; Pines, J.; Weaver, M.; Carini, G. A.; Thayer, J. B.; Shawn, O.; Kenney, C. J.; Haller, G.

    2014-03-01

    After improving the PCB level electronics the next step in our continuing upgrade program of LCLS Cornell-SLAC Pixel Array Detector (CSPAD) cameras is the use of a new improved ASIC named CSPAD V1.5. The upgraded ASIC includes on chip DACs to set the bias currents of all amplifiers. The new chip also supports power cycling by design. Together this simplifies the PCB level complexity and eases the integration of many ASICs into one camera. Homogeneity across the full reticle size chip was improved by redesigning the power distribution. The upgrade included modifications of the gain latches and the per pixel comparators. Results from the upgraded cameras used at LCLS will be presented and discussed.

  12. Hybridization Schemes for Ag Films on V(1 0 0)

    SciTech Connect

    Kralj,M.

    2005-01-01

    The electronic structure of ultra thin silver films deposited on a V(1 0 0) substrate is investigated by means of angle resolved photoemission spectroscopy. We focus on the details of the electronic structure related to the hybridization between the quantized film states of s-p origin and substrate electronic states. Two distinct regions of the surface Brillouin zone (SBZ) are found to be of particular importance: the SBZ center and the region that is typically more than 0.2 Angstroms {sup -1} outside the zone center. In relation to these SBZ parts two different hybridization schemes are identified and discussed. The first one influences the parabolic curvature of the quantum well state dispersion in the proximity of SBZ center, i.e., the effective mass. The second one relates to prominent changes of the quantum well state dispersion due to the interaction with the particular substrate bulk band and dramatically affects the photoemission intensity.

  13. End stopping in V1 is sensitive to contrast

    PubMed Central

    Yazdanbakhsh, Arash; Livingstone, Margaret S

    2009-01-01

    Common situations that result in different perceptions of grouping and border ownership, such as shadows and occlusion, have distinct sign-of-contrast relationships at their edge-crossing junctions. Here we report a property of end stopping in V1 that distinguishes among different sign-of-contrast situations, thereby obviating the need for explicit junction detectors. We show that the inhibitory effect of the end zones in end-stopped cells is highly selective for the relative sign of contrast between the central activating stimulus and stimuli presented at the end zones. Conversely, the facilitatory effect of end zones in length-summing cells is not selective for the relative sign of contrast between the central activating stimulus and stimuli presented at the end zones. This finding indicates that end stopping belongs in the category of cortical computations that are selective for sign of contrast, such as direction selectivity and disparity selectivity, but length summation does not. PMID:16633342

  14. Hybridization schemes for Ag films on V(1 0 0)

    NASA Astrophysics Data System (ADS)

    Kralj, Marko

    2005-12-01

    The electronic structure of ultra thin silver films deposited on a V(1 0 0) substrate is investigated by means of angle resolved photoemission spectroscopy. We focus on the details of the electronic structure related to the hybridization between the quantized film states of s-p origin and substrate electronic states. Two distinct regions of the surface Brillouin zone (SBZ) are found to be of particular importance: the SBZ center and the region that is typically more than 0.2 Å -1 outside the zone center. In relation to these SBZ parts two different hybridization schemes are identified and discussed. The first one influences the parabolic curvature of the quantum well state dispersion in the proximity of SBZ center, i.e., the effective mass. The second one relates to prominent changes of the quantum well state dispersion due to the interaction with the particular substrate bulk band and dramatically affects the photoemission intensity.

  15. Aqueous Alteration of Carbonaceous Chondrites: New Insights from Comparative Studies of Two Unbrecciated CM2 Chondrites, Y 791198 and ALH 81002

    NASA Technical Reports Server (NTRS)

    Chizmadia, L. J.; Brearley, A. J.

    2004-01-01

    Carbonaceous chondrites are an important resource for understanding the physical and chemical conditions in the early solar system. In particular, a long-standing question concerns the role of water in the cosmochemical evolution of carbonaceous chondrites. It is well established that extensive hydration of primary nebular phases occurred in the CM and CI chondrites, but the location where this alteration occurred remains controversial. In the CM2 chondrites, hydration formed secondary phases such as serpentine, tochilinite, pentlandite, carbonate and PCP. There are several textural observations which suggest that alteration occurred before the accretion of the final CM parent asteroid, i.e. preaccretionary alteration. Conversely, there is a significant body of evidence that supports parent-body alteration. In order to test these two competing hypotheses further, we studied two CM chondrites, Y-791198 and ALH81002, two meteorites that exhibit widely differing degrees of aqueous alteration. In addition, both meteorites have primary accretionary textures, i.e. experienced minimal asteroidal brecciation. Brecciation significantly complicates the task of unraveling alteration histories, mixing components that have been altered to different degrees from different locations on the same asteroidal parent body. Alteration in Y-791198 is mostly confined to chondrule mesostases, FeNi metal and fine-grained matrix and rims. In comparison, the primary chondrule silicates in ALH81002 have undergone extensive replacement by secondary hydrous phases. This study focuses on compositional and textural relationships between chondrule mesostasis and the associated rim materials. Our hypothesis is: both these components are highly susceptible to aqueous alteration and should be sensitive recorders of the alteration process. For parent body alteration, we expect systematic coupled mineralogical and compositional changes in rims and altered mesostasis, as elemental exchange between these

  16. Investigation of rat bone fracture healing using pulsed 1.5 MHz, 30 mW/cm(2) burst ultrasound--axial distance dependency.

    PubMed

    Fung, Chak-Hei; Cheung, Wing-Hoi; Pounder, Neill M; de Ana, F Javier; Harrison, Andrew; Leung, Kwok-Sui

    2014-03-01

    This study investigated the effect of LIPUS on fracture healing when fractures were exposed to ultrasound at three axial distances: z=0 mm, 60 mm, and 130 mm. We applied LIPUS to rat fracture at these three axial distances mimicking the exposure condition of human fractures at different depths under the soft tissue. Measurement of LIPUS shows pressure variations in near field (nearby transducer); uniform profile was found beyond it (far field). We asked whether different positions of the fracture within the ultrasound field cause inconsistent biological effect during the healing process. Closed femoral fractured Sprague-Dawley rats were randomized into control, near-field (0mm), mid-near field (60 mm) or far-field (130 mm) groups. Daily LIPUS treatment (plane, but apodized source, see details in the text; 2.2 cm in diameter; 1.5 MHz sine waves repeating at 1 kHz PRF; spatial average temporal average intensity, ISATA=30 mW/cm(2)) was given to fracture site at the three axial distances. Weekly radiographs and endpoint microCT, histomorphometry, and mechanical tests were performed. The results showed that the 130 mm group had the highest tissue mineral density; and significantly higher mechanical properties than control at week 4. The 60 mm and 0 mm groups had significantly higher (i.e. p<0.05) woven bone percentage than control group in radiological, microCT and histomorphometry measurements. In general, LIPUS at far field augmented callus mineralization and mechanical properties; while near field and mid-near field enhanced woven bone formation. Our results indicated the therapeutic effect of LIPUS is dependent on the axial distance of the ultrasound beam. Therefore, the depth of fracture under the soft tissue affects the biological effect of LIPUS. Clinicians have to be aware of the fracture depth when LIPUS is applied transcutaneously. PMID:24239510

  17. One-year Outcomes of Pachymetry and Epithelium Thicknesses after Accelerated (45 mW/cm2) Transepithelial Corneal Collagen Cross-linking for Keratoconus Patients

    PubMed Central

    Zhang, Xiaoyu; Sun, Ling; Chen, Yingjun; Li, Meiyan; Tian, Mi; Zhou, Xingtao

    2016-01-01

    The thickness of corneal pachymetry and the epithelium after accelerated (45 mW/cm2) transepithelial corneal collagen cross-linking (CXL) for keratoconus were assessed in this prospective case series study. Twenty-eight patients were treated for keratoconus. The mean Kmax was 56.18 ± 7.90. The thinnest point, as assessed by optical coherence tomography (OCT), was 443.18 ± 39.75 μm. Accelerated transepithelial CXL was performed, and corrected distance visual acuity (CDVA), corneal topography, and OCT were recorded at 1 week postoperatively as well as at 1, 3, 6, and 12 months. The surgery was uneventful in all eyes. Postoperative epithelial edema was observed and faded in 3 days. The postoperative Kmax was 54.56 ± 8.81, 55.78 ± 8.11, 56.37 ± 8.71, 55.80 ± 7.92, and 55.47 ± 8.24 at 1 week, 1 month, 3 months, 6 months, and 12 months, respectively (all, P > 0.05). The thinnest postoperative corneal point, 439.04 ± 44.99 μm, was observed at 12 months (P = 0.109). The epithelial thickness decreased during the first postoperative week then showed a gradual recovery. Postoperative pachymetry thickness showed no significant changes for up to 12 months. Postoperative epithelial thickness decreased temporarily, then stabilized at month 12. Accelerated transepithelial CXL was shown to be effective and safe for the treatment of keratoconus. PMID:27597655

  18. One-year Outcomes of Pachymetry and Epithelium Thicknesses after Accelerated (45 mW/cm(2)) Transepithelial Corneal Collagen Cross-linking for Keratoconus Patients.

    PubMed

    Zhang, Xiaoyu; Sun, Ling; Chen, Yingjun; Li, Meiyan; Tian, Mi; Zhou, Xingtao

    2016-01-01

    The thickness of corneal pachymetry and the epithelium after accelerated (45 mW/cm(2)) transepithelial corneal collagen cross-linking (CXL) for keratoconus were assessed in this prospective case series study. Twenty-eight patients were treated for keratoconus. The mean Kmax was 56.18 ± 7.90. The thinnest point, as assessed by optical coherence tomography (OCT), was 443.18 ± 39.75 μm. Accelerated transepithelial CXL was performed, and corrected distance visual acuity (CDVA), corneal topography, and OCT were recorded at 1 week postoperatively as well as at 1, 3, 6, and 12 months. The surgery was uneventful in all eyes. Postoperative epithelial edema was observed and faded in 3 days. The postoperative Kmax was 54.56 ± 8.81, 55.78 ± 8.11, 56.37 ± 8.71, 55.80 ± 7.92, and 55.47 ± 8.24 at 1 week, 1 month, 3 months, 6 months, and 12 months, respectively (all, P > 0.05). The thinnest postoperative corneal point, 439.04 ± 44.99 μm, was observed at 12 months (P = 0.109). The epithelial thickness decreased during the first postoperative week then showed a gradual recovery. Postoperative pachymetry thickness showed no significant changes for up to 12 months. Postoperative epithelial thickness decreased temporarily, then stabilized at month 12. Accelerated transepithelial CXL was shown to be effective and safe for the treatment of keratoconus. PMID:27597655

  19. Hydrogen and carbon isotopic ratios of polycyclic aromatic compounds in two CM2 carbonaceous chondrites and implications for prebiotic organic synthesis

    NASA Astrophysics Data System (ADS)

    Huang, Yongsong; Aponte, José C.; Zhao, Jiaju; Tarozo, Rafael; Hallmann, Christian

    2015-09-01

    Study of meteoritic organic compounds offers a unique opportunity to understand the origins of the organic matter in the early Solar System. Meteoritic polycyclic aromatic hydrocarbons (PAHs) and heteropolycyclic aromatic compounds (HACs) have been studied for over fifty years, however; their hydrogen stable isotopic ratios (δD) have never been reported. Compound-specific δD measurements of PAHs and HACs are important, in part because the carbon isotopic ratios (δ13C) of various meteoritic PAHs cannot be readily distinguished from their terrestrial counterparts and it is difficult to rule out terrestrial contamination based on carbon isotopic ratios alone. In this study, we have extracted and identified more than sixty PAHs and HACs present in two CM2 carbonaceous chondrites Murchison and LON 94101. Their carbon and hydrogen stable isotopic ratios (δ13C and δD) were measured and used to discuss about their synthetic environments and formation mechanisms. The concentration of aromatic compounds is ∼30% higher in Murchison than in the Antarctic meteorite LON 94101, but both samples contained similar suites of PAHs and HACs. All PAHs and HACs found exhibited positive δD values (up to 1100‰) consistent with an extraterrestrial origin, indicating the relatively low δ13C values are indeed an inherent feature of the meteoritic aromatic compounds. The hydrogen isotopic data suggest aromatic compounds in carbonaceous chondrites were mainly formed in the cold interstellar environments. Molecular level variations in hydrogen and carbon isotopic values offer new insights to the formation pathways for the aromatic compounds in carbonaceous chondrites.

  20. Targeting Voltage Gated Sodium Channels NaV1.7, NaV1.8, and NaV1.9 for Treatment of Pathological Cough

    PubMed Central

    Muroi, Yukiko

    2015-01-01

    Recent advances in our understanding of voltage-gated sodium channels (NaVs) lead to the rational hypothesis that drugs capable of selective blockade of NaV subtypes may be a safe and effective strategy for the treatment of unwanted cough. Among the nine NaV subtypes (NaV1.1–NaV1.9), the afferent nerves involved in initiating cough, in common with nociceptive neurons in the somatosensory system, express mainly NaV1.7, NaV1.8, and NaV1.9. Although knowledge about the effect of selectively blocking these channels on the cough reflex is limited, their biophysical properties indicate that each may contribute to the hypertussive and allotussive state that typifies subacute and chronic nonproductive cough. PMID:24272479

  1. 28 CFR 10.2 - Language of registration statement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ON ACTIVITIES WITHIN THE UNITED STATES Registration Statement § 10.2 Language of registration statement. Registration statements must be in English if possible. If in a foreign language they must be... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Language of registration statement....

  2. 28 CFR 10.2 - Language of registration statement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ON ACTIVITIES WITHIN THE UNITED STATES Registration Statement § 10.2 Language of registration statement. Registration statements must be in English if possible. If in a foreign language they must be... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Language of registration statement....

  3. 28 CFR 10.2 - Language of registration statement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ON ACTIVITIES WITHIN THE UNITED STATES Registration Statement § 10.2 Language of registration statement. Registration statements must be in English if possible. If in a foreign language they must be... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Language of registration statement....

  4. Determining temperature distribution in tissue in the focal plane of the high (>100 W/cm(2)) intensity focused ultrasound beam using phase shift of ultrasound echoes.

    PubMed

    Karwat, Piotr; Kujawska, Tamara; Lewin, Peter A; Secomski, Wojciech; Gambin, Barbara; Litniewski, Jerzy

    2016-02-01

    In therapeutic applications of High Intensity Focused Ultrasound (HIFU) the guidance of the HIFU beam and especially its focal plane is of crucial importance. This guidance is needed to appropriately target the focal plane and hence the whole focal volume inside the tumor tissue prior to thermo-ablative treatment and beginning of tissue necrosis. This is currently done using Magnetic Resonance Imaging that is relatively expensive. In this study an ultrasound method, which calculates the variations of speed of sound in the locally heated tissue volume by analyzing the phase shifts of echo-signals received by an ultrasound scanner from this very volume is presented. To improve spatial resolution of B-mode imaging and minimize the uncertainty of temperature estimation the acoustic signals were transmitted and received by 8 MHz linear phased array employing Synthetic Transmit Aperture (STA) technique. Initially, the validity of the algorithm developed was verified experimentally in a tissue-mimicking phantom heated from 20.6 to 48.6 °C. Subsequently, the method was tested using a pork loin sample heated locally by a 2 MHz pulsed HIFU beam with focal intensity ISATA of 129 W/cm(2). The temperature calibration of 2D maps of changes in the sound velocity induced by heating was performed by comparison of the algorithm-determined changes in the sound velocity with the temperatures measured by thermocouples located in the heated tissue volume. The method developed enabled ultrasound temperature imaging of the heated tissue volume from the very inception of heating with the contrast-to-noise ratio of 3.5-12 dB in the temperature range 21-56 °C. Concurrently performed, conventional B-mode imaging revealed CNR close to zero dB until the temperature reached 50 °C causing necrosis. The data presented suggest that the proposed method could offer an alternative to MRI-guided temperature imaging for prediction of the location and extent of the thermal lesion prior to applying the

  5. 26 CFR 1.414(v)-1 - Catch-up contributions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 5 2011-04-01 2011-04-01 false Catch-up contributions. 1.414(v)-1 Section 1.414(v)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.414(v)-1...

  6. 26 CFR 1.414(v)-1 - Catch-up contributions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 5 2012-04-01 2011-04-01 true Catch-up contributions. 1.414(v)-1 Section 1.414(v)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.414(v)-1...

  7. 26 CFR 1.414(v)-1 - Catch-up contributions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 5 2014-04-01 2014-04-01 false Catch-up contributions. 1.414(v)-1 Section 1.414(v)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES (CONTINUED) Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.414(v)-1...

  8. 26 CFR 1.414(v)-1 - Catch-up contributions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 5 2010-04-01 2010-04-01 false Catch-up contributions. 1.414(v)-1 Section 1.414(v)-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Pension, Profit-Sharing, Stock Bonus Plans, Etc. § 1.414(v)-1 Catch-up...

  9. LANL C10.2 Projects in FY13

    SciTech Connect

    Batha, Steven H.; Fincke, James R.; Schmitt, Mark J.

    2012-06-07

    LANL has two projects in C10.2: Defect-Induced Mix Experiment (DIME) (ongoing, several runs at Omega; NIF shots this summer); and Shock/Shear (tested at Omega for two years; NIF shots in second half of FY13). Each project is jointly funded by C10.2, other C10 MTEs, and Science Campaigns. DIME is investigating 4{pi} and feature-induced mix in spherically convergent ICF implosions by using imaging of the mix layer. DIME prepared for NIF by demonstrating its PDD mix platform on Omega including imaging mid-Z doped layers and defects. DIME in FY13 will focus on PDD symmetry-dependent mix and moving burn into the mix region for validation of mix/burn models. Re-Shock and Shear are two laser-driven experiments designed to study the turbulent mixing of materials. In FY-2012 43 shear and re-shock experimental shots were executed on the OMEGA laser and a complete time history obtained for both. The FY-2013 goal is to transition the experiment to NIF where the larger scale will provide a longer time period for mix layer growth.

  10. Kinetic Analysis of Membrane Potential Dye Response to NaV1.7 Channel Activation Identifies Antagonists with Pharmacological Selectivity against NaV1.5.

    PubMed

    Finley, Michael; Cassaday, Jason; Kreamer, Tony; Li, Xinnian; Solly, Kelli; O'Donnell, Greg; Clements, Michelle; Converso, Antonella; Cook, Sean; Daley, Chris; Kraus, Richard; Lai, Ming-Tain; Layton, Mark; Lemaire, Wei; Staas, Donnette; Wang, Jixin

    2016-06-01

    The NaV1.7 voltage-gated sodium channel is a highly valued target for the treatment of neuropathic pain due to its expression in pain-sensing neurons and human genetic mutations in the gene encoding NaV1.7, resulting in either loss-of-function (e.g., congenital analgesia) or gain-of-function (e.g., paroxysmal extreme pain disorder) pain phenotypes. We exploited existing technologies in a novel manner to identify selective antagonists of NaV1.7. A full-deck high-throughput screen was developed for both NaV1.7 and cardiac NaV1.5 channels using a cell-based membrane potential dye FLIPR assay. In assay development, known local anesthetic site inhibitors produced a decrease in maximal response; however, a subset of compounds exhibited a concentration-dependent delay in the onset of the response with little change in the peak of the response at any concentration. Therefore, two methods of analysis were employed for the screen: one to measure peak response and another to measure area under the curve, which would capture the delay-to-onset phenotype. Although a number of compounds were identified by a selective reduction in peak response in NaV1.7 relative to 1.5, the AUC measurement and a subsequent refinement of this measurement were able to differentiate compounds with NaV1.7 pharmacological selectivity over NaV1.5 as confirmed in electrophysiology. PMID:26861708

  11. CAST-10-2/DOA 2 Airfoil Studies Workshop Results

    NASA Technical Reports Server (NTRS)

    Ray, Edward J. (Compiler); Hill, Acquilla S. (Compiler)

    1989-01-01

    During the period of September 23 through 27, 1988, the Transonic Aerodynamics Division at the Langely Research Center hosted an International Workshop on CAST-10-2/DOA 2 Airfoil Studies. The CAST-10 studies were the outgrowth of several cooperative study agreements among the NASA, the NAE of Canada, the DLR of West Germany, and the ONERA of France. Both theoretical and experimental CAST-10 airfoil results that were obtained form an extensive series of tests and studies, were reviewed. These results provided an opportunity to make direct comparisons of adaptive wall test section (AWTS) results from the NASA 0.3-meter Transonic Cryogenic Tunnel and ONERA T-2 AWTS facilities with conventional ventilated wall wind tunnel results from the Canadian high Reynolds number two-dimensional test facility. Individual papers presented during the workshop are included.

  12. Low-level laser therapy, at 60 J/cm2 associated with a Biosilicate® increase in bone deposition and indentation biomechanical properties of callus in osteopenic rats

    NASA Astrophysics Data System (ADS)

    Fangel, Renan; Sérgio Bossini, Paulo; Cláudia Renno, Ana; Araki Ribeiro, Daniel; Chenwei Wang, Charles; Luri Toma, Renata; Okino Nonaka, Keico; Driusso, Patrícia; Antonio Parizotto, Nivaldo; Oishi, Jorge

    2011-07-01

    We investigate the effects of a novel bioactive material (Biosilicate®) and low-level laser therapy (LLLT), at 60 J/cm2, on bone-fracture consolidation in osteoporotic rats. Forty female Wistar rats are submitted to the ovariectomy, to induce osteopenia. Eight weeks after the ovariectomy, the animals are randomly divided into four groups, with 10 animals each: bone defect control group; bone defect filled with Biosilicate group; bone defect irradiated with laser at 60 J/cm2 group; bone defect filled with Biosilicate and irradiated with LLLT, at 60 J/cm2 group. Laser irradiation is initiated immediately after surgery and performed every 48 h for 14 days. Histopathological analysis points out that bone defects are predominantly filled with the biomaterial in specimens treated with Biosilicate. In the 60-J/cm2 laser plus Biosilicate group, the biomaterial fills all bone defects, which also contained woven bone and granulation tissue. Also, the biomechanical properties are increased in the animals treated with Biosilicate associated to lasertherapy. Our results indicate that laser therapy improves bone repair process in contact with Biosilicate as a result of increasing bone formation as well as indentation biomechanical properties.

  13. Folded or Not? Tracking Bet v 1 Conformation in Recombinant Allergen Preparations

    PubMed Central

    Seutter von Loetzen, Christian; Schweimer, Kristian; Bellinghausen, Iris; Treudler, Regina; Simon, Jan C.; Vogel, Lothar; Völker, Elke; Randow, Stefanie; Reuter, Andreas; Rösch, Paul; Vieths, Stefan; Holzhauser, Thomas; Schiller, Dirk

    2015-01-01

    Background Recombinant Bet v 1a (rBet v 1a) has been used in allergy research for more than three decades, including clinical application of so-called hypoallergens. Quantitative IgE binding to rBet v 1a depends on its native protein conformation, which might be compromised upon heterologous expression, purification, or mutational engineering of rBet v 1a. Objective To correlate experimental/theoretical comparisons of IgE binding of defined molar ratios of folded/misfolded recombinant Bet v 1a variants and to determine accuracy and precision of immuno- and physicochemical assays routinely used to assess the quality of recombinant allergen preparations. Methods rBet v 1a and its misfolded variant rBet v 1aS112P/R145P were heterologously expressed and purified from Escherichia coli. Structural integrities and oligomerisation of the recombinant allergens were evaluated by 1H-nuclear magnetic resonance (1H-NMR), circular dichroism (CD) spectroscopy, and dynamic light scattering (DLS). IgE binding of defined combinations of rBet v 1a and rBet v 1aS112P/R145P was assessed using immunoblotting (IB), enzyme-linked immunosorbent assay (ELISA) and mediator release (MR) of humanized rat basophilic leukemia cells sensitized with serum IgE of subjects allergic to birch pollen. Experimental and theoretically expected results of the analyses were compared. Results 1H-NMR spectra of rBet v 1a and rBet v 1aS112P/R145P demonstrate a native and highly disordered protein conformations, respectively. The CD spectra suggested typical alpha-helical and beta-sheet secondary structure content of rBet v 1a and random coil for rBet v 1aS112P/R145P. The hydrodynamic radii (RH) of 2.49 ± 0.39 nm (rBet v 1a) and 3.1 ± 0.56 nm (rBet v 1aS112P/R145P) showed monomeric dispersion of both allergens in solution. Serum IgE of birch pollen allergic subjects bound to 0.1% rBet v 1a in the presence of 99.9% of non-IgE binding rBet v 1aS112P/R145P. Immunoblot analysis overestimated, whereas ELISA and

  14. Long-range cortical connections give rise to a robust velocity map of V1.

    PubMed

    Sheridan, Phillip

    2015-11-01

    This paper proposes a two-dimensional velocity model (2DVM) of the primary visual cortex (V1). The model's novel aspect is that it specifies a particular pattern of long-range cortical temporal connections, via the Connection Algorithm, and shows how the addition of these connections to well-known spatial properties of V1 transforms V1 into a velocity map. The map implies a number of organizational properties of V1: (1) the singularity of each orientation pinwheel contributes to the detection of slow-moving spots across the visual field; (2) the speed component of neuronal velocity selectivity decreases monotonically across each joint orientation contour line for parallel motion and increases monotonically for orthogonal motion; (3) the cells that are direction selective to slow-moving objects are situated in the periphery of V1; and (4) neurons in distinct pinwheels tend to be connected to neurons with similar tuning preferences in other pinwheels. The model accounts for various types of known illusionary perceptions of human vision: perceptual filling-in, illusionary orientation and visual crowding. The three distinguishing features of 2DVM are: (1) it unifies the functional properties of the conventional energy model of V1; (2) it directly relates the functional properties to the known structure of the upper layers of V1; and (3) it implies that the spatial selectivity features of V1 are side effects of its more important role as a velocity map of the visual field. PMID:26343820

  15. A V1-vascular vasopressin antagonist suitable for radioiodination and photoaffinity labeling

    SciTech Connect

    Thibonnier, M.; Chehade, N.; Hinko, A. )

    1990-06-01

    We have previously characterized the V1-vascular arginine vasopressin (AVP) receptors of human platelets. We now report on a radiomonoiodinated and photoreactive V1-vascular AVP antagonist (V1-ag) to be used for the purification of human V1-vascular AVP receptors. The V1-ag, d(CH2)5Tyr(Me)Tyr(NH2)AVP was modified by radiomonoiodination of d(CH2)5-Tyr(Me)Tyr(NH2)AVP with the Iodogen technique, and derivatization of d(CH2)5Tyr(Me)Tyr(125I)(NH2)-AVP with the photoreactive crosslinker, N-hydroxysuccinimidyl-4-azidobenzoate (HSAB) (each step included HPLC purification). In competition experiments, the affinity of these V1-ag for the human platelet AVP receptors remained excellent. Irreversible photoaffinity labeling of the platelet V1-vascular AVP receptor was successfully achieved by UV lamp exposure (365 nm, 20 min). Thus, AzBz-d(CH2)5Tyr(Me)Tyr(125I)(NH2)AVP is a promising tool to use for the purification of human V1-vascular AVP receptors.

  16. Vasopressin receptors V1a and V2 are not osmosensors.

    PubMed

    Lykke, Kasper; Assentoft, Mette; Fenton, Robert A; Rosenkilde, Mette M; MacAulay, Nanna

    2015-08-01

    Herein, we investigated whether G protein-coupled signaling via the vasopressin receptors of the V1a and V2 subtypes (V1aR and V2R) could be obtained as a direct response to hyperosmolar challenges and/or whether hyperosmolar challenges could augment classical vasopressin-dependent V1aR signaling. The V1aR-dependent response was monitored indirectly via its effects on aquaporin 4 (AQP4) when heterologously expressed in Xenopus oocytes and V1aR and V2R function was directly monitored following heterologous expression in COS-7 cells. A tendency toward an osmotically induced, V1aR-mediated reduction in AQP4-dependent water permeability was observed, although osmotic challenges failed to mimic vasopressin-dependent V1aR-mediated internalization of AQP4. Direct monitoring of inositol phosphate (IP) production of V1aR-expressing COS-7 cells demonstrated an efficient vasopressin-dependent response that was, however, independent of hyperosmotic challenges. Similarly, the cAMP production by the V2R was unaffected by hyperosmotic challenges although, in contrast to the V1aR, the V2R displayed an ability to support alternative signaling (IP production) at higher concentration of vasopressin. V1aR and V2R respond directly to vasopressin exposure, but they do not have an ability to act as osmo- or volume sensors when exposed to an osmotic gradient in the absence or presence of vasopressin. PMID:26311834

  17. Vasopressin receptors V1a and V2 are not osmosensors

    PubMed Central

    Lykke, Kasper; Assentoft, Mette; Fenton, Robert A; Rosenkilde, Mette M; MacAulay, Nanna

    2015-01-01

    Herein, we investigated whether G protein-coupled signaling via the vasopressin receptors of the V1a and V2 subtypes (V1aR and V2R) could be obtained as a direct response to hyperosmolar challenges and/or whether hyperosmolar challenges could augment classical vasopressin-dependent V1aR signaling. The V1aR-dependent response was monitored indirectly via its effects on aquaporin 4 (AQP4) when heterologously expressed in Xenopus oocytes and V1aR and V2R function was directly monitored following heterologous expression in COS-7 cells. A tendency toward an osmotically induced, V1aR-mediated reduction in AQP4-dependent water permeability was observed, although osmotic challenges failed to mimic vasopressin-dependent V1aR-mediated internalization of AQP4. Direct monitoring of inositol phosphate (IP) production of V1aR-expressing COS-7 cells demonstrated an efficient vasopressin-dependent response that was, however, independent of hyperosmotic challenges. Similarly, the cAMP production by the V2R was unaffected by hyperosmotic challenges although, in contrast to the V1aR, the V2R displayed an ability to support alternative signaling (IP production) at higher concentration of vasopressin. V1aR and V2R respond directly to vasopressin exposure, but they do not have an ability to act as osmo- or volume sensors when exposed to an osmotic gradient in the absence or presence of vasopressin. PMID:26311834

  18. Properties of V1 neurons tuned to conjunctions of visual features: application of the V1 saliency hypothesis to visual search behavior.

    PubMed

    Zhaoping, Li; Zhe, Li

    2012-01-01

    From a computational theory of V1, we formulate an optimization problem to investigate neural properties in the primary visual cortex (V1) from human reaction times (RTs) in visual search. The theory is the V1 saliency hypothesis that the bottom-up saliency of any visual location is represented by the highest V1 response to it relative to the background responses. The neural properties probed are those associated with the less known V1 neurons tuned simultaneously or conjunctively in two feature dimensions. The visual search is to find a target bar unique in color (C), orientation (O), motion direction (M), or redundantly in combinations of these features (e.g., CO, MO, or CM) among uniform background bars. A feature singleton target is salient because its evoked V1 response largely escapes the iso-feature suppression on responses to the background bars. The responses of the conjunctively tuned cells are manifested in the shortening of the RT for a redundant feature target (e.g., a CO target) from that predicted by a race between the RTs for the two corresponding single feature targets (e.g., C and O targets). Our investigation enables the following testable predictions. Contextual suppression on the response of a CO-tuned or MO-tuned conjunctive cell is weaker when the contextual inputs differ from the direct inputs in both feature dimensions, rather than just one. Additionally, CO-tuned cells and MO-tuned cells are often more active than the single feature tuned cells in response to the redundant feature targets, and this occurs more frequently for the MO-tuned cells such that the MO-tuned cells are no less likely than either the M-tuned or O-tuned neurons to be the most responsive neuron to dictate saliency for an MO target. PMID:22719829

  19. Dynamic evolution of V1R putative pheromone receptors between Mus musculus and Mus spretus

    PubMed Central

    Kurzweil, Vanessa C; Getman, Mike; Green, Eric D; Lane, Robert P

    2009-01-01

    Background The mammalian vomeronasal organ (VNO) expresses two G-protein coupled receptor gene families that mediate pheromone responses, the V1R and V2R receptor genes. In rodents, there are ~150 V1R genes comprising 12 subfamilies organized in gene clusters at multiple chromosomal locations. Previously, we showed that several of these subfamilies had been extensively modulated by gene duplications, deletions, and gene conversions around the time of the evolutionary split of the mouse and rat lineages, consistent with the hypothesis that V1R repertoires might be involved in reinforcing speciation events. Here, we generated genome sequence for one large cluster containing two V1R subfamilies in Mus spretus, a closely related and sympatric species to Mus musculus, and investigated evolutionary change in these repertoires along the two mouse lineages. Results We describe a comparison of spretus and musculus with respect to genome organization and synteny, as well as V1R gene content and phylogeny, with reference to previous observations made between mouse and rat. Unlike the mouse-rat comparisons, synteny seems to be largely conserved between the two mouse species. Disruption of local synteny is generally associated with differences in repeat content, although these differences appear to arise more from deletion than new integrations. Even though unambiguous V1R orthology is evident, we observe dynamic modulation of the functional repertoires, with two of seven V1Rb and one of eleven V1Ra genes lost in spretus, two V1Ra genes becoming pseudogenes in musculus, two additional orthologous pairs apparently subject to strong adaptive selection, and another divergent orthologous pair that apparently was subjected to gene conversion. Conclusion Therefore, eight of the 18 (~44%) presumptive V1Ra/V1Rb genes in the musculus-spretus ancestor appear to have undergone functional modulation since these two species diverged. As compared to the rat-mouse split, where modulation is

  20. Molecular evolutionary characterization of a V1R subfamily unique to strepsirrhine primates.

    PubMed

    Yoder, Anne D; Chan, Lauren M; dos Reis, Mario; Larsen, Peter A; Campbell, C Ryan; Rasoloarison, Rodin; Barrett, Meredith; Roos, Christian; Kappeler, Peter; Bielawski, Joseph; Yang, Ziheng

    2014-01-01

    Vomeronasal receptor genes have frequently been invoked as integral to the establishment and maintenance of species boundaries among mammals due to the elaborate one-to-one correspondence between semiochemical signals and neuronal sensory inputs. Here, we report the most extensive sample of vomeronasal receptor class 1 (V1R) sequences ever generated for a diverse yet phylogenetically coherent group of mammals, the tooth-combed primates (suborder Strepsirrhini). Phylogenetic analysis confirms our intensive sampling from a single V1R subfamily, apparently unique to the strepsirrhine primates. We designate this subfamily as V1Rstrep. The subfamily retains extensive repertoires of gene copies that descend from an ancestral gene duplication that appears to have occurred prior to the diversification of all lemuriform primates excluding the basal genus Daubentonia (the aye-aye). We refer to the descendent clades as V1Rstrep-α and V1Rstrep-β. Comparison of the two clades reveals different amino acid compositions corresponding to the predicted ligand-binding site and thus potentially to altered functional profiles between the two. In agreement with previous studies of the mouse lemur (genus, Microcebus), the majority of V1Rstrep gene copies appear to be intact and under strong positive selection, particularly within transmembrane regions. Finally, despite the surprisingly high number of gene copies identified in this study, it is nonetheless probable that V1R diversity remains underestimated in these nonmodel primates and that complete characterization will be limited until high-coverage assembled genomes are available. PMID:24398377

  1. Molecular Evolutionary Characterization of a V1R Subfamily Unique to Strepsirrhine Primates

    PubMed Central

    Yoder, Anne D.; Chan, Lauren M.; dos Reis, Mario; Larsen, Peter A.; Campbell, C. Ryan; Rasoloarison, Rodin; Barrett, Meredith; Roos, Christian; Kappeler, Peter; Bielawski, Joseph; Yang, Ziheng

    2014-01-01

    Vomeronasal receptor genes have frequently been invoked as integral to the establishment and maintenance of species boundaries among mammals due to the elaborate one-to-one correspondence between semiochemical signals and neuronal sensory inputs. Here, we report the most extensive sample of vomeronasal receptor class 1 (V1R) sequences ever generated for a diverse yet phylogenetically coherent group of mammals, the tooth-combed primates (suborder Strepsirrhini). Phylogenetic analysis confirms our intensive sampling from a single V1R subfamily, apparently unique to the strepsirrhine primates. We designate this subfamily as V1Rstrep. The subfamily retains extensive repertoires of gene copies that descend from an ancestral gene duplication that appears to have occurred prior to the diversification of all lemuriform primates excluding the basal genus Daubentonia (the aye-aye). We refer to the descendent clades as V1Rstrep-α and V1Rstrep-β. Comparison of the two clades reveals different amino acid compositions corresponding to the predicted ligand-binding site and thus potentially to altered functional profiles between the two. In agreement with previous studies of the mouse lemur (genus, Microcebus), the majority of V1Rstrep gene copies appear to be intact and under strong positive selection, particularly within transmembrane regions. Finally, despite the surprisingly high number of gene copies identified in this study, it is nonetheless probable that V1R diversity remains underestimated in these nonmodel primates and that complete characterization will be limited until high-coverage assembled genomes are available. PMID:24398377

  2. Morphological and neurochemical comparisons between pulvinar and V1 projections to V2

    PubMed Central

    Marion, Roan; Li, Keji; Purushothaman, Gopathy; Jiang, Yaoguang; Casagrande, Vivien A.

    2012-01-01

    The flow of visual information is clear at the earliest stages: the retina provides the driving (main signature) activity for the lateral geniculate nucleus (LGN), which, in turn, drives the primary visual cortex (V1). These driving pathways can be distinguished anatomically from other modulatory pathways that innervate LGN and V1. The path of visual information after V1, however, is less clear. There are two primary feedforward projections to the secondary visual cortex (V2), one from the lateral/inferior pulvinar and the other from V1. Because both lateral/inferior pulvinar and V2 can't be driven visually following V1 removal, either or both of these inputs to V2 could be drivers. Retinogeniculate and geniculocortical projections are privileged over modulatory projections by their layer of termination, bouton size, and the presence of vesicular glutamate transporter 2 (Vglut2) or parvalbumin (PV). It has been suggested that such properties might also distinguish drivers from modulators in extrastriate cortex. We tested this hypothesis by comparing lateral pulvinar-to-V2 and V1-to-V2 projections with LGN-to-V1 projections. We found that V1 and lateral pulvinar projections to V2 are similar in that they target the same layers and lack PV. Projections from pulvinar to V2, however, bear a greater similarity to projections from LGN to V1 because of their larger bouton sizes (measured at the same location in V2) and positive staining for Vglut2. These data lend support to the hypothesis that the pulvinar could act as a driver for V2. PMID:22826174

  3. Effect of low-level laser therapy (685 nm, 3 J/cm(2)) on functional recovery of the sciatic nerve in rats following crushing lesion.

    PubMed

    Takhtfooladi, Mohammad Ashrafzadeh; Jahanbakhsh, Fatemeh; Takhtfooladi, Hamed Ashrafzadeh; Yousefi, Kambiz; Allahverdi, Amin

    2015-04-01

    Previous studies have shown that low-level laser therapy (LLLT) promotes posttraumatic nerve regeneration. The objective of the present study was to assess the efficacy of 685-nm LLLT at the dosage of 3 J/cm(2) in the functional recovery of the sciatic nerve in rats following crushing injury. The left sciatic nerves of 20 male Wistar rats were subjected to controlled crush injury by a hemostatic tweezers, and the rats were randomly allocated into two experimental groups as follows: control group and laser group. Laser irradiation (685 nm wavelength; 15 mW, CW, 3 J/cm(2), spot of 0.028 cm(2)) was started on the postsurgical first day, above the site of injury, and was continued for 21 consecutive days. Functional recovery was evaluated at 3 weeks postoperatively by measuring the sciatic functional index (SFI) and sciatic static index (SSI) at weekly intervals. The treated rats showed improvement in motion pattern. The SFI and SSI results were significant when comparing two groups on the 14th and 21st postoperative days (p < 0.05). There were intra-group differences detected in laser group in different periods (p < 0.05). Low-level laser irradiation, with the parameters used in the present study, accelerated and improved sciatic nerve function in rats after crushing injury. PMID:25595127

  4. Systematic Study of Rayleigh-Taylor Growth in Directly Driven Plastic Targets in a Laser-Intensity Range from ~2 x 10^14 to ~1.5 x 10^15 W/cm^2

    SciTech Connect

    Smalyuk, V.A.; Hu, S.X.; Goncharov, V.N.; Meyerhofer, D.D.; Sangster, T.C.; Stoeckl, C.; Yaakobi, B.

    2008-09-05

    Direct-drive, Rayleigh–Taylor (RT) growth experiments were performed using planar plastic targets on the OMEGA Laser Facility [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] at laser intensities between ~2 x 10^14 and ~1.5 x 10^15 W/cm^2. The primary purpose of the experiments was to test fundamental physics in hydrocodes at the range of drive intensities relevant to ignition designs. The target acceleration was measured with a streak camera using side-on, x-ray radiography, while RT growth was measured with a framing camera using face-on radiography. In a laser-intensity range from 2 to 5 x 10^14 W/cm^2, the measured RT growth agrees well with two-dimensional simulations, based on a local model of thermal-electron transport. The RT growth at drive intensities above ~1.0 x 10^15 W/cm^2 was strongly stabilized compared to the local model predictions. The experiments demonstrate that standard simulations, based on a local model of electron thermal transport, break down at peak intensities of ignition designs, although they work well at lower intensities. These results also imply that direct-drive ignition targets are significantly more stable than previously calculated using local electron-transport models at peak intensities of ignition designs. The preheating effects by nonlocal electron transport and hot electrons were identified as some of the stabilizing mechanisms.

  5. rBet v 1 immunotherapy of sensitized mice with Streptococcus thermophilus as vehicle and adjuvant

    PubMed Central

    Petrarca, Claudia; Clemente, Emanuela; Toto, Valentina; Iezzi, Manuela; Rossi, Cosmo; Zanotta, Stefania; Mistrello, Gianni; Zanoni, Ivan; Granucci, Francesca; Arioli, Stefania; Mora, Diego; Guglielmetti, Simone; Paganelli, Roberto; Di Gioacchino, Mario

    2014-01-01

    Lactobacilli are able to induce upregulation of co-stimulatory molecules in DCs with Th1 cytokines production and increase in Treg activity. This could explain the observed effectiveness of the prolonged administration of lactobacilli in the prevention of allergic disorders in infants and envisage the possible use of bacteria expressing the allergen for the specific immunotherapy of allergic diseases. Hence, we evaluated Streptococcus thermophilus (ST) expressing rBet v 1 as allergen delivery tool and adjuvant factor for immunotherapy in Betv1-sensitized mice. rBet v 1 gene was introduced and expressed in ST (ST[rBet v 1]). BALB/c mice were sensitized with rBet v 1 and then treated with either ST alone, ST[rBet v 1], or the combination of ST and rBet v 1, for 20 days. After 2 aerosol challenges, Treg frequency, in vitro allergen-induced cytokines, rBet v 1-specific IgE and IgG2a, and bronchial histology were made in harvested spleen, sera, and lung. Results were compared with those obtained from not-treated/sensitized mice. ST[rBet v 1] induced immunological and histological changes typical of successful SIT: increased frequency of Tregs and expression of Foxp3; decreased allergen-specific IgE/IgG2a ratio; decrease of in vitro rBet v 1-induced IL-4 from spleen cells; increased allergen-induced IL-10 and IFN-γ; drop of bronchial eosinophilia. ST and ST+rBet v 1 combination, even though induced a slight increase in the frequency of Tregs and moderate allergen-induced IL-10, were ineffective in reducing bronchial eosinophilia, allergen induced IL-4 and rBet v 1-specific IgE/IgG2a ratio. ST[rBet v 1] has tolerogenic and Th-1 skewing properties and efficiently delivers the allergen to the gut immune-system restraining and readdressing the established specific Th2 response toward the allergen in mice. PMID:24603094

  6. rBet v 1 immunotherapy of sensitized mice with Streptococcus thermophilus as vehicle and adjuvant.

    PubMed

    Petrarca, Claudia; Clemente, Emanuela; Toto, Valentina; Iezzi, Manuela; Rossi, Cosmo; Zanotta, Stefania; Mistrello, Gianni; Zanoni, Ivan; Granucci, Francesca; Arioli, Stefania; Mora, Diego; Guglielmetti, Simone; Paganelli, Roberto; Di Gioacchino, Mario

    2014-01-01

    Lactobacilli are able to induce upregulation of co-stimulatory molecules in DCs with Th1 cytokines production and increase in Treg activity. This could explain the observed effectiveness of the prolonged administration of lactobacilli in the prevention of allergic disorders in infants and envisage the possible use of bacteria expressing the allergen for the specific immunotherapy of allergic diseases. Hence, we evaluated Streptococcus thermophilus (ST) expressing rBet v 1 as allergen delivery tool and adjuvant factor for immunotherapy in Betv1-sensitized mice. rBet v 1 gene was introduced and expressed in ST (ST[rBet v 1]). BALB/c mice were sensitized with rBet v 1 and then treated with either ST alone, ST[rBet v 1], or the combination of ST and rBet v 1, for 20 days. After 2 aerosol challenges, Treg frequency, in vitro allergen-induced cytokines, rBet v 1-specific IgE and IgG2a, and bronchial histology were made in harvested spleen, sera, and lung. Results were compared with those obtained from not-treated/sensitized mice. ST[rBet v 1] induced immunological and histological changes typical of successful SIT: increased frequency of Tregs and expression of Foxp3; decreased allergen-specific IgE/IgG2a ratio; decrease of in vitro rBet v 1-induced IL-4 from spleen cells; increased allergen-induced IL-10 and IFN-γ; drop of bronchial eosinophilia. ST and ST+rBet v 1 combination, even though induced a slight increase in the frequency of Tregs and moderate allergen-induced IL-10, were ineffective in reducing bronchial eosinophilia, allergen induced IL-4 and rBet v 1-specific IgE/IgG2a ratio. ST[rBet v 1] has tolerogenic and Th-1 skewing properties and efficiently delivers the allergen to the gut immune-system restraining and readdressing the established specific Th2 response toward the allergen in mice. PMID:24603094

  7. Accurate prediction of V1 location from cortical folds in a surface coordinate system

    PubMed Central

    Hinds, Oliver P.; Rajendran, Niranjini; Polimeni, Jonathan R.; Augustinack, Jean C.; Wiggins, Graham; Wald, Lawrence L.; Rosas, H. Diana; Potthast, Andreas; Schwartz, Eric L.; Fischl, Bruce

    2008-01-01

    Previous studies demonstrated substantial variability of the location of primary visual cortex (V1) in stereotaxic coordinates when linear volume-based registration is used to match volumetric image intensities (Amunts et al., 2000). However, other qualitative reports of V1 location (Smith, 1904; Stensaas et al., 1974; Rademacher et al., 1993) suggested a consistent relationship between V1 and the surrounding cortical folds. Here, the relationship between folds and the location of V1 is quantified using surface-based analysis to generate a probabilistic atlas of human V1. High-resolution (about 200 μm) magnetic resonance imaging (MRI) at 7 T of ex vivo human cerebral hemispheres allowed identification of the full area via the stria of Gennari: a myeloarchitectonic feature specific to V1. Separate, whole-brain scans were acquired using MRI at 1.5 T to allow segmentation and mesh reconstruction of the cortical gray matter. For each individual, V1 was manually identified in the high-resolution volume and projected onto the cortical surface. Surface-based intersubject registration (Fischl et al., 1999b) was performed to align the primary cortical folds of individual hemispheres to those of a reference template representing the average folding pattern. An atlas of V1 location was constructed by computing the probability of V1 inclusion for each cortical location in the template space. This probabilistic atlas of V1 exhibits low prediction error compared to previous V1 probabilistic atlases built in volumetric coordinates. The increased predictability observed under surface-based registration suggests that the location of V1 is more accurately predicted by the cortical folds than by the shape of the brain embedded in the volume of the skull. In addition, the high quality of this atlas provides direct evidence that surface-based intersubject registration methods are superior to volume-based methods at superimposing functional areas of cortex, and therefore are better

  8. The Bet v 1 fold: an ancient, versatile scaffold for binding of large, hydrophobic ligands

    PubMed Central

    2008-01-01

    Background The major birch pollen allergen, Bet v 1, is a member of the ubiquitous PR-10 family of plant pathogenesis-related proteins. In recent years, a number of diverse plant proteins with low sequence similarity to Bet v 1 was identified. In addition, determination of the Bet v 1 structure revealed the existence of a large superfamily of structurally related proteins. In this study, we aimed to identify and classify all Bet v 1-related structures from the Protein Data Bank and all Bet v 1-related sequences from the Uniprot database. Results Structural comparisons of representative members of already known protein families structurally related to Bet v 1 with all entries of the Protein Data Bank yielded 47 structures with non-identical sequences. They were classified into eleven families, five of which were newly identified and not included in the Structural Classification of Proteins database release 1.71. The taxonomic distribution of these families extracted from the Pfam protein family database showed that members of the polyketide cyclase family and the activator of Hsp90 ATPase homologue 1 family were distributed among all three superkingdoms, while members of some bacterial families were confined to a small number of species. Comparison of ligand binding activities of Bet v 1-like superfamily members revealed that their functions were related to binding and metabolism of large, hydrophobic compounds such as lipids, hormones, and antibiotics. Phylogenetic relationships within the Bet v 1 family, defined as the group of proteins with significant sequence similarity to Bet v 1, were determined by aligning 264 Bet v 1-related sequences. A distance-based phylogenetic tree yielded a classification into 11 subfamilies, nine exclusively containing plant sequences and two subfamilies of bacterial proteins. Plant sequences included the pathogenesis-related proteins 10, the major latex proteins/ripening-related proteins subfamily, and polyketide cyclase

  9. Sodium channel diversity in the vestibular ganglion: NaV1.5, NaV1.8, and tetrodotoxin-sensitive currents.

    PubMed

    Liu, Xiao-Ping; Wooltorton, Julian R A; Gaboyard-Niay, Sophie; Yang, Fu-Chia; Lysakowski, Anna; Eatock, Ruth Anne

    2016-05-01

    Firing patterns differ between subpopulations of vestibular primary afferent neurons. The role of sodium (NaV) channels in this diversity has not been investigated because NaV currents in rodent vestibular ganglion neurons (VGNs) were reported to be homogeneous, with the voltage dependence and tetrodotoxin (TTX) sensitivity of most neuronal NaV channels. RT-PCR experiments, however, indicated expression of diverse NaV channel subunits in the vestibular ganglion, motivating a closer look. Whole cell recordings from acutely dissociated postnatal VGNs confirmed that nearly all neurons expressed NaV currents that are TTX-sensitive and have activation midpoints between -30 and -40 mV. In addition, however, many VGNs expressed one of two other NaV currents. Some VGNs had a small current with properties consistent with NaV1.5 channels: low TTX sensitivity, sensitivity to divalent cation block, and a relatively negative voltage range, and some VGNs showed NaV1.5-like immunoreactivity. Other VGNs had a current with the properties of NaV1.8 channels: high TTX resistance, slow time course, and a relatively depolarized voltage range. In two NaV1.8 reporter lines, subsets of VGNs were labeled. VGNs with NaV1.8-like TTX-resistant current also differed from other VGNs in the voltage dependence of their TTX-sensitive currents and in the voltage threshold for spiking and action potential shape. Regulated expression of NaV channels in primary afferent neurons is likely to selectively affect firing properties that contribute to the encoding of vestibular stimuli. PMID:26936982

  10. Versican V1 Isoform Induces Neuronal Differentiation and Promotes Neurite Outgrowth

    PubMed Central

    Wu, Yaojiong; Sheng, Wang; Chen, Liwen; Dong, Haiheng; Lee, Vivian; Lu, Fred; Wong, C. Shun; Lu, Wei-Yang; Yang, Burton B.

    2004-01-01

    The chondroitin sulfate proteoglycan versican is one of the major extracellular components in the developing and adult brain. Here, we show that isoforms of versican play different roles in neuronal differentiation and neurite outgrowth. Expression of versican V1 isoform in PC12 cells induced complete differentiation, whereas expression of V2 induced an aborted differentiation accompanied by apoptosis. V1 promoted neurite outgrowth of hippocampal neurons, but V2 failed to do so. V1 transfection enhanced expression of epidermal growth factor receptor and integrins, and facilitated sustained extracellular signal-regulated kinase/MAPK phosphorylation. Blockade of the epidermal growth factor receptor, β1 integrin, or Src significantly inhibited neuronal differentiation. Finally, we demonstrated that versican V1 isoform also promoted differentiation of neural stem cells into neurons. Our results have implications for understanding how versican regulates neuronal development, function, and repair. PMID:14978219

  11. Correlation of sensitizing capacity and T-cell recognition within the Bet v 1 family

    PubMed Central

    Kitzmüller, Claudia; Zulehner, Nora; Roulias, Anargyros; Briza, Peter; Ferreira, Fatima; Faé, Ingrid; Fischer, Gottfried F.; Bohle, Barbara

    2015-01-01

    Background Bet v 1 is the main sensitizing allergen in birch pollen. Like many other major allergens, it contains an immunodominant T cell–activating region (Bet v 1142-156). Api g 1, the Bet v 1 homolog in celery, lacks the ability to sensitize and is devoid of major T-cell epitopes. Objective We analyzed the T-cell epitopes of Mal d 1, the nonsensitizing Bet v 1 homolog in apple, and assessed possible differences in uptake and antigen processing of Bet v 1, Api g 1, and Mal d 1. Methods For epitope mapping, Mal d 1–specific T-cell lines were stimulated with overlapping synthetic 12-mer peptides. The surface binding, internalization, and intracellular degradation of Bet v 1, Api g 1, and Mal d 1 by antigen-presenting cells were compared by using flow cytometry. All proteins were digested with endolysosomal extracts, and the resulting peptides were identified by means of mass spectrometry. The binding of Bet v 1142-156 and the homologous region in Mal d 1 by HLA class II molecules was analyzed in silico. Results Like Api g 1, Mal d 1 lacked dominant T-cell epitopes. The degree of surface binding and the kinetics of uptake and endolysosomal degradation of Bet v 1, Api g 1, and Mal d 1 were comparable. Endolysosomal degradation of Bet v 1 and Mal d 1 resulted in very similar fragments. The Bet v 1142-156 and Mal d 1141-155 regions showed no striking difference in their binding affinities to the most frequent HLA-DR alleles. Conclusion The sensitizing activity of different Bet v 1 homologs correlates with the presence of immunodominant T-cell epitopes. However, the presence of Bet v 1142-156 is not conferred by differential antigen processing. PMID:25670010

  12. Modulation of V1 Spike Response by Temporal Interval of Spatiotemporal Stimulus Sequence

    PubMed Central

    Kim, Taekjun; Kim, HyungGoo R.; Kim, Kayeon; Lee, Choongkil

    2012-01-01

    The spike activity of single neurons of the primary visual cortex (V1) becomes more selective and reliable in response to wide-field natural scenes compared to smaller stimuli confined to the classical receptive field (RF). However, it is largely unknown what aspects of natural scenes increase the selectivity of V1 neurons. One hypothesis is that modulation by surround interaction is highly sensitive to small changes in spatiotemporal aspects of RF surround. Such a fine-tuned modulation would enable single neurons to hold information about spatiotemporal sequences of oriented stimuli, which extends the role of V1 neurons as a simple spatiotemporal filter confined to the RF. In the current study, we examined the hypothesis in the V1 of awake behaving monkeys, by testing whether the spike response of single V1 neurons is modulated by temporal interval of spatiotemporal stimulus sequence encompassing inside and outside the RF. We used two identical Gabor stimuli that were sequentially presented with a variable stimulus onset asynchrony (SOA): the preceding one (S1) outside the RF and the following one (S2) in the RF. This stimulus configuration enabled us to examine the spatiotemporal selectivity of response modulation from a focal surround region. Although S1 alone did not evoke spike responses, visual response to S2 was modulated for SOA in the range of tens of milliseconds. These results suggest that V1 neurons participate in processing spatiotemporal sequences of oriented stimuli extending outside the RF. PMID:23091631

  13. Protein kinase A modulation of CaV1.4 calcium channels

    NASA Astrophysics Data System (ADS)

    Sang, Lingjie; Dick, Ivy E.; Yue, David T.

    2016-07-01

    The regulation of L-type Ca2+ channels by protein kinase A (PKA) represents a crucial element within cardiac, skeletal muscle and neurological systems. Although much work has been done to understand this regulation in cardiac CaV1.2 Ca2+ channels, relatively little is known about the closely related CaV1.4 L-type Ca2+ channels, which feature prominently in the visual system. Here we find that CaV1.4 channels are indeed modulated by PKA phosphorylation within the inhibitor of Ca2+-dependent inactivation (ICDI) motif. Phosphorylation of this region promotes the occupancy of calmodulin on the channel, thus increasing channel open probability (PO) and Ca2+-dependent inactivation. Although this interaction seems specific to CaV1.4 channels, introduction of ICDI1.4 to CaV1.3 or CaV1.2 channels endows these channels with a form of PKA modulation, previously unobserved in heterologous systems. Thus, this mechanism may not only play an important role in the visual system but may be generalizable across the L-type channel family.

  14. Protein kinase A modulation of CaV1.4 calcium channels

    PubMed Central

    Sang, Lingjie; Dick, Ivy E.; Yue, David T.

    2016-01-01

    The regulation of L-type Ca2+ channels by protein kinase A (PKA) represents a crucial element within cardiac, skeletal muscle and neurological systems. Although much work has been done to understand this regulation in cardiac CaV1.2 Ca2+ channels, relatively little is known about the closely related CaV1.4 L-type Ca2+ channels, which feature prominently in the visual system. Here we find that CaV1.4 channels are indeed modulated by PKA phosphorylation within the inhibitor of Ca2+-dependent inactivation (ICDI) motif. Phosphorylation of this region promotes the occupancy of calmodulin on the channel, thus increasing channel open probability (PO) and Ca2+-dependent inactivation. Although this interaction seems specific to CaV1.4 channels, introduction of ICDI1.4 to CaV1.3 or CaV1.2 channels endows these channels with a form of PKA modulation, previously unobserved in heterologous systems. Thus, this mechanism may not only play an important role in the visual system but may be generalizable across the L-type channel family. PMID:27456671

  15. Protein kinase A modulation of CaV1.4 calcium channels.

    PubMed

    Sang, Lingjie; Dick, Ivy E; Yue, David T

    2016-01-01

    The regulation of L-type Ca(2+) channels by protein kinase A (PKA) represents a crucial element within cardiac, skeletal muscle and neurological systems. Although much work has been done to understand this regulation in cardiac CaV1.2 Ca(2+) channels, relatively little is known about the closely related CaV1.4 L-type Ca(2+) channels, which feature prominently in the visual system. Here we find that CaV1.4 channels are indeed modulated by PKA phosphorylation within the inhibitor of Ca(2+)-dependent inactivation (ICDI) motif. Phosphorylation of this region promotes the occupancy of calmodulin on the channel, thus increasing channel open probability (PO) and Ca(2+)-dependent inactivation. Although this interaction seems specific to CaV1.4 channels, introduction of ICDI1.4 to CaV1.3 or CaV1.2 channels endows these channels with a form of PKA modulation, previously unobserved in heterologous systems. Thus, this mechanism may not only play an important role in the visual system but may be generalizable across the L-type channel family. PMID:27456671

  16. Statistical Comparison of Spike Responses to Natural Stimuli in Monkey Area V1 With Simulated Responses of a Detailed Laminar Network Model for a Patch of V1

    PubMed Central

    Schuch, Klaus; Logothetis, Nikos K.; Maass, Wolfgang

    2011-01-01

    A major goal of computational neuroscience is the creation of computer models for cortical areas whose response to sensory stimuli resembles that of cortical areas in vivo in important aspects. It is seldom considered whether the simulated spiking activity is realistic (in a statistical sense) in response to natural stimuli. Because certain statistical properties of spike responses were suggested to facilitate computations in the cortex, acquiring a realistic firing regimen in cortical network models might be a prerequisite for analyzing their computational functions. We present a characterization and comparison of the statistical response properties of the primary visual cortex (V1) in vivo and in silico in response to natural stimuli. We recorded from multiple electrodes in area V1 of 4 macaque monkeys and developed a large state-of-the-art network model for a 5 × 5-mm patch of V1 composed of 35,000 neurons and 3.9 million synapses that integrates previously published anatomical and physiological details. By quantitative comparison of the model response to the “statistical fingerprint” of responses in vivo, we find that our model for a patch of V1 responds to the same movie in a way which matches the statistical structure of the recorded data surprisingly well. The deviation between the firing regimen of the model and the in vivo data are on the same level as deviations among monkeys and sessions. This suggests that, despite strong simplifications and abstractions of cortical network models, they are nevertheless capable of generating realistic spiking activity. To reach a realistic firing state, it was not only necessary to include both N-methyl-d-aspartate and GABAB synaptic conductances in our model, but also to markedly increase the strength of excitatory synapses onto inhibitory neurons (>2-fold) in comparison to literature values, hinting at the importance to carefully adjust the effect of inhibition for achieving realistic dynamics in current network

  17. Fully Enzymatic Membraneless Glucose|Oxygen Fuel Cell That Provides 0.275 mA cm(-2) in 5 mM Glucose, Operates in Human Physiological Solutions, and Powers Transmission of Sensing Data.

    PubMed

    Ó Conghaile, Peter; Falk, Magnus; MacAodha, Domhnall; Yakovleva, Maria E; Gonaus, Christoph; Peterbauer, Clemens K; Gorton, Lo; Shleev, Sergey; Leech, Dónal

    2016-02-16

    Coimmobilization of pyranose dehydrogenase as an enzyme catalyst, osmium redox polymers [Os(4,4'-dimethoxy-2,2'-bipyridine)2(poly(vinylimidazole))10Cl](+) or [Os(4,4'-dimethyl-2,2'-bipyridine)2(poly(vinylimidazole))10Cl](+) as mediators, and carbon nanotube conductive scaffolds in films on graphite electrodes provides enzyme electrodes for glucose oxidation. The recombinant enzyme and a deglycosylated form, both expressed in Pichia pastoris, are investigated and compared as biocatalysts for glucose oxidation using flow injection amperometry and voltammetry. In the presence of 5 mM glucose in phosphate-buffered saline (PBS) (50 mM phosphate buffer solution, pH 7.4, with 150 mM NaCl), higher glucose oxidation current densities, 0.41 mA cm(-2), are obtained from enzyme electrodes containing the deglycosylated form of the enzyme. The optimized glucose-oxidizing anode, prepared using deglycosylated enzyme coimmobilized with [Os(4,4'-dimethyl-2,2'-bipyridine)2(poly(vinylimidazole))10Cl](+) and carbon nanotubes, was coupled with an oxygen-reducing bilirubin oxidase on gold nanoparticle dispersed on gold electrode as a biocathode to provide a membraneless fully enzymatic fuel cell. A maximum power density of 275 μW cm(-2) is obtained in 5 mM glucose in PBS, the highest to date under these conditions, providing sufficient power to enable wireless transmission of a signal to a data logger. When tested in whole human blood and unstimulated human saliva maximum power densities of 73 and 6 μW cm(-2) are obtained for the same fuel cell configuration, respectively. PMID:26750758

  18. Integrated Assessment of Hadley Centre (HadCM2) Climate-Change Impacts on Agricultural Productivity and Irrigation Water Supply in the Conterminous United States. Part II. Regional Agricultural Production in 2030 and 2095.

    SciTech Connect

    Izaurralde, R Cesar C.; Rosenberg, Norman J.; Brown, Robert A.; Thomson, Allison M.

    2003-06-30

    This study used scenarios of the HadCM2 GCM and the EPIC agroecosystem model to evaluate climate change impacts on crop yields and ecosystem processes. Baseline climate data were obtained from records for 1961-1990. The scenario runs for 2025-2034 and 2090-2099 were extracted from a HadCM2 run. EPIC was run on 204 representative farms under current climate and two 10-y periods centered on 2030 and 2095, each at CO2 concentrations of 365 and 560 ppm. Texas, New Mexico, Colorado, Utah, Arizona, and California are projected to experience significant temperature increases by 2030. Slight cooling is expected by 2030 in Alabama, Florida, Maine, Montana, Idaho, and Utah. Larger areas are projected to experience increased warming by 2095. Uniform precipitation increases are expected by 2030 in the NE. These increases are predicted to expand to the eastern half of the country by 2095. EPIC simulated yield increases for the Great Lakes, Corn Belt and Northeast regions. Simulated yields of irrigated corn yields were predicted to increase in almost all regions. Soybean yields could decrease in the Northern and Southern Plains, the Corn Belt, Delta, Appalachian, and Southeast regions and increase in the Lakes and Northeast regions. Simulated wheat yields exhibited upward yield trends under scenarios of climate change. National corn production in 2030 and 2095 could be affected by changes in three major producing regions. In 2030, corn production could increase in the Corn Belt and Lakes regions but decrease in the Northern Plains leading to an overall decrease in national production. National wheat production is expected to increase during both future periods. A proxy indicator was developed to provide a sense of where in the country, and when water would be available to satisfy change in irrigation demand for corn and alfalfa production as these are influenced by the HadCM2 scenarios and CO2-fertilization.

  19. The impact on midlevel vision of statistically optimal divisive normalization in V1

    PubMed Central

    Coen-Cagli, Ruben; Schwartz, Odelia

    2013-01-01

    The first two areas of the primate visual cortex (V1, V2) provide a paradigmatic example of hierarchical computation in the brain. However, neither the functional properties of V2 nor the interactions between the two areas are well understood. One key aspect is that the statistics of the inputs received by V2 depend on the nonlinear response properties of V1. Here, we focused on divisive normalization, a canonical nonlinear computation that is observed in many neural areas and modalities. We simulated V1 responses with (and without) different forms of surround normalization derived from statistical models of natural scenes, including canonical normalization and a statistically optimal extension that accounted for image nonhomogeneities. The statistics of the V1 population responses differed markedly across models. We then addressed how V2 receptive fields pool the responses of V1 model units with different tuning. We assumed this is achieved by learning without supervision a linear representation that removes correlations, which could be accomplished with principal component analysis. This approach revealed V2-like feature selectivity when we used the optimal normalization and, to a lesser extent, the canonical one but not in the absence of both. We compared the resulting two-stage models on two perceptual tasks; while models encompassing V1 surround normalization performed better at object recognition, only statistically optimal normalization provided systematic advantages in a task more closely matched to midlevel vision, namely figure/ground judgment. Our results suggest that experiments probing midlevel areas might benefit from using stimuli designed to engage the computations that characterize V1 optimality. PMID:23857950

  20. Comparison of the Spatial Limits on Direction Selectivity in Visual Areas MT and V1

    PubMed Central

    Priebe, Nicholas J.; Lisberger, Stephen G.

    2008-01-01

    We recorded responses to apparent motion from directionally selective neurons in primary visual cortex (V1) of anesthetized monkeys and middle temporal area (MT) of awake monkeys. Apparent motion consisted of multiple stationary stimulus flashes presented in sequence, characterized by their temporal separation (Δt) and spatial separation (Δx). Stimuli were 8° square patterns of 100% correlated random dots that moved at apparent speeds of 16 or 32°/s. For both V1 and MT, the difference between the response to the preferred and null directions declined with increasing flash separation. For each neuron, we estimated the maximum flash separation for which directionally selective responses were observed. For the range of speeds we used, Δx provided a better description of the limitation on directional responses than did Δt. When comparing MT and V1 neurons of similar preferred speed, there was no difference in the maximum Δx between our samples from the two areas. In both V1 and MT, the great majority of neurons had maximal values of Δx in the 0.25-1° range. Mean values were almost identical between the two areas. For most neurons, larger flash separations led to both weaker responses to the preferred direction and increased responses to the opposite direction. The former mechanism was slightly more dominant in MT and the latter slightly more dominant in V1. We conclude that V1 and MT neurons lose direction selectivity for similar values of Δx, supporting the hypothesis that basic direction selectivity in MT is inherited from V1, at least over the range of stimulus speeds represented by both areas. PMID:15483064

  1. Expression of ATP6V1C1 during oral carcinogenesis.

    PubMed

    Oliveira Alves, M G; Carta, Cfl; Padín-Iruegas, M-E; Pérez-Sayáns, M; Suarez-Peñaranda, J M; Issa, J S; García-García, A; Almeida, J D

    2016-05-01

    We investigated the gene and protein expressions of V-type ATPase protein subunit C1 (ATP6V1C1) in cases of oral squamous cell carcinoma (OSCC) and contralateral normal mucosa in smokers, nonsmokers and former smokers. Subjects were separated into five groups of 15: group 1, smokers with OSCC; group 2, normal contralateral mucosa of OSCC patients; group 3, chronic smokers; group 4, former smokers who had stopped smoking 1 year earlier; group 5, individuals who had never smoked. Exfoliative cytology specimens from oral mucosa of smokers, former smokers and nonsmokers showed normal gene and protein expression. We found significantly greater gene expression in the OSCC group than in the nonsmoker groups. No difference in gene expression was observed between normal contralateral mucosa and nonsmoker groups, smoker and nonsmoker groups or former smoker and nonsmoker groups. We observed intense immunostaining for ATP6V1C1 protein in all cases of OSCC and weak or no staining in smoker, former smoker and nonsmoker groups. Significantly greater expression of ATP6V1C1 protein was observed in the OSCC group compared to the other groups, which supports the role of ATP6V1C1 in effecting changes associated with oral cancer. Analysis of the mucosae of chronic smokers, former smokers and the normal contralateral mucosa of patients with OSCC showed unaltered ATP6V1C1 gene and protein expression. Early stages of carcinogenesis, represented by altered epithelium of chronic smokers, had neither gene nor protein alterations as seen in OSCC. Therefore, we infer that the changes in ATP6V1C1 occur during later stages of carcinogenesis. Our preliminary study provides a basis for future studies of using ATP6V1C1 levels for detecting early stage OSCC. PMID:26984774

  2. Rationally Targeted Mutations at the V1V2 Domain of the HIV-1 Envelope to Augment Virus Neutralization by Anti-V1V2 Monoclonal Antibodies.

    PubMed

    Shen, Guomiao; Upadhyay, Chitra; Zhang, Jing; Pan, Ruimin; Zolla-Pazner, Susan; Kong, Xiang-Peng; Hioe, Catarina E

    2015-01-01

    HIV-1 envelope glycoproteins (Env) are the only viral antigens present on the virus surface and serve as the key targets for virus-neutralizing antibodies. However, HIV-1 deploys multiple strategies to shield the vulnerable sites on its Env from neutralizing antibodies. The V1V2 domain located at the apex of the HIV-1 Env spike is known to encompass highly variable loops, but V1V2 also contains immunogenic conserved elements recognized by cross-reactive antibodies. This study evaluates human monoclonal antibodies (mAbs) against V2 epitopes which overlap with the conserved integrin α4β7-binding LDV/I motif, designated as the V2i (integrin) epitopes. We postulate that the V2i Abs have weak or no neutralizing activities because the V2i epitopes are often occluded from antibody recognition. To gain insights into the mechanisms of the V2i occlusion, we evaluated three elements at the distal end of the V1V2 domain shown in the structure of V2i epitope complexed with mAb 830A to be important for antibody recognition of the V2i epitope. Amino-acid substitutions at position 179 that restore the LDV/I motif had minimal effects on virus sensitivity to neutralization by most V2i mAbs. However, a charge change at position 153 in the V1 region significantly increased sensitivity of subtype C virus ZM109 to most V2i mAbs. Separately, a disulfide bond introduced to stabilize the hypervariable region of V2 loop also enhanced virus neutralization by some V2i mAbs, but the effects varied depending on the virus. These data demonstrate that multiple elements within the V1V2 domain act independently and in a virus-dependent fashion to govern the antibody recognition and accessibility of V2i epitopes, suggesting the need for multi-pronged strategies to counter the escape and the shielding mechanisms obstructing the V2i Abs from neutralizing HIV-1. PMID:26491873

  3. 38 CFR 10.2 - Evidence required of loss, destruction or mutilation of adjusted service certificate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., destruction or mutilation of adjusted service certificate. 10.2 Section 10.2 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUSTED COMPENSATION Adjusted Compensation; General § 10.2... an adjusted service certificate issued pursuant to the provisions of section 501 of the World...

  4. 38 CFR 10.2 - Evidence required of loss, destruction or mutilation of adjusted service certificate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., destruction or mutilation of adjusted service certificate. 10.2 Section 10.2 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF VETERANS AFFAIRS ADJUSTED COMPENSATION Adjusted Compensation; General § 10.2... an adjusted service certificate issued pursuant to the provisions of section 501 of the World...

  5. 46 CFR 30.10-2a - Anniversary date-TB/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Anniversary date-TB/ALL. 30.10-2a Section 30.10-2a Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Definitions § 30.10-2a Anniversary date—TB/ALL. The term anniversary date means the day and the month of each year,...

  6. 46 CFR 30.10-2a - Anniversary date-TB/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Anniversary date-TB/ALL. 30.10-2a Section 30.10-2a Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS GENERAL PROVISIONS Definitions § 30.10-2a Anniversary date—TB/ALL. The term anniversary date means the day and the month of each year,...

  7. Receptive-field Properties of V1 and V2 Neurons in Mice and Macaque monkeys

    PubMed Central

    Van den Bergh, Gert; Zhang, Bin; Arckens, Lutgarde; Chino, Yuzo M.

    2010-01-01

    We report the results of extracellular single-unit recording experiments where we quantitatively analyzed the receptive-field (RF) properties of neurons in V1 and an adjacent extrastriate visual area (V2L) of anesthetized mice with emphasis on the RF center-surround organization. We compared the results with the RF center-surround organization of V1 and V2 neurons in macaque monkeys. If species differences in spatial scale are taken into consideration, mouse V1 and V2L neurons had remarkably fine stimulus selectivity, and the majority of response properties in V2L were not different from those in V1. The RF center-surround organization of mouse V1 neurons was qualitatively similar to that for macaque monkeys (i.e., the RF center is surrounded by extended suppressive regions). However, unlike in monkey V2, a significant proportion of cortical neurons, largely complex cells in V2L, did not exhibit quantifiable RF surround suppression. Simple cells had smaller RF centers than complex cells, and the prevalence and strength of surround suppression were greater in simple cells than in complex cells. These findings, particularly on the RF center-surround organization of visual cortical neurons, give new insights into the principles governing cortical circuits in the mouse visual cortex and should provide further impetus for the use of mice in studies on the genetic and molecular basis of RF development and synaptic plasticity. PMID:20394058

  8. Effects of surround suppression on response adaptation of V1 neurons to visual stimuli

    PubMed Central

    LI, Peng; JIN, Cai-Hong; JIANG, San; LI, Miao-Miao; WANG, Zi-Lu; ZHU, Hui; CHEN, Cui-Yun; HUA, Tian-Miao

    2014-01-01

    The influence of intracortical inhibition on the response adaptation of visual cortical neurons remains in debate. To clarify this issue, in the present study the influence of surround suppression evoked through the local inhibitory interneurons on the adaptation effects of neurons in the primary visual cortex (V1) were observed. Moreover, the adaptations of V1 neurons to both the high-contrast visual stimuli presented in the classical receptive field (CRF) and to the costimulation presented in the CRF and the surrounding nonclassical receptive field (nCRF) were compared. The intensities of surround suppression were modulated with different sized grating stimuli. The results showed that the response adaptation of V1 neurons decreased significantly with the increase of surround suppression and this adaptation decrease was due to the reduction of the initial response of V1 neurons to visual stimuli. However, the plateau response during adaptation showed no significant changes. These findings indicate that the adaptation effects of V1 neurons may not be directly affected by surround suppression, but may be dynamically regulated by a negative feedback network and be finely adjusted by its initial spiking response to stimulus. This adaptive regulation is not only energy efficient for the central nervous system, but also beneficially acts to maintain the homeostasis of neuronal response to long-presenting visual signals. PMID:25297081

  9. Attention-dependent representation of a size illusion in human V1

    PubMed Central

    Fang, Fang; Boyaci, Huseyin; Kersten, Daniel; Murray, Scott O.

    2008-01-01

    Summary One of the most fundamental properties of human primary visual cortex (V1) is its retinotopic organization, which makes it an ideal candidate for encoding spatial properties of objects such as size. However, three-dimensional (3D) contextual information can lead to size illusions that are reflected in the spatial pattern of activity in V1 [1]. A critical question is how complex 3D contextual information can influence spatial activity patterns in V1. Here we assessed whether changes in the spatial distribution of activity in V1 depend on the focus of attention, which would be suggestive of feedback of 3D contextual information from higher visual areas. We presented two 3D rings at close and far apparent depths in a 3D scene. When fixating its center, the far ring appeared to be larger and occupy a more eccentric portion of the visual field, relative to the close ring. Using fMRI, we found that the spatial distribution of V1 activity induced by the far ring was also shifted towards a more eccentric representation of the visual field, while that induced by the close ring was shifted towards the foveal representation, consistent with their perceptual appearances. This effect was significantly reduced when the focus of spatial attention was narrowed with a demanding central fixation task. We reason that focusing attention on the fixation task resulted in reduced activity in – and therefore reduced feedback from – higher visual areas that process the 3D depth cues. PMID:18993076

  10. Low level laser therapy (AlGaInP) applied at 5J/cm2 reduces the proliferation of Staphylococcus aureus MRSA in infected wounds and intact skin of rats*

    PubMed Central

    Silva, Daniela Conceição Gomes Gonçalves e; Plapler, Helio; da Costa, Mateus Matiuzzi; Silva, Silvio Romero Gonçalves e; de Sá, Maria da Conceição Aquino; Silva, Benedito Sávio Lima e

    2013-01-01

    BACKGROUND Laser therapy is a low cost, non-invasive procedure with good healing results. Doubts exist as to whether laser therapy action on microorganisms can justify research aimed at investigating its possible effects on bacteria-infected wounds. OBJECTIVE To assess the effect of low intensity laser on the rate of bacterial contamination in infected wounds in the skin of rats. METHODS An experimental study using 56 male Wistar rats. The animals were randomly divided into eight groups of seven each. Those in the "infected" groups were infected by Staphylococcus aureus MRSA in the dorsal region. Red laser diode (AlGaInP) 658nm, 5J/cm2 was used to treat the animals in the "treated" groups in scan for 3 consecutive days. Samples were drawn before inoculating bacteria and following laser treatment. For statistical analysis we used the nonparametric Wilcoxon (paired data) method with a significance level of p <0.05. RESULTS The statistical analysis of median values showed that the groups submitted to laser treatment had low bacterial proliferation. CONCLUSION The laser (AlGaInP), with a dose of 5J/cm2 in both intact skin and in wounds of rats infected with Staphylococcus aureus MRSA, is shown to reduce bacterial proliferation. PMID:23539003

  11. Two temporal channels in human V1 identified using fMRI.

    PubMed

    Horiguchi, Hiroshi; Nakadomari, Satoshi; Misaki, Masaya; Wandell, Brian A

    2009-08-01

    Human visual sensitivity to a fairly broad class of dynamic stimuli can be modeled accurately using two temporal channels. Here, we analyze fMRI measurements of the temporal step response to spatially uniform stimuli to estimate these channels in human primary visual cortex (V1). In agreement with the psychophysical literature, the V1 fMRI temporal responses are modeled accurately as a mixture of two (transient and sustained) channels. We derive estimates of the relative contributions from these two channels at a range of eccentricities. We find that all portions of V1 contain a significant transient response. The central visual field representation includes a significant sustained response, but the amplitude of the sustained channel signal declines with eccentricity. The sustained signals may reflect the emphasis on pattern recognition and color in the central visual field; the dominant transient response in the visual periphery may reflect responses in the human visual attention system. PMID:19361561

  12. [Structure of Response and Dynamics of Preferred Orientation in Cat's V1 Neurons].

    PubMed

    Kozhukhov, S A; Saltykov, K A; Lazareva, N A

    2016-01-01

    Preferred orientation of V1 neurons was changed during the respons time course. In order to reveal mechanisms of such changes, spike trains of single neurons to flashed bars of different orientations were studied by means of principal component and frequency-domain analysis of the spike density functions. There was found out that: 1. contribution of each of the components was dependent on the stimulus orientation. 2. the principal components of V1 neurons responses contain different kinds of transient and sustained parts and rhythmic oscillations in the theta/alpha and beta-bands. 3. There was no correlation between transient parts as well as between rhythmic oscillations within the same frequency band in different components. Taken together, the data obtained allow us to suggest that during generation of response there is a shift of dominance of the components with different orientations which determines the dynamics of the preferred orientations of V1 neurons. PMID:27263274

  13. Crystal structure of yeast V1-ATPase in the autoinhibited state.

    PubMed

    Oot, Rebecca A; Kane, Patricia M; Berry, Edward A; Wilkens, Stephan

    2016-08-01

    Vacuolar ATPases (V-ATPases) are essential proton pumps that acidify the lumen of subcellular organelles in all eukaryotic cells and the extracellular space in some tissues. V-ATPase activity is regulated by a unique mechanism referred to as reversible disassembly, wherein the soluble catalytic sector, V1, is released from the membrane and its MgATPase activity silenced. The crystal structure of yeast V1 presented here shows that activity silencing involves a large conformational change of subunit H, with its C-terminal domain rotating ~150° from a position near the membrane in holo V-ATPase to a position at the bottom of V1 near an open catalytic site. Together with biochemical data, the structure supports a mechanistic model wherein subunit H inhibits ATPase activity by stabilizing an open catalytic site that results in tight binding of inhibitory ADP at another site. PMID:27295975

  14. Independent anatomical and functional measures of the V1/V2 boundary in human visual cortex.

    PubMed

    Bridge, Holly; Clare, Stuart; Jenkinson, Mark; Jezzard, Peter; Parker, Andrew J; Matthews, Paul M

    2005-01-01

    The cerebral cortex has both anatomical and functional specialization, but the level of correspondence between the two in the human brain has remained largely elusive. Recent successes in high-resolution magnetic resonance imaging of myeloarchitecture patterns in the cortex suggest that it may now be possible to compare directly human anatomy and function in vivo. We independently investigated the anatomical and functional borders between primary and secondary human visual areas (V1 and V2) in vivo. Functional borders were mapped with functional magnetic resonance imaging (fMRI) using a narrow, vertical black and white contrast-reversing wedge. In three separate scanning sessions, anatomical images were collected at three different slice orientations (300 microm x 300 microm, slice thickness, 1.5 mm). The anatomical signature of V1 was determined by the presence of a hypointense band in the middle of the cortical gray matter. The band was identified in between 81% and 33% (mean 57%) of V1 defined using fMRI, and less than 5% of the identified band was in cortex outside V1. Intensity profiles taken through the gray matter on the V1 and V2 sides of the functional border indicate a measurable difference in the size of the hypointense band for all subjects. This is the first demonstration that the definition of V1 by fMRI closely matches the anatomically defined striate cortex in the human brain. The development of very high-resolution structural MRI may permit the definition of cortical areas based on myeloarchitecture when functional definition is not possible. PMID:15831070

  15. Depth-dependent detection of microampere currents delivered to monkey V1.

    PubMed

    Tehovnik, Edward J; Slocum, Warren M

    2009-04-01

    Monkeys can detect electrical stimulation delivered to the striate cortex (area V1). We examined whether such stimulation is layer dependent. While remaining fixated on a spot of light, a rhesus monkey was required to detect a 100-ms train of electrical stimulation delivered to a site within area V1. A monkey signaled the delivery of stimulation by depressing a lever after which he was rewarded with a drop of apple juice. Control trials were interleaved during which time no stimulation was delivered and the monkey was rewarded for not depressing the lever. Biphasic pulses were delivered at 200 Hz, and the current was typically at or < 30 muA using 0.2-ms cathode-first biphasic pulses. For some experiments, the pulse duration was varied from 0.05 to 0.7 ms and anode-first pulses were used. The current threshold for detecting cathode-first pulses 50% of the time was the lowest (< 10 muA) when stimulation was delivered to the deepest layers of V1 (between 1.0 and 2.5 mm below the cortical surface). Also, the shortest chronaxies (< 0.2 ms) and the shortest latencies (< 200 ms) for detecting the stimulation were observed at these depths. Finally, anode-first pulses were most effective at evoking a detection response in superficial V1 and cathode-first pulses were most effective at evoking a detection response in deep V1 (> 1.75 mm below the cortical surface). Accordingly, the deepest layers of V1 are the most sensitive for the induction of a detection response to electrical stimulation in monkeys. PMID:19519630

  16. Determinants of Versican-V1 Proteoglycan Processing by the Metalloproteinase ADAMTS5*

    PubMed Central

    Foulcer, Simon J.; Nelson, Courtney M.; Quintero, Maritza V.; Kuberan, Balagurunathan; Larkin, Jonathan; Dours-Zimmermann, Maria T.; Zimmermann, Dieter R.; Apte, Suneel S.

    2014-01-01

    Proteolysis of the Glu441-Ala442 bond in the glycosaminoglycan (GAG) β domain of the versican-V1 variant by a disintegrin-like and metalloproteinase domain with thrombospondin type 1 motif (ADAMTS) proteases is required for proper embryo morphogenesis. However, the processing mechanism and the possibility of additional ADAMTS-cleaved processing sites are unknown. We demonstrate here that if Glu441 is mutated, ADAMTS5 cleaves inefficiently at a proximate upstream site but normally does not cleave elsewhere within the GAGβ domain. Chondroitin sulfate (CS) modification of versican is a prerequisite for cleavage at the Glu441-Ala442 site, as demonstrated by reduced processing of CS-deficient or chondroitinase ABC-treated versican-V1. Site-directed mutagenesis identified the N-terminal CS attachment sites Ser507 and Ser525 as essential for processing of the Glu441-Ala442 bond by ADAMTS5. A construct including only these two GAG chains, but not downstream GAG attachment sites, was cleaved efficiently. Therefore, CS chain attachment to Ser507 and Ser525 is necessary and sufficient for versican proteolysis by ADAMTS5. Mutagenesis of Glu441 and an antibody to a peptide spanning Thr432-Gly445 (i.e. containing the scissile bond) reduced versican-V1 processing. ADAMTS5 lacking the C-terminal ancillary domain did not cleave versican, and an ADAMTS5 ancillary domain construct bound versican-V1 via the CS chains. We conclude that docking of ADAMTS5 with two N-terminal GAG chains of versican-V1 via its ancillary domain is required for versican processing at Glu441-Ala442. V1 proteolysis by ADAMTS1 demonstrated a similar requirement for the N-terminal GAG chains and Glu441. Therefore, versican cleavage can be inhibited substantially by mutation of Glu441, Ser507, and Ser525 or by an antibody to the region of the scissile bond. PMID:25122765

  17. Population Response Propagation to Extrastriate Areas Evoked by Intracortical Electrical Stimulation in V1

    PubMed Central

    Fehérvári, Tamás D.; Yagi, Tetsuya

    2016-01-01

    The mouse visual system has multiple extrastriate areas surrounding V1 each with a distinct representation of the visual field and unique functional and connectivity profiles, which are believed to form two parallel processing streams, similar to the ventral and dorsal streams in primates. At the same time, mouse visual areas have a high degree of interconnectivity, in particular V1 sends input to all higher visual areas. The study of these direct connections can further our understanding of the cortical processing of visual signals in the early mammalian cortex. Several studies have been published about the anatomy of these connections, but an in vivo electrophysiological characterization and comparison of the transmission to multiple extrastriate areas has not yet been reported. We used intracortical electrical stimulation combined with RH1691 VSD imaging in adult C57BL/6 mice in urethane anesthesia to analyze interareal transmission from V1 to extrastriate areas in superficial cortical layers. We found seven extrastriate response sites (five lateral, two medial) in a spatial pattern similar to area maps of the mouse visual cortex and, by shifting the location of V1 stimulation, demonstrated that the evoked responses in LM and AL were in accordance with the visuotopic mappings of these areas known from anatomy and in vivo studies. These two sites, considered to be gateways to their processing streams, had shorter latencies and faster transmission speeds than other extrastriate response sites. Short latency differences between response sites, and that TTX injection into LM reduced but did not eliminate other extrastriate responses indicated that the evoked cortical activity was, at least partially, transmitted directly from V1 to extrastriate areas. This study reports on analysis of interareal transmission from V1 to multiple extrastriate areas in mouse using intracortical electrical stimulation in vivo. PMID:26903816

  18. Empowering Reentrant Projections from V5 to V1 Boosts Sensitivity to Motion.

    PubMed

    Romei, Vincenzo; Chiappini, Emilio; Hibbard, Paul B; Avenanti, Alessio

    2016-08-22

    Evidence from macaques [1] and humans [2, 3] has shown that back projections from extrastriate areas to the primary visual area (V1) determine whether visual awareness will arise. For example, reentrant projections from the visual motion area (V5) to V1 are considered to be critical for awareness of motion [2, 3]. If these projections are also instrumental to functional processing of moving stimuli [4-8], then increasing synaptic efficacy in V5-V1 connections should induce functionally relevant short-term plastic changes, resulting in enhanced perception of visual motion. Using transcranial magnetic stimulation (TMS), we applied a novel cortico-cortical paired associative stimulation (ccPAS) protocol to transiently enhance visual motion sensitivity and demonstrate both the functional relevance of V5-V1 reentrant projections to motion perception and their plasticity. Specifically, we found that ccPAS aimed at strengthening reentrant connectivity from V5 to V1 (but not in the opposite direction) enhanced the human ability to perceive coherent visual motion. This perceptual enhancement followed the temporal profile of Hebbian plasticity [9-18] and was observed only when an optimal timing of 20 ms between TMS pulses [2, 3, 5, 6] was used, not when TMS pulses were delivered synchronously. Thus, plastic change is critically dependent on both the direction and timing of connectivity; if either of these requirements was not met, perceptual enhancement did not take place. We therefore provide novel causal evidence that V5-V1 back projections, instrumental to motion perception, are functionally malleable. These findings have implications for theoretical models of visual awareness and for the rehabilitation of visual deficits. PMID:27524488

  19. REACTION AND DEACTIVATION OF HCl (v = 1, 2) BY Cl, Br, AND H ATOMS

    SciTech Connect

    Macdonald, R.G.; Moore, C.Bradley

    1980-02-01

    Total decay rates for HCl(v = 2, 1) were measured in the range 294 - 439 K for Cl, 295 - 390 K for Br, and at 296 K for H. HCl(v = 2) was produced directly by pulsed laser excitation of the overtone. The fraction of HCl(v = 2) relaxed to HCl(v = 1) was determined. For HCl(v = 2) + Cl, relaxation gave entirely HCl(v = 1) within an experimental uncertainty of ± 10%, the total relaxation rate was large, k/v = 5 {Angstrom}{sup 2} , and rates varied only slightly with temperature. For Br + HCl(v = 2) reaction to HBr(v = 0) + Cl is exoergic by about kT. Relaxation to HCl(v = 1) is the dominant process. Reaction contributes roughly 17% and 34% to the loss of HCl(v = 2) at 295 and 390 K, respectively. In constrast to the result for Br and for O (reported previously) H + HCl(v = 2) gives 65% H{sub 2} + Cl and only 35% HCl(v = 1) +H. For HCl(v = 1) + H Cl, O the vibrational excitation energy is greater than the activation energy for reaction. The relaxation rates are between 1/2 and 1/3 of the A values for the measured thermal exchange rates Aexp(-{Delta}E{sub act}/RT). For HCl(v = 1) + Br, well below threshold, the rate is some 20 times less than for HCl(v = 1) + Cl. The rate for HCl(v = 2) + Br, just above reaction threshold is not dramatically larger. The ratios of vibrational relaxation rates for HCl(v = 2) vs HCl(v = 1) are 5.0 ± 1.3, 4.2 ± 0.4, and 5.0 ± 1.3 for O, Cl, and Br, respectively. Any first order linear perturbation treatment gives rates proportional to v; the data scale more closely as v{sup 2}.

  20. Central V4 Receptive Fields Are Scaled by the V1 Cortical Magnification and Correspond to a Constant Sized Sampling of the V1 Surface

    PubMed Central

    Motter, Brad C.

    2009-01-01

    The mapping of the topographic representation of the visual field onto cortical areas changes throughout the hierarchy of cortical visual areas. The changes are believed to reflect the establishment of modules with different spatial processing emphasis. The receptive fields (RFs) of neurons within these modules, however, may not be governed by the same spatial topographic map parameters. Here it is shown that the RFs of area V4 neurons (centered 1–12 degs in eccentricity) are based on a circularly symmetric sampling of the primary visual cortical retinotopic map. No eccentricity dependent magnification beyond that observed in V1 is apparent in the V4 neurons. The size and shape of V4 RFs can be explained by a simple, constant sized, 2D Gaussian sample of visual input from the retinotopic map laid out across the surface of V1. Inferences about the spatial scale of interactions within the receptive fields of neurons cannot be based on a visual area’s apparent cortical magnification derived from topographic mapping. PMID:19420243

  1. Phase-matched four-wave mixing of sub-100-TW/ cm2 femtosecond laser pulses in isolated air-guided modes of a hollow photonic-crystal fiber.

    PubMed

    Konorov, S O; Serebryannikov, E E; Akimov, D A; Ivanov, A A; Alfimov, M V; Zheltikov, A M

    2004-12-01

    Hollow-core photonic-crystal fibers are shown to allow propagation and nonlinear-optical frequency conversion of high-intensity ultrashort laser pulses in the regime of isolated guided modes confined in the hollow gas-filled fiber core. With a specially designed dispersion of such modes, the 3omega=2omega+2omega-omega four-wave mixing of fundamental (omega) and second-harmonic (2omega) sub-100- TW/ cm(2) femtosecond pulses of a Cr:forsterite laser can be phase matched in a hollow photonic-crystal fiber within a spectral band of more than 10 nm, resulting in the efficient generation of femtosecond pulses in a well-resolved higher-order air-guided mode of 417-nm radiation. PMID:15697544

  2. Determination of the type of stacking faults in single-crystal high-purity diamond with a low dislocation density of <50 cm-2 by synchrotron X-ray topography

    NASA Astrophysics Data System (ADS)

    Masuya, Satoshi; Hanada, Kenji; Uematsu, Takumi; Moribayashi, Tomoya; Sumiya, Hitoshi; Kasu, Makoto

    2016-04-01

    The properties of stacking faults in a single-crystal high-purity diamond with a very low dislocation density of <50 cm-2 and a very low impurity concentration of <0.1 ppm were investigated by synchrotron X-ray topography. We found stacking faults on the {111} plane and determined the fault vector f of the stacking faults to be \\textbf{f} = a/3< 111> on the basis of the f · g extinction criteria. Furthermore, we have found that the partial dislocations are of the Shockley type on the basis of the b · g extinction criteria. Consequently, we concluded that the stacking faults are of the Shockley type and formed because of the decomposition of dislocations with \\textbf{b} = a/2< 1\\bar{1}0> into dislocations with \\textbf{b} = a/6< 2\\bar{1}1> and a/6< 1\\bar{2}\\bar{1}> .

  3. Hyperammonaemia in V1a vasopressin receptor knockout mice caused by the promoted proteolysis and reduced intrahepatic blood volume.

    PubMed

    Hiroyama, Masami; Aoyagi, Toshinori; Fujiwara, Yoko; Oshikawa, Sayuri; Sanbe, Atsushi; Endo, Fumio; Tanoue, Akito

    2007-06-15

    An analysis of arginine-vasopressin (AVP) V1a receptor-deficient (V1aR-/-) mice revealed that glucose homeostasis and lipid metabolism were altered in the mutant mice. Here, we used V1aR-/- mice to investigate whether the deficiency of the V1a receptor, which led to altered insulin sensitivity, affected protein metabolism. The serum 3-methylhistidine levels were increased in V1aR-/- mice under feeding conditions, indicating that proteolysis was enhanced in muscle tissue from V1aR-/- mice. Furthermore, serum amino acid profiling revealed that the amino acid levels, including glycogenic and branched-chain amino acids, were reduced in V1aR-/- mice. In addition, an alanine-loading test showed that gluconeogenesis was enhanced in V1aR-/- mice. Blood ammonia, which is a by-product of amino acid catabolism, was two times higher in V1aR-/- mice without hepatopathy under the feeding and fasting conditions than in wild-type mice. Amino acid profiling also revealed that the amino acid pattern was not typical of a urea-cycle enzymatic disorder. An ammonia tolerance test and an indocyanine green elimination test showed that V1aR-/- mice had lower ammonia clearance due to a decreased intrahepatic circulating blood volume. Metabolic acidosis, including lactic- and keto-acidosis, was not observed in V1aR-/- mice. These results provide evidence that proteolysis promotes the production of glucose in the muscles of V1aR-/- mice and that hyperammonaemia is caused by promoted protein catabolism and reduced intrahepatic blood volume. Thus, our study with V1aR-/- mice indicates that AVP plays a physiological role via the V1a receptor in regulating both protein catabolism and glucose homeostasis. PMID:17379633

  4. A new allergen from ragweed (Ambrosia artemisiifolia) with homology to art v 1 from mugwort.

    PubMed

    Léonard, Renaud; Wopfner, Nicole; Pabst, Martin; Stadlmann, Johannes; Petersen, Bent O; Duus, Jens Ø; Himly, Martin; Radauer, Christian; Gadermaier, Gabriele; Razzazi-Fazeli, Ebrahim; Ferreira, Fatima; Altmann, Friedrich

    2010-08-27

    Art v 1, the major pollen allergen of the composite plant mugwort (Artemisia vulgaris) has been identified recently as a thionin-like protein with a bulky arabinogalactan-protein moiety. A close relative of mugwort, ragweed (Ambrosia artemisiifolia) is an important allergen source in North America, and, since 1990, ragweed has become a growing health concern in Europe as well. Weed pollen-sensitized patients demonstrated IgE reactivity to a ragweed pollen protein of apparently 29-31 kDa. This reaction could be inhibited by the mugwort allergen Art v 1. The purified ragweed pollen protein consisted of a 57-amino acid-long defensin-like domain with high homology to Art v 1 and a C-terminal proline-rich domain. This part contained hydroxyproline-linked arabinogalactan chains with one galactose and 5 to 20 and more alpha-arabinofuranosyl residues with some beta-arabinoses in terminal positions as revealed by high field NMR. The ragweed protein contained only small amounts of the single hydroxyproline-linked beta-arabinosyl residues, which form an important IgE binding determinant in Art v 1. cDNA clones for this protein were obtained from ragweed flowers. Immunological characterization revealed that the recombinant ragweed protein reacted with >30% of the weed pollen allergic patients. Therefore, this protein from ragweed pollen constitutes a novel important ragweed allergen and has been designated Amb a 4. PMID:20576600

  5. Combined sodium ion sensitivity in agonist binding and internalization of vasopressin V1b receptors.

    PubMed

    Koshimizu, Taka-Aki; Kashiwazaki, Aki; Taniguchi, Junichi

    2016-01-01

    Reducing Na(+) in the extracellular environment may lead to two beneficial effects for increasing agonist binding to cell surface G-protein coupled receptors (GPCRs): reduction of Na(+)-mediated binding block and reduce of receptor internalization. However, such combined effects have not been explored. We used Chinese Hamster Ovary cells expressing vasopressin V1b receptors as a model to explore Na(+) sensitivity in agonist binding and receptor internalization. Under basal conditions, a large fraction of V1b receptors is located intracellularly, and a small fraction is in the plasma membrane. Decreases in external Na(+) increased cell surface [(3)H]AVP binding and decreased receptor internalization. Substitution of Na(+) by Cs(+) or NH4(+) inhibited agonist binding. To suppress receptor internalization, the concentration of NaCl, but not of CsCl, had to be less than 50 mM, due to the high sensitivity of the internalization machinery to Na(+) over Cs(+). Iso-osmotic supplementation of glucose or NH4Cl maintained internalization of the V1b receptor, even in a low-NaCl environment. Moreover, iodide ions, which acted as a counter anion, inhibited V1b agonist binding. In summary, we found external ionic conditions that could increase the presence of high-affinity state receptors at the cell surface with minimum internalization during agonist stimulations. PMID:27138239

  6. Versican isoform V1 regulates proliferation and migration in high-grade gliomas.

    PubMed

    Onken, Julia; Moeckel, Sylvia; Leukel, Petra; Leidgens, Verena; Baumann, Fusun; Bogdahn, Ulrich; Vollmann-Zwerenz, Arabel; Hau, Peter

    2014-10-01

    Versican is a large chondroitin sulphate proteoglycan produced by several tumor cell types, including high-grade gliomas. Increased expression of distinct versican isoforms in the extracellular matrix plays a role in tumor cell growth, adhesion and migration. We have recently shown that transforming growth factor (TGF-beta)2, an important modulator of glioma invasion, interacts with versican isoforms V0/V1 during malignant progression of glioma in vitro. However, the distinct subtype of versican that modulates these effects could not be specified. Here, we show that transient down-regulation of V1 by siRNA leads to a significant reduction of proliferation and migration in glioblastoma cell lines and glioblastoma progenitor cells, whereas tumor cell attachment stays unaffected. We conclude that V1 plays a predominant role in modulating central pathophysiological mechanisms as proliferation and migration in glioblastoma. Considering that TGF-beta is a master regulator of glioma pathophysiology, and that V0/1 is induced by TGF-beta2, therapeutic regulation of V1 may induce meaningful effects on glioma cell migration not only in vitro, but also in vivo. PMID:25064688

  7. SSE-GIS v1.03 Web Mapping Application Now Available

    Atmospheric Science Data Center

    2016-07-07

    ... invite you to visit the site.  The Surface meteorology and Solar Energy (SSE) v1.0.3 Web Mapping Application provides new web-based ... pilot parameters and near-real time data sets at ( http://power.larc.nasa.gov ) We hope you and your team enjoy this SSE-GIS release ...

  8. Combined sodium ion sensitivity in agonist binding and internalization of vasopressin V1b receptors

    PubMed Central

    Koshimizu, Taka-aki; Kashiwazaki, Aki; Taniguchi, Junichi

    2016-01-01

    Reducing Na+ in the extracellular environment may lead to two beneficial effects for increasing agonist binding to cell surface G-protein coupled receptors (GPCRs): reduction of Na+-mediated binding block and reduce of receptor internalization. However, such combined effects have not been explored. We used Chinese Hamster Ovary cells expressing vasopressin V1b receptors as a model to explore Na+ sensitivity in agonist binding and receptor internalization. Under basal conditions, a large fraction of V1b receptors is located intracellularly, and a small fraction is in the plasma membrane. Decreases in external Na+ increased cell surface [3H]AVP binding and decreased receptor internalization. Substitution of Na+ by Cs+ or NH4+ inhibited agonist binding. To suppress receptor internalization, the concentration of NaCl, but not of CsCl, had to be less than 50 mM, due to the high sensitivity of the internalization machinery to Na+ over Cs+. Iso-osmotic supplementation of glucose or NH4Cl maintained internalization of the V1b receptor, even in a low-NaCl environment. Moreover, iodide ions, which acted as a counter anion, inhibited V1b agonist binding. In summary, we found external ionic conditions that could increase the presence of high-affinity state receptors at the cell surface with minimum internalization during agonist stimulations. PMID:27138239

  9. Different glutamate receptors convey feedforward and recurrent processing in macaque V1.

    PubMed

    Self, Matthew W; Kooijmans, Roxana N; Supèr, Hans; Lamme, Victor A; Roelfsema, Pieter R

    2012-07-01

    Neurons in the primary visual cortex (V1) receive feedforward input from the thalamus, which shapes receptive-field properties. They additionally receive recurrent inputs via horizontal connections within V1 and feedback from higher visual areas that are thought to be important for conscious visual perception. Here, we investigated what roles different glutamate receptors play in conveying feedforward and recurrent inputs in macaque V1. As a measure of recurrent processing, we used figure-ground modulation (FGM), the increased activity of neurons representing figures compared with background, which depends on feedback from higher areas. We found that feedforward-driven activity was strongly reduced by the AMPA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX), whereas this drug had no effect on FGM. In contrast, blockers of the NMDA receptor reduced FGM, whereas their effect on visually driven activity varied with the subunit specificity of the drug. The NMDA receptor blocker 2-amino-5-phosphonovalerate (APV) caused a slight reduction of the visual response, whereas ifenprodil, which targets NMDA receptors containing the NMDA receptor NR2B subunit, increased the visual response. These findings demonstrate that glutamate receptors contribute differently to feedforward and recurrent processing in V1 and suggest ways to selectively disrupt recurrent processing so that its role in visual perception can be elucidated. PMID:22615394

  10. Visual recognition memory, manifest as long-term habituation, requires synaptic plasticity in V1

    PubMed Central

    Cooke, Sam F.; Komorowski, Robert W.; Kaplan, Eitan S.; Gavornik, Jeffrey P.; Bear, Mark F.

    2015-01-01

    Familiarity with stimuli that bring neither reward nor punishment, manifested through behavioural habituation, enables organisms to detect novelty and devote cognition to important elements of the environment. Here we describe in mice a form of long-term behavioural habituation to visual grating stimuli that is selective for stimulus orientation. Orientation-selective habituation (OSH) can be observed both in exploratory behaviour in an open arena, and in a stereotyped motor response to visual stimuli in head-restrained mice. We show that the latter behavioural response, termed a vidget, requires V1. Parallel electrophysiological recordings in V1 reveal that plasticity, in the form of stimulus-selective response potentiation (SRP), occurs in layer 4 of V1 as OSH develops. Local manipulations of V1 that prevent and reverse electrophysiological modifications likewise prevent and reverse memory demonstrated behaviourally. These findings suggest that a form of long-term visual recognition memory is stored via synaptic plasticity in primary sensory cortex. PMID:25599221

  11. Decavanadate Toxicology and Pharmacological Activities: V10 or V1, Both or None?

    PubMed Central

    Aureliano, M.

    2016-01-01

    This review covers recent advances in the understanding of decavanadate toxicology and pharmacological applications. Toxicological in vivo studies point out that V10 induces several changes in several oxidative stress parameters, different from the ones observed for vanadate (V1). In in vitro studies with mitochondria, a particularly potent V10 effect, in comparison with V1, was observed in the mitochondrial depolarization (IC50 = 40 nM) and oxygen consumption (99 nM). It is suggested that mitochondrial membrane depolarization is a key event in decavanadate induction of necrotic cardiomyocytes death. Furthermore, only decavanadate species and not V1 potently inhibited myosin ATPase activity stimulated by actin (IC50 = 0.75 μM) whereas exhibiting lower inhibition activities for Ca2+-ATPase activity (15 μM) and actin polymerization (17 μM). Because both calcium pump and actin decavanadate interactions lead to its stabilization, it is likely that V10 interacts at specific locations with these proteins that protect against hydrolysis but, on the other hand, it may induce V10 reduction to oxidovanadium(IV). Putting it all together, it is suggested that the pharmacological applications of V10 species and compounds whose mechanism of action is still to be clarified might involve besides V10 and V1 also vanadium(IV) species. PMID:26904166

  12. Robust Supersolidity in the V1- V2 Extended Bose-Hubbard Model

    NASA Astrophysics Data System (ADS)

    Greene, Nicole; Pixley, Jedediah

    2016-05-01

    Motivated by ultra-cold atomic gases with long-range interactions in an optical lattice we study the effects of the next-nearest neighbor interaction on the extended Bose-Hubbard model on a square lattice. Using the variational Gutzwiller approach with a four-site unit cell we determine the ground state phase diagrams as a function of the model parameters. We focus on the interplay of each interaction between the nearest neighbor (V1) , the next-nearest neighbor (V2) , and the onsite repulsion (U). We find various super-solid phases that can be described by one of the ordering wave-vectors (π, 0), (0, π) , and (π, π) . In the limits V1, V2 V1, V2 >U we find phases reminiscent of the limit V2 = 0 but with a richer super solid structure. For V1

  13. Ability of NCAR RegCM2 in reproducing the dominant physical processes during the anomalous rainfall episodes in the summer of 1991 over the Yangtze-Huaihe valley

    NASA Astrophysics Data System (ADS)

    Luo, Y.; Zhao, Y. C.; Ding, Y. H.

    2002-03-01

    The excessively torrential rainfall over the Yangtze-Huaihe valley during the summer of 1991 is simulated with an updated version of the second generation NCAR regional climate model (RegCM2) as a case study to evaluate the model's performance in reproducing the daily precipitation and the associated physical factors contributing to the generation of the anomalous rainfall. This simulation is driven by large-scale atmospheric lateral boundary conditions derived from the European Center for Medium Range Weather Forecast (ECMWF) analysis. The simulation period is May to August 1991. The model domain covers East Asia and its adjacent oceanic regions, The model resolution is 60 km x 60 km in the horizontal and 23 layers in the vertical. The model can reasonably reproduce the daily precipitation events over East Asia for the summer of 1991, especially in the Yangtze-Huaihe valley where the anomalous rainfall occurred. The spatial and temporal structure of some important physical variables and processes related to the generation of the anomalous rainfall are analyzed, The time evolution of simulated upward vertical motion and horizontal convergence agrees with the five rainfall episodes over this subregion. The water vapor feeding the rainfall is mostly transported by the horizontal atmospheric motions from outside of the region rather than from local sources. The subtropical high over the western Pacific Ocean controls the progress and retreat of the summer monsoon over East Asia, and the RegCM2 can simulate the northward migration and southward retreat of subtropical high over the western Pacific Ocean. Furthermore, the model can represent the daily variation of the low level jet, which is crucial in the water vapor transport to the Yangtze-Huaihe valley.

  14. AVP-induced pulmonary vasodilation during specific V1 receptor block in conscious dogs.

    PubMed

    Nyhan, D P; Clougherty, P W; Murray, P A

    1987-09-01

    Our objectives were 1) to determine whether exogenously administered arginine vasopressin (AVP) can exert a vasoactive influence on the pulmonary circulation of conscious dogs during specific vasopressinergic-1 (V1) receptor block, and 2) to assess the extent to which the pulmonary vascular response to AVP during V1 receptor block is mediated by either sympathetic beta-adrenergic or cholinergic receptor activation or by cyclooxygenase pathway activation. Multipoint pulmonary vascular pressure-cardiac index (P/Q) plots were constructed during normoxia in conscious dogs by stepwise constriction of the thoracic inferior vena cava to reduce Q. In dogs pretreated with a specific V1 receptor antagonist [d(CH2)5 AVP, 10 micrograms/kg iv], AVP infusion (7.6 ng.kg-1 X min-1 iv) increased (P less than 0.01) Q from 139 +/- 6 to 175 +/- 8 ml.min-1 X kg-1, and decreased (P less than 0.01) the pulmonary vascular pressure gradient (pulmonary arterial pressure-pulmonary capillary wedge pressure: PAP-PCWP) over the entire range of Q studied (140 to 80 ml.min-1 X kg-1). This pulmonary vasodilator response to AVP during V1 block was also observed following sympathetic beta-adrenergic block alone, following combined sympathetic beta-adrenergic and cholinergic block, and following cyclooxygenase pathway inhibition. Thus exogenous administration of AVP during specific V1 receptor block results in active, nonflow-dependent pulmonary vasodilation. This pulmonary vasodilator response is not mediated by reflex activation of sympathetic beta-adrenergic or cholinergic receptors or by metabolites of the cyclooxygenase pathway over a broad range of Q. PMID:2888317

  15. Chromatic detection from cone photoreceptors to V1 neurons to behavior in rhesus monkeys

    PubMed Central

    Hass, Charles A.; Angueyra, Juan M.; Lindbloom-Brown, Zachary; Rieke, Fred; Horwitz, Gregory D.

    2015-01-01

    Chromatic sensitivity cannot exceed limits set by noise in the cone photoreceptors. To determine how close neurophysiological and psychophysical chromatic sensitivity come to these limits, we developed a parameter-free model of stimulus encoding in the cone outer segments, and we compared the sensitivity of the model to the psychophysical sensitivity of monkeys performing a detection task and to the sensitivity of individual V1 neurons. Modeled cones had a temporal impulse response and a noise power spectrum that were derived from in vitro recordings of macaque cones, and V1 recordings were made during performance of the detection task. The sensitivity of the simulated cone mosaic, the V1 neurons, and the monkeys were tightly yoked for low-spatiotemporal-frequency isoluminant modulations, indicating high-fidelity signal transmission for this class of stimuli. Under the conditions of our experiments and the assumptions for our model, the signal-to-noise ratio for these stimuli dropped by a factor of ∼3 between the cones and perception. Populations of weakly correlated V1 neurons narrowly exceeded the monkeys' chromatic sensitivity but fell well short of the cones' chromatic sensitivity, suggesting that most of the behavior-limiting noise lies between the cone outer segments and the output of V1. The sensitivity gap between the cones and behavior for achromatic stimuli was larger than for chromatic stimuli, indicating greater postreceptoral noise. The cone mosaic model provides a means to compare visual sensitivity across disparate stimuli and to identify sources of noise that limit visual sensitivity. PMID:26523737

  16. Comparative Immunogenicity of Evolved V1V2-Deleted HIV-1 Envelope Glycoprotein Trimers

    PubMed Central

    Tong, Tommy; van Montfort, Thijs; Eggink, Dirk; Montefiori, David; Olson, William C.; Moore, John P.; Binley, James M.; Berkhout, Ben; Sanders, Rogier W.

    2013-01-01

    Despite almost 30 years of research, no effective vaccine has yet been developed against HIV-1. Probably such a vaccine would need to induce both an effective T cell and antibody response. Any vaccine component focused on inducing humoral immunity requires the HIV-1 envelope (Env) glycoprotein complex as it is the only viral protein exposed on the virion surface. HIV-1 has evolved several mechanisms to evade broadly reactive neutralizing antibodies. One such a mechanism involves variable loop domains, which are highly flexible structures that shield the underlying conserved epitopes. We hypothesized that removal of such loops would increase the exposure and immunogenicity of these conserved regions. Env variable loop deletion however often leads to protein misfolding and aggregation because hydrophobic patches becoming solvent accessible. We have therefore previously used virus evolution to acquire functional Env proteins lacking the V1V2 loop. We then expressed them in soluble (uncleaved) gp140 forms. Three mutants were found to perform optimally in terms of protein expression, stability, trimerization and folding. In this study, we characterized the immune responses to these antigens in rabbits. The V1V2 deletion mutant ΔV1V2.9.VK induced a prominent response directed to epitopes that are not fully available on the other Env proteins tested but that effectively bound and neutralized the ΔV1V2 Env virus. This Env variant also induced more efficient neutralization of the tier 1 virus SF162. The immune refocusing effect was lost after booster immunization with a full-length gp140 protein with intact V1V2 loops. Collectively, this result suggests that deletion of variable domains could alter the specificity of the humoral immune response, but did not result in broad neutralization of neutralization-resistant virus isolates. PMID:23840716

  17. Single-Trial Analysis of V1 Responses Suggests Two Transmission States

    NASA Technical Reports Server (NTRS)

    Shah, A. S.; Knuth, K. H.; Truccolo, W. A.; Mehta, A. D.; McGinnis, T.; OConnell, N.; Ding, M.; Bressler, S. L.; Schroeder, C. E.

    2002-01-01

    Sensory processing in the visual, auditory, and somatosensory systems is often studied by recording electrical activity in response to a stimulus of interest. Typically, multiple trial responses to the stimulus are averaged to isolate the stereotypic response from noise. However, averaging ignores dynamic variability in the neuronal response, which is potentially critical to understanding stimulus-processing schemes. Thus, we developed the multiple component, Event-Related Potential (mcERP) model. This model asserts that multiple components, defined as stereotypic waveforms, comprise the stimulus-evoked response and that these components may vary in amplitude and latency from trial to trial. Application of this model to data recorded simultaneously from all six laminae of V1 in an awake, behaving monkey performing a visual discrimination yielded three components. The first component localized to granular V1, the second was located in supragranular V1, and the final component displayed a multi-laminar distribution. These modeling results, which take into account single-trial response dynamics, illustrated that the initial activation of VI occurs in the granular layer followed by activation in the supragranular layers. This finding is expected because the average response in those layers demonstrates the same progression and because anatomical evidence suggests that the feedforward input in V1 enters the granular layer and progresses to supragranular layers. In addition to these findings, the granular component of the model displayed several interesting trial-to-trial characteristics including (1) a bimodal latency distribution, (2) a latency-related variation in response amplitude, (3) a latency correlation with the supragranular component, and (4) an amplitude and latency association with the multi-laminar component. Direct analyses of the single-trial data were consistent with these model predictions. These findings suggest that V1 has at least 2 transmission

  18. Chromatic detection from cone photoreceptors to V1 neurons to behavior in rhesus monkeys.

    PubMed

    Hass, Charles A; Angueyra, Juan M; Lindbloom-Brown, Zachary; Rieke, Fred; Horwitz, Gregory D

    2015-01-01

    Chromatic sensitivity cannot exceed limits set by noise in the cone photoreceptors. To determine how close neurophysiological and psychophysical chromatic sensitivity come to these limits, we developed a parameter-free model of stimulus encoding in the cone outer segments, and we compared the sensitivity of the model to the psychophysical sensitivity of monkeys performing a detection task and to the sensitivity of individual V1 neurons. Modeled cones had a temporal impulse response and a noise power spectrum that were derived from in vitro recordings of macaque cones, and V1 recordings were made during performance of the detection task. The sensitivity of the simulated cone mosaic, the V1 neurons, and the monkeys were tightly yoked for low-spatiotemporal-frequency isoluminant modulations, indicating high-fidelity signal transmission for this class of stimuli. Under the conditions of our experiments and the assumptions for our model, the signal-to-noise ratio for these stimuli dropped by a factor of ∼3 between the cones and perception. Populations of weakly correlated V1 neurons narrowly exceeded the monkeys' chromatic sensitivity but fell well short of the cones' chromatic sensitivity, suggesting that most of the behavior-limiting noise lies between the cone outer segments and the output of V1. The sensitivity gap between the cones and behavior for achromatic stimuli was larger than for chromatic stimuli, indicating greater postreceptoral noise. The cone mosaic model provides a means to compare visual sensitivity across disparate stimuli and to identify sources of noise that limit visual sensitivity. PMID:26523737

  19. Collisional Removal of O2(b1Σ ^+g, v = 1) by Atomic Oxygen

    NASA Astrophysics Data System (ADS)

    Kalogerakis, K. S.; Pejaković, D. A.; Copeland, R. A.; Slanger, T. G.

    2004-12-01

    In the thermosphere, energy transfer between excited O atoms and ground-state molecular oxygen produces O2 in the first two vibrational levels of the b1Σ ^+g state: O(1D) + O2 -> O(3P) + O2(b1Σ ^+g, v = 0, 1). Subsequent radiative decay of O2(b1Σ ^+g, v = 0, 1) to the ground state O2(X3Σ ^-g) results in the Atmospheric Band emissions. Atmospheric observations suggest that above ˜120 km O(3P) plays an important role in removing O2(b1Σ ^+g, v = 1). Therefore, knowledge of the rate coefficient for collisional removal of O2(b1Σ ^+g<, v = 1) by O(3P) is important for detailed understanding of the Atmospheric Band emissions. Measurements are reported of the room-temperature rate coefficient for removal of O2(b1Σ ^+g, v = 1) by O(3P). A commercial F2 laser with pulsed energy output of up to 50 mJ at 157 nm is used to photodissociate a large fraction of molecular oxygen in a O2/N2 mixture. Photodissociation of an O2 molecule produces a ground-state oxygen atom O(3P) and an excited oxygen atom O(1D), and O(1D) rapidly transfers energy to the remaining O2 to produce O2(b1Σ ^+g, v = 0, 1). The O2(b1Σ ^+g, v = 1) population is monitored by observing emission in the O2 (b-X) 1--1 band at 771 nm. To extract the O2(b1Σ ^+g, v = 1) + O(3P) rate coefficient, knowledge of the O(3P) partial pressure or, equivalently, the fraction of dissociated O2, is necessary. Based on the F2 laser fluence, the signal dependence on the fraction of dissociation, and computer modeling, the signals measured in our experiments correspond to about 50% dissociation. Our measurements yield a preliminary value of the rate coefficient for O2(b1Σ ^+g, v = 1) removal by O(3P) of 6 × 10-12 cm3s-1. The results will be compared to the rate coefficients for corresponding processes in the ground and a1Δ g states of O2, and implications of the results for modeling of the upper atmosphere will be discussed. This work is supported by the NSF Aeronomy Program under grant ATM-0209229. The F2 laser was

  20. Replacement of olivine by serpentine in the Queen Alexandra Range 93005 carbonaceous chondrite (CM2): Reactant-product compositional relations, and isovolumetric constraints on reaction stoichiometry and elemental mobility during aqueous alteration

    NASA Astrophysics Data System (ADS)

    Velbel, Michael A.; Tonui, Eric K.; Zolensky, Michael E.

    2015-01-01

    Isovolumetric replacement of euhedral and anhedral olivine by serpentine produced both centripetal and meshwork textures in the CM2 chondrites ALH 81002 and Nogoya. The compositions of these textural varieties of serpentine are uniform within narrow limits within each previously studied meteorite, independent of the composition of olivine being replaced, and different between the two meteorites. In QUE 93005 (CM2), coarse olivines of widely varying compositions (Fo<76-99) are replaced in a texturally similar manner by compositionally uniform serpentine (Mg0.73±0.05Fe0.27±0.05)3Si2O5(OH)4. The narrow compositional range of serpentine replacing coarse olivine indicates that the aqueous solution from which the serpentine formed was compositionally uniform on scales at least as large as the meteorite (∼2.5 cm in longest dimension). Isovolumetric textures and compositional observations constrain elemental redistribution from coarse olivine to serpentine and to surrounding phases during serpentinization. Regardless of olivine's composition, isovolumetric replacement of coarse olivines by serpentine of the observed composition released more Mg and Si from olivine than was required to form the serpentine. Excess Mg and Si released by olivine destruction and not retained in serpentine were exported from the replaced volume. Olivines with different Fa/Fo proportions contributed different amounts of Fe and Mg to the serpentine. Ferroan olivines released more Fe than required to form the serpentines replacing them, so some of the Fe released from ferroan olivine was exported from the replaced volumes. Forsteritic olivines released less Fe than required to form the serpentines replacing them, so some Fe was imported into the replaced volumes augmenting the small amount of Fe released from forsteritic olivine. In QUE 93005 Fo83.8 is the threshold composition between Fe-exporting and Fe-importing behavior in individual olivine-serpentine pairs, which released exactly the

  1. Characterization of micron-sized Fe,Ni metal grains in fine-grained rims in the Y-791198 CM2 carbonaceous chondrite: Implications for asteroidal and preaccretionary models for aqueous alteration.

    NASA Astrophysics Data System (ADS)

    Chizmadia, L. J.; Xu, Y.; Schwappach, C.; Brearley, A. J.

    2008-11-01

    The presence of apparently unaltered, micron-sized Fe,Ni metal grains, juxtaposed against hydrated fine-grained rim materials in the CM2 chondrite Yamato (Y-) 791198 has been cited as unequivocal evidence of preaccretionary alteration. We have examined the occurrence, composition, and textural characteristics of 60 Fe,Ni metal grains located in fine-grained rims in Y-791198 using scanning electron microscopy (SEM) and electron microprobe analysis. In addition, three metal grains, prepared by focused ion beam (FIB) sample preparation techniques were studied by transmission electron microscopy (TEM). The metal grains are heterogeneously distributed within the rims. Electron microprobe analyses show that all the metal grains are kamacite with minor element contents (P, Cr, and Co) that lie either within or close to the range for other CM2 metal grains. X-ray maps obtained by electron microprobe show S, P, and/or Ca enrichments on the outermost parts of many of the metal grains. Z-contrast STEM imaging of FIB-prepared Fe,Ni metal grains show the presence of a small amount of a lower Z secondary phase on the surface of the grains and within indentations on the grain surfaces. Energy-filtered TEM (EFTEM) compositional mapping shows that these pits are enriched in oxygen and depleted in Fe relative to the metal. These observations are consistent with pitting corrosion of the metal on the edges of the grains and we suggest may be the result of the formation of Fe(OH)2, a common oxidation product of Fe metal. The presence of such a layer could have inhibited further alteration of the metal grains. These findings are consistent with alteration by an alkaline fluid as suggested by Zolensky et al. (1989), but the location of this alteration remains unconstrained, because Y-791198 was recovered from Antarctica and therefore may have experienced incipient terrestrial alteration. However, we infer that the extremely low degree of oxidation of the metal is inconsistent with

  2. Integrated Assessment of Hadley Centre (HadCM2) Climate Change Projections on Agricultural Productivity and Irrigation Water Supply in the Conterminous United States.I. Climate change scenarios and impacts on irrigation water supply simulated with the HUMUS model.

    SciTech Connect

    Rosenberg, Norman J.; Brown, Robert A.; Izaurralde, R Cesar C.; Thomson, Allison M.

    2003-06-30

    This paper describes methodology and results of a study by researchers at PNNL contributing to the water sector study of the U.S. National Assessment of Climate Change. The vulnerability of water resources in the conterminous U.S. to climate change in 10-y periods centered on 2030 and 2095--as projected by the HadCM2 general circulation model--was modeled with HUMUS (Hydrologic Unit Model of the U.S.). HUMUS consists of a GIS that provides data on soils, land use and climate to drive the hydrology model Soil Water Assessment Tool (SWAT). The modeling was done at the scale of the 2101 8-digit USGS hydrologic unit areas (HUA). Results are aggregated to the 4-digit and 2-digit (Major Water Resource Region, MWRR) scales for various purposes. Daily records of temperature and precipitation for 1961-1990 provided the baseline climate. Water yields (WY)--sum of surface and subsurface runoff--increases from the baseline period over most of the U.S. in 2030 and 2095. In 2030, WY increases in the western US and decreases in the central and southeast regions. Notably, WY increases by 139 mm from baseline in the Pacific NW. Decreased WY is projected for the Lower Mississippi and Texas Gulf basins, driven by higher temperatures and reduced precipitation. The HadCM2 2095 scenario projects a climate significantly wetter than baseline, resulting in WY increases of 38%. WY increases are projected throughout the eastern U.S. WY also increases in the western U.S. Climate change also affects the seasonality of the hydrologic cycle. Early snowmelt is induced in western basins, leading to dramatically increased WYs in late winter and early spring. The simulations were run at current (365 ppm) and elevated (560 ppm) atmospheric CO2 concentrations to account for the potential impacts of the CO2-fertilization effect. The effects of climate change scenario were considerably greater than those due to elevated CO2 but the latter, overall, decreased losses and augmented increases in water yield.

  3. 46 CFR 30.10-2 - Accommodation space-TB/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Accommodation space-TB/ALL. 30.10-2 Section 30.10-2... Accommodation space—TB/ALL. The term accommodation space means any public space such as a hall, dining room... that contains no cooking appliances, and a similar space open to the passengers and crew....

  4. 46 CFR 30.10-2 - Accommodation space-TB/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Accommodation space-TB/ALL. 30.10-2 Section 30.10-2... Accommodation space—TB/ALL. The term accommodation space means any public space such as a hall, dining room... that contains no cooking appliances, and a similar space open to the passengers and crew....

  5. 46 CFR 30.10-2 - Accommodation space-TB/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Accommodation space-TB/ALL. 30.10-2 Section 30.10-2... Accommodation space—TB/ALL. The term accommodation space means any public space such as a hall, dining room... that contains no cooking appliances, and a similar space open to the passengers and crew....

  6. 46 CFR 30.10-2 - Accommodation space-TB/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Accommodation space-TB/ALL. 30.10-2 Section 30.10-2... Accommodation space—TB/ALL. The term accommodation space means any public space such as a hall, dining room... that contains no cooking appliances, and a similar space open to the passengers and crew....

  7. 46 CFR 30.10-2 - Accommodation space-TB/ALL.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Accommodation space-TB/ALL. 30.10-2 Section 30.10-2... Accommodation space—TB/ALL. The term accommodation space means any public space such as a hall, dining room... that contains no cooking appliances, and a similar space open to the passengers and crew....

  8. Featural and temporal attention selectively enhance task-appropriate representations in human V1

    PubMed Central

    Warren, Scott; Yacoub, Essa; Ghose, Geoffrey

    2015-01-01

    Our perceptions are often shaped by focusing our attention toward specific features or periods of time irrespective of location. We explore the physiological bases of these non-spatial forms of attention by imaging brain activity while subjects perform a challenging change detection task. The task employs a continuously varying visual stimulus that, for any moment in time, selectively activates functionally distinct subpopulations of primary visual cortex (V1) neurons. When subjects are cued to the timing and nature of the change, the mapping of orientation preference across V1 was systematically shifts toward the cued stimulus just prior to its appearance. A simple linear model can explain this shift: attentional changes are selectively targeted toward neural subpopulations representing the attended feature at the times the feature was anticipated. Our results suggest that featural attention is mediated by a linear change in the responses of task-appropriate neurons across cortex during appropriate periods of time. PMID:25501983

  9. Nonlinear V1 responses to natural scenes revealed by neural network analysis.

    PubMed

    Prenger, Ryan; Wu, Michael C-K; David, Stephen V; Gallant, Jack L

    2004-01-01

    A key goal in the study of visual processing is to obtain a comprehensive description of the relationship between visual stimuli and neuronal responses. One way to guide the search for models is to use a general nonparametric regression algorithm, such as a neural network. We have developed a multilayer feed-forward network algorithm that can be used to characterize nonlinear stimulus-response mapping functions of neurons in primary visual cortex (area V1) using natural image stimuli. The network is capable of extracting several known V1 response properties such as: orientation and spatial frequency tuning, the spatial phase invariance of complex cells, and direction selectivity. We present details of a method for training networks and visualizing their properties. We also compare how well conventional explicit models and those developed using neural networks can predict novel responses to natural scenes. PMID:15288891

  10. Dependence of V2 illusory contour response on V1 cell properties and topographic organization.

    PubMed

    Cohen, Amelia; Buia, Calin; Tiesinga, Paul

    2014-06-01

    An illusory contour is an image that is perceived as a contour in the absence of typical contour characteristics, such as a change in luminance or chromaticity across the stimulus. In cats and primates, cells that respond to illusory contours are sparse in cortical area V1, but are found in greater numbers in cortical area V2. We propose a model capable of illusory contour detection that is based on a realistic topographic organization of V1 cells, which reproduces the responses of individual cell types measured experimentally. The model allows us to explain several experimentally observed properties of V2 cells including variability in orientation tuning and inducer spacing preference. As a practical application, the model can be used to estimate the relationship between the severity of a cortical injury in the primary visual cortex and the deterioration of V2 cell responses to real and illusory contours. PMID:24801874

  11. Physical Parameters of Erupting Luminous Blue Variables: NGC 2363-V1 Caught in the Act

    NASA Astrophysics Data System (ADS)

    Drissen, Laurent; Crowther, Paul A.; Smith, Linda J.; Robert, Carmelle; Roy, Jean-René; Hillier, D. John

    2001-01-01

    A quantitative study of the luminous blue variable NGC 2363-V1 in the Magellanic galaxy NGC 2366 (D=3.44 Mpc) is presented, based on ultraviolet and optical Hubble Space Telescope STIS spectroscopy. Contemporary WFPC2 and William Herschel Telescope imaging reveals a modest V-band brightness increase of ~0.2 mag per year between 1996 January-1997 November, reaching V=17.4 mag, corresponding to MV=-10.4 mag. Subsequently, V1 underwent a similar decrease in V-band brightness, together with a UV brightening of 0.35 mag from 1997 November to 1999 November. The optical spectrum of V1 is dominated by H emission lines, with Fe II, He I and Na I also detected. In the ultraviolet, a forest of Fe absorption features and numerous absorption lines typical of mid-B supergiants (such as Si II, Si III, Si IV, C III, C IV) are observed. From a spectral analysis with the non-LTE, line-blanketed code of Hillier & Miller, we derive stellar parameters of T*=11 kK, R*=420 Rsolar, log (L/Lsolar)=6.35 during 1997 November, and T*=13 kK, R*=315 Rsolar, log (L/Lsolar)=6.4 for 1999 July. The wind properties of V1 are also exceptional, with M~=4.4×10-4Msolar yr-1 and v∞~=300 km s-1, allowing for a clumped wind (filling factor=0.3) and assuming H/He~4 by number. The presence of Fe lines in the UV and optical spectrum of V1 permits an estimate of the heavy elemental abundance of NGC 2363 from our spectral synthesis. Although some deficiencies remain, allowance for charge exchange reactions in our calculations supports a SMC-like metallicity, that has previously been determined for NGC 2363 from nebular oxygen diagnostics. Considering a variety of possible progenitor stars, V1 has definitely undergone a giant eruption, with a substantial increase in stellar luminosity, radius, and almost certainly mass-loss rate, such that its stellar radius increased at an average rate of ~4 km s-1 during 1992 October-1995 February. The stellar properties of V1 are compared to other LBVs, including η Car

  12. Vibrational Relaxation of H2 \\(v = 1, J = 1\\) on Pd(111)

    NASA Astrophysics Data System (ADS)

    Gostein, M.; Watts, E.; Sitz, G. O.

    1997-10-01

    We have observed the relaxation of H2 from the rovibrational state v = 1,J = 1 into ( v = 0, J = 5, and J = 7) upon scattering from Pd(111). The relaxation probability is 0.04+/-0.01 into J = 5 and 0.03+/-0.01 into J = 7. Relaxation does not occur when the surface is saturated with H atoms at low temperature. Furthermore, relaxation occurs with significant loss of vibrational energy, 50-120 meV, to the substrate. The relaxation mechanism is most likely electronically nonadiabatic. The survival probability of the incident H2 \\(v = 1,J = 1\\) is 0.05+/-0.01 for a clean surface, but nearly unity for an H-saturated surface.

  13. MREG V1.1 : a multi-scale image registration algorithm for SAR applications.

    SciTech Connect

    Eichel, Paul H.

    2013-08-01

    MREG V1.1 is the sixth generation SAR image registration algorithm developed by the Signal Processing&Technology Department for Synthetic Aperture Radar applications. Like its predecessor algorithm REGI, it employs a powerful iterative multi-scale paradigm to achieve the competing goals of sub-pixel registration accuracy and the ability to handle large initial offsets. Since it is not model based, it allows for high fidelity tracking of spatially varying terrain-induced misregistration. Since it does not rely on image domain phase, it is equally adept at coherent and noncoherent image registration. This document provides a brief history of the registration processors developed by Dept. 5962 leading up to MREG V1.1, a full description of the signal processing steps involved in the algorithm, and a user's manual with application specific recommendations for CCD, TwoColor MultiView, and SAR stereoscopy.

  14. Explosive Model Tarantula V1/JWL++ Calibration of LX-17: #2

    SciTech Connect

    Souers, P C; Vitello, P

    2009-05-01

    Tarantula V1 is a kinetic package for reactive flow codes that seeks to describe initiation, failure, dead zones and detonation simultaneously. The most important parameter is P1, the pressure between the initiation and failure regions. Both dead zone formation and failure can be largely controlled with this knob. However, V1 does failure with low settings and dead zones with higher settings, so that it cannot fulfill its purpose in the current format. To this end, V2 is under test. The derivation of the initiation threshold P0 is discussed. The derivation of the initiation pressure-tau curve as an output of Tarantula shows that the initiation package is sound. A desensitization package is also considered.

  15. Evaluation of the Early Access STR Kit v1 on the Ion Torrent PGM™ platform.

    PubMed

    Guo, Fei; Zhou, Yishu; Liu, Feng; Yu, Jiao; Song, He; Shen, Hongying; Zhao, Bin; Jia, Fei; Hou, Guangwei; Jiang, Xianhua

    2016-07-01

    The Early Access STR Kit v1 is designed to detect 25-plex loci with next generation sequencing (NGS) technology on the Ion Torrent PGM™ platform, including 16 of 20 expanded Combined DNA Index System (CODIS) core loci (CSF1PO, D1S1656, D2S1338, D2S441, D3S1358, D5S818, D7S820, D8S1179, D10S1248, D13S317, D16S539, D19S433, D21S11, TH01, TPOX and vWA), 8 non-CODIS core loci (D1S1677, D2S1776, D4S2408, D5S2500.AC008791, D6S1043, D6S474, D9S2157 and D14S1434) and Amelogenin. In this study, we compared the Early Access STR Kit v1 with the Ion Torrent™ HID STR 10-plex to find out its improvements and explored an appropriate analytical threshold to enhance the performance. In addition, seven experiments were conducted to evaluate the Early Access STR Kit v1 such as studies of repeatability, concordance, sensitivity, mixtures, degraded samples, case-type samples and pedigrees. Other than a little discordance (0.95%) with CE-STR results observed at D21S11, NGS-STR results correctly reflected the sample being tested. Repeatable results were obtained from both initial PCRs and emPCRs aside from a few variations of allele coverage. Full profiles could be obtained from 100pg input DNA and >48.84% profiles from 10pg input DNA. Mixtures were easily detected at 9:1 and 1:9 ratios. This system could be adapted to case-type samples and degraded samples. As a whole, the Early Access STR Kit v1 is a robust, reliable and reproducible assay for NGS-STR typing and a potential tool for human identification. PMID:27082757

  16. BSND and ATP6V1G3: Novel Immunohistochemical Markers for Chromophobe Renal Cell Carcinoma

    PubMed Central

    Shinmura, Kazuya; Igarashi, Hisaki; Kato, Hisami; Koda, Kenji; Ogawa, Hiroshi; Takahashi, Seishiro; Otsuki, Yoshiro; Yoneda, Tatsuaki; Kawanishi, Yuichi; Funai, Kazuhito; Takayama, Tatsuya; Ozono, Seiichiro; Sugimura, Haruhiko

    2015-01-01

    Abstract Differentiating between chromophobe renal cell carcinoma (RCC) and other RCC subtypes can be problematic using routine light microscopy. This study aimed to identify novel immunohistochemical markers useful for a differential diagnosis between chromophobe RCC and other RCC subtypes. We selected 3 genes (including BSND and ATP6V1G3) that showed specific transcriptional expression in chromophobe RCC using expression data (n = 783) from The Cancer Genome Atlas (TCGA) database. A subsequent immunohistochemical examination of 186 RCCs obtained in our patient series resulted in a strong diffuse positivity of BSND and ATP6V1G3 proteins (both of which are involved in the regulation of membrane transport) in all the chromophobe RCC specimens (23/23 cases, 100%) but not in the clear cell RCC specimens (0/153 cases, 0%) or the papillary RCC specimens (0/10 cases, 0%). BSND and ATP6V1G3 protein expressions were also detected in renal oncocytoma (13/14 cases, 92.9%) and in the distal nephron, including the collecting duct, in the normal kidney. A computational analysis of TCGA data suggested that DNA methylation was involved in the differential expression pattern of both genes among RCC subtypes. Finally, an immunohistochemical analysis showed lung carcinomas were negative (0/85 cases, 0%) for the expression of both proteins. These results suggest that BSND and ATP6V1G3 are excellent novel immunohistochemical markers for differentiating between chromophobe RCC and other subtypes of RCC, including clear cell and papillary RCCs.

  17. BSND and ATP6V1G3: Novel Immunohistochemical Markers for Chromophobe Renal Cell Carcinoma.

    PubMed

    Shinmura, Kazuya; Igarashi, Hisaki; Kato, Hisami; Koda, Kenji; Ogawa, Hiroshi; Takahashi, Seishiro; Otsuki, Yoshiro; Yoneda, Tatsuaki; Kawanishi, Yuichi; Funai, Kazuhito; Takayama, Tatsuya; Ozono, Seiichiro; Sugimura, Haruhiko

    2015-06-01

    Differentiating between chromophobe renal cell carcinoma (RCC) and other RCC subtypes can be problematic using routine light microscopy. This study aimed to identify novel immunohistochemical markers useful for a differential diagnosis between chromophobe RCC and other RCC subtypes. We selected 3 genes (including BSND and ATP6V1G3) that showed specific transcriptional expression in chromophobe RCC using expression data (n = 783) from The Cancer Genome Atlas (TCGA) database. A subsequent immunohistochemical examination of 186 RCCs obtained in our patient series resulted in a strong diffuse positivity of BSND and ATP6V1G3 proteins (both of which are involved in the regulation of membrane transport) in all the chromophobe RCC specimens (23/23 cases, 100%) but not in the clear cell RCC specimens (0/153 cases, 0%) or the papillary RCC specimens (0/10 cases, 0%). BSND and ATP6V1G3 protein expressions were also detected in renal oncocytoma (13/14 cases, 92.9%) and in the distal nephron, including the collecting duct, in the normal kidney. A computational analysis of TCGA data suggested that DNA methylation was involved in the differential expression pattern of both genes among RCC subtypes. Finally, an immunohistochemical analysis showed lung carcinomas were negative (0/85 cases, 0%) for the expression of both proteins. These results suggest that BSND and ATP6V1G3 are excellent novel immunohistochemical markers for differentiating between chromophobe RCC and other subtypes of RCC, including clear cell and papillary RCCs. PMID:26091477

  18. Precise visuotopic organization of the blind spot representation in primate V1.

    PubMed

    Azzi, João C B; Gattass, Ricardo; Lima, Bruss; Soares, Juliana G M; Fiorani, Mario

    2015-06-01

    The optic disk is a region of the retina consisting mainly of ganglion cell axons and blood vessels, which generates a visual scotoma known as the blind spot (BS). Information present in the surroundings of the BS can be used to complete the missing information. However, the neuronal mechanisms underlying these perceptual phenomena are poorly understood. We investigate the topography of the BS representation (BSR) in cortical area V1 of the capuchin monkey, using single and multiple electrodes. Receptive fields (RFs) of neurons inside the BSR were investigated using two distinct automatic bias-free mapping methods. The first method (local mapping) consisted of randomly flashing small white squares. For the second mapping method (global mapping), we used a single long bar that moved in one of eight directions. The latter stimulus was capable of eliciting neuronal activity inside the BSR, possibly attributable to long-range surround activity taking place outside the borders of the BSR. Importantly, we found that the neuronal activity inside the BSR is organized topographically in a manner similar to that found in other portions of V1. On average, the RFs inside the BS were larger than those outside. However, no differences in orientation or direction tuning were found between the two regions. We propose that area V1 exhibits a continuous functional topographic map, which is not interrupted in the BSR, as expected by the distribution of photoreceptors in the retina. Thus V1 topography is better described as "visuotopic" rather than as a discontinuous "retinotopic" map. PMID:25761953

  19. Precise visuotopic organization of the blind spot representation in primate V1

    PubMed Central

    Azzi, João C. B.; Lima, Bruss; Soares, Juliana G. M.; Fiorani, Mario

    2015-01-01

    The optic disk is a region of the retina consisting mainly of ganglion cell axons and blood vessels, which generates a visual scotoma known as the blind spot (BS). Information present in the surroundings of the BS can be used to complete the missing information. However, the neuronal mechanisms underlying these perceptual phenomena are poorly understood. We investigate the topography of the BS representation (BSR) in cortical area V1 of the capuchin monkey, using single and multiple electrodes. Receptive fields (RFs) of neurons inside the BSR were investigated using two distinct automatic bias-free mapping methods. The first method (local mapping) consisted of randomly flashing small white squares. For the second mapping method (global mapping), we used a single long bar that moved in one of eight directions. The latter stimulus was capable of eliciting neuronal activity inside the BSR, possibly attributable to long-range surround activity taking place outside the borders of the BSR. Importantly, we found that the neuronal activity inside the BSR is organized topographically in a manner similar to that found in other portions of V1. On average, the RFs inside the BS were larger than those outside. However, no differences in orientation or direction tuning were found between the two regions. We propose that area V1 exhibits a continuous functional topographic map, which is not interrupted in the BSR, as expected by the distribution of photoreceptors in the retina. Thus V1 topography is better described as “visuotopic” rather than as a discontinuous “retinotopic” map. PMID:25761953

  20. New, potent, selective, and short-acting peptidic V1a receptor agonists.

    PubMed

    Wisniewski, Kazimierz; Galyean, Robert; Tariga, Hiroe; Alagarsamy, Sudarkodi; Croston, Glenn; Heitzmann, Joshua; Kohan, Arash; Wisniewska, Halina; Laporte, Régent; Rivière, Pierre J-M; Schteingart, Claudio D

    2011-07-14

    [Arg(8)]vasopressin (AVP) produces vasoconstriction via V(1a) receptor (V(1a)R)-mediated vascular smooth muscle cell contraction and is being used to increase blood pressure in septic shock, a form of vasodilatory hypotension. However, AVP also induces V(2) receptor (V(2)R)-mediated antidiuresis, vasodilation, and coagulation factor release, all deleterious in septic shock. The V(1a)R agonist terlipressin (H-Gly(3)[Lys(8)]VP) also lacks selectivity vs the V(2)R and has sizably longer duration of action than AVP, preventing rapid titration of its vasopressor effect in the clinic. We designed and synthesized new short acting V(1a)R selective analogues of general structure [Xaa(2),Ile(3),Yaa(4),Zaa(8)]VP. The most potent and selective compounds in in vitro functional assays (e.g., [Phe(2),Ile(3),Asn(Me(2))(4),Orn(8)]VP (31), [Phe(2),Ile(3),Asn((CH(2))(3)OH)(4),Orn(8)]VP (34), [Phe(2),Ile(3),Hgn(4),Orn(iPr)(8)]VP (45), [Phe(2),Ile(3),Asn(Et)(4),Dab(8)]VP (49), [Thi(2),Ile(3),Orn(iPr)(8)]VP (59), [Cha(2),Ile(3),Asn(4),Orn(iPr)(8)]VP (68)) were tested by intravenous bolus in rats for duration of vasopressive action. Analogues 31, 34, 45, and 49 were as short-acting as AVP. Compound 45, FE 202158, is currently undergoing clinical trials in septic shock. PMID:21688787

  1. Selective V(1a) agonism attenuates vascular dysfunction and fluid accumulation in ovine severe sepsis.

    PubMed

    Rehberg, Sebastian; Yamamoto, Yusuke; Sousse, Linda; Bartha, Eva; Jonkam, Collette; Hasselbach, Anthony K; Traber, Lillian D; Cox, Robert A; Westphal, Martin; Enkhbaatar, Perenlei; Traber, Daniel L

    2012-11-15

    Vasopressin analogs are used as a supplement to norepinephrine in septic shock. The isolated effects of vasopressin agonists on sepsis-induced vascular dysfunction, however, remain controversial. Because V(2)-receptor stimulation induces vasodilation and procoagulant effects, a higher V(1a)- versus V(2)-receptor selectivity might be advantageous. We therefore hypothesized that a sole, titrated infusion of the selective V(1a)-agonist Phe(2)-Orn(8)-Vasotocin (POV) is more effective than the mixed V(1a)-/V(2)-agonist AVP for the treatment of vascular and cardiopulmonary dysfunction in methicillin resistant staphylococcus aureus pneumonia-induced, ovine sepsis. After the onset of hemodynamic instability, awake, chronically instrumented, mechanically ventilated, and fluid resuscitated sheep were randomly assigned to receive continuous infusions of either POV, AVP, or saline solution (control; each n = 6). AVP and POV were titrated to maintain mean arterial pressure above baseline - 10 mmHg. When compared with that of control animals, AVP and POV reduced neutrophil migration (myeloperoxidase activity, alveolar neutrophils) and plasma levels of nitric oxide, resulting in higher mean arterial pressures and a reduced vascular leakage (net fluid balance, chest and abdominal fluid, pulmonary bloodless wet-to-dry-weight ratio, alveolar and septal edema). Notably, POV stabilized hemodynamics at lower doses than AVP. In addition, POV, but not AVP, reduced myocardial and pulmonary tissue concentrations of 3-nitrotyrosine, VEGF, and angiopoietin-2, thereby leading to an abolishment of cumulative fluid accumulation (POV, 9 ± 15 ml/kg vs. AVP, 110 ± 13 ml/kg vs. control, 213 ± 16 ml/kg; P < 0.001 each) and an attenuated cardiopulmonary dysfunction (left ventricular stroke work index, PaO(2)-to-FiO(2) ratio) versus control animals. Highly selective V(1a)-agonism appears to be superior to unselective vasopressin analogs for the treatment of sepsis-induced vascular dysfunction. PMID

  2. Poblano v1.0 : a Matlab toolbox for gradient-based optimization.

    SciTech Connect

    Dunlavy, Daniel M.; Acar, Evrim; Kolda, Tamara Gibson

    2010-03-01

    We present Poblano v1.0, a Matlab toolbox for solving gradient-based unconstrained optimization problems. Poblano implements three optimization methods (nonlinear conjugate gradients, limited-memory BFGS, and truncated Newton) that require only first order derivative information. In this paper, we describe the Poblano methods, provide numerous examples on how to use Poblano, and present results of Poblano used in solving problems from a standard test collection of unconstrained optimization problems.

  3. Neural activities in V1 create the bottom-up saliency map of natural scenes.

    PubMed

    Chen, Cheng; Zhang, Xilin; Wang, Yizhou; Zhou, Tiangang; Fang, Fang

    2016-06-01

    A saliency map is the bottom-up contribution to the deployment of exogenous attention. It, as well as its underlying neural mechanism, is hard to identify because of the influence of top-down signals. A recent study showed that neural activities in V1 could create a bottom-up saliency map (Zhang et al. in Neuron 73(1):183-192, 2012). In this paper, we tested whether their conclusion can generalize to complex natural scenes. In order to avoid top-down influences, each image was presented with a low contrast for only 50 ms and was followed by a high contrast mask, which rendered the whole image invisible to participants (confirmed by a forced-choice test). The Posner cueing paradigm was adopted to measure the spatial cueing effect (i.e., saliency) by an orientation discrimination task. A positive cueing effect was found, and the magnitude of the cueing effect was consistent with the saliency prediction of a computational saliency model. In a following fMRI experiment, we used the same masked natural scenes as stimuli and measured BOLD signals responding to the predicted salient region (relative to the background). We found that the BOLD signal in V1, but not in other cortical areas, could well predict the cueing effect. These results suggest that the bottom-up saliency map of natural scenes could be created in V1, providing further evidence for the V1 saliency theory (Li in Trends Cogn Sci 6(1):9-16, 2002). PMID:26879771

  4. Spatial Attention and Temporal Expectation Under Timed Uncertainty Predictably Modulate Neuronal Responses in Monkey V1.

    PubMed

    Sharma, Jitendra; Sugihara, Hiroki; Katz, Yarden; Schummers, James; Tenenbaum, Joshua; Sur, Mriganka

    2015-09-01

    The brain uses attention and expectation as flexible devices for optimizing behavioral responses associated with expected but unpredictably timed events. The neural bases of attention and expectation are thought to engage higher cognitive loci; however, their influence at the level of primary visual cortex (V1) remains unknown. Here, we asked whether single-neuron responses in monkey V1 were influenced by an attention task of unpredictable duration. Monkeys covertly attended to a spot that remained unchanged for a fixed period and then abruptly disappeared at variable times, prompting a lever release for reward. We show that monkeys responded progressively faster and performed better as the trial duration increased. Neural responses also followed monkey's task engagement-there was an early, but short duration, response facilitation, followed by a late but sustained increase during the time monkeys expected the attention spot to disappear. This late attentional modulation was significantly and negatively correlated with the reaction time and was well explained by a modified hazard function. Such bimodal, time-dependent changes were, however, absent in a task that did not require explicit attentional engagement. Thus, V1 neurons carry reliable signals of attention and temporal expectation that correlate with predictable influences on monkeys' behavioral responses. PMID:24836689

  5. Genetic networks specifying the functional architecture of orientation domains in V1

    NASA Astrophysics Data System (ADS)

    Liedtke, Joscha; Wolf, Fred

    2015-03-01

    Although genetic information is critically important for brain development and structure, it is widely believed that neocortical functional architecture is largely shaped by activity dependent mechanisms. Here we show theoretically that mathematical models of genetic networks of principal neurons interacting by long range axonal morphogen transport can generate morphogen patterns that exactly prescribe the functional architecture of the primary visual cortex (V1) as experimentally observed. We analyze in detail an example genetic network that encodes the functional architecture of V1 by a dynamically generated morphogen pattern. We use analytical methods from weakly non-linear analysis [Cross & Hohenberg 1993] complemented by numerical simulations to obtain solutions of the model. In particular we find that the pinwheel statistics are in quantitative agreement with high precision experimental measurements [Kaschube et al. 2010]. This theory opens a novel perspective on the experimentally observed robustness of V1's architecture against radically abnormal developmental conditions such a dark rearing [White et al. 2001]. Furthermore, it provides for the first time a scheme how the pattern of a complex cortical architecture can be specified using only a small genetic bandwidth.

  6. Cholinergic suppression of visual responses in primate V1 is mediated by GABAergic inhibition

    PubMed Central

    Aoki, Chiye; Hawken, Michael J.

    2012-01-01

    Acetylcholine (ACh) has been implicated in selective attention. To understand the local circuit action of ACh, we iontophoresed cholinergic agonists into the primate primary visual cortex (V1) while presenting optimal visual stimuli. Consistent with our previous anatomical studies showing that GABAergic neurons in V1 express ACh receptors to a greater extent than do excitatory neurons, we observed suppressed visual responses in 36% of recorded neurons outside V1's primary thalamorecipient layer (4c). This suppression is blocked by the GABAA receptor antagonist gabazine. Within layer 4c, ACh release produces a response gain enhancement (Disney AA, Aoki C, Hawken MJ. Neuron 56: 701–713, 2007); elsewhere, ACh suppresses response gain by strengthening inhibition. Our finding contrasts with the observation that the dominant mechanism of suppression in the neocortex of rats is reduced glutamate release. We propose that in primates, distinct cholinergic receptor subtypes are recruited on specific cell types and in specific lamina to yield opposing modulatory effects that together increase neurons' responsiveness to optimal stimuli without changing tuning width. PMID:22786955

  7. Cholinergic suppression of visual responses in primate V1 is mediated by GABAergic inhibition.

    PubMed

    Disney, Anita A; Aoki, Chiye; Hawken, Michael J

    2012-10-01

    Acetylcholine (ACh) has been implicated in selective attention. To understand the local circuit action of ACh, we iontophoresed cholinergic agonists into the primate primary visual cortex (V1) while presenting optimal visual stimuli. Consistent with our previous anatomical studies showing that GABAergic neurons in V1 express ACh receptors to a greater extent than do excitatory neurons, we observed suppressed visual responses in 36% of recorded neurons outside V1's primary thalamorecipient layer (4c). This suppression is blocked by the GABA(A) receptor antagonist gabazine. Within layer 4c, ACh release produces a response gain enhancement (Disney AA, Aoki C, Hawken MJ. Neuron 56: 701-713, 2007); elsewhere, ACh suppresses response gain by strengthening inhibition. Our finding contrasts with the observation that the dominant mechanism of suppression in the neocortex of rats is reduced glutamate release. We propose that in primates, distinct cholinergic receptor subtypes are recruited on specific cell types and in specific lamina to yield opposing modulatory effects that together increase neurons' responsiveness to optimal stimuli without changing tuning width. PMID:22786955

  8. Muscarinic Acetylcholine Receptors in Macaque V1 Are Most Frequently Expressed by Parvalbumin-Immunoreactive Neurons

    PubMed Central

    Disney, Anita A.; Aoki, Chiye

    2010-01-01

    Acetylcholine (ACh) is believed to underlie mechanisms of arousal and attention in mammals. ACh also has a demonstrated functional effect in visual cortex that is both diverse and profound. We have reported previously that cholinergic modulation in V1 of the macaque monkey is strongly targeted toward GABAergic interneurons. Here we examine the localization of m1 and m2 muscarinic receptor subtypes across subpopulations of GABAergic interneurons—identified by their expression of the calcium-binding proteins parvalbumin, calbindin, and calretinin—using dual-immunofluorescence confocal microscopy in V1 of the macaque monkey. In doing so, we find that the vast majority (87%) of parvalbumin-immunoreactive neurons express m1-type muscarinic ACh receptors. m1 receptors are also expressed by 60% of calbindin-immunoreactive neurons and 40% of calretinin-immunoreactive neurons. m2 AChRs, on the other hand, are expressed by only 31% of parvalbumin neurons, 23% of calbindin neurons, and 25% of calretinin neurons. Parvalbumin-immunoreactive cells comprise ≈75% of the inhibitory neuronal population in V1 and included in this large subpopulation are neurons known to veto and regulate the synchrony of principal cell spiking. Through the expression of m1 ACh receptors on nearly all of these PV cells, the cholinergic system avails itself of powerful control of information flow through and processing within the network of principal cells in the cortical circuit. PMID:18265004

  9. Development and matching of binocular orientation preference in mouse V1

    PubMed Central

    Bhaumik, Basabi; Shah, Nishal P.

    2014-01-01

    Eye-specific thalamic inputs converge in the primary visual cortex (V1) and form the basis of binocular vision. For normal binocular perceptions, such as depth and stereopsis, binocularly matched orientation preference between the two eyes is required. A critical period of binocular matching of orientation preference in mice during normal development is reported in literature. Using a reaction diffusion model we present the development of RF and orientation selectivity in mouse V1 and investigate the binocular orientation preference matching during the critical period. At the onset of the critical period the preferred orientations of the modeled cells are mostly mismatched in the two eyes and the mismatch decreases and reaches levels reported in juvenile mouse by the end of the critical period. At the end of critical period 39% of cells in binocular zone in our model cortex is orientation selective. In literature around 40% cortical cells are reported as orientation selective in mouse V1. The starting and the closing time for critical period determine the orientation preference alignment between the two eyes and orientation tuning in cortical cells. The absence of near neighbor interaction among cortical cells during the development of thalamo-cortical wiring causes a salt and pepper organization in the orientation preference map in mice. It also results in much lower % of orientation selective cells in mice as compared to ferrets and cats having organized orientation maps with pinwheels. PMID:25104927

  10. Purification and characterization of the V1 vasopressin receptor from rat liver

    SciTech Connect

    Fishman, J.B.; Dickey, B.F.; Attisano, C.; Fine, R.E.

    1987-05-01

    The rat liver V1 vasopressin receptor was purified approximately 21,000-fold from rat liver microsomes. The receptor was solubilized from membranes using the zwitterionic detergent CHAPS (3-((3-cholamidopropyl) dimethylammonio)-1-propanesulfonate). Since the V1 receptor loses its ability to bind ligand when solubilized, the authors devised a liposome reconstitution system to assay vasopressin binding activity during purification. The purified receptor exhibits a K/sub d/ of 6 nm, when, prior to solubilization, the membranes were exposed to 1 m vasopressin. This resulted in the association of a pertussis-toxin insensitive guanine-nucleotide binding protein with the receptor during most of the purification procedure. The authors are further characterizing the V1-associated G-proteins. In the absence of this association, the receptor has a K/sub d/ of 30 nM. Crosslinking of SVI-vasopressin to a partially purified preparation of receptor demonstrated that the receptor had a molecular weight of approximately 68,000 under reducing conditions, and 58,000 under non-reducing conditions. The purification procedure may prove useful in purifying a number of small peptide hormone receptors (e.g., bradykinin, angiotensin II) and perhaps their associated G-proteins as well.

  11. Phosphate solubilizing ability of Emericella nidulans strain V1 isolated from vermicompost.

    PubMed

    Bhattacharya, Satya Sunder; Barman, Soma; Ghosh, Ranjan; Duary, Raj Kumar; Goswami, Linee; Mandal, Narayan C

    2013-10-01

    Phosphorus is one of the key factors that regulate soil fertility. Its deficiencies in soil are largely replenished by chemical fertilizers. The present study was aimed to isolate efficient phosphate solubilizing fungal strains from Eisenia fetida vermicompost. Out of total 30 fungal strains the most efficient phosphate solubilizing one was Emericella (Aspergillus) nidulans V1 (MTCC 11044), identified by custom sequencing of beta-tubulin gene and BLAST analysis. This strain solubilized 13 to 36% phosphate from four different rock phosphates. After three days of incubation of isolated culture with black Mussorie phosphate rock, the highest percentage of phosphate solubilization was 35.5 +/- 1.01 with a pH drop of 4.2 +/- 0.09. Kinetics of solubilization and acid production showed a linear relationship until day five of incubation. Interestingly, from zero to tenth day of incubation, solubility of soil phosphate increased gradually from 4.31 +/- 1.57 to 13.65 +/- 1.82 (mg kg(-1)) recording a maximum of 21.23 +/- 0.54 on day 45 in respect of the V1 isolate. Further, enhanced phosphorus uptake by Phaseolus plants with significant pod yield due to soil inoculation of Emericella nidulans V1 (MTCC 11044), demonstrated its prospect as an effective biofertilizer for plant growth. PMID:24266109

  12. Neural activities in v1 create a bottom-up saliency map.

    PubMed

    Zhang, Xilin; Zhaoping, Li; Zhou, Tiangang; Fang, Fang

    2012-01-12

    The bottom-up contribution to the allocation of exogenous attention is a saliency map, whose neural substrate is hard to identify because of possible contamination by top-down signals. We obviated this possibility using stimuli that observers could not perceive, but that nevertheless, through orientation contrast between foreground and background regions, attracted attention to improve a localized visual discrimination. When orientation contrast increased, so did the degree of attraction, and two physiological measures: the amplitude of the earliest (C1) component of the ERP, which is associated with primary visual cortex, and fMRI BOLD signals in areas V1-V4 (but not the intraparietal sulcus). Significantly, across observers, the degree of attraction correlated with the C1 amplitude and just the V1 BOLD signal. These findings strongly support the proposal that a bottom-up saliency map is created in V1, challenging the dominant view that the saliency map is generated in the parietal cortex. PMID:22243756

  13. Septal oxytocin administration impairs peer affiliation via V1a receptors in female meadow voles.

    PubMed

    Anacker, Allison M J; Christensen, Jennifer D; LaFlamme, Elyssa M; Grunberg, Diana M; Beery, Annaliese K

    2016-06-01

    The peptide hormone oxytocin (OT) plays an important role in social behaviors, including social bond formation. In different contexts, however, OT is also associated with aggression, social selectivity, and reduced affiliation. Female meadow voles form social preferences for familiar same-sex peers under short, winter-like day lengths in the laboratory, and provide a means of studying affiliation outside the context of reproductive pair bonds. Multiple lines of evidence suggest that the actions of OT in the lateral septum (LS) may decrease affiliative behavior, including greater density of OT receptors in the LS of meadow voles that huddle less. We infused OT into the LS of female meadow voles immediately prior to cohabitation with a social partner to determine its effects on partner preference formation. OT prevented the formation of preferences for the partner female. Co-administration of OT with a specific OT receptor antagonist did not reverse the effect, but co-administration of OT with a specific vasopressin 1a receptor (V1aR) antagonist did, indicating that OT in the LS likely acted through V1aRs to decrease partner preference. Receptor autoradiography revealed dense V1aR binding in the LS of female meadow voles. These results suggest that the LS is a brain region that may be responsible for inhibitory effects of OT administration on affiliation, which will be important to consider in therapeutic administrations of OT. PMID:26974500

  14. Functional Organization of Color Domains in V1 and V2 of Macaque Monkey Revealed by Optical Imaging

    PubMed Central

    Lu, Haidong D.; Roe, Anna W.

    2009-01-01

    Areas V1 and V2 of Macaque monkey visual cortex are characterized by unique cytochrome-oxidase (CO)--staining patterns. Initial electrophysiological studies associated CO blobs in V1 with processing of surface properties such as color and brightness and the interblobs with contour information processing. However, many subsequent studies showed controversial results, some supporting this proposal and others failing to find significant functional differences between blobs and interblobs. In this study, we have used optical imaging to map color-selective responses in V1 and V2. In V1, we find striking “blob-like” patterns of color response. Fine alignment of optical maps and CO-stained tissue revealed that color domains in V1 strongly associate with CO blobs. We also find color domains in V1 align along centers of ocular dominance columns. Furthermore, color blobs in V1 have low orientation selectivity and do not overlap with centers of orientation domains. In V2, color domains coincide with thin stripes; orientation-selective domains coincide with thick and pale stripes. We conclude that color and orientation-selective responses are preferentially located in distinct CO compartments in V1 and V2. We propose that the term “blob” encompasses both the concept of “CO blob” and “color domain” in V1. PMID:17576751

  15. Key comparison BIPM.RI(I)-K6 of the standards for absorbed dose to water at 10 g cm-2 of the NPL, United Kingdom and the BIPM in accelerator photon beams

    NASA Astrophysics Data System (ADS)

    Picard, S.; Burns, D. T.; Roger, P.; Duane, S.; Bass, G. A.; Manning, J. W.; Shipley, D. R.

    2015-01-01

    A comparison of the dosimetry for accelerator photon beams was carried out between the National Physical Laboratory (NPL) and the Bureau International des Poids et Mesures (BIPM) from 23 September to 7 October 2014. The comparison was based on the determination of absorbed dose to water at 10 g cm-2 for three radiation qualities at the NPL. The results, reported as ratios of the NPL and the BIPM evaluations (and with the combined standard uncertainties given in parentheses), are 1.0000(62) at 6 MV, 0.9999(70) at 10 MV and 0.9993(80) at 25 MV. This result is the seventh in the on-going BIPM.RI(I)-K6 series of comparisons. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  16. Key comparison BIPM.RI(I)-K6 of the standards for absorbed dose to water at 10 g cm-2 of the NMIJ, Japan and the BIPM in accelerator photon beams

    NASA Astrophysics Data System (ADS)

    Picard, S.; Burns, D. T.; Roger, P.; Shimizu, M.; Morishita, Y.; Kato, M.; Tanaka, T.; Kurosawa, T.; Saito, N.

    2016-01-01

    A comparison of the dosimetry for accelerator photon beams was carried out between the National Metrology Institute of Japan (NMIJ) and the Bureau International des Poids et Mesures (BIPM) from 9 to 23 April 2015. The comparison was based on the determination of absorbed dose to water at 10 g cm-2 for three radiation qualities at the NMIJ. The results, reported as ratios of the NMIJ and the BIPM evaluations (and with the combined standard uncertainties given in parentheses), are 0.9966 (47) at 6 MV, 0.9965 (60) at 10 MV and 0.9953 (50) at 15 MV. This result is the eighth in the on-going BIPM.RI(I)-K6 series of comparisons. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  17. Enhanced therapeutic anti-inflammatory effect of betamethasone on topical administration with low-frequency, low-intensity (20 kHz, 100 mW/cm(2)) ultrasound exposure on carrageenan-induced arthritis in a mouse model.

    PubMed

    Cohen, Gadi; Natsheh, Hiba; Sunny, Youhan; Bawiec, Christopher R; Touitou, Elka; Lerman, Melissa A; Lazarovici, Philip; Lewin, Peter A

    2015-09-01

    The purpose of this work was to investigate whether low-frequency, low-intensity (20 kHz, <100 mW/cm(2), spatial-peak, temporal-peak intensity) ultrasound, delivered with a lightweight (<100 g), tether-free, fully wearable, battery-powered applicator, is capable of reducing inflammation in a mouse model of rheumatoid arthritis. The therapeutic, acute, anti-inflammatory effect was estimated from the relative swelling induced in mice hindlimb paws. In an independent, indirect approach, the inflammation was bio-imaged by measuring glycolytic activity with near-infrared labeled 2-deoxyglucose. The outcome of the experiments indicated that the combination of ultrasound exposure and topical application of 0.1% (w/w) betamethasone gel resulted in statistically significantly (p < 0.05) enhanced anti-inflammatory activity in comparison with drug or ultrasound treatment alone. The present study underscores the potential benefits of low-frequency, low-intensity ultrasound-assisted drug delivery. However, the proof of concept presented indicates the need for additional experiments to systematically evaluate and optimize the potential of, and the conditions for, tolerable low-frequency, low-intensity ultrasound-promoted non-invasive drug delivery. PMID:26003010

  18. Vasopressin V(1A) receptors mediate the increase in gastric mucosal oxygenation during hypercapnia.

    PubMed

    Vollmer, Christian; Schwartges, Ingo; Naber, Silke; Beck, Christopher; Bauer, Inge; Picker, Olaf

    2013-04-01

    Hypercapnia (HC) improves systemic oxygen delivery (DO₂) and microvascular hemoglobin oxygenation of the mucosa (μHbO₂). Simultaneously, HC increases plasma levels of vasopressin. Although vasopressin is generally regarded a potent vasoconstrictor particularly in the splanchnic region, its effects on splanchnic microcirculation during HC is unclear. The aim of this study was to evaluate the role of endogenous vasopressin on gastric mucosal oxygenation and hemodynamic variables during physiological (normocapnia) and hypercapnic conditions. Five dogs were repeatedly anesthetized to study the effect of vasopressin V(1A) receptor blockade ([Pmp¹,Tyr(Me)²]-Arg⁸-Vasopressin, 35  μg/kg) on hemodynamic variables and μHbO₂ during normocapnia or HC (end-tidal CO₂ 70  mmHg). In a control group, animals were subjected to HC alone. μHbO₂ was measured by reflectance spectrophotometry, systemic DO₂ was calculated from intermittent blood gas analysis, and cardiac output was measured by transpulmonary thermodilution. Data are presented as mean±s.e.m. for n=5 animals. During HC alone, DO₂ increased from 12±1 to 16±1 ml/kg per min and μHbO₂ from 70±4 to 80±2%. By contrast, additional vasopressin V(1A) receptor blockade abolished the increase in μHbO₂ (80±2 vs. 69±2%) without altering the increase in DO₂ (16±1 vs. 19±2  ml/kg per min). Vasopressin V1A receptor blockade (VB) during normocapnia neither affected DO₂ (13±1 vs. 14±1  ml/kg per min) nor μHbO₂ (75±3 vs. 71±5%). Vasopressin V(1A) receptor blockade abolished the increase in μHbO₂ during HC independent of DO₂. Thus, in contrast to its generally vasoconstrictive properties, the vasopressin V1A receptors seem to mediate the increase in gastric microcirculatory mucosal oxygenation induced by acute HC. PMID:23359662

  19. Observing Campaign on Hubble's First Variable in M31: M31_V1

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2010-07-01

    An observing campaign is being carried out on M31_V1, the first variable star discovered in M31 by Edwin Hubble. The Hubble Heritage Team, with Dr. Keith Noll (STScI) as P.I., plans to observe M31_V1 with HST, and needs to know the phase of this Cepheid variable. Although basic parameters are known for this star, no recent photometry exists, so observations are required to generate current phase information. In 1925 Edwin Hubble published a note in The Observatory (vol. 48, 139) on "Cepheids in Spiral Nebulae." In 1929, he published a seminal paper in the Astrophysical Journal (vol. 69, 103), "A Spiral Nebula as a Stellar System, Messier 31." This paper discussed in detail the galaxy and the 50 variable stars he found in its outer regions. Hubble remarked that the 40 Cepheids found showed the period-luminosity relationship in a conspicuous manner, enabling distance to the galaxy to be calculated. Furthermore, he said that the results of his calculations supported the value determined by Harlow Shapley of the zero point of the period-luminosity relation. This confirmation of the zero point had significant implications for future extragalactic distance determinations. As the first of the variables on Hubble's list, V1, a Cepheid, is a historical curiosity. M31_V1 is magnitude 19.4V. B-V = +1.28, period is 30.41 days, and amplitude ~ 1.2 magnitudes in B, likely smaller in V. Five nights of data obtained by Arne Henden, AAVSO, show that the variable appears to have peaked on 2010 June 19 at about R=18 and as of July 2 was on its way down. It is recommended that observers use either an Rc filter or observe unfiltered. About an hour or more of exposure per integration will be required to reach S/N = 20, depending on your equipment and sky brightness; multiple exposures and stacking might be necessary to avoid saturating the background. The field is not crowded, and the variable itself is not blended. Contamination from the M31 background should n! ot be prohibitive

  20. Central V1b receptor antagonism in lactating rats: impairment of maternal care but not of maternal aggression.

    PubMed

    Bayerl, D S; Klampfl, S M; Bosch, O J

    2014-12-01

    Maternal behaviour in rodents is mediated by the central oxytocin and vasopressin systems, amongst others. The role of vasopressin, acting via the V1a receptor (V1aR), on maternal care and maternal aggression has recently been described. However, a potential involvement of the V1b receptor (V1bR) in maternal behaviour has only been demonstrated in knockout mice. The present study aimed to examine the effects of central pharmacological manipulation of the V1bR on maternal behaviour in lactating Wistar rats. On pregnancy day 18, female rats were implanted with a guide cannula targeting the lateral ventricle. After parturition, dams received an acute central infusion of a specific V1bR agonist (d[Leu4,Lys8]VP) or V1bR antagonist (SSR149415) once daily, followed by observations of maternal care [lactation day (LD) 1], maternal motivation in the pup retrieval test (LD 2), anxiety-related behaviour on the elevated plus-maze (LD 3) and maternal aggression in the maternal defence test followed by maternal care monitoring (LD 4). Our data demonstrate that, under nonstress conditions, the V1bR antagonist decreased the occurrence of both nursing and mother-pup interaction, whereas the V1bR agonist did not affect either parameter. Under stress conditions (i.e. after the maternal defence test), mother-pup interaction was decreased by infusion of the V1bR antagonist. During the maternal defence test, neither treatment affected aggressive or non-aggressive behaviour. Finally, neither treatment altered maternal motivation or anxiety. In conclusion, central V1bR antagonism modulates aspects of maternal care but not of maternal aggression or maternal motivation in lactating rats. These findings further extend our knowledge on the vasopressin system as a vital mediator of maternal behaviour. PMID:25283607

  1. Complete nucleotide sequence of little cherry virus 1 (LChV-1) infecting sweet cherry in China.

    PubMed

    Wang, Jiawei; Zhu, Dongzi; Tan, Yue; Zong, Xiaojuan; Wei, Hairong; Hammond, Rosemarie W; Liu, Qingzhong

    2016-03-01

    Little cherry virus 1 (LChV-1), associated with little cherry disease (LCD), has a significant impact on fruit quality of infected sweet cherry trees. We report the full genome sequence of an isolate of LChV-1 from Taian, China (LChV-1-TA), detected by small-RNA deep sequencing and amplified by overlapping RT-PCR. The LChV-1-TA genome was 16,932 nt in length and contained nine open reading frames (ORFs), with sequence identity at the overall genome level of 76%, 76%, and 78% to LChV-1 isolates Y10237 (UW2 isolate), EU715989 (ITMAR isolate) and JX669615 (V2356 isolate), respectively. Based on the phylogenetic analysis of HSP70h amino acid sequences of Closteroviridae family members, LChV-1-TA was grouped into a well-supported cluster with the members of the genus Velarivirus and was also closely related to other LChV-1 isolates. This is the first report of the complete nucleotide sequence of LChV-1 infecting sweet cherry in China. PMID:26733294

  2. Protease recognition sites in Bet v 1a are cryptic, explaining its slow processing relevant to its allergenicity

    PubMed Central

    Freier, Regina; Dall, Elfriede; Brandstetter, Hans

    2015-01-01

    Despite a high similarity with homologous protein families, only few proteins trigger an allergic immune response with characteristic TH2 polarization. This puzzling observation is illustrated by the major birch pollen allergen Bet v 1a and its hypoallergenic protein isoforms, e.g., Bet v 1d. Given the key role of proteolytic processing in antigen presentation and T cell polarization, we investigated the recognition of Bet v 1 isoforms by the relevant protease cathepsin S. We found that at moderately acidic pH values Bet v 1a bound to cathepsin S with significantly lower affinity and was more slowly cleaved than its hypoallergenic isoform Bet v 1d. Only at pH values ≤4.5 the known proteolytic cleavage sites in Bet v 1a became accessible, resulting in a strong increase in affinity towards cathepsin S. Antigen processing and class II MHC loading occurs at moderately acidic compartments where processing of Bet v 1a and Bet v 1d differs distinctly. This difference translates into low and high density class II MHC loading and subsequently in TH2 and TH1 polarization, respectively. PMID:26235974

  3. Complete nucleotide sequence of little cherry virus 1 (LChV-1) infecting sweet cherry in China

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little cherry virus 1 (LChV-1), associated with little cherry disease (LCD), has a significant impact on fruit quality of infected sweet cherry trees. We report the full genome sequence of an isolate of LChV-1 from China, detected by small RNA deep sequencing and amplified by overlapping RT-PCR. The...

  4. Dissociation between Neural Signatures of Stimulus and Choice in Population Activity of Human V1 during Perceptual Decision-Making

    PubMed Central

    Choe, Kyoung Whan; Blake, Randolph

    2014-01-01

    Primary visual cortex (V1) forms the initial cortical representation of objects and events in our visual environment, and it distributes information about that representation to higher cortical areas within the visual hierarchy. Decades of work have established tight linkages between neural activity occurring in V1 and features comprising the retinal image, but it remains debatable how that activity relates to perceptual decisions. An actively debated question is the extent to which V1 responses determine, on a trial-by-trial basis, perceptual choices made by observers. By inspecting the population activity of V1 from human observers engaged in a difficult visual discrimination task, we tested one essential prediction of the deterministic view: choice-related activity, if it exists in V1, and stimulus-related activity should occur in the same neural ensemble of neurons at the same time. Our findings do not support this prediction: while cortical activity signifying the variability in choice behavior was indeed found in V1, that activity was dissociated from activity representing stimulus differences relevant to the task, being advanced in time and carried by a different neural ensemble. The spatiotemporal dynamics of population responses suggest that short-term priors, perhaps formed in higher cortical areas involved in perceptual inference, act to modulate V1 activity prior to stimulus onset without modifying subsequent activity that actually represents stimulus features within V1. PMID:24523561

  5. Charge state and incident energy dependence of K X-ray emission as a function of target thickness for 50-165 MeV Cu ions incident on 11-250 μg/cm 2 Cu

    NASA Astrophysics Data System (ADS)

    Momoi, T.; Shima, K.; Umetani, K.; Moriyama, M.; Ishihara, T.; Mikumo, T.

    1986-05-01

    Thin self-supporting Cu targets in 11-250 μg/cm 2 thickness were bombarded with 50-165 MeV Cu qi+ ions (7 ⩽ qi⩽ 24) to investigate the target thickness dependence of inner shell vacancy production processes in the symmetric collision of Cu + Cu. Doppler-shifted projectile K X-rays were discriminated from the target K X-rays, and the projectile and target K X-ray yields were separately measured as a function of target thickness. The K X-ray yields emitted from the projectile and the target Cu atoms are strongly dependent on the projectile initial charge state and target thickness for all the investigated collision systems of Cu qi+ + Cu. From the observed K X-ray yields, K-shell vacancy production cross sections averaged over the target thickness t of projectile overlineσ KV and target overlineσ ∗KV were separately derived taking into account the fluorescence yield that can be estimated from the Kα X-ray energy shift. When the values of overlineσ KV and overlineσ ∗KV are extrapolated to zero foil thickness, the K shell vacancy formed in the collision has been found to be equally shared between projectile and target in a single collision. With the increase of penetration depth, however, the values of overlineσ ∗KV are greater than those of overlineσ KV presumably due to electron transfer of a target K electron to the projectile K vacancy. the evolution process of projectile excited states as a function of target thickness and the resulting variation of projectile and target K X-ray emissions are discussed.

  6. Low-voltage back-gated atmospheric pressure chemical vapor deposition based graphene-striped channel transistor with high-κ dielectric showing room-temperature mobility > 11,000 cm(2)/V·s.

    PubMed

    Smith, Casey; Qaisi, Ramy; Liu, Zhihong; Yu, Qingkai; Hussain, Muhammad Mustafa

    2013-07-23

    Utilization of graphene may help realize innovative low-power replacements for III-V materials based high electron mobility transistors while extending operational frequencies closer to the THz regime for superior wireless communications, imaging, and other novel applications. Device architectures explored to date suffer a fundamental performance roadblock due to lack of compatible deposition techniques for nanometer-scale dielectrics required to efficiently modulate graphene transconductance (gm) while maintaining low gate capacitance-voltage product (CgsVgs). Here we show integration of a scaled (10 nm) high-κ gate dielectric aluminum oxide (Al2O3) with an atmospheric pressure chemical vapor deposition (APCVD)-derived graphene channel composed of multiple 0.25 μm stripes to repeatedly realize room-temperature mobility of 11,000 cm(2)/V·s or higher. This high performance is attributed to the APCVD graphene growth quality, excellent interfacial properties of the gate dielectric, conductivity enhancement in the graphene stripes due to low tox/Wgraphene ratio, and scaled high-κ dielectric gate modulation of carrier density allowing full actuation of the device with only ±1 V applied bias. The superior drive current and conductance at Vdd = 1 V compared to other top-gated devices requiring undesirable seed (such as aluminum and poly vinyl alcohol)-assisted dielectric deposition, bottom gate devices requiring excessive gate voltage for actuation, or monolithic (nonstriped) channels suggest that this facile transistor structure provides critical insight toward future device design and process integration to maximize CVD-based graphene transistor performance. PMID:23777434

  7. Pregnane-10,2-carbolactones from a Hawaiian Marine Sponge in the Genus Myrmekioderma.

    PubMed

    Dai, Jingqiu; Yoshida, Wesley Y; Kelly, Michelle; Williams, Philip

    2016-05-27

    Four new pregnanes, 3β,4β-dihydroxy-17-methyl-17α-pregna-5,13-diene-10,2-carbolactone (1), 6β-chloro-3β-hydroxy-17-methyl-17α-pregna-4,13-diene-10,2-carbolactone (2), 3β-hydroxy-6β-methoxy-17-methyl-17α-pregna-4,13-diene-10,2-carbolactone (3), and 3β,6β-dihydroxy-17-methyl-17α-pregna-4,13-diene-10,2-carbolactone (4), were isolated from an undescribed species of Myrmekioderma Ehlers along with the known pregnane carbolactone (5). The structures of the new compounds were determined by spectroscopic methods and comparison with previously described compounds. Compound 5 showed almost 4-fold activation of pregnane X receptor, while 2 inhibited BACE1 with an IC50 value of 82 μM. PMID:27104967

  8. 42 CFR 10.2 - Summary of 340B Drug Pricing Program.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Summary of 340B Drug Pricing Program. 10.2 Section... 340B DRUG PRICING PROGRAM General Provisions § 10.2 Summary of 340B Drug Pricing Program. Section 340B...(a)(1) and 340B(a)(2)(A).Manufacturers participating in the 340B Drug Pricing Program (340B...

  9. 42 CFR 10.2 - Summary of 340B Drug Pricing Program.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Summary of 340B Drug Pricing Program. 10.2 Section... 340B DRUG PRICING PROGRAM General Provisions § 10.2 Summary of 340B Drug Pricing Program. Section 340B...(a)(1) and 340B(a)(2)(A). Manufacturers participating in the 340B Drug Pricing Program (340B...

  10. Outbursting Comet P/2010 V1 (Ikeya-Murakami): A Miniature Comet Holmes

    NASA Astrophysics Data System (ADS)

    Ishiguro, Masateru; Jewitt, David; Hanayama, Hidekazu; Usui, Fumihiko; Sekiguchi, Tomohiko; Yanagisawa, Kenshi; Kuroda, Daisuke; Yoshida, Michitoshi; Ohta, Kouji; Kawai, Nobuyuki; Miyaji, Takeshi; Fukushima, Hideo; Watanabe, Jun-ichi

    2014-05-01

    The short-period comet P/2010 V1 (Ikeya-Murakami, hereafter "V1") was discovered visually by two amateur astronomers. The appearance of the comet was peculiar, consisting of an envelope, a spherical coma near the nucleus and a tail extending in the anti-solar direction. We investigated the brightness and the morphological development of the comet by taking optical images with ground-based telescopes. Our observations show that V1 experienced a large-scale explosion between UT 2010 October 31 and November 3. The color of the comet was consistent with the Sun (g' - R C = 0.61 ± 0.20, R C - I C = 0.20 ± 0.20, and B - R C = 0.93 ± 0.25), suggesting that dust particles were responsible for the brightening. We used a dynamical model to understand the peculiar morphology, and found that the envelope consisted of small grains (0.3-1 μm) expanding at a maximum speed of 500 ± 40 m s-1, while the tail and coma were composed of a wider range of dust particle sizes (0.4-570 μm) and expansion speeds 7-390 m s-1. The total mass of ejecta is ~5 × 108 kg and kinetic energy ~5 × 1012 J. These values are much smaller than in the historic outburst of 17P/Holmes in 2007, but the energy per unit mass (1 × 104 J kg-1) is comparable. The energy per unit mass is about 10% of the energy released during the crystallization of amorphous water ice suggesting that crystallization of buried amorphous ice can supply the mass and energy of the outburst ejecta.

  11. Temperature-Dependent Vibrational Relaxation of NO(v=1) by O Atoms

    NASA Astrophysics Data System (ADS)

    Hwang, E. S.; Castle, K. J.; Dodd, J. A.

    2001-12-01

    For altitudes above about 80 km, oxygen molecules are increasingly dissociated by solar VUV absorption, and O atoms, together with O2 and N2, become a principal constituent of the atmosphere. Collisions of O with ground vibrational state NO efficiently excite NO(v=1), cooling the upper atmosphere by converting a portion of the ambient kinetic energy into 5.3-μ m IR emission which escapes into space. In recent years our group has worked to better characterize the vibrational energy transfer (VET) efficiencies for the NO(v)-O system. In our experiments vibrational relaxation rates are measured; they can be related to the corresponding uppumping rates through detailed balance. The experiment employs a cw microwave source to form O atoms, combined with photolysis of a trace amount of added NO2 to produce vibrationally excited NO. A double-jacketed quartz injector allows the introduction of O and NO2 into the reaction volume while minimizing wall-induced recombination and thermal decomposition, respectively. Oxygen atoms are detected through two-photon laser-induced fluorescence, cross-calibrated against a normalized O-atom signal resulting from photolysis of a known concentration of NO2. The experiment has been used to perform updated 295 K measurements for NO(v=1,2)-O relaxation, and 295-825 K measurements for NO(v=1)-O relaxation. A modest temperature dependence is observed. The variable temperature measurements provide key information for the accurate modeling of the lower thermospheric energy budget and IR radiant intensities. We also present associated quasiclassical trajectory calculations and TIME-GCM predictions of atmospheric temperature and density.

  12. The C-H Peripheral Stalk Base: A Novel Component in V1-ATPase Assembly

    PubMed Central

    Hildenbrand, Zacariah L.; Molugu, Sudheer K.; Stock, Daniela; Bernal, Ricardo A.

    2010-01-01

    Vacuolar ATPases (V-ATPases) are molecular machines responsible for creating electrochemical gradients and preserving pH-dependent cellular compartments by way of proton translocation across the membrane. V-ATPases employ a dynamic rotary mechanism that is driven by ATP hydrolysis and the central rotor stalk. Regulation of this rotational catalysis is the result of a reversible V1Vo-domain dissociation that is required to preserve ATP during instances of cellular starvation. Recently the method by which the free V1-ATPase abrogates the hydrolytic breakdown of ATP upon dissociating from the membrane has become increasingly clear. In this instance the central stalk subunit F adopts an extended conformation to engage in a bridging interaction tethering the rotor and stator components together. However, the architecture by which this mechanism is stabilized has remained ambiguous despite previous work. In an effort to elucidate the method by which the rotational catalysis is maintained, the architecture of the peripheral stalks and their respective binding interactions was investigated using cryo-electron microscopy. In addition to confirming the bridging interaction exuded by subunit F for the first time in a eukaryotic V-ATPase, subunits C and H are seen interacting with one another in a tight interaction that provides a base for the three EG peripheral stalks. The formation of a CE3G3H sub-assembly appears to be unique to the dissociated V-ATPase and highlights the stator architecture in addition to revealing a possible intermediate in the assembly mechanism of the free V1-ATPase. PMID:20838636

  13. A Convolutional Subunit Model for Neuronal Responses in Macaque V1

    PubMed Central

    Vintch, Brett; Movshon, J. Anthony

    2015-01-01

    The response properties of neurons in the early stages of the visual system can be described using the rectified responses of a set of self-similar, spatially shifted linear filters. In macaque primary visual cortex (V1), simple cell responses can be captured with a single filter, whereas complex cells combine a set of filters, creating position invariance. These filters cannot be estimated using standard methods, such as spike-triggered averaging. Subspace methods like spike-triggered covariance can recover multiple filters but require substantial amounts of data, and recover an orthogonal basis for the subspace in which the filters reside, rather than the filters themselves. Here, we assume a linear-nonlinear-linear-nonlinear (LN-LN) cascade model in which the first LN stage consists of shifted (“convolutional”) copies of a single filter, followed by a common instantaneous nonlinearity. We refer to these initial LN elements as the “subunits” of the receptive field, and we allow two independent sets of subunits, each with its own filter and nonlinearity. The second linear stage computes a weighted sum of the subunit responses and passes the result through a final instantaneous nonlinearity. We develop a procedure to directly fit this model to electrophysiological data. When fit to data from macaque V1, the subunit model significantly outperforms three alternatives in terms of cross-validated accuracy and efficiency, and provides a robust, biologically plausible account of receptive field structure for all cell types encountered in V1. SIGNIFICANCE STATEMENT We present a new subunit model for neurons in primary visual cortex that significantly outperforms three alternative models in terms of cross-validated accuracy and efficiency, and provides a robust and biologically plausible account of the receptive field structure in these neurons across the full spectrum of response properties. PMID:26538653

  14. Mechanism of osthole inhibition of vascular Ca(v)1.2 current.

    PubMed

    Fusi, Fabio; Sgaragli, Giampietro; Ha, Le Minh; Cuong, Nguyen Manh; Saponara, Simona

    2012-04-01

    Osthole is a coumarin extracted from Cnidium monnieri (L.) Cusson. The medicinal plant is widely used in Vietnamese as well as Chinese traditional medicine as a vasodilating and antihypertensive agent. Here we have tested the proposition that the block of Ca(v)1.2 channels is mainly responsible for its vascular activity. An in-depth analysis of the effect of osthole on Ca(v)1.2 current (I(Ca1.2)) was performed in rat tail artery myocytes using the whole-cell patch-clamp method. Osthole decreased I(Ca1.2) in a concentration- and voltage-dependent manner. At holding potentials of -50 and -80mV, the pIC(50) values were 4.78±0.07 and 4.36±0.08, respectively; the latter corresponded to the drug apparent dissociation constant for resting channels, K(R), of 47.8μM. Osthole speeded up the inactivation kinetics of I(Ca1.2) and shifted the voltage dependence of the inactivation curve to more negative potentials in a concentration-dependent manner, with an apparent dissociation constant for inactivated channels (K(I)) of 6.88μM. Block of I(Ca1.2) was frequency-dependent and the rate of recovery from inactivation was slowed down. In conclusion, osthole is a vascular Ca(v)1.2 channel antagonist stabilizing the channel in its inactivated state. This mechanism may account for the systolic blood pressure reduction induced by the drug in animal models of hypertension and points to osthole as a lead for the development of novel antihypertensive agents. PMID:22329900

  15. Outbursting comet P/2010 V1 (Ikeya-Murakami): A miniature comet Holmes

    SciTech Connect

    Ishiguro, Masateru; Jewitt, David; Hanayama, Hidekazu; Miyaji, Takeshi; Fukushima, Hideo; Watanabe, Jun-ichi; Usui, Fumihiko; Sekiguchi, Tomohiko; Yanagisawa, Kenshi; Kuroda, Daisuke; Yoshida, Michitoshi; Ohta, Kouji; Kawai, Nobuyuki

    2014-05-20

    The short-period comet P/2010 V1 (Ikeya-Murakami, hereafter {sup V}1{sup )} was discovered visually by two amateur astronomers. The appearance of the comet was peculiar, consisting of an envelope, a spherical coma near the nucleus and a tail extending in the anti-solar direction. We investigated the brightness and the morphological development of the comet by taking optical images with ground-based telescopes. Our observations show that V1 experienced a large-scale explosion between UT 2010 October 31 and November 3. The color of the comet was consistent with the Sun (g' – R {sub C} = 0.61 ± 0.20, R {sub C} – I {sub C} = 0.20 ± 0.20, and B – R {sub C} = 0.93 ± 0.25), suggesting that dust particles were responsible for the brightening. We used a dynamical model to understand the peculiar morphology, and found that the envelope consisted of small grains (0.3-1 μm) expanding at a maximum speed of 500 ± 40 m s{sup –1}, while the tail and coma were composed of a wider range of dust particle sizes (0.4-570 μm) and expansion speeds 7-390 m s{sup –1}. The total mass of ejecta is ∼5 × 10{sup 8} kg and kinetic energy ∼5 × 10{sup 12} J. These values are much smaller than in the historic outburst of 17P/Holmes in 2007, but the energy per unit mass (1 × 10{sup 4} J kg{sup –1}) is comparable. The energy per unit mass is about 10% of the energy released during the crystallization of amorphous water ice suggesting that crystallization of buried amorphous ice can supply the mass and energy of the outburst ejecta.

  16. Geologic Map of the V-1 Snegurochka Planitia Quadrangle: Progress Report

    NASA Technical Reports Server (NTRS)

    Hurwitz, Debra M.

    2008-01-01

    Geologic mapping of Snegurochka Planitia (V-1) reveals a complex stratigraphy of tectonic and volcanic features that can provide insight into the geologic history of Venus and Archean Earth [1,2] including 1) crustal thickening environments and processes, 2) the nature of diapirism, 3) the nature and origin of deformation belts, and 4) the origin and context of regional plains-forming volcanism. This abstract presents our progress in mapping the spatial and stratigraphic relationships of these features in the region surrounding the north pole of Venus.

  17. Serological Profile of Torque Teno Sus Virus Species 1 (TTSuV1) in Pigs and Antigenic Relationships between Two TTSuV1 Genotypes (1a and 1b), between Two Species (TTSuV1 and -2), and between Porcine and Human Anelloviruses

    PubMed Central

    Huang, Yao-Wei; Harrall, Kylie K.; Dryman, Barbara A.; Opriessnig, Tanja; Vaughn, Eric M.; Roof, Michael B.

    2012-01-01

    The family Anelloviridae includes human and animal torque teno viruses (TTVs) with extensive genetic diversity. The antigenic diversity among anelloviruses has never been assessed. Using torque teno sus virus (TTSuV) as a model, we describe here the first investigation of the antigenic relationships among different anelloviruses. Using a TTSuV genotype 1a (TTSuV1a) or TTSuV1b enzyme-linked immunosorbent assay (ELISA) based on the respective putative ORF1 capsid antigen and TTSuV1-specific real-time PCR, the combined serological and virological profile of TTSuV1 infection in pigs was determined and compared with that of TTSuV2. TTSuV1 is likely not associated with porcine circovirus-associated disease (PCVAD), because both the viral loads and antibody levels were not different between affected and unaffected pigs and because there was no synergistic effect of concurrent PCV2/TTSuV1 infections. We did observe a higher correlation of IgG antibody levels between anti-TTSuV1a and -TTSuV1b than between anti-TTSuV1a or -1b and anti-TTSuV2 antibodies in these sera, implying potential antigenic cross-reactivity. To confirm this, rabbit antisera against the putative capsid proteins of TTSuV1a, TTSuV1b, or TTSuV2 were generated, and the antigenic relationships among these TTSuVs were analyzed by an ELISA and by an immunofluorescence assay (IFA) using PK-15 cells transfected with one of the three TTSuV ORF1 constructs. The results demonstrate antigenic cross-reactivity between the two genotypes TTSuV1a and TTSuV1b but not between the two species TTSuV1a or -1b and TTSuV2. Furthermore, an anti-genogroup 1 human TTV antiserum did not react with any of the three TTSuV antigens. These results have important implications for an understanding of the diversity of anelloviruses as well as for the classification and vaccine development of TTSuVs. PMID:22811540

  18. Vasopressin eliminates the expression of familiar odor bias in neonatal female mice through V1aR

    PubMed Central

    Hammock, Elizabeth A.D.; Law, Caitlin S.; Levitt, Pat

    2014-01-01

    Summary V1aR has a well established role in the neural regulation of adult mammalian social behavior. The role of V1aR in developmentally emerging social behavior is less well understood. We mapped V1aR at post-natal day 8 (P8) and demonstrate developmentally-specific expression in the neocortex and hippocampus. We tested the ability of male and female C57BL/6J mice to show orienting bias to a familiar odor at this age. We demonstrate that females, but not males, show an orienting bias for odors previously paired with the mother, which is eliminated by V1aR signaling. Arginine-vasopressin (AVP) and the vasopressin V1a receptor (V1aR) acting within the forebrain are involved in social behavior in adult animals. Much less is known about the function of V1aR in neurobehavioral development. In the present study, at post-natal day 8 (P8) in neonatal C57BL/6J mice, we map V1aR and use an olfactory exposure paradigm to assess a role for V1aR on olfactory preferences. In addition to V1aR in the lateral septum and ventral tegmental area, we observe V1aR in the neocortex and hippocampus, not typically observed in adult mice, implicating a developmental sensitive period for V1aR to modulate these brain areas in an experience-dependent manner. Males and females were tested on P8 for orienting preferences after exposure to a non-social odor, presented either when the mother was in the home cage (contingent) or when the mother had been removed from the home cage (not contingent). Wild-type female mice show a selective orienting bias toward the exposed odor, but only in the contingent condition. Males did not show orienting bias after either training condition. Female Avpr1a-/- mice showed strong familiar odor bias, regardless of the training condition. This finding led us to test the ability of AVP to diminish odor bias in females. Central application of AVP eliminated odor bias in Avpr1a+/+, but not Avpr1a-/- female mice. Together, these data indicate that AVP acting at V1a

  19. Developmental pathway for potent V1V2-directed HIV-neutralizing antibodies.

    PubMed

    Doria-Rose, Nicole A; Schramm, Chaim A; Gorman, Jason; Moore, Penny L; Bhiman, Jinal N; DeKosky, Brandon J; Ernandes, Michael J; Georgiev, Ivelin S; Kim, Helen J; Pancera, Marie; Staupe, Ryan P; Altae-Tran, Han R; Bailer, Robert T; Crooks, Ema T; Cupo, Albert; Druz, Aliaksandr; Garrett, Nigel J; Hoi, Kam H; Kong, Rui; Louder, Mark K; Longo, Nancy S; McKee, Krisha; Nonyane, Molati; O'Dell, Sijy; Roark, Ryan S; Rudicell, Rebecca S; Schmidt, Stephen D; Sheward, Daniel J; Soto, Cinque; Wibmer, Constantinos Kurt; Yang, Yongping; Zhang, Zhenhai; Mullikin, James C; Binley, James M; Sanders, Rogier W; Wilson, Ian A; Moore, John P; Ward, Andrew B; Georgiou, George; Williamson, Carolyn; Abdool Karim, Salim S; Morris, Lynn; Kwong, Peter D; Shapiro, Lawrence; Mascola, John R

    2014-05-01

    Antibodies capable of neutralizing HIV-1 often target variable regions 1 and 2 (V1V2) of the HIV-1 envelope, but the mechanism of their elicitation has been unclear. Here we define the developmental pathway by which such antibodies are generated and acquire the requisite molecular characteristics for neutralization. Twelve somatically related neutralizing antibodies (CAP256-VRC26.01-12) were isolated from donor CAP256 (from the Centre for the AIDS Programme of Research in South Africa (CAPRISA)); each antibody contained the protruding tyrosine-sulphated, anionic antigen-binding loop (complementarity-determining region (CDR) H3) characteristic of this category of antibodies. Their unmutated ancestor emerged between weeks 30-38 post-infection with a 35-residue CDR H3, and neutralized the virus that superinfected this individual 15 weeks after initial infection. Improved neutralization breadth and potency occurred by week 59 with modest affinity maturation, and was preceded by extensive diversification of the virus population. HIV-1 V1V2-directed neutralizing antibodies can thus develop relatively rapidly through initial selection of B cells with a long CDR H3, and limited subsequent somatic hypermutation. These data provide important insights relevant to HIV-1 vaccine development. PMID:24590074

  20. Looming sensitive cortical regions without V1 input: evidence from a patient with bilateral cortical blindness

    PubMed Central

    Hervais-Adelman, Alexis; Legrand, Lore B.; Zhan, Minye; Tamietto, Marco; de Gelder, Beatrice; Pegna, Alan J.

    2015-01-01

    Fast and automatic behavioral responses are required to avoid collision with an approaching stimulus. Accordingly, looming stimuli have been found to be highly salient and efficient attractors of attention due to the implication of potential collision and potential threat. Here, we address the question of whether looming motion is processed in the absence of any functional primary visual cortex and consequently without awareness. For this, we investigated a patient (TN) suffering from complete, bilateral damage to his primary visual cortex. Using an fMRI paradigm, we measured TN's brain activation during the presentation of looming, receding, rotating, and static point lights, of which he was unaware. When contrasted with other conditions, looming was found to produce bilateral activation of the middle temporal areas, as well as the superior temporal sulcus and inferior parietal lobe (IPL). The latter are generally thought to be involved in multisensory processing of motion in extrapersonal space, as well as attentional capture and saliency. No activity was found close to the lesioned V1 area. This demonstrates that looming motion is processed in the absence of awareness through direct subcortical projections to areas involved in multisensory processing of motion and saliency that bypass V1. PMID:26557059

  1. Synchronization Dynamics in Response to Plaid Stimuli in Monkey V1

    PubMed Central

    Lima, Bruss; Singer, Wolf; Chen, Nan-Hui

    2010-01-01

    Gamma synchronization has generally been associated with grouping processes in the visual system. Here, we examine in monkey V1 whether gamma oscillations play a functional role in segmenting surfaces of plaid stimuli. Local field potentials (LFPs) and spiking activity were recorded simultaneously from multiple sites in the opercular and calcarine regions while the monkeys were presented with sequences of single and superimposed components of plaid stimuli. In accord with the previous studies, responses to the single components (gratings) exhibited strong and sustained gamma-band oscillations (30–65 Hz). The superposition of the second component, however, led to profound changes in the temporal structure of the responses, characterized by a drastic reduction of gamma oscillations in the spiking activity and systematic shifts to higher frequencies in the LFP (∼10% increase). Comparisons between cerebral hemispheres and across monkeys revealed robust subject-specific spectral signatures. A possible interpretation of our results may be that single gratings induce strong cooperative interactions among populations of cells that share similar response properties, whereas plaids lead to competition. Overall, our results suggest that the functional architecture of the cortex is a major determinant of the neuronal synchronization dynamics in V1. PMID:19812238

  2. Monocular activation of V1 and V2 in amblyopic adults measured with fMRI

    PubMed Central

    Conner, Ian P; Odom, J Vernon; Schwartz, Terry L; Mendola, Janine D

    2007-01-01

    Purpose Although previous neuroimaging efforts clearly indicate visual cortical dysfunction in adults with amblyopia, the extent of abnormalities remains unclear. Methods This fMRI study directly compared activity in visual cortex produced by monocular stimulation in 18 adults (6 esotropic strabismics, 6 anisometropes, and 6 controls). Measures were made in three cortical regions of interest, individually defined using standard retinotopic mapping techniques in the nonamblyopic eye, corresponding to extrafoveal V1, extrafoveal V2, and the foveal representation at the occipital pole. Fixation stability was monitored and found not to differ significantly between subject groups. Results Overall results showed depressed fMRI signal magnitude for amblyopic eyes compared with sound eyes, although a few subjects did not show this trend. Assessment of the spatial extent of activation using an ocular dominance index did show significantly larger interocular differences for both strabismics and anisometropes compared with control subjects for whom eye dominance was carefully defined. In addition, both amblyopic groups showed less cortical area able to be significantly driven by either eye. The magnitude of these effects was equivalent in V1, V2, and the foveal representation, as well as between amblyopic groups. No difference was detected in the strength of signal from the nasal versus temporal retina in either amblyopic group. Conclusions Asymmetries in magnitude of monocular activation do occur in subjects with amblyopia, but these basic measures are limited in terms of sensitivity for mild to moderate amblyopia and for specificity between subtypes. PMID:17434776

  3. Adaptation of the simple or complex nature of V1 receptive fields to visual statistics.

    PubMed

    Fournier, Julien; Monier, Cyril; Pananceau, Marc; Frégnac, Yves

    2011-08-01

    Receptive fields in primary visual cortex (V1) are categorized as simple or complex, depending on their spatial selectivity to stimulus contrast polarity. We studied the dependence of this classification on visual context by comparing, in the same cell, the synaptic responses to three classical receptive field mapping protocols: sparse noise, ternary dense noise and flashed Gabor noise. Intracellular recordings revealed that the relative weights of simple-like and complex-like receptive field components were scaled so as to make the same receptive field more simple-like with dense noise stimulation and more complex-like with sparse or Gabor noise stimulations. However, once these context-dependent receptive fields were convolved with the corresponding stimulus, the balance between simple-like and complex-like contributions to the synaptic responses appeared to be invariant across input statistics. This normalization of the linear/nonlinear input ratio suggests a previously unknown form of homeostatic control of V1 functional properties, optimizing the network nonlinearities to the statistical structure of the visual input. PMID:21765424

  4. V1 neurons respond differently to object motion versus motion from eye movements

    PubMed Central

    Troncoso, Xoana G.; McCamy, Michael B.; Jazi, Ali Najafian; Cui, Jie; Otero-Millan, Jorge; Macknik, Stephen L.; Costela, Francisco M.; Martinez-Conde, Susana

    2015-01-01

    How does the visual system differentiate self-generated motion from motion in the external world? Humans can discern object motion from identical retinal image displacements induced by eye movements, but the brain mechanisms underlying this ability are unknown. Here we exploit the frequent production of microsaccades during ocular fixation in the primate to compare primary visual cortical responses to self-generated motion (real microsaccades) versus motion in the external world (object motion mimicking microsaccades). Real and simulated microsaccades were randomly interleaved in the same viewing condition, thereby producing equivalent oculomotor and behavioural engagement. Our results show that real microsaccades generate biphasic neural responses, consisting of a rapid increase in the firing rate followed by a slow and smaller-amplitude suppression that drops below baseline. Simulated microsaccades generate solely excitatory responses. These findings indicate that V1 neurons can respond differently to internally and externally generated motion, and expand V1's potential role in information processing and visual stability during eye movements. PMID:26370518

  5. CaV1.3 as pacemaker channels in adrenal chromaffin cells: specific role on exo- and endocytosis?

    PubMed

    Comunanza, Valentina; Marcantoni, Andrea; Vandael, David H; Mahapatra, Satyajit; Gavello, Daniela; Carabelli, Valentina; Carbone, Emilio

    2010-01-01

    Voltage-gated L-type calcium channels (LTCCs) are expressed in adrenal chromaffin cells. Besides shaping the action potential (AP), LTCCs are involved in the excitation-secretion coupling controlling catecholamine release and in Ca (2+) -dependent vesicle retrieval. Of the two LTCCs expressed in chromaffin cells (CaV1.2 and CaV1.3), CaV1.3 possesses the prerequisites for pacemaking spontaneously firing cells: low-threshold, steep voltage-dependence of activation and slow inactivation. By using CaV1 .3 (-/-) KO mice and the AP-clamp it has been possible to resolve the time course of CaV1.3 pacemaker currents, which is similar to that regulating substantia nigra dopaminergic neurons. In mouse chromaffin cells CaV1.3 is coupled to fast-inactivating BK channels within membrane nanodomains and controls AP repolarization. The ability to carry subthreshold Ca (2+) currents and activate BK channels confers to CaV1.3 the unique feature of driving Ca (2+) loading during long interspike intervals and, possibly, to control the Ca (2+) -dependent exocytosis and endocytosis processes that regulate catecholamine secretion and vesicle recycling. PMID:21084859

  6. Integrate-and-fire vs Poisson models of LGN input to V1 cortex: noisier inputs reduce orientation selectivity.

    PubMed

    Lin, I-Chun; Xing, Dajun; Shapley, Robert

    2012-12-01

    One of the reasons the visual cortex has attracted the interest of computational neuroscience is that it has well-defined inputs. The lateral geniculate nucleus (LGN) of the thalamus is the source of visual signals to the primary visual cortex (V1). Most large-scale cortical network models approximate the spike trains of LGN neurons as simple Poisson point processes. However, many studies have shown that neurons in the early visual pathway are capable of spiking with high temporal precision and their discharges are not Poisson-like. To gain an understanding of how response variability in the LGN influences the behavior of V1, we study response properties of model V1 neurons that receive purely feedforward inputs from LGN cells modeled either as noisy leaky integrate-and-fire (NLIF) neurons or as inhomogeneous Poisson processes. We first demonstrate that the NLIF model is capable of reproducing many experimentally observed statistical properties of LGN neurons. Then we show that a V1 model in which the LGN input to a V1 neuron is modeled as a group of NLIF neurons produces higher orientation selectivity than the one with Poisson LGN input. The second result implies that statistical characteristics of LGN spike trains are important for V1's function. We conclude that physiologically motivated models of V1 need to include more realistic LGN spike trains that are less noisy than inhomogeneous Poisson processes. PMID:22684587

  7. Sodium channel Na(v)1.6 is expressed along nonmyelinated axons and it contributes to conduction.

    PubMed

    Black, Joel A; Renganathan, Muthukrishnan; Waxman, Stephen G

    2002-09-30

    Nodes of Ranvier in myelinated fibers exhibit a complex architecture in which specific molecules organize in distinct nodal, paranodal and juxtaparanodal domains to support saltatory conduction. The clustering of sodium channel Na(v)1.6 within the nodal membrane has led to its identification as the major nodal sodium channel in myelinated axons. In contrast, much less is known about the molecular architecture of nonmyelinated fibers. In the present study, Na(v)1.6 is shown to be a significant component of nonmyelinated PNS axons. In DRG C-fibers, Na(v)1.6 is distributed continuously from terminal receptor fields in the skin to the dorsal root entry zone in the spinal cord. Na(v)1.6 is also present in the nerve endings of corneal C-fibers. Analysis of compound action potential recordings from wildtype and med mice, which lack Na(v)1.6, indicates that Na(v)1.6 plays a functional role in nonmyelinated fibers where it contributes to action potential conduction. These observations indicate that Na(v)1.6 functions not only in saltatory conduction in myelinated axons but also in continuous conduction in nonmyelinated axons. PMID:12399104

  8. TASP0434299: A Novel Pyridopyrimidin-4-One Derivative as a Radioligand for Vasopressin V1B Receptor.

    PubMed

    Koga, Kazumi; Yoshinaga, Mitsukane; Uematsu, Yoshikatsu; Nagai, Yuji; Miyakoshi, Naoki; Shimoda, Yoko; Fujinaga, Masayuki; Minamimoto, Takafumi; Zhang, Ming-Rong; Higuchi, Makoto; Ohtake, Norikazu; Suhara, Tetsuya; Chaki, Shigeyuki

    2016-06-01

    A novel pyridopyrimidin-4-one derivative, N-tert-butyl-2-[2-(3-methoxyphenyl)-6-[3-(morpholin-4-yl)propoxy]-4-oxopyrido[2,3-d]pyrimidin-3(4H)-yl]acetamide (TASP0434299), was characterized as a radioligand candidate for arginine vasopressin 1B (V1B) receptor. TASP0434299 exhibited high binding affinities for human and rat V1B receptors with IC50 values of 0.526 and 0.641 nM, respectively, and potent antagonistic activity at the human V1B receptor with an IC50 value of 0.639 nM without apparent binding affinities for other molecules at 1 μM. [(3)H]TASP0434299 bound to membranes expressing the human V1B receptor as well as those prepared from the rat anterior pituitary in a saturable manner. The binding of [(3)H]TASP0434299 to the membranes was dose-dependently displaced by several ligands for the V1B receptor. In addition, the intravenous administration of [(3)H]TASP0434299 to rats produced a saturable radioactive accumulation in the anterior pituitary where the V1B receptor is enriched, and it was dose-dependently blocked by the oral administration of 2-[2-(3-chloro-4-fluorophenyl)-6-[3-(morpholin-4-yl)propoxy]-4-oxopyrido[2,3-d]pyrimidin-3(4H)-yl]-N-isopropylacetamide hydrochloride, a V1B receptor antagonist, indicating that [(3)H]TASP0434299 can be used as an in vivo radiotracer to measure the occupancy of the V1B receptor. Finally, the intravenous administration of [(11)C]TASP0434299 provided positron emission tomographic images of the V1B receptor in the pituitary in an anesthetized monkey, and the signal was blocked by pretreatment with an excess of unlabeled TASP0434299. These results indicate that radiolabeled TASP0434299 is the first radioligand to be capable of quantifying the V1B receptor selectively in both in vitro and in vivo studies and will provide a clinical biomarker for determining the occupancy of the V1B receptor during drug development or for monitoring the levels of the V1B receptor in diseased conditions. PMID:27029585

  9. Roles of Voltage-Gated Tetrodotoxin-Sensitive Sodium Channels NaV1.3 and NaV1.7 in Diabetes and Painful Diabetic Neuropathy.

    PubMed

    Yang, Linlin; Li, Quanmin; Liu, Xinming; Liu, Shiguang

    2016-01-01

    Diabetes mellitus (DM) is a common chronic medical problem worldwide; one of its complications is painful peripheral neuropathy, which can substantially erode quality of life and increase the cost of management. Despite its clinical importance, the pathogenesis of painful diabetic neuropathy (PDN) is complex and incompletely understood. Voltage-gated sodium channels (VGSCs) link many physiological processes to electrical activity by controlling action potentials in all types of excitable cells. Two isoforms of VGSCs, NaV1.3 and NaV1.7, which are encoded by the sodium voltage-gated channel alpha subunit 3 and 9 (Scn3A and Scn9A) genes, respectively, have been identified in both peripheral nociceptive neurons of dorsal root ganglion (DRG) and pancreatic islet cells. Recent advances in our understanding of tetrodotoxin-sensitive (TTX-S) sodium channels NaV1.3 and NaV1.7 lead to the rational doubt about the cause-effect relation between diabetes and painful neuropathy. In this review, we summarize the roles of NaV1.3 and NaV1.7 in islet cells and DRG neurons, discuss the link between DM and painful neuropathy, and present a model, which may provide a starting point for further studies aimed at identifying the mechanisms underlying diabetes and painful neuropathy. PMID:27608006

  10. Design and analysis report for the RL10-2B breadboard low thrust engine

    NASA Technical Reports Server (NTRS)

    Brown, J. R.; Foust, R. R.; Galler, D. E.; Kanic, P. G.; Kmiec, T. D.; Limerick, C. D.; Peckham, R. J.; Swartwout, T.

    1984-01-01

    The breadboard low thrust RL10-2B engine is described. A summary of the analysis and design effort to define the multimode thrust concept applicable to the requirements for the upper stage vehicles is provided. Baseline requirements were established for operation of the RL10-2B engine under the following conditions: (1) tank head idle at low propellant tank pressures without vehicle propellant conditioning or settling thrust; (2) pumped idle at a ten percent thrust level for low G deployment and/or vehicle tank pressurization; and (3) full thrust (15,000 lb.). Several variations of the engine configuration were investigated and results of the analyses are included.

  11. Collisional vibrational energy transfer of OH (A 2Sigma + , v'=1)

    NASA Astrophysics Data System (ADS)

    Williams, Leah R.; Crosley, David R.

    1996-05-01

    Vibrational energy transfer (VET) and quenching of the v'=1 level of A 2Σ+ OH have been studied using laser-induced fluorescence in a discharge flow cell at room temperature. VET cross sections (Å2) are N2, 30.1±2.8; O2, 2.8±0.3; Ar, 0.56±0.05; H2O, 8.6±0.6. The rotational energy distribution in v'=0 following the VET event was determined for nine colliders. It is nonthermal, generally populating high rotational levels. There are three broad categories of colliders that cause varying degrees of vibrational to rotational energy transfer; H2, D2, and CH4 show the least; N2, CO2, CF4, and N2O more; and O2 and Ar the most, with about one-third of the vibrational energy appearing as OH rotation.

  12. Insulator to Correlated Metal Transition in V1−xMoxO2

    SciTech Connect

    Holman, K.; McQueen, T; Williams, A; Klimczuk, T; Stephens, P; Zandbergen, H; Xu, Q; Ronning, F; Cava, R

    2009-01-01

    Although many materials display the transition from insulating to metallic behavior on doping, only a few, such as VO2, have the right combination of crystal structure and physical properties to serve as model systems. Here we report the electronic and structural characteristics of the insulator to metal transition in V1-xMoxO2, which we have studied over the range 0.0=x=0.50 through characterization of the electrical resistivity, magnetic susceptibility, specific heat, and average- and short-range crystal structures. We find that metal-metal pairing exists in small domains in the doped metallic phases and an unexpected phenomenology for the crossover between a Curie-Weiss insulating regime and an intermediate mass metallic regime. An electronic phase diagram is presented.

  13. Negative functional MRI response correlates with decreases in neuronal activity in monkey visual area V1.

    PubMed

    Shmuel, Amir; Augath, Mark; Oeltermann, Axel; Logothetis, Nikos K

    2006-04-01

    Most functional brain imaging studies use task-induced hemodynamic responses to infer underlying changes in neuronal activity. In addition to increases in cerebral blood flow and blood oxygenation level-dependent (BOLD) signals, sustained negative responses are pervasive in functional imaging. The origin of negative responses and their relationship to neural activity remain poorly understood. Through simultaneous functional magnetic resonance imaging and electrophysiological recording, we demonstrate a negative BOLD response (NBR) beyond the stimulated regions of visual cortex, associated with local decreases in neuronal activity below spontaneous activity, detected 7.15 +/- 3.14 mm away from the closest positively responding region in V1. Trial-by-trial amplitude fluctuations revealed tight coupling between the NBR and neuronal activity decreases. The NBR was associated with comparable decreases in local field potentials and multiunit activity. Our findings indicate that a significant component of the NBR originates in neuronal activity decreases. PMID:16547508

  14. CO (v = 1-0) emission in the molecular shock regions of OMC-1

    NASA Technical Reports Server (NTRS)

    Grasdalen, G. L.; Hackwell, John A.; Lynch, David K.; Russell, Ray W.

    1992-01-01

    Using the new Aerospace spectrometer on the Kuiper Airborne Observatory, we have obtained observations of the molecular shocks associated with OMC-1. Unexpectedly these observations reveal (b = 1-0) emission from CO at 4.6 microns superposed on a strong continuum. Our observations strongly suggest that both the emission feature and the continuum are produced in molecular shocks. Since the (v = 1-0) band of CO is only excited in high-velocity shocks, we may be observing for the first time the primary driving mechanism in these regions. Even if these features are produced by scattering, the characteristics will provide new constraints on the conditions in and the geometry of the shock regions.

  15. A User's Manual for MASH V1.5 - A Monte Carlo Adjoint Shielding Code System

    SciTech Connect

    C. O. Slater; J. M. Barnes; J. O. Johnson; J.D. Drischler

    1998-10-01

    The Monte Carlo ~djoint ~ielding Code System, MASH, calculates neutron and gamma- ray environments and radiation protection factors for armored military vehicles, structures, trenches, and other shielding configurations by coupling a forward discrete ordinates air- over-ground transport calculation with an adjoint Monte Carlo treatment of the shielding geometry. Efficiency and optimum use of computer time are emphasized. The code system includes the GRTUNCL and DORT codes for air-over-ground transport calculations, the MORSE code with the GIFT5 combinatorial geometry package for adjoint shielding calculations, and several peripheral codes that perform the required data preparations, transformations, and coupling functions. The current version, MASH v 1.5, is the successor to the original MASH v 1.0 code system initially developed at Oak Ridge National Laboratory (ORNL). The discrete ordinates calculation determines the fluence on a coupling surface surrounding the shielding geometry due to an external neutron/gamma-ray source. The Monte Carlo calculation determines the effectiveness of the fluence at that surface in causing a response in a detector within the shielding geometry, i.e., the "dose importance" of the coupling surface fluence. A coupling code folds the fluence together with the dose importance, giving the desired dose response. The coupling code can determine the dose response as a function of the shielding geometry orientation relative to the source, distance from the source, and energy response of the detector. This user's manual includes a short description of each code, the input required to execute the code along with some helpful input data notes, and a representative sample problem.

  16. Atherosclerosis Susceptibility in Mice Is Independent of the V1 Immunoglobulin Heavy Chain Gene

    PubMed Central

    Centa, Monica; Gruber, Sabrina; Nilsson, Daniel; Polyzos, Konstantinos A.; Johansson, Daniel K.; Hansson, Göran K.; Ketelhuth, Daniel F.J.; Binder, Christoph J.

    2016-01-01

    Objective— The V1 (VHS107.1.42) immunoglobulin heavy chain gene is thought to be critical in producing IgM natural antibodies of the T15-idiotype that protect against both atherosclerosis and infection from Streptococcus pneumoniae. Our aim was to determine whether genetic loss of the V1 gene increased atherosclerotic plaque burden in vivo because of a reduction in the T15-idiotype or other atheroprotective antibodies. Approach and Results— We crossed VHS107.1.42-deficient mice with the atherosclerosis-prone Apoe−/− and Ldlr−/− strains. Although these double knockout strains manifested no defects in B-cell development, we did observe a substantial reduction in early immune responses against phosphocholine after immunization. However, the titers of plasma antibodies reacting against defined atherosclerotic antigens such as oxidized low-density lipoprotein, as well as the T15-idiotype, were unaffected by loss of the VHS107.1.42 gene in hypercholesterolemic mice. Furthermore, we observed no increase in atherosclerotic lesion formation, either within the aortic arch or aortic root. Robust deposition of IgM within atherosclerotic plaques could also be readily observed in both control and experimental mice. Conclusions— Our data indicate that IgM-dependent protection against atherosclerosis is unlikely to be dependent on antibodies that use the VHS107.1.42 gene, in contrast to the acute immune response conferred by this heavy chain in the response to phosphocholine and in providing resistance against lethal S pneumoniae infection. PMID:26564818

  17. A mathematical model of color and orientation processing in V1.

    PubMed

    Smirnova, Elena Y; Chizhkova, Ekaterina A; Chizhov, Anton V

    2015-10-01

    Orientation processing in the primary visual cortex (V1) has been experimentally investigated in detail and reproduced in models, while color processing remains unclear. Thus, we have constructed a mathematical model of color and orientation processing in V1. The model is mainly based on the following experimental evidence concerning color blobs: A blob contains overlapping neuronal patches activated by different hues, so that each blob represents a full gamut of hue and might be structured with a loop (Xiao et al. in NeuroImage 35:771-786, 2007). The proposed model describes a set of orientation hypercolumns and color blobs, in which color and orientation preferences are represented by the poloidal and toroidal angles of a torus, correspondingly. The model consists of color-insensitive (CI) and color-sensitive (CS) neuronal populations, which are described by a firing-rate model. The set of CI neurons is described by the classical ring model (Ben-Yishai et al. in Proc Natl Acad Sci USA 92:3844-3848, 1995) with recurrent connections in the orientation space; similarly, the set of CS neurons is described in the color space and also receives input from CI neurons of the same orientation preference. The model predictions are as follows: (1) responses to oriented color stimuli are significantly stronger than those to non-oriented color stimuli; (2) the activity of CS neurons in total is higher than that of CI neurons; (3) a random color can be illusorily perceived in the case of gray oriented stimulus; (4) in response to two-color stimulus in the marginal phase, the network chooses either one of the colors or the intermediate color; (5) input to a blob has rather continual representation of a hue than discrete one (with two narrowly tuned opponent signals). PMID:26330361

  18. Tuning dissimilarity explains short distance decline of spontaneous spike correlation in macaque V1.

    PubMed

    Chu, Cheng C J; Chien, Ping F; Hung, Chou P

    2014-03-01

    Fast spike correlation is a signature of neural ensemble activity thought to underlie perception, cognition, and action. To relate spike correlation to tuning and other factors, we focused on spontaneous activity because it is the common 'baseline' across studies that test different stimuli, and because variations in correlation strength are much larger across cell pairs than across stimuli. Is the probability of spike correlation between two neurons a graded function of lateral cortical separation, independent of functional tuning (e.g. orientation preferences)? Although previous studies found a steep decline in fast spike correlation with horizontal cortical distance, we hypothesized that, at short distances, this decline is better explained by a decline in receptive field tuning similarity. Here we measured macaque V1 tuning via parametric stimuli and spike-triggered analysis, and we developed a generalized linear model (GLM) to examine how different combinations of factors predict spontaneous spike correlation. Spike correlation was predicted by multiple factors including color, spatiotemporal receptive field, spatial frequency, phase and orientation but not ocular dominance beyond layer 4. Including these factors in the model mostly eliminated the contribution of cortical distance to fast spike correlation (up to our recording limit of 1.4mm), in terms of both 'correlation probability' (the incidence of pairs that have significant fast spike correlation) and 'correlation strength' (each pair's likelihood of fast spike correlation). We suggest that, at short distances and non-input layers, V1 fast spike correlation is determined more by tuning similarity than by cortical distance or ocular dominance. PMID:24486852

  19. CaV1.2 Signaling Complexes in the Heart

    PubMed Central

    Harvey, Robert D.; Hell, Johannes W.

    2012-01-01

    L-type Ca2+ channels (LTCCs) are essential for generation of the electrical and mechanical properties of cardiac muscle. Furthermore, regulation of LTCC activity plays a central role in mediating the effects of sympathetic stimulation on the heart. The primary mechanism responsible for this regulation involves β-adrenergic receptor (βAR) stimulation of cAMP production and subsequent activation of protein kinase A (PKA). Although it is well established that PKA-dependent phosphorylation regulates LTCC function, there is still much we do not understand. However, it has recently become clear that the interaction of the various signaling proteins involved is not left to completely stochastic events due to random diffusion. The primary LTCC expressed in cardiac muscle, CaV1.2, forms a supramolecular signaling complex that includes the β2AR, G proteins, adenylyl cyclases, phosphodiesterases, PKA, and protein phosphatases. In some cases, the protein interactions with CaV1.2 appear to be direct, in other cases they involve scaffolding proteins such as A kinase anchoring proteins and caveolin-3. Functional evidence also suggests that the targeting of these signaling proteins to specific membrane domains plays a critical role in maintaining the fidelity of receptor mediated LTCC regulation. This information helps explain the phenomenon of compartmentation, whereby different receptors, all linked to the production of a common diffusible second messenger, can vary in their ability to regulate LTCC activity. The purpose of this review is to examine our current understanding of the signaling complexes involved in cardiac LTCC regulation. PMID:23266596

  20. Defect structure of epitaxial CrxV1-x thin films on MgO(001)

    SciTech Connect

    Kaspar, Tiffany C.; Bowden, Mark E.; Wang, Chongmin; Shutthanandan, V.; Manandhar, Sandeep; van Ginhoven, Renee M.; Wirth, Brian D.; Kurtz, Richard J.

    2014-01-01

    Epitaxial thin films of CrxV1-x over the entire composition range were deposited on MgO(001) by molecular beam epitaxy. The films exhibited the expected 45° in-plane rotation with no evidence of phase segregation or spinodal decomposition. Pure Cr, with the largest lattice mismatch to MgO, exhibited full relaxation and cubic lattice parameters. As the lattice mismatch decreased with alloy composition, residual epitaxial strain was observed. For 0.2 ≤ x ≤ 0.4 the films were coherently strained to the substrate with associated tetragonal distortion; near the lattice-matched composition of x = 0.33, the films exhibited strain-free pseudomorphic matching to MgO. Unusually, films on the Cr-rich side of the lattice-matched composition exhibited more in-plane compression than expected from the bulk lattice parameters; this result was confirmed with both x-ray diffraction and Rutherford backscattering spectrometry channeling measurements. Although thermal expansion mismatch in the heterostructure may play a role, the dominant mechanism for this phenomenon is still unknown. High resolution transmission electron microscopy was utilized to characterize the misfit dislocation network present at the film/MgO interface. Dislocations were found to be present with a non-uniform distribution, which is attributed to the Volmer-Weber growth mode of the films. The CrxV1-x / MgO(001) system can serve as a model system to study both the fundamentals of defect formation in bcc films and the interplay between nanoscale defects such as dislocations and radiation damage.

  1. Smooth muscle cell α2δ-1 subunits are essential for vasoregulation by CaV1.2 channels

    PubMed Central

    Bannister, John P.; Adebiyi, Adebowale; Zhao, Guiling; Narayanan, Damodaran; Thomas, Candice M.; Feng, Jessie Y.; Jaggar, Jonathan H.

    2009-01-01

    Rationale Voltage-dependent L-type (CaV1.2) Ca2+ channels are a heteromeric complex formed from pore forming α1 and auxiliary α2δ and β subunits. CaV1.2 channels are the principal Ca2+ influx pathway in arterial myocytes and regulate multiple physiological functions, including contraction. The macromolecular composition of arterial myocyte CaV1.2 channels remains poorly understood, with no studies having examined the molecular identity or physiological functions of α2δ subunits. Objective Investigate the functional significance of α2δ subunits in myocytes of resistance-size (100–200 μm diameter) cerebral arteries. Methods and Results α2δ-1 was the only α2δ isoform expressed in cerebral artery myocytes. Pregabalin, an α2δ-1/-2 ligand, and an α2δ-1 antibody, inhibited CaV1.2 currents in isolated myocytes. Acute pregabalin application reversibly dilated pressurized arteries. Using a novel application of surface biotinylation, data indicated that >95 % of CaV1.2 α1 and α2δ-1 subunits are present in the arterial myocyte plasma membrane. α2δ-1 knockdown using shRNA reduced plasma membrane-localized CaV1.2 α1 subunits, caused a corresponding elevation in cytosolic CaV1.2 α1 subunits, decreased intracellular Ca2+ concentration, inhibited pressure-induced vasoconstriction (“myogenic tone”), and attenuated pregabalin-induced vasodilation. Prolonged (24 hour) pregabalin exposure did not alter total α2δ-1 or CaV1.2 α1 proteins, but decreased plasma membrane expression of each subunit, which reduced myogenic tone. Conclusions α2δ-1 is essential for plasma membrane expression of arterial myocyte CaV1.2 α1 subunits. α2δ-1 targeting can block CaV1.2 channels directly and inhibit surface expression of CaV1.2 α1 subunits, leading to vasodilation. These data identify α2δ-1 as a novel molecular target in arterial myocytes, manipulation of which regulates contractility. PMID:19797702

  2. Pervasive and ongoing positive selection in the vomeronasal-1 receptor (V1R) repertoire of mouse lemurs.

    PubMed

    Hohenbrink, Philipp; Radespiel, Ute; Mundy, Nicholas I

    2012-12-01

    Chemosensory genes are frequently the target of positive selection and are often present in large gene families, but little is known about heterogeneity of selection in these cases and its relation to function. Here, we use the vomeronasal-1 receptor (V1R) repertoire of mouse lemurs (Microcebus spp.) as a model system to study patterns of selection of chemosensory genes at several different levels. Mouse lemurs are small nocturnal strepsirrhine primates and have a large (~200 loci) repertoire of V1R loci that are likely important for intraspecific pheromonal communication and interspecific interactions, for example, recognition of predator cues. We investigated signals and patterns of positive selection among the 105 identified full length V1R loci in the gray mouse lemur and within 7 V1R loci amplified across multiple mouse lemur species. Phylogenetic reconstructions of published sequences revealed at least nine monophyletic clusters of V1Rs in gray mouse lemurs that have diversified since the split between lemurs and lorisoid primates. A large majority of clusters evolved under significant positive selection. Similar results were found in V1Rs of closely related greater galagos. Comparison with function of related V1R clusters in mice suggested a potential relationship between receptor function and strength of selection. Interestingly, most codons identified as being under positive selection are located in the extracellular domains of the receptors and hence likely indicate the position of residues involved in ligand binding. Positive selection was also detected within five V1R loci (=71% of analyzed loci) sequenced from 6 to 10 mouse lemur species, indicating ongoing selection within the genus, which may be related to sexual selection and, potentially, speciation processes. Variation in strength of positive selection on V1Rs showed no simple relationship to cluster size. The diversity of V1R loci in mouse lemurs reflects their adaptive evolution and is most

  3. NaV1.5 sodium channel window currents contribute to spontaneous firing in olfactory sensory neurons

    PubMed Central

    Frenz, Christopher T.; Hansen, Anne; Dupuis, Nicholas D.; Shultz, Nicole; Levinson, Simon R.; Finger, Thomas E.

    2014-01-01

    Olfactory sensory neurons (OSNs) fire spontaneously as well as in response to odor; both forms of firing are physiologically important. We studied voltage-gated Na+ channels in OSNs to assess their role in spontaneous activity. Whole cell patch-clamp recordings from OSNs demonstrated both tetrodotoxin-sensitive and tetrodotoxin-resistant components of Na+ current. RT-PCR showed mRNAs for five of the nine different Na+ channel α-subunits in olfactory tissue; only one was tetrodotoxin resistant, the so-called cardiac subtype NaV1.5. Immunohistochemical analysis indicated that NaV1.5 is present in the apical knob of OSN dendrites but not in the axon. The NaV1.5 channels in OSNs exhibited two important features: 1) a half-inactivation potential near −100 mV, well below the resting potential, and 2) a window current centered near the resting potential. The negative half-inactivation potential renders most NaV1.5 channels in OSNs inactivated at the resting potential, while the window current indicates that the minor fraction of noninactivated NaV1.5 channels have a small probability of opening spontaneously at the resting potential. When the tetrodotoxin-sensitive Na+ channels were blocked by nanomolar tetrodotoxin at the resting potential, spontaneous firing was suppressed as expected. Furthermore, selectively blocking NaV1.5 channels with Zn2+ in the absence of tetrodotoxin also suppressed spontaneous firing, indicating that NaV1.5 channels are required for spontaneous activity despite resting inactivation. We propose that window currents produced by noninactivated NaV1.5 channels are one source of the generator potentials that trigger spontaneous firing, while the upstroke and propagation of action potentials in OSNs are borne by the tetrodotoxin-sensitive Na+ channel subtypes. PMID:24872539

  4. Questioning the Specificity of ASRS-v1.1 to Accurately Detect ADHD in Substance Abusing Populations

    ERIC Educational Resources Information Center

    Chiasson, Jean-Pierre; Stavro, Katherine; Rizkallah, Elie; Lapierre, Luc; Dussault, Maxime; Legault, Louis; Potvin, Stephane

    2012-01-01

    Objective: To assess the specificity of the Adult ADHD Self-Report Scale (ASRS-v1.1) in detecting ADHD among individuals with substance use disorders (SUDs). Method: A chart review of 183 SUD patients was conducted. Patients were screened for ADHD with the ASRS-v1.1 and were later assessed by a psychiatrist specialized in ADHD. Results: Among SUD…

  5. Deletion of the L-type Calcium Channel CaV1.3 but not CaV1.2 Results in a Diminished sAHP in Mouse CA1 Pyramidal Neurons

    PubMed Central

    Gamelli, Amy E.; McKinney, Brandon C.; White, Jessica A.; Murphy, Geoffrey G.

    2009-01-01

    Trains of action potentials in CA1 pyramidal neurons are followed by a prolonged calcium-dependent post-burst afterhyperpolarization (AHP) that serves to limit further firing to a sustained depolarizing input. A reduction in the AHP accompanies acquisition of several types of learning and increases in the AHP are correlated with age-related cognitive impairment. The AHP develops primarily as the result of activation of outward calcium-activated potassium currents; however the precise source of calcium for activation of the AHP remains unclear. There is substantial experimental evidence suggesting that calcium influx via voltage-gated L-type calcium channels (L-VGCCs) contributes to the generation of the AHP. Two L-VGCC subtypes are predominately expressed in the hippocampus, CaV1.2 and CaV1.3, however it is not known which L-VGCC subtype is involved in generation of the AHP. This ambiguity is due in large part to the fact that at present there are no subunit-specific agonists or antagonists. Therefore, using mice in which the gene encoding CaV1.2 or CaV1.3 was deleted, we sought to determine the impact of alterations in levels of these two L-VCGG subtypes on neuronal excitability. No differences in any AHP measure were seen between neurons from CaV1.2 knockout mice and controls. However, the total area of the AHP was significantly smaller in neurons from CaV1.3 knockout mice as compared to neurons from wildtype controls. A significant reduction in the amplitude of the AHP was also seen at the 1 sec time point in neurons from CaV1.3 knockout mice as compared to those from controls. Reductions in both the area and 1 sec amplitude suggest the involvement of calcium influx via CaV1.3 in the slow AHP (sAHP). Thus, the results of our study demonstrate that deletion of CaV1.3, but not CaV1.2, significantly impacts the generation of the sAHP. PMID:20014384

  6. Structure of HIV-1 gp120 V1/V2 domain with broadly neutralizing antibody PG9

    SciTech Connect

    McLellan, Jason S.; Pancera, Marie; Carrico, Chris; Gorman, Jason; Julien, Jean-Philippe; Khayat, Reza; Louder, Robert; Pejchal, Robert; Sastry, Mallika; Dai, Kaifan; O’Dell, Sijy; Patel, Nikita; Shahzad-ul-Hussan, Syed; Yang, Yongping; Zhang, Baoshan; Zhou, Tongqing; Zhu, Jiang; Boyington, Jeffrey C.; Chuang, Gwo-Yu; Diwanji, Devan; Georgiev, Ivelin; Kwon, Young Do; Lee, Doyung; Louder, Mark K.; Moquin, Stephanie; Schmidt, Stephen D.; Yang, Zhi-Yong; Bonsignori, Mattia; Crump, John A.; Kapiga, Saidi H.; Sam, Noel E.; Haynes, Barton F.; Burton, Dennis R.; Koff, Wayne C.; Walker, Laura M.; Phogat, Sanjay; Wyatt, Richard; Orwenyo, Jared; Wang, Lai-Xi; Arthos, James; Bewley, Carole A.; Mascola, John R.; Nabel, Gary J.; Schief, William R.; Ward, Andrew B.; Wilson, Ian A.; Kwong, Peter D.

    2012-12-13

    Variable regions 1 and 2 (V1/V2) of human immunodeficiency virus-1 (HIV-1) gp120 envelope glycoprotein are critical for viral evasion of antibody neutralization, and are themselves protected by extraordinary sequence diversity and N-linked glycosylation. Human antibodies such as PG9 nonetheless engage V1/V2 and neutralize 80% of HIV-1 isolates. Here we report the structure of V1/V2 in complex with PG9. V1/V2 forms a four-stranded {beta}-sheet domain, in which sequence diversity and glycosylation are largely segregated to strand-connecting loops. PG9 recognition involves electrostatic, sequence-independent and glycan interactions: the latter account for over half the interactive surface but are of sufficiently weak affinity to avoid autoreactivity. The structures of V1/V2-directed antibodies CH04 and PGT145 indicate that they share a common mode of glycan penetration by extended anionic loops. In addition to structurally defining V1/V2, the results thus identify a paradigm of antibody recognition for highly glycosylated antigens, which - with PG9 - involves a site of vulnerability comprising just two glycans and a strand.

  7. Structures of HIV-1-Env V1V2 with broadly neutralizing antibodies reveal commonalities that enable vaccine design

    PubMed Central

    Gorman, Jason; Soto, Cinque; Yang, Max M.; Davenport, Thaddeus M.; Guttman, Miklos; Bailer, Robert T.; Chambers, Michael; Chuang, Gwo-Yu; DeKosky, Brandon J.; Doria-Rose, Nicole A.; Druz, Aliaksandr; Ernandes, Michael J.; Georgiev, Ivelin S.; Jarosinski, Marissa C.; Joyce, M. Gordon; Lemmin, Thomas M.; Leung, Sherman; Louder, Mark K.; McDaniel, Jonathan R.; Narpala, Sandeep; Pancera, Marie; Stuckey, Jonathan; Wu, Xueling; Yang, Yongping; Zhang, Baoshan; Zhou, Tongqing; Mullikin, James C.; Baxa, Ulrich; Georgiou, George; McDermott, Adrian B.; Bonsignori, Mattia; Haynes, Barton F.; Moore, Penny L.; Morris, Lynn; Lee, Kelly K.; Shapiro, Lawrence; Mascola, John R.; Kwong, Peter D.

    2016-01-01

    Broadly neutralizing antibodies (bNAbs) against HIV-1-Env V1V2 arise in multiple donors. However, atomic-level interactions had only been determined with antibodies from a single donor, making commonalities in recognition uncertain. Here we report the co-crystal structure of V1V2 with antibody CH03 from a second donor and model Env interactions of antibody CAP256-VRC26 from a third. These V1V2-directed bNAbs utilized strand-strand interactions between a protruding antibody loop and a V1V2 strand, but differed in their N-glycan recognition. Ontogeny analysis indicated protruding loops to develop early, with glycan interactions maturing over time. Altogether, the multidonor information suggested V1V2-directed bNAbs to form an ‘extended class’, for which we engineered ontogeny-specific antigens: Env trimers with chimeric V1V2s that interacted with inferred ancestor and intermediate antibodies. The ontogeny-based design of vaccine antigens described here may provide a general means for eliciting antibodies of a desired class. PMID:26689967

  8. Structures of HIV-1 Env V1V2 with broadly neutralizing antibodies reveal commonalities that enable vaccine design.

    PubMed

    Gorman, Jason; Soto, Cinque; Yang, Max M; Davenport, Thaddeus M; Guttman, Miklos; Bailer, Robert T; Chambers, Michael; Chuang, Gwo-Yu; DeKosky, Brandon J; Doria-Rose, Nicole A; Druz, Aliaksandr; Ernandes, Michael J; Georgiev, Ivelin S; Jarosinski, Marissa C; Joyce, M Gordon; Lemmin, Thomas M; Leung, Sherman; Louder, Mark K; McDaniel, Jonathan R; Narpala, Sandeep; Pancera, Marie; Stuckey, Jonathan; Wu, Xueling; Yang, Yongping; Zhang, Baoshan; Zhou, Tongqing; Mullikin, James C; Baxa, Ulrich; Georgiou, George; McDermott, Adrian B; Bonsignori, Mattia; Haynes, Barton F; Moore, Penny L; Morris, Lynn; Lee, Kelly K; Shapiro, Lawrence; Mascola, John R; Kwong, Peter D

    2016-01-01

    Broadly neutralizing antibodies (bNAbs) against HIV-1 Env V1V2 arise in multiple donors. However, atomic-level interactions had previously been determined only with antibodies from a single donor, thus making commonalities in recognition uncertain. Here we report the cocrystal structure of V1V2 with antibody CH03 from a second donor and model Env interactions of antibody CAP256-VRC26 from a third donor. These V1V2-directed bNAbs used strand-strand interactions between a protruding antibody loop and a V1V2 strand but differed in their N-glycan recognition. Ontogeny analysis indicated that protruding loops develop early, and glycan interactions mature over time. Altogether, the multidonor information suggested that V1V2-directed bNAbs form an 'extended class', for which we engineered ontogeny-specific antigens: Env trimers with chimeric V1V2s that interacted with inferred ancestor and intermediate antibodies. The ontogeny-based design of vaccine antigens described here may provide a general means for eliciting antibodies of a desired class. PMID:26689967

  9. Design, synthesis and pharmacological characterization of fluorescent peptides for imaging human V1b vasopressin or oxytocin receptors

    PubMed Central

    Corbani, Maithé; Trueba, Miguel; Stoev, Stoytcho; Murat, Brigitte; Mion, Julie; Boulay, Véra; Guillon, Gilles; Manning, Maurice

    2011-01-01

    Among the four known vasopressin and oxytocin receptors, the specific localization of the V1b isoform is poorly described due to the lack of selective pharmacological tools. In an attempt to address this need, we decided to design, synthesize and characterize fluorescent selective V1b analogues. Starting with the selective V1b agonist, [deamino-Cys1, Leu4, Lys8]vasopressin (d[Leu4,Lys8]VP) synthesized earlier, we added blue, green or red fluorophores to the lysine residue at position 8, either directly or by the use of linkers of different lengths. Among the nine analogues synthesized, two exhibited very promising properties. These are d[Leu4, Lys (Alexa 647)8]VP (3) and d[Leu4, Lys (11-aminoundecanoyl-Alexa 647)8]VP (9). They remained full V1b agonists with nanomolar affinity and specifically decorated the plasma membrane of CHO cells stably transfected with the human V1b receptor. These new selective fluorescent peptides will allow the cellular localisation of V1b or OT receptor isoforms in native tissues. PMID:21428295

  10. Turkey Astrovirus Type 1 (TAstV-1) and Chicken Astrovirus (CAstV) Detection in Brazilian Chicken Flocks.

    PubMed

    Espinoza, Luis Luna; Beserra, Laila A R; Soares, Rodrigo M; Gregori, Fabio

    2016-09-01

    Astrovirus is a common cause of enteritis in humans and domestic animals. Here we report the detection of turkey astrovirus type 1 (TAstV-1) and chicken astrovirus (CAstV) in avian farms. Sixty fecal sample pools (five or six birds of the same flock), from chickens without apparent clinical symptoms of enteric disease from farms located in six Brazilian states, were screened by an ORF1b PCR, followed by nucleotide sequencing of amplified products and phylogenetic analysis. Six samples tested positive for TAstV-1 and two for CAstV. One positive sample of each detected virus (TAstV-1 and CAstV) had the complete ORF2 sequenced. Data for the ORF2 sequence indicate that Brazilian TAstV-1 was divergent from TAstV-1 (United States), previously described infecting turkeys, and Brazilian CAstV clustered together with the U.K. group, subgroup B-II, associated with enteritis and growth retardation in chicks. This study provides updated information about CAstV and the first report of detection of TAstV-1 in Brazilian chickens, supporting the diagnostic of enteritis and epidemiologic surveillance in poultry health. PMID:27610731

  11. Ca2+ entry into neurons is facilitated by cooperative gating of clustered CaV1.3 channels

    PubMed Central

    Moreno, Claudia M; Dixon, Rose E; Tajada, Sendoa; Yuan, Can; Opitz-Araya, Ximena; Binder, Marc D; Santana, Luis F

    2016-01-01

    CaV1.3 channels regulate excitability in many neurons. As is the case for all voltage-gated channels, it is widely assumed that individual CaV1.3 channels behave independently with respect to voltage-activation, open probability, and facilitation. Here, we report the results of super-resolution imaging, optogenetic, and electrophysiological measurements that refute this long-held view. We found that the short channel isoform (CaV1.3S), but not the long (CaV1.3L), associates in functional clusters of two or more channels that open cooperatively, facilitating Ca2+ influx. CaV1.3S channels are coupled via a C-terminus-to-C-terminus interaction that requires binding of the incoming Ca2+ to calmodulin (CaM) and subsequent binding of CaM to the pre-IQ domain of the channels. Physically-coupled channels facilitate Ca2+ currents as a consequence of their higher open probabilities, leading to increased firing rates in rat hippocampal neurons. We propose that cooperative gating of CaV1.3S channels represents a mechanism for the regulation of Ca2+ signaling and electrical activity. DOI: http://dx.doi.org/10.7554/eLife.15744.001 PMID:27187148

  12. Down-regulation of CaV1.2 channels during hypertension: how fewer CaV1.2 channels allow more Ca2+ into hypertensive arterial smooth muscle

    PubMed Central

    Tajada, Sendoa; Cidad, Pilar; Colinas, Olaia; Santana, L Fernando; López-López, José R; Pérez-García, M Teresa

    2013-01-01

    Hypertension is a clinical syndrome characterized by increased arterial tone. Although the mechanisms are varied, the generally accepted view is that increased CaV1.2 channel function is a common feature of this pathological condition. Here, we investigated the mechanisms underlying vascular dysfunction in a mouse model of genetic hypertension. Contrary to expectation, we found that whole-cell CaV1.2 currents (ICa) were lower in hypertensive (BPH line) than normotensive (BPN line) myocytes. However, local CaV1.2 sparklet activity was higher in BPH cells, suggesting that the relatively low ICa in these cells was produced by a few hyperactive CaV1.2 channels. Furthermore, our data suggest that while the lower expression of the pore-forming α1c subunit of CaV1.2 currents underlies the lower ICa in BPH myocytes, the increased sparklet activity was due to a different composition in the auxiliary subunits of the CaV1.2 complexes. ICa currents in BPN cells were produced by channels composed of α1c/α2δ/β3 subunits, while in BPH myocytes currents were probably generated by the opening of channels formed by α1c/α2δ/β2 subunits. In addition, Ca2+ sparks evoked large conductance, Ca2+-activated K+ (BK) currents of lower magnitude in BPH than in BPN myocytes, because BK channels were less sensitive to Ca2+. Our data are consistent with a model in which a decrease in the global number of CaV1.2 currents coexist with the existence of a subpopulation of highly active channels that dominate the resting Ca2+ influx. The decrease in BK channel activity makes the hyperpolarizing brake ineffective and leads BPH myocytes to a more contracted resting state. PMID:24167226

  13. Identification of the V1 region as a linear neutralizing epitope of the simian immunodeficiency virus SIVmac envelope glycoprotein.

    PubMed Central

    Jurkiewicz, E; Hunsmann, G; Schäffner, J; Nisslein, T; Lüke, W; Petry, H

    1997-01-01

    The sequence variability of viral structure polypeptides has been associated with immune escape mechanisms. The V1 region of simian immunodeficiency virus (SIV) is a highly variable region of the SIVmac env gene. Here, we describe the V1 region as a linear neutralizing epitope. V1 region-specific neutralizing antibodies (NAb) were first demonstrated in a rabbit infected with a recombinant vaccinia virus carrying the env gene of human immunodeficiency virus type 2 strain ben (HIV-2ben). Since we detected in this animal V1 region-specific NAb that were able to neutralize not only human immunodeficiency virus type 2 but also SIVmac32H, we investigated whether a similar immune response is evoked in macaques (Macaca mulatta) either infected with SIVmac or immunized with the external glycoprotein (gp130) of the same virus. Distinctly lower NAb titers were found in the SIVmac-infected animals than in the gp130-immunized macaques. Since the NAb titers in both groups were high enough for competition experiments, we used five overlapping peptides encompassing the whole V1 region for a detailed identification of the epitope. In each of the 12 macaques investigated, we detected a high level of NAb reacting with at least one peptide located in the central part of the V1 region. The relatively high degree of divergence, especially within the central part of the V1 region, which characterized the evolution of the retroviral sequences from the original inoculum in the infected macaques suggests the development of escape mutants. Furthermore, 3 of 12 animals developed NAb directed against the amino-terminal end of the V1 region epitope. Sequence analysis, however, revealed relatively low levels of genetic drift and genetic variability within this part of the V1 region. The induction of V1 env-specific NAb not only in gp130-immunized macaques but also in SIVmac-infected animals in combination with the increased genetic variability of this region in vivo indicates a marked biological

  14. Activation of Wnt/β-catenin signaling by hydrogen peroxide transcriptionally inhibits NaV1.5 expression.

    PubMed

    Wang, Ning; Huo, Rong; Cai, Benzhi; Lu, Yan; Ye, Bo; Li, Xiang; Li, Faqian; Xu, Haodong

    2016-07-01

    Oxidants and canonical Wnt/β-catenin signaling have been shown to decrease cardiac Na(+) channel activity by suppressing NaV1.5 expression. Our aims are to determine if hydrogen peroxide (H2O2), one oxidant of reactive oxygen species (ROS), activates Wnt/β-catenin signaling and promotes β-catenin nuclear activity, leading to suppression of NaV1.5 expression and if this suppression requires the interaction of β-catenin with its nuclear partner, TCF4 (also called TCF7L2) to decrease SCN5a promoter activity. The results demonstrated that H2O2 increased β-catenin, but not TCF4 nuclear localization determined by immunofluorescence without affecting total β-catenin protein level. Furthermore, H2O2 exerted a dose- and time-dependent suppressive effect on NaV1.5 expression. RT-PCR and/or Western blot analyses revealed that overexpressing active form of β-catenin or stabilizing β-catenin by GSK-3β inhibitors, LiCl and Bio, suppressed NaV1.5 expression in HL-1 cells. In contrast, destabilization of β-catenin by a constitutively active GSK-3β mutant (S9A) upregulated NaV1.5 expression. Whole-cell recording showed that LiCl significantly inhibited Na(+) channel activity in these cells. Using immunoprecipitation (IP), we showed that β-catenin interacted with TCF4 indicating that β-catenin as a co-transfactor, regulates NaV1.5 expression through TCF4. Analyses of the SCN5a promoter sequences among different species by using VISTA tools indicated that SCN5a promoter harbors TCF4 binding sites. Chromatin IP assays demonstrated that both β-catenin and TCF4 were recruited in the SCN5a promoter, and regulated its activity. Luciferase promoter assays exhibited that β-catenin inhibited the SCN5a promoter activity at a dose-dependent manner and this inhibition required TCF4. Small interfering (Si) RNA targeting β-catenin significantly increased SCN5a promoter activity, leading to enhanced NaV1.5 expression. As expected, β-catenin SiRNA prevents H2O2 suppressive effects

  15. BADGER v1.0: A Fortran equation of state library

    NASA Astrophysics Data System (ADS)

    Heltemes, T. A.; Moses, G. A.

    2012-12-01

    The BADGER equation of state library was developed to enable inertial confinement fusion plasma codes to more accurately model plasmas in the high-density, low-temperature regime. The code had the capability to calculate 1- and 2-T plasmas using the Thomas-Fermi model and an individual electron accounting model. Ion equation of state data can be calculated using an ideal gas model or via a quotidian equation of state with scaled binding energies. Electron equation of state data can be calculated via the ideal gas model or with an adaptation of the screened hydrogenic model with ℓ-splitting. The ionization and equation of state calculations can be done in local thermodynamic equilibrium or in a non-LTE mode using a variant of the Busquet equivalent temperature method. The code was written as a stand-alone Fortran library for ease of implementation by external codes. EOS results for aluminum are presented that show good agreement with the SESAME library and ionization calculations show good agreement with the FLYCHK code. Program summaryProgram title: BADGERLIB v1.0 Catalogue identifier: AEND_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEND_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 41 480 No. of bytes in distributed program, including test data, etc.: 2 904 451 Distribution format: tar.gz Programming language: Fortran 90. Computer: 32- or 64-bit PC, or Mac. Operating system: Windows, Linux, MacOS X. RAM: 249.496 kB plus 195.630 kB per isotope record in memory Classification: 19.1, 19.7. Nature of problem: Equation of State (EOS) calculations are necessary for the accurate simulation of high energy density plasmas. Historically, most EOS codes used in these simulations have relied on an ideal gas model. This model is inadequate for low

  16. IBCSO v1 - The first release of the International Bathymetric Chart of the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Schenke, H. W.; Arndt, J.

    2012-12-01

    The International Bathymetric Chart of the Southern Ocean (IBCSO) is an expert group of the Scientific Committee on Antarctic Research (SCAR) since the XXVIII SCAR Conference held on 30th July 2004 in Bremen Germany and a regional mapping project of the General Bathymetric Chart of the Ocean (GEBCO) operated under the joint auspices of the Intergovernmental Oceanographic Commission (IOC) (of UNESCO) and the International Hydrographic Organization (IHO). The objective of IBCSO was to produce the first seamless bathymetric grid for the area south of latitude 60° S surrounding Antarctica. The IBCSO is going to be highly beneficial many scientific investigations. These include (a) interpretation of seabed geology, (b) the building of habitat models and maps, and (c) mapping and tracing of deep ocean current pathways. In addition the IBCSO is going to serve as an indispensable database for new nautical Charts in the Southern Ocean to improve the safety of navigation in Antarctic waters. After the inaugural meeting in 2004, the Editorial Board was then established at the 1st IBCSO Meeting at Santa Barbara in 2007 including representatives from several SCAR member countries. Since then, plenty of institutions holding bathymetric data in the Southern Ocean have been asked for a contribution to the IBCSO dataset. After the time consuming gathering, compilation and analyses of bathymetric data, finally the first version of the IBCSO is close to be released. Besides the grid an adjacent map has been developed, which is also going to be released in the near future. It is proposed to give an overview in what has been done in the IBCSO project in the last years for the creation of IBCSO v1. This will include acknowledgements to the data contributors and a short explanation of the working steps data acquisition, homogenization, cleaning and gridding. Previews of the new grid are going to demonstrate the improvement that has been achieved by IBCSO v1 compared to other bathymetric

  17. Selective silencing of NaV1.7 decreases excitability and conduction in vagal sensory neurons

    PubMed Central

    Muroi, Yukiko; Ru, Fei; Kollarik, Marian; Canning, Brendan J; Hughes, Stephen A; Walsh, Stacey; Sigg, Martin; Carr, Michael J; Undem, Bradley J

    2011-01-01

    Abstract There has been much information learned in recent years about voltage gated sodium channel (NaV) subtypes in somatosensory pain signalling, but much less is known about the role of specific sodium channel subtypes in the vagal sensory system. In this study, we developed a technique using adeno-associated viruses (AAVs) to directly introduce shRNA against NaV1.7 subtype gene into the vagal sensory ganglia of guinea pigsin vivo. NaV1.7 gene expression in nodose ganglia was effectively and selectively reduced without influencing the expression of other sodium channel subtype genes including NaV1.1, 1.2, 1.3 1.6, 1.8, or 1.9. Using a whole cell patch-clamp technique, this effect on NaV1.7 gene expression coincided with a reduction in tetrodotoxin-sensitive sodium current, a requirement for much larger depolarizing stimulus to initiate action potentials, and reduction in repetitive action potential discharge. Extracellular recordings in the isolated vagus nerve revealed that the conduction of action potentials in sensory A- and C-fibres in many neurons was effectively abolished after NaV1.7 shRNA introduction. Moreover, bilateral NaV1.7 shRNA injected animals survived for several months and the vagal reflex behaviour, exemplified by citric acid-induced coughing, was significantly suppressed. These data indicate that selectively silencing NaV1.7 ion channel expression leads to a substantial decrease in neural excitability and conduction block in vagal afferent nerves. PMID:22005676

  18. Vinpocetine is a potent blocker of rat NaV1.8 tetrodotoxin-resistant sodium channels.

    PubMed

    Zhou, Xiaoping; Dong, Xiao-Wei; Crona, James; Maguire, Maureen; Priestley, Tony

    2003-08-01

    Vinpocetine is a clinically used synthetic vincamine derivative with a diverse pharmacological profile that includes action at several ion channels, principally "generic" populations of sodium channels that give rise to tetrodotoxin-sensitive conductances. A number of cell types are known to express tetrodotoxin-resistant (TTXr) sodium conductances, the molecular bases of which have remained elusive until recently. One such TTXr channel, termed NaV1.8, is of particular interest because of its prominent and selective expression in peripheral afferent nerves. The effects of vinpocetine on TTXr channels specifically, are unknown. We have assessed the effects of the drug on cloned rat NaV1.8 channels expressed in a dorsal root ganglion-derived cell line, ND7/23. Vinpocetine produced a concentration- and state-dependent inhibition of NaV1.8 sodium channel activity. Voltage-clamp experiments revealed an approximately 3-fold increase in vinpocetine potency when whole-cell NaV1.8 conductances were elicited from relatively depolarized potentials (-35 mV; IC50 = 3.5 microM) compared with hyperpolarized holding potentials (-90 mV; IC50 = 10.4 microM). Vinpocetine also produced an approximately 22 mV leftward shift in the voltage dependence of NaV1.8 channel inactivation but did not affect the voltage range of channel activation. These properties are reminiscent of several other known sodium channel blockers and suggested that vinpocetine may exhibit frequency-dependent block. Accordingly, tonic block of NaV1.8 channels by vinpocetine (3 microM) increased proportionally with increasing depolarizing commands over the frequency range 0.1 to 1Hz. In summary, the present data demonstrate that vinpocetine is capable of blocking NaV1.8 sodium channel activity and suggest a potential additional utility in various sensory abnormalities arising from abnormal peripheral nerve activity. PMID:12730276

  19. 25 CFR 10.2 - Who is responsible for developing and maintaining the policies and standards for detention and...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Who is responsible for developing and maintaining the policies and standards for detention and holding facilities in Indian country? 10.2 Section 10.2 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER INDIAN COUNTRY DETENTION FACILITIES AND PROGRAMS § 10.2 Who is responsible...

  20. NIMS Radiance Point Spectra of Ida and Dactyl V1.0

    NASA Astrophysics Data System (ADS)

    Granahan, J. C.

    2013-08-01

    This data volume contains radiometrically corrected point spectra of asteroid 243 Ida and a spectrum of the asteroid satellite Dactyl (Ida I) as acquired by the Galileo spacecraft Near Infrared Mapping Spectrometer (NIMS) on August 28, 1993. They record the spectra collected as the Galileo spacecraft approached the 243 Ida system. These data are products of the calibration of the raw data number files idu002tn.qub, idu005tn.qub, idu006tn.qub, idu007tn.qub, idu019tn.qub, idu020tn.qub, idu022tn.qub, idu028tn.qub, idu032tn.qub, idu033tn.qub, and idu035tn.qub (DATA SET ID ='GO-A-NIMS-3-TUBE-V1.0') with calibration factors acquired during the Jovian tour of the Galileo mission. These raw data .qub files are archived in the Imaging Node of the NASA Planetary Data System (PDS). The calibrated spectra consist of radiance and incidence/flux measurements for wavelengths between 0.7 - 5.2 micrometers.

  1. Unusual Galactic Cosmic Ray Intensity and Spectral Changes Observed by V1 Near The Heliopause

    NASA Astrophysics Data System (ADS)

    Webber, W. R.; Quenby, J. J.

    2015-06-01

    We discuss here two unusual increases of cosmic ray intensity that were observed by V1 in the last 1.1 AU before it crossed the heliopause in 2012 August, at 121.5 AU. These two increases are roughly similar in amplitude and result in a total increase in ˜1 GV cosmic ray nuclei of over 50% and 0.01 GV electrons of a factor ˜2. During the first increase the changes in the B field are small. After the first increase the B field changes become large and during the second increase the B field variations and cosmic ray changes are correlated to within ± one day. During these time intervals, the rigidity dependence of the increases of GCR H and He nuclei from 100-600 MeV/nuc resemble those used to describe the solar modulation near the Earth during a large transient decrease but the ratio between the intensity changes of H, He, and electrons are different. The magnitude of these increases at Voyager is ˜1/3 of the modulation that is required to produce the total modulation of protons, helium nuclei, and electrons between the local interstellar intensities and those observed at the Earth at the 2009 sunspot minima. This may imply that a significant part of the residual solar modulation at times of sunspot minima occurs near the heliopause itself.

  2. Versican V1 Overexpression Induces a Myofibroblast-Like Phenotype in Cultured Fibroblasts

    PubMed Central

    Carthy, Jon M.; Meredith, Anna J.; Boroomand, Seti; Abraham, Thomas; Luo, Zongshu; Knight, Darryl; McManus, Bruce M.

    2015-01-01

    Background Versican, a chondroitin sulphate proteoglycan, is one of the key components of the provisional extracellular matrix expressed after injury. The current study evaluated the hypothesis that a versican-rich matrix alters the phenotype of cultured fibroblasts. Methods and Results The full-length cDNA for the V1 isoform of human versican was cloned and the recombinant proteoglycan was expressed in murine fibroblasts. Versican expression induced a marked change in fibroblast phenotype. Functionally, the versican-expressing fibroblasts proliferated faster and displayed enhanced cell adhesion, but migrated slower than control cells. These changes in cell function were associated with greater N-cadherin and integrin β1 expression, along with increased FAK phosphorylation. The versican-expressing fibroblasts also displayed expression of smooth muscle α-actin, a marker of myofibroblast differentiation. Consistent with this observation, the versican fibroblasts displayed increased synthetic activity, as measured by collagen III mRNA expression, as well as a greater capacity to contract a collagen lattice. These changes appear to be mediated, at least in part, by an increase in active TGF-β signaling in the versican expressing fibroblasts, and this was measured by phosphorylation and nuclear accumulation of SMAD2. Conclusions Collectively, these data indicate versican expression induces a myofibroblast-like phenotype in cultured fibroblasts. PMID:26176948

  3. Understanding layer 4 of the cortical circuit: a model based on cat V1.

    PubMed

    Miller, Kenneth D

    2003-01-01

    This paper reviews theoretical and experimental results on the processing of layer 4, the input-recipient layer, of cat primary visual cortex (V1). A wide range of experimental data can be understood from a model in which response tuning of layer 4 cells is largely determined by a local interplay of feedforward excitation (from thalamus) and feedforward inhibition (from layer 4 inhibitory interneurons driven by thalamus). Feedforward inhibition dominates excitation, inherits its tuning from the thalamic input and sharpens the tuning of excitatory cells. At least a strong component of the feedforward inhibition received by a cell is spatially opponent to the excitation it receives, meaning that inhibition is driven by dark in regions of the visual field in which excitation is driven by light, and vice versa. The idea of opponent inhibition can be generalized to mean inhibition driven by input patterns that are strongly anti-correlated with the patterns that excite a cell. This paper argues that dominant feedforward opponent inhibition may be a general principle of cortical layer 4. This leads to the suggestion that the properties that show columnar organization--invariance across the vertical depth of cortex--may be properties that are shared by 'opposite' (anticorrelated) stimulus pairs. This contrasts with the more common idea that a column represents a set of cells that all share similar stimulus preferences. PMID:12466218

  4. Chest pain in a patient with a tall R wave in V1

    PubMed Central

    McManus, Kenneth; Condos, Gregory; Lin, Andrew

    2014-01-01

    An 83-year-old man 2 days postoperative from L3 to L5 laminectomy developed sudden onset of chest pain. Initial ECGs demonstrated a tall R wave in V1 and ST-segment depression in leads V2–V5. A posterior ECG was performed, but failed to demonstrate ST elevations. The patient was initially treated as an non-ST-segment elevation myocardial infarction with weight-based enoxaparin. On further review, the patient's ECG was identified as a STEMI equivalent, and he underwent cardiac catheterisation. He was noted to have a near complete occlusion of the posterior descending branch of the right coronary artery (RCA). Bare-metal stents were placed in the proximal and distal RCA, with restored flow distal to the lesions. The patient was transferred to the intensive care unit for observation, and was noted to develop atrial fibrillation. Rate control was achieved with diltiazem, and the patient was started on dabigatran. Medical therapy including aspirin and clopidogrel was initiated, and the patient was discharged home. PMID:25150241

  5. Identification of novel NaV1.7 antagonists using high throughput screening platforms.

    PubMed

    Klement, Goran; Babich, Olga; Larsson, Olof; Lund, Per-Eric; Malmberg, Asa; Sandberg, Lars; Sands, Zara A; Dabrowski, Michael

    2012-11-01

    Congenital Insensitivity to Pain (CIP) is a loss of function mutation resulting in a truncated NaV1.7 protein, suggesting a pivotal role in pain signaling and rendering it an important pharmaceutical target for multiple pain conditions. The structural homology in the NaV-channel family makes it challenging to design effective analgesic compounds without inducing for example cardiotoxicity or seizure liabilities. An additional approach to structural isoform selectivity is to identify compounds with use- or state-dependent profiles, i.e. inhibition efficacy based on the gating of the ion channel. In general nerve cells in damaged or inflamed tissue are more depolarized and electrically active compared to healthy nerve cells in for instance the heart. This observation has led to the design of two types of screening protocols emulating the voltage condition of peripheral neurons or cardiac tissue. The two voltage protocols have been developed to identify both use- and state-dependent antagonists. In this paper we describe an attempt to merge the two different protocols into one to increase screening efficacy, while retaining relevant state- and use-dependent pharmacology. The new protocol is constructed of two stimulation pulses and a slow voltage ramp for simultaneous assessment of resting and state-dependent block. By comparing all protocols we show that the new protocol indeed filter compounds for state-dependence and increase the prediction power of selecting use-dependent compounds. PMID:22934951

  6. Slow Feature Analysis on Retinal Waves Leads to V1 Complex Cells

    PubMed Central

    Dähne, Sven; Wilbert, Niko; Wiskott, Laurenz

    2014-01-01

    The developing visual system of many mammalian species is partially structured and organized even before the onset of vision. Spontaneous neural activity, which spreads in waves across the retina, has been suggested to play a major role in these prenatal structuring processes. Recently, it has been shown that when employing an efficient coding strategy, such as sparse coding, these retinal activity patterns lead to basis functions that resemble optimal stimuli of simple cells in primary visual cortex (V1). Here we present the results of applying a coding strategy that optimizes for temporal slowness, namely Slow Feature Analysis (SFA), to a biologically plausible model of retinal waves. Previously, SFA has been successfully applied to model parts of the visual system, most notably in reproducing a rich set of complex-cell features by training SFA with quasi-natural image sequences. In the present work, we obtain SFA units that share a number of properties with cortical complex-cells by training on simulated retinal waves. The emergence of two distinct properties of the SFA units (phase invariance and orientation tuning) is thoroughly investigated via control experiments and mathematical analysis of the input-output functions found by SFA. The results support the idea that retinal waves share relevant temporal and spatial properties with natural visual input. Hence, retinal waves seem suitable training stimuli to learn invariances and thereby shape the developing early visual system such that it is best prepared for coding input from the natural world. PMID:24810948

  7. Substructure of direction-selective receptive fields in macaque V1.

    PubMed

    Livingstone, Margaret S; Conway, Bevil R

    2003-05-01

    We used two-dimensional (2-D) sparse noise to map simultaneous and sequential two-spot interactions in simple and complex direction-selective cells in macaque V1. Sequential-interaction maps for both simple and complex cells showed preferred-direction facilitation and null-direction suppression for same-contrast stimulus sequences and the reverse for inverting-contrast sequences, although the magnitudes of the interactions were weaker for the simple cells. Contrast-sign selectivity in complex cells indicates that direction-selective interactions in these cells must occur in antecedent simple cells or in simple-cell-like dendritic compartments. Our maps suggest that direction selectivity, and on and off segregation perpendicular to the orientation axis, can occur prior to receptive-field elongation along the orientation axis. 2-D interaction maps for some complex cells showed elongated alternating facilitatory and suppressive interactions as predicted if their inputs were orientation-selective simple cells. The negative interactions, however, were less elongated than the positive interactions, and there was an inflection at the origin in the positive interactions, so the interactions were chevron-shaped rather than band-like. Other complex cells showed only two round interaction regions, one negative and one positive. Several explanations for the map shapes are considered, including the possibility that directional interactions are generated directly from unoriented inputs. PMID:12740412

  8. Oxidation characteristics of Ti-25Al-10Nb-3V-1Mo intermetallic alloy

    NASA Technical Reports Server (NTRS)

    Wallace, Terryl A.; Clark, Ronald K.; Sankaran, Sankara N.; Wiedemann, Karl E.

    1990-01-01

    Static oxidation kinetics of the super-alpha 2 titanium-aluminide alloy Ti-25Al-10Nb-3V-1Mo (at. percent) were investigated in air over the temperature range of 650 to 1000 C using thermogravimetric analysis. The oxidation kinetics were complex at all exposure temperatures and displayed up to three distinct oxidation rates. Breakaway oxidation occurred after long exposure times at high temperatures. Oxidation products were determined using x ray diffraction techniques, electron microprobe analysis, and energy dispersive x ray analysis. Oxide scale morphology was examined by scanning electron microscopy of the surfaces and cross sections of oxidized specimens. The oxides during the parabolic stages were compact and multilayered, consisting primarily of TiO2 doped with Nb, a top layer of Al2O3, and a thin bottom layer of TiN. The transition between the second and third parabolic stage was found to be linked to the formation of a TiAl layer at the oxide-metal interface. Porosity was formed during the third stage, causing degradation of the oxide and the beginning of breakaway oxidation.

  9. Oxidation characteristics of Ti-25Al-10Nb-3V-1Mo

    NASA Technical Reports Server (NTRS)

    Wallace, T. A.; Clark, R. K.; Wiedemann, K. E.; Sankaran, S. N.

    1992-01-01

    Static oxidation kinetics of the super-alpha 2 titanium-aluminide alloy Ti-25Al-10Nb-3V-1Mo (at. percent) were investigated in air over the temperature range of 650 to 1000 C using thermogravimetric analysis. The oxidation kinetics were complex at all exposure temperatures and displayed up to three distinct oxidation rates. Breakaway oxidation occurred after long exposure times at high temperatures. Oxidation products were determined using X-ray diffraction techniques, electron microprobe analysis, and energy dispersive X-ray analysis. Oxide scale morphology was examined by scanning electron microscopy of the surfaces and cross sections of oxidized specimens. The oxides during the parabolic stages were compact and multilayered, consisting primarily of TiO2 doped with Nb, a top layer of Al2O3, and a thin bottom layer of TiN. The transition between the second and third parabolic stage was found to be linked to the formation of a TiAl layer at the oxide-metal interface. Porosity was formed during the third stage, causing degradation of the oxide and the beginning of breakaway oxidation.

  10. An Na+-pumping V1V0-ATPase complex in the thermophilic bacterium Clostridium fervidus.

    PubMed Central

    Höner zu Bentrup, K; Ubbink-Kok, T; Lolkema, J S; Konings, W N

    1997-01-01

    Energy transduction in the anaerobic, thermophilic bacterium Clostridium fervidus relies exclusively on Na+ as the coupling ion. The Na+ ion gradient across the membrane is generated by a membrane-bound ATPase (G. Speelmans, B. Poolman, T. Abee, and W. N. Konings, J. Bacteriol. 176:5160-5162, 1994). The Na+-ATPase complex was purified to homogeneity. It migrates as a single band in native polyacrylamide gel electrophoresis and catalyzes Na+-stimulated ATPase activity. Denaturing gel electrophoresis showed that the complex consists of at least six different polypeptides with apparent molecular sizes of 66, 61, 51, 37, 26, and 17 kDa. The N-terminal sequences of the 66- and 51-kDa subunits were found to be significantly homologous to subunits A and B, respectively, of the Na+-translocating V-type ATPase of Enterococcus hirae. The purified V1V0 protein complex was reconstituted in a mixture of Escherichia coli phosphatidylethanolamine and egg yolk phosphatidylcholine and shown to catalyze the uptake of Na+ ions upon hydrolysis of ATP. Na+ transport was completely abolished by monensin, whereas valinomycin stimulated the uptake rate. This is indicative of electrogenic sodium transport. The presence of the protonophore SF6847 had no significant effect on the uptake, indicating that Na+ translocation is a primary event and in the cell is not accomplished by an H+-translocating pump in combination with an Na+-H+ antiporter. PMID:9023212

  11. Monochromaticity of orientation maps in v1 implies minimum variance for hypercolumn size.

    PubMed

    Afgoustidis, Alexandre

    2015-01-01

    In the primary visual cortex of many mammals, the processing of sensory information involves recognizing stimuli orientations. The repartition of preferred orientations of neurons in some areas is remarkable: a repetitive, non-periodic, layout. This repetitive pattern is understood to be fundamental for basic non-local aspects of vision, like the perception of contours, but important questions remain about its development and function. We focus here on Gaussian Random Fields, which provide a good description of the initial stage of orientation map development and, in spite of shortcomings we will recall, a computable framework for discussing general principles underlying the geometry of mature maps. We discuss the relationship between the notion of column spacing and the structure of correlation spectra; we prove formulas for the mean value and variance of column spacing, and we use numerical analysis of exact analytic formulae to study the variance. Referring to studies by Wolf, Geisel, Kaschube, Schnabel, and coworkers, we also show that spectral thinness is not an essential ingredient to obtain a pinwheel density of π, whereas it appears as a signature of Euclidean symmetry. The minimum variance property associated to thin spectra could be useful for information processing, provide optimal modularity for V1 hypercolumns, and be a first step toward a mathematical definition of hypercolumns. A measurement of this property in real maps is in principle possible, and comparison with the results in our paper could help establish the role of our minimum variance hypothesis in the development process. PMID:25859421

  12. Membrane Potential Dynamics of Spontaneous and Visually Evoked Gamma Activity in V1 of Awake Mice

    PubMed Central

    Perrenoud, Quentin; Pennartz, Cyriel M. A.; Gentet, Luc J.

    2016-01-01

    Cortical gamma activity (30–80 Hz) is believed to play important functions in neural computation and arises from the interplay of parvalbumin-expressing interneurons (PV) and pyramidal cells (PYRs). However, the subthreshold dynamics underlying its emergence in the cortex of awake animals remain unclear. Here, we characterized the intracellular dynamics of PVs and PYRs during spontaneous and visually evoked gamma activity in layers 2/3 of V1 of awake mice using targeted patch-clamp recordings and synchronous local field potentials (LFPs). Strong gamma activity patterned in short bouts (one to three cycles), occurred when PVs and PYRs were depolarizing and entrained their membrane potential dynamics regardless of the presence of visual stimulation. PV firing phase locked unconditionally to gamma activity. However, PYRs only phase locked to visually evoked gamma bouts. Taken together, our results indicate that gamma activity corresponds to short pulses of correlated background synaptic activity synchronizing the output of cortical neurons depending on external sensory drive. PMID:26890123

  13. V1.42In1.83Mo15Se19

    PubMed Central

    Gougeon, Patrick; Gall, Philippe; Salloum, Diala; Potel, Michel

    2010-01-01

    The structure of the title compound, vanadium indium penta­deca­molybdenum nona­deca­selenide, V1.42In1.83Mo15Se19, is isotypic with In2.9Mo15Se19 [Grüttner et al. (1979 ▶). Acta Cryst. B35, 285–292]. It is characterized by two cluster units Mo6Sei 8Sea 6 and Mo9Sei 11Sea 6 (where i represents inner and a apical atoms) that are present in a 1:1 ratio. The cluster units are centered at Wyckoff positions 2b and 2c and have point-group symmetry and , respectively. The clusters are inter­connected through additional Mo—Se bonds. In the title compound, the V3+ cations replace the trivalent indium atoms present in In2.9Mo15Se19, and a deficiency is observed on the monovalent indium site. One Mo, one Se and the V atom are situated on mirror planes, and two other Se atoms and the In atom are situated on threefold rotation axes. PMID:21587348

  14. Mutations in KCNH1 and ATP6V1B2 cause Zimmermann-Laband syndrome.

    PubMed

    Kortüm, Fanny; Caputo, Viviana; Bauer, Christiane K; Stella, Lorenzo; Ciolfi, Andrea; Alawi, Malik; Bocchinfuso, Gianfranco; Flex, Elisabetta; Paolacci, Stefano; Dentici, Maria Lisa; Grammatico, Paola; Korenke, Georg Christoph; Leuzzi, Vincenzo; Mowat, David; Nair, Lal D V; Nguyen, Thi Tuyet Mai; Thierry, Patrick; White, Susan M; Dallapiccola, Bruno; Pizzuti, Antonio; Campeau, Philippe M; Tartaglia, Marco; Kutsche, Kerstin

    2015-06-01

    Zimmermann-Laband syndrome (ZLS) is a developmental disorder characterized by facial dysmorphism with gingival enlargement, intellectual disability, hypoplasia or aplasia of nails and terminal phalanges, and hypertrichosis. We report that heterozygous missense mutations in KCNH1 account for a considerable proportion of ZLS. KCNH1 encodes the voltage-gated K(+) channel Eag1 (Kv10.1). Patch-clamp recordings showed strong negative shifts in voltage-dependent activation for all but one KCNH1 channel mutant (Gly469Arg). Coexpression of Gly469Arg with wild-type KCNH1 resulted in heterotetrameric channels with reduced conductance at positive potentials but pronounced conductance at negative potentials. These data support a gain-of-function effect for all ZLS-associated KCNH1 mutants. We also identified a recurrent de novo missense change in ATP6V1B2, encoding the B2 subunit of the multimeric vacuolar H(+) ATPase, in two individuals with ZLS. Structural analysis predicts a perturbing effect of the mutation on complex assembly. Our findings demonstrate that KCNH1 mutations cause ZLS and document genetic heterogeneity for this disorder. PMID:25915598

  15. Cold-aggravated pain in humans caused by a hyperactive NaV1.9 channel mutant.

    PubMed

    Leipold, Enrico; Hanson-Kahn, Andrea; Frick, Miya; Gong, Ping; Bernstein, Jonathan A; Voigt, Martin; Katona, Istvan; Oliver Goral, R; Altmüller, Janine; Nürnberg, Peter; Weis, Joachim; Hübner, Christian A; Heinemann, Stefan H; Kurth, Ingo

    2015-01-01

    Gain-of-function mutations in the human SCN11A-encoded voltage-gated Na(+) channel NaV1.9 cause severe pain disorders ranging from neuropathic pain to congenital pain insensitivity. However, the entire spectrum of the NaV1.9 diseases has yet to be defined. Applying whole-exome sequencing we here identify a missense change (p.V1184A) in NaV1.9, which leads to cold-aggravated peripheral pain in humans. Electrophysiological analysis reveals that p.V1184A shifts the voltage dependence of channel opening to hyperpolarized potentials thereby conferring gain-of-function characteristics to NaV1.9. Mutated channels diminish the resting membrane potential of mouse primary sensory neurons and cause cold-resistant hyperexcitability of nociceptors, suggesting a mechanistic basis for the temperature dependence of the pain phenotype. On the basis of direct comparison of the mutations linked to either cold-aggravated pain or pain insensitivity, we propose a model in which the physiological consequence of a mutation, that is, augmented versus absent pain, is critically dependent on the type of NaV1.9 hyperactivity. PMID:26645915

  16. Role of spinal V1a receptors in regulation of arterial pressure during acute and chronic osmotic stress.

    PubMed

    Veitenheimer, Britta; Osborn, John W

    2011-02-01

    Vasopressinergic neurons in the paraventricular nucleus project to areas in the spinal cord from which sympathetic nerves originate. This pathway is hypothesized to be involved in the regulation of mean arterial pressure (MAP), particularly under various conditions of osmotic stress. Several studies measuring sympathetic nerve activity support this hypothesis. However, the evidence that spinal vasopressin influences MAP under physiological or pathophysiological conditions in conscious animals is limited. The purpose of this study was to investigate, in conscious rats, if the increases in MAP during acute or chronic osmotic stimuli are due to activation of spinal vasopressin (V1a) receptors. Three conditions of osmotic stress were examined: acute intravenous hypertonic saline, 24- and 48-h water deprivation, and 4 wk of DOCA-salt treatment. Rats were chronically instrumented with an indwelling catheter for intrathecal injections and a radiotelemeter to measure MAP. In normotensive rats, intrathecal vasopressin and V1a agonist increased MAP, heart rate, and motor activity; these responses were blocked by pretreatment with an intrathecal V1a receptor antagonist. However, when the intrathecal V1a antagonist was given during the three conditions of osmotic stress to investigate the role of "endogenous" vasopressin, the antagonist had no effect on MAP, heart rate, or motor activity. Contrary to the hypothesis suggested by previous studies, these findings indicate that spinal V1a receptors are not required for elevations of MAP under conditions of acute or chronic osmotic stress in conscious rats. PMID:21123759

  17. Mapping tRNA structure in solution using double-strand-specific ribonuclease V1 from cobra venom.

    PubMed Central

    Lockard, R E; Kumar, A

    1981-01-01

    A method for mapping all base-paired stems in both elongation and initiator tRNAs is described using double-stranded-specific ribonuclease V1 from the venom of the cobra Naja naja oxiana. 32p-end-labeled RNA is first partially digested with double-strand-specific V1 nuclease under near physiological conditions, and the resultant fragments are than electrophoretically fractionated by size in adjacent lanes of a polyacrylamide gel run in 90% formamide. After autoradiography, the base-paired nucleotides are definitively located by comparing V1 generated bands with fragments of known length produced by both Neurospora endonuclease and base-specific ribonucleases. Using the substrates yeast tRNAPhe an E, coli tRNAfMet of known three-dimensional structure, we find V1 nuclease to cleave entirely within every base-paired stem. Our studies also reveal that nuclease V1 will digest paired nucleotides not hydrogen-bonded by standard Watson-Crick base-pairing. In yeast tRNAPhe cleavage of both wobble base-pairs and nucleotides involved in tertiary base-base hydrogen bonding is demonstrated. Images PMID:7031604

  18. Evidence for involvement of central vasopressin V1b and V2 receptors in stress-induced baroreflex desensitization

    PubMed Central

    Milutinović-Smiljanić, Sanja; Šarenac, Olivera; Lozić-Djurić, Maja; Murphy, David; Japundžić-Žigon, Nina

    2013-01-01

    Background and Purpose It is well recognized that vasopressin modulates the neurogenic control of the circulation. Here, we report the central mechanisms by which vasopressin modulates cardiovascular response to stress induced by immobilization. Experimental Approach Experiments were performed in conscious male Wistar rats equipped with radiotelemetric device for continuous measurement of haemodynamic parameters: systolic and diastolic BP and heart rate (HR). The functioning of the spontaneous baro-receptor reflex (BRR) was evaluated using the sequence method and the following parameters were evaluated: BRR sensitivity (BRS) and BRR effectiveness index (BEI). Key Results Under baseline physiological conditions intracerebroventricular injection of 100 and 500 ng of selective non-peptide V1a or V1b or V2 receptor antagonist did not modify BP, HR and BRR. Rats exposed to 15 min long stress by immobilization exhibited increase of BP, HR, reduction of BRS and no change in BEI. Pretreatment of rats with V1a receptor antagonist did not modulate the BP, HR, BRS and BEI response to stress. Pretreatment of rats with V1b receptor and V2 receptor antagonist, at both doses, prevented BRR desensitization and tachycardia, but failed to modulate stress-induced hypertension. Conclusions and Implications Vasopressin by the stimulation of central V1b- and V2-like receptors mediates stress-induced tachycardia and BRR desensitization. If these mechanisms are involved, BRR desensitization in heart failure and hypertension associated with poor outcome, they could be considered as novel targets for cardiovascular drug development. PMID:23488898

  19. Cold-aggravated pain in humans caused by a hyperactive NaV1.9 channel mutant

    PubMed Central

    Leipold, Enrico; Hanson-Kahn, Andrea; Frick, Miya; Gong, Ping; Bernstein, Jonathan A.; Voigt, Martin; Katona, Istvan; Oliver Goral, R.; Altmüller, Janine; Nürnberg, Peter; Weis, Joachim; Hübner, Christian A.; Heinemann, Stefan H.; Kurth, Ingo

    2015-01-01

    Gain-of-function mutations in the human SCN11A-encoded voltage-gated Na+ channel NaV1.9 cause severe pain disorders ranging from neuropathic pain to congenital pain insensitivity. However, the entire spectrum of the NaV1.9 diseases has yet to be defined. Applying whole-exome sequencing we here identify a missense change (p.V1184A) in NaV1.9, which leads to cold-aggravated peripheral pain in humans. Electrophysiological analysis reveals that p.V1184A shifts the voltage dependence of channel opening to hyperpolarized potentials thereby conferring gain-of-function characteristics to NaV1.9. Mutated channels diminish the resting membrane potential of mouse primary sensory neurons and cause cold-resistant hyperexcitability of nociceptors, suggesting a mechanistic basis for the temperature dependence of the pain phenotype. On the basis of direct comparison of the mutations linked to either cold-aggravated pain or pain insensitivity, we propose a model in which the physiological consequence of a mutation, that is, augmented versus absent pain, is critically dependent on the type of NaV1.9 hyperactivity. PMID:26645915

  20. The Functional Property Changes of Muscular Na(v)1.4 and Cardiac Na(v)1.5 Induced by Scorpion Toxin BmK AGP-SYPU1 Mutants Y42F and Y5F.

    PubMed

    Meng, Xiangxue; Xu, Yijia; Zhao, Mingyi; Wang, Fangyang; Ma, Yuanyuan; Jin, Yao; Liu, Yanfeng; Song, Yongbo; Zhang, Jinghai

    2015-05-19

    Scorpion toxins are invaluable therapeutic leads and pharmacological tools which influence the voltage-gated sodium channels. However, the details were still unclear about the structure-function relationship of scorpion toxins on VGSC subtypes. In the previous study, we reported one α-type scorpion toxin Bmk AGP-SYPU1 and its two mutants (Y5F and Y42F) which had been demonstrated to ease pain in mice acetic acid writhing test. However, the function of Bmk AGP-SYPU1 on VGSCs is still unknown. In this study, we examined the effects of BmK AGP-SYPU1 and its two mutants (Y5F and Y42F) on hNa(v)1.4 and hNa(v)1.5 heterologously expressed CHO cell lines by using Na⁺-specialized fluorescent dye and whole-cell patch clamp. The data showed that BmK AGP-SYPU1 displayed as an activator of hNa(v)1.4 and hNa(v)1.5, which might indeed contribute to its biotoxicity to muscular and cardiac system and exhibited the functional properties of both the α-type and β-type scorpion toxin. Notably, Y5F mutant exhibited lower activatory effects on hNa(v)1.4 and hNa(v)1.5 compared with BmK AGP-SYPU1. Y42F was an enhanced activator and confirmed that the conserved Tyr42 was the key amino acid involved in bioactivity or biotoxicity. These data provided a deep insight into the structure-function relationship of BmK AGP-SYPU1, which may be the guidance for engineering α-toxin with high selectivity on VGSC subtypes. PMID:25919575

  1. Detection and spectroscopy of the v1 + v3 band of N2O by difference-frequency spectrometer at 3 microm.

    PubMed

    Bruno, A; Pesce, G; Rusciano, G; Sasso, A

    2002-09-01

    We report the realisation of a laser spectrometer in the mid-infrared spectral region based on difference-frequency generation in a periodically poled LiNbO3 crystal. Tunable coherent radiation around 3 microm was produced by mixing a diode-pumped monolithic cw Nd-YAG laser and an injection-locked diode laser at 0.785 microm. High sensitivity N2O detection was demonstrated by observing pure absorption spectra of lines in the v1 + v3 combination band. We estimate a minimum detectable pressure of pure N2O of 1 x 10(-2) Pa with 0.9 m absorption path-length, corresponding to an absorbance of 3 x 10(-4). Nitrous oxide was also detected in presence of O2, N2 and air. Collisional broadening coefficients for the P(33) line at 3447.678 per cm are reported for N2O-N2 and N2O-O2 mixtures. PMID:12353698

  2. Vscape V1.1.0. An interactive tool for metastable vacua

    NASA Astrophysics Data System (ADS)

    van den Broek, Korneel

    2008-01-01

    Vscape is an interactive tool for studying the one-loop effective potential of an ungauged supersymmetric model of chiral multiplets. The program allows the user to define a supersymmetric model by specifying the superpotential. The F-terms and the scalar and fermionic mass matrices are calculated symbolically. The program then allows you to search numerically for (meta)stable minima of the one-loop effective potential. Additional commands enable you to further study specific minima, by, e.g., computing the mass spectrum for those vacua. Vscape combines the flexibility of symbolic software, with the speed of a numerical package. Program summaryProgram title:Vscape 1.1.1 Catalogue identifier: ADZW_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADZW_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 80 507 No. of bytes in distributed program, including test data, etc.: 6 708 938 Distribution format: tar.gz Programming language: C++ Computer: Pentium 4 PC Computers: need (GNU) C++ compiler, Linux standard GNU installation (./configure; make; make install). A precompiled Windows XP version is included in the distribution package Operating system: Linux, Windows XP using cygwin RAM: 10 MB Word size: 32 bits Classification: 11.6 External routines: GSL ( http://www.gnu.org/software/gsl/), CLN ( http://www.ginac.de/CLN/), GiNaC ( http://directory.fsf.org/GiNaC.html) Nature of problem:Vscape is an interactive tool for studying the one-loop effective potential of an ungauged supersymmetric model of chiral multiplets. The program allows the user to define a supersymmetric model by specifying the superpotential. The F-terms and the scalar and fermionic mass matrices are calculated symbolically. The program then allows you to search numerically for (meta)stable minima of

  3. Application of the MASH v1.0 Code System to radiological warfare radiation threats

    SciTech Connect

    Johnson, J.O.; Santoro, R.T.; Smith, M.S.

    1994-03-01

    Nuclear hardening capabilities of US and foreign ground force systems is a primary concern of the Department of Defense (DoD) and US Army. The Monte Carlo Adjoint Shielding Code System -- MASH v1.0 was developed at Oak Ridge National Laboratory (ORNL) to analyze these capabilities, i.e. the shielding effectiveness, for prompt radiation from a nuclear weapon detonation. Rapidly changing world events and the proliferation of nuclear weapons related technology have increased the kinds of nuclear threats to include intentionally dispersed radiation sources and fallout from tactical nuclear weapons used in the modern AirLand battlefield scenario. Consequently, a DoD area of increasing interest focuses on determining the shielding effectiveness of foreign and US armored vehicles to radiological warfare and fallout radiation threats. To demonstrate the applicability of MASH for analyzing dispersed radiation source problems, calculations have been completed for two distributed sources; a dispersed radiation environment simulated by a uniformly distributed {sup 60}Co source, and a {sup 235}U fission weapon fallout source. Fluence and dose assessments were performed for the free-field, the inside of a steel-walled two-meter box, in a phantom standing in the free-field, and in a phantom standing in the two-meter box. The results indicate substantial radiation protection factors for the {sup 60}Co dispersed radiation source and the fallout source compared to the prompt radiation protection factors. The dose protection factors ranged from 40 to 95 for the two-meter box and from 55 to 123 for the mid-gut position of the phantom standing in the box. The results further indicate that a {sup 60}Co source might be a good first order approximation for a tactical fission weapon fallout protection factor analysis.

  4. Primate area V1: largest response gain for receptive fields in the straight-ahead direction.

    PubMed

    Przybyszewski, Andrzej W; Kagan, Igor; Snodderly, D Max

    2014-10-01

    Although neuronal responses in behaving monkeys are typically studied while the monkey fixates straight ahead, it is known that eye position modulates responses of visual neurons. The modulation has been found to enhance neuronal responses when the receptive field is placed in the straight-ahead position for neurons receiving input from the peripheral but not the central retina. We studied the effect of eye position on the responses of V1 complex cells receiving input from the central retina (1.1-5.7° eccentricity) while minimizing the effect of fixational eye movements. Contrast response functions were obtained separately with drifting light and dark bars. Data were fit with the Naka-Rushton equation: r(c)=Rmax×c/(c+c50)+s, where r(c) is mean spike rate at contrast c, Rmax is the maximum response, c50 is the contrast that elicits half of Rmax, and s is the spontaneous activity. Contrast sensitivity as measured by c50 was not affected by eye position. For dark bars, there was a statistically significant decline in the normalized Rmax with increasing deviation from straight ahead. Data for bright bars showed a similar trend with a less rapid decline. Our results indicate that neurons representing the central retina show a bias for the straight-ahead position resulting from modulation of the response gain without an accompanying modulation of contrast sensitivity. The modulation is especially obvious for dark stimuli, which might be useful for directing attention to hazardous situations such as dark holes or shadows concealing important objects (Supplement 1: Video Abstract, Supplemental digital content 1, http://links.lww.com/WNR/A295). PMID:25055141

  5. Topography and homogeneity of monkey V1 studied through subdurally recorded pattern-evoked potentials.

    PubMed

    Dagnelie, G; Spekreijse, H; van Dijk, B

    1989-12-01

    Using small checkerboard stimulus fields, we have recorded visually evoked potentials (VEPs) in an alert rhesus monkey from an array of 35 electrodes chronically implanted between dura and arachnoid to study mass neuronal activity in striate and peristriate visual cortex. Although the principal purpose of this work was to study in detail cortical mapping in this particular animal for future intracortical recordings, we report here the usefulness of our approach for the non-invasive study of cortical processing, in particular of cortical magnification and receptive-field properties over the central 6 degrees of the visual field. The striate and extrastriate components in the pattern onset VEP both have a double negative-going waveform, with N-P-N peak latencies of 75-100-135 ms and 90-115-160 ms, respectively, for small element sizes and moderate contrasts; latencies may be 5 ms shorter for large element sizes and high contrast. We found little activity at electrode locations over visual areas beyond V2. The waveforms and timing permit some careful speculation concerning intracortical processing and VEP generation. The complex logarithmic form of the retinotopical projection provides a satisfactory model for our data, if a value of 1-1.2 degrees is used for the offset parameter a. Our data suggest that the most abundant receptive-field size in foveal striate cortex has a center diameter of 12'. This size remains constant up to 2 degrees eccentricity, and increases only slowly up to 4 degrees. The smallest receptive-field sizes seem to be independent of eccentricity throughout the central 4 degrees of V1, with a value of 4-8', in agreement with single-cell data reported by Dow et al. (1981) and Van Essen et al. (1984). PMID:2487121

  6. Phase Locking of Multiple Single Neurons to the Local Field Potential in Cat V1.

    PubMed

    Martin, Kevan A C; Schröder, Sylvia

    2016-02-24

    The local field potential (LFP) is thought to reflect a temporal reference for neuronal spiking, which may facilitate information coding and orchestrate the communication between neural populations. To explore this proposed role, we recorded the LFP and simultaneously the spike activity of one to three nearby neurons in V1 of anesthetized cats during the presentation of drifting sinusoidal gratings, binary dense noise stimuli, and natural movies. In all stimulus conditions and during spontaneous activity, the average LFP power at frequencies >20 Hz was higher when neurons were spiking versus not spiking. The spikes were weakly but significantly phase locked to all frequencies of the LFP. The average spike phase of the LFP was stable across high and low levels of LFP power, but the strength of phase locking at low frequencies (≤10 Hz) increased with increasing LFP power. In a next step, we studied how strong stimulus responses of single neurons are reflected in the LFP and the LFP-spike relationship. We found that LFP power was slightly increased and phase locking was slightly stronger during strong compared with weak stimulus-locked responses. In summary, the coupling strength between high frequencies of the LFP and spikes was not strongly modulated by LFP power, which is thought to reflect spiking synchrony, nor was it strongly influenced by how strongly the neuron was driven by the stimulus. Furthermore, a comparison between neighboring neurons showed no clustering of preferred LFP phase. We argue that hypotheses on the relevance of phase locking in their current form are inconsistent with our findings. PMID:26911695

  7. Quality Assessment and Collection V1.1 Reprocessing of the Suomi NPP VIIRS LAND Records

    NASA Astrophysics Data System (ADS)

    Devadiga, S.; Davidson, C. C.; Sarkar, S.; Ye, G.; Hattori, M.; Praderas, C.; Kalb, V.; Nguyen, A.; Hamilton, C.; Kuyper, J.; Roman, M. O.; Mauoka, E.

    2014-12-01

    The Land Product Evaluation and Algorithm Testing Element (PEATE) is an important element of the Suomi National Polar-orbiting Partnership (SNPP) at NASA's Goddard Space Flight Center. The primary goals of NASA's Land PEATE are to assess the quality of the Visible Infrared Imaging Radiometer Suite (VIIRS) Land operational products made by the Interface Data Processing System (IDPS), and to recommend improvements to the operational algorithms to meet NASA's Land science needs. The Land PEATE uses a version of the MODIS Adaptive Processing System (MODAPS), NPPDAPS, which has been modified to run the IDPS operational algorithms, as well as software provided by the NASA SNPP Land Science Team. Since the early pre-launch period (c. 2009) the Land PEATE has used the MODIS Land Data Operational Product Evaluation (LDOPE) team for evaluation of the data records generated by NPPDAPS.In June 2014, Land PEATE completed Collection V1.1 reprocessing of the SNPP VIIRS Land products from the beginning (Jan 19, 2012) of the SNPP mission to current day using the best of the IDPS operational and NASA Land science team provided algorithms. The processing used the refined LUTs provided by the NASA VIIRS Calibration Support Team (VCST) for the L1B Sensor Data Records (SDR), including LUTs for calibration and stray light correction of the VIIRS Day/Night Band. In addition to generating the operational SDRs, Intermediate Products (IPs), and Environmental Data Records (EDRs) this reprocessing also produced Diagnostics Data Records, MODIS heritage L3 gridded products using the VIIRS observations. This paper describes approaches used to assess the quality of the products from operational processing and reprocessing of VIIRS records at Land PEATE. The paper also presents results from inter-comparison of records from this reprocessing with the MODIS heritage products. Our analysis verified that MODIS quality data records can be produced using the VIIRS observations, however with additional

  8. Neurons in cat V1 show significant clustering by degree of tuning

    PubMed Central

    Ziskind, Avi J.; Emondi, Al A.; Kurgansky, Andrei V.; Rebrik, Sergei P.

    2015-01-01

    Neighboring neurons in cat primary visual cortex (V1) have similar preferred orientation, direction, and spatial frequency. How diverse is their degree of tuning for these properties? To address this, we used single-tetrode recordings to simultaneously isolate multiple cells at single recording sites and record their responses to flashed and drifting gratings of multiple orientations, spatial frequencies, and, for drifting gratings, directions. Orientation tuning width, spatial frequency tuning width, and direction selectivity index (DSI) all showed significant clustering: pairs of neurons recorded at a single site were significantly more similar in each of these properties than pairs of neurons from different recording sites. The strength of the clustering was generally modest. The percent decrease in the median difference between pairs from the same site, relative to pairs from different sites, was as follows: for different measures of orientation tuning width, 29–35% (drifting gratings) or 15–25% (flashed gratings); for DSI, 24%; and for spatial frequency tuning width measured in octaves, 8% (drifting gratings). The clusterings of all of these measures were much weaker than for preferred orientation (68% decrease) but comparable to that seen for preferred spatial frequency in response to drifting gratings (26%). For the above properties, little difference in clustering was seen between simple and complex cells. In studies of spatial frequency tuning to flashed gratings, strong clustering was seen among simple-cell pairs for tuning width (70% decrease) and preferred frequency (71% decrease), whereas no clustering was seen for simple-complex or complex-complex cell pairs. PMID:25652921

  9. CaV1.2 beta-subunit coordinates CaMKII-triggered cardiomyocyte death and afterdepolarizations.

    PubMed

    Koval, Olha M; Guan, Xiaoquan; Wu, Yuejin; Joiner, Mei-Ling; Gao, Zhan; Chen, Biyi; Grumbach, Isabella M; Luczak, Elizabeth D; Colbran, Roger J; Song, Long-Sheng; Hund, Thomas J; Mohler, Peter J; Anderson, Mark E

    2010-03-16

    Excessive activation of calmodulin kinase II (CaMKII) causes arrhythmias and heart failure, but the cellular mechanisms for CaMKII-targeted proteins causing disordered cell membrane excitability and myocardial dysfunction remain uncertain. Failing human cardiomyocytes exhibit increased CaMKII and voltage-gated Ca(2+) channel (Ca(V)1.2) activity, and enhanced expression of a specific Ca(V)1.2 beta-subunit protein isoform (beta(2a)). We recently identified Ca(V)1.2 beta(2a) residues critical for CaMKII phosphorylation (Thr 498) and binding (Leu 493), suggesting the hypothesis that these amino acids are crucial for cardiomyopathic consequences of CaMKII signaling. Here we show WT beta(2a) expression causes cellular Ca(2+) overload, arrhythmia-triggering cell membrane potential oscillations called early afterdepolarizations (EADs), and premature death in paced adult rabbit ventricular myocytes. Prevention of intracellular Ca(2+) release by ryanodine or global cellular CaMKII inhibition reduced EADs and improved cell survival to control levels in WT beta(2a)-expressing ventricular myocytes. In contrast, expression of beta(2a) T498A or L493A mutants mimicked the protective effects of ryanodine or global cellular CaMKII inhibition by reducing Ca(2+) entry through Ca(V)1.2 and inhibiting EADs. Furthermore, Ca(V)1.2 currents recorded from cells overexpressing CaMKII phosphorylation- or binding-incompetent beta(2a) subunits were incapable of entering a CaMKII-dependent high-activity gating mode (mode 2), indicating that beta(2a) Thr 498 and Leu 493 are required for Ca(V)1.2 activation by CaMKII in native cells. These data show that CaMKII binding and phosphorylation sites on beta(2a) are concise but pivotal components of a molecular and biophysical and mechanism for EADs and impaired survival in adult cardiomyocytes. PMID:20194790

  10. Persistent modification of Na{sub v}1.9 following chronic exposure to insecticides and pyridostigmine bromide

    SciTech Connect

    Nutter, Thomas J. Cooper, Brian Y.

    2014-06-15

    Many veterans of the 1991 Gulf War (GW) returned from that conflict with a widespread chronic pain affecting deep tissues. Recently, we have shown that a 60 day exposure to the insecticides permethrin, chlorpyrifos, and pyridostigmine bromide (NTPB) had little influence on nociceptor action potential forming Na{sub v}1.8, but increased K{sub v}7 mediated inhibitory currents 8 weeks after treatment. Using the same exposure regimen, we used whole cell patch methods to examine whether the influences of NTPB could be observed on Na{sub v}1.9 expressed in muscle and vascular nociceptors. During a 60 day exposure to NTPB, rats exhibited lowered muscle pain thresholds and increased rest periods, but these measures subsequently returned to normal levels. Eight and 12 weeks after treatments ceased, DRG neurons were excised from the sensory ganglia. Whole cell patch studies revealed little change in voltage dependent activation and deactivation of Na{sub v}1.9, but significant increases in the amplitude of Na{sub v}1.9 were observed 8 weeks after exposure. Cellular studies, at the 8 week delay, revealed that NTPB also significantly prolonged action potential duration and afterhyperpolarization (22 °C). Acute application of permethrin (10 μM) also increased the amplitude of Na{sub v}1.9 in skin, muscle and vascular nociceptors. In conclusion, chronic exposure to Gulf War agents produced long term changes in the amplitude of Na{sub v}1.9 expressed in muscle and vascular nociceptors. The reported increases in K{sub v}7 amplitude may have been an adaptive response to increased Na{sub v}1.9, and effectively suppressed behavioral pain measures in the post treatment period. Factors that alter the balance between Na{sub v}1.9 and K{sub v}7 could release spontaneous discharge and produce chronic deep tissue pain. - Highlights: • Rats were treated 60 days with permethrin, chlorpyrifos and pyridostigmine bromide. • 8 weeks after treatments, Nav1.9 activation and deactivation were

  11. A temporal frequency-dependent functional architecture in human V1 revealed by high-resolution fMRI.

    PubMed

    Sun, Pei; Ueno, Kenichi; Waggoner, R Allen; Gardner, Justin L; Tanaka, Keiji; Cheng, Kang

    2007-11-01

    Although cortical neurons with similar functional properties often cluster together in a columnar organization, only ocular dominance columns, the columnar structure representing segregated anatomical input (from one of the two eyes), have been found in human primary visual cortex (V1). It has yet to be shown whether other columnar organizations that arise only from differential responses to stimulus properties also exist in human V1. Using high-resolution functional magnetic resonance imaging, we have found such a functional architecture containing domains that respond preferentially to either low or high temporal frequency. PMID:17934459

  12. Spectroscopy of the W Virginis star V1 (K 307 ) in the globular cluster M12

    NASA Astrophysics Data System (ADS)

    Klochkova, V. G.; Panchuk, V. E.; Tavolganskaya, N. S.; Kovtyukh, V. V.

    2003-11-01

    High-resolution CCD spectra have been obtained for the first time for the W Virginis star V1 (K 307) in the globular cluster M12 and its closest neighbor K 307b ( m pg=14m; the angular distance from the W Vir star is δ<1 arcsec). We determined the fundamental parameters ( T eff=5600 K, log g=1.3, and T eff=4200 K, log g=1.0 for the W Vir star and the neighboring star, respectively) and their detailed chemical composition. The derived metallicities of the two stars ([Fe/H]=-1.27 and -1.22 relative to the solar value) are in good agreement with the metallicities of other cluster members. Changed CNO abundances were found in the atmosphere of the W Vir star: a small carbon overabundance, [C/Fe]=+0.30 dex, and a large nitrogen overabundance, [N/Fe]=+1.15 dex, with oxygen being underabundant, [O/Fe]≈-0.2 dex. The C/O ratio is ≥1. Na and the α-process elements Mg, Al, Si, Ca, and Ti are variously enhanced with respect to iron. We found an enhanced abundance of s-process metals relative to iron: [X/Fe]=+0.34 for Y, Zr, and Ba. The overabundance of the heavier metals La, Ce, and Nd with respect to iron is larger: [X/Fe]=+0.49. The largest overabundance was found for the r-process element europium, [Eu/Fe]=+0.82. The spectrum of the W Vir star exhibits the Hα and Hβ absorption-emission profiles and the He I λ5876 Å emission line, which are traditionally interpreted as a result of shock passage in the atmosphere. However, the radial velocities determined from absorption and emission features are in conflict with the formation pattern of a strong shock. The high luminosity log L/ L ⊙ = 2.98, the chemica peculiarities, and the spectral peculiarity are consistent with the post-AGB evolution in the instability strip. The pattern of relative elemental abundances [X/Fe]in the atmosphere of the neighboring star K 307b is solar. Statistically significant differences were found only for sodium and α-process elements: the mean overabundance of light metals is [X/Fe]=+0.35.

  13. Extraction of Surface-Related Features in a Recurrent Model of V1-V2 Interactions

    PubMed Central

    Weidenbacher, Ulrich; Neumann, Heiko

    2009-01-01

    Background Humans can effortlessly segment surfaces and objects from two-dimensional (2D) images that are projections of the 3D world. The projection from 3D to 2D leads partially to occlusions of surfaces depending on their position in depth and on viewpoint. One way for the human visual system to infer monocular depth cues could be to extract and interpret occlusions. It has been suggested that the perception of contour junctions, in particular T-junctions, may be used as cue for occlusion of opaque surfaces. Furthermore, X-junctions could be used to signal occlusion of transparent surfaces. Methodology/Principal Findings In this contribution, we propose a neural model that suggests how surface-related cues for occlusion can be extracted from a 2D luminance image. The approach is based on feedforward and feedback mechanisms found in visual cortical areas V1 and V2. In a first step, contours are completed over time by generating groupings of like-oriented contrasts. Few iterations of feedforward and feedback processing lead to a stable representation of completed contours and at the same time to a suppression of image noise. In a second step, contour junctions are localized and read out from the distributed representation of boundary groupings. Moreover, surface-related junctions are made explicit such that they are evaluated to interact as to generate surface-segmentations in static images. In addition, we compare our extracted junction signals with a standard computer vision approach for junction detection to demonstrate that our approach outperforms simple feedforward computation-based approaches. Conclusions/Significance A model is proposed that uses feedforward and feedback mechanisms to combine contextually relevant features in order to generate consistent boundary groupings of surfaces. Perceptually important junction configurations are robustly extracted from neural representations to signal cues for occlusion and transparency. Unlike previous proposals

  14. High heat transfer oxidizer heat exchanger design and analysis. [RL10-2B engine

    NASA Technical Reports Server (NTRS)

    Kmiec, Thomas D.; Kanic, Paul G.; Peckham, Richard J.

    1987-01-01

    The RL10-2B engine, a derivative of the RL10, is capable of multimode thrust operation. This engine operates at two low thrust levels: tank head idle (THI), which is approximately 1 to 2% of full thrust, and pumped idle (PI), which is 10% of full thrust. Operation at THI provides vehicle propellant settling thrust and efficient engine thermal conditioning; PI operation provides vehicle tank pre-pressurization and maneuver thrust for low-g deployment. Stable combustion of the RL10-2B engine during the low thrust operating modes can be accomplished by using a heat exchanger to supply gaseous oxygen to the propellant injector. The oxidizer heat exchanger (OHE) vaporizes the liquid oxygen using hydrogen as the energy source. The design, concept verification testing and analysis for such a heat exchanger is discussed. The design presented uses a high efficiency compact core to vaporize the oxygen, and in the self-contained unit, attenuates any pressure and flow oscillations which result from unstable boiling in the core. This approach is referred to as the high heat transfer design. An alternative approach which prevents unstable boiling of the oxygen by limiting the heat transfer is referred to as the low heat transfer design and is reported in Pratt & Whitney report FR-19135-2.

  15. A monoclonal antibody that targets a NaV1.7 channel voltage sensor for pain and itch relief

    PubMed Central

    Lee, Jun-Ho; Park, Chul-Kyu; Chen, Gang; Han, Qingjian; Xie, Rou-Gang; Liu, Tong; Ji, Ru-Rong; Lee, Seok-Yong

    2014-01-01

    Summary Voltage-gated sodium (NaV) channels control the upstroke of the action potentials in excitable cells. Multiple studies have shown distinct roles of NaV channel subtypes in human physiology and diseases, but subtype-specific therapeutics are lacking and the current efforts have been limited to small molecules. Here we present a monoclonal antibody that targets the voltage-sensor paddle of NaV1.7, the subtype critical for pain sensation. This antibody not only inhibits NaV1.7 with high selectivity but also effectively suppresses inflammatory and neuropathic pain in mice. Interestingly, the antibody inhibits acute and chronic itch, despite well-documented differences in pain and itch modulation. Using this antibody, we discovered that NaV1.7 plays a key role in spinal cord nociceptive and pruriceptive synaptic transmission. Our studies reveal that NaV1.7 is a target for itch management and the antibody has therapeutic potential for suppressing pain and itch. Our antibody strategy may have broad applications for voltage-gated cation channels. PMID:24856969

  16. Alterations of Ca(v)1.2 and 5-hydroxytryptamine in rat hearts after positional asphyxia.

    PubMed

    Li, X-F; Huang, Q-Y

    2015-01-01

    We investigated alterations of cardiac Ca(v)1.2 and 5-hydroxytryptamine (5-HT) associated with positional asphyxia. Male rats were divided into five groups: a control group with no restraint, group 1 restrained for 1 h, group 2 restrained for 2 h, group 3 restrained for 4 h, and group 4 restrained for 8 h. The rats that were restrained for 8 h ultimately suffered fatal asphyxia. After the restraint periods, the rats were sacrificed and immunohistochemistry was performed to evaluate the expressions of Ca(v)1.2 and 5-HT in the heart. Sections were analyzed by digital image analysis. Cardiac expression of Ca(v)1.2 and 5-HT proteins were significantly decreased by positional asphyxia in the rat, shown by integrated optical density (IOD) compared to controls. Our findings indicate that Ca(v)1.2 and 5-HT alterations could cause abnormal cardiac function, and the proteins investigated here may be useful for investigating the mechanisms underlying positional asphyxia. PMID:26471941

  17. Functional Characterization of the Extra-Classical Receptive Field in Macaque V1: Contrast, Orientation, and Temporal Dynamics

    PubMed Central

    Henry, Christopher A.; Joshi, Siddhartha; Xing, Dajun; Shapley, Robert M.; Hawken, Michael J.

    2013-01-01

    Neurons in primary visual cortex, V1, very often have extra-classical receptive fields (eCRFs). The eCRF is defined as the region of visual space where stimuli cannot elicit a spiking response but can modulate the response of a stimulus in the classical receptive field (CRF). We investigated the dependence of the eCRF on stimulus contrast and orientation in macaque V1 cells for which the laminar location was determined. The eCRF was more sensitive to contrast than the CRF across the whole population of V1 cells with the greatest contrast differential in layer 2/3. We confirmed that many V1 cells experience stronger suppression for collinear than orthogonal stimuli in the eCRF. Laminar analysis revealed that the predominant bias for collinear suppression was found in layers 2/3 and 4b. The laminar pattern of contrast and orientation dependence suggests that eCRF suppression may derive from different neural circuits in different layers, and may be comprised of two distinct components: orientation-tuned and untuned suppression. On average tuned suppression was delayed by about 25 milliseconds compared to the onset of untuned suppression. Therefore, response modulation by the eCRF develops dynamically and rapidly in time. PMID:23554504

  18. Exploring the ligand recognition properties of the human vasopressin V1a receptor using QSAR and molecular modeling studies.

    PubMed

    Contreras-Romo, Martha C; Martínez-Archundia, Marlet; Deeb, Omar; Slusarz, Magdalena J; Ramírez-Salinas, Gema; Garduño-Juárez, Ramón; Quintanar-Stephano, Andrés; Ramírez-Galicia, Guillermo; Correa-Basurto, José

    2014-02-01

    Vaptans are compounds that act as non-peptide vasopressin receptor antagonists. These compounds have diverse chemical structures. In this study, we used a combined approach of protein folding, molecular dynamics simulations, docking, and quantitative structure-activity relationship (QSAR) to elucidate the detailed interaction of the vasopressin receptor V1a (V1aR) with some of its blockers (134). QSAR studies were performed using MLR analysis and were gathered into one group to perform an artificial neural network (ANN) analysis. For each molecule, 1481 molecular descriptors were calculated. Additionally, 15 quantum chemical descriptors were calculated. The final equation was developed by choosing the optimal combination of descriptors after removing the outliers. Molecular modeling enabled us to obtain a reliable tridimensional model of V1aR. The docking results indicated that the great majority of ligands reach the binding site under π-π, π-cation, and hydrophobic interactions. The QSAR studies demonstrated that the heteroatoms N and O are important for ligand recognition, which could explain the structural diversity of ligands that reach V1aR. PMID:24010681

  19. Using AppleWorks V1.3 To Construct Data Base Files for the Apple IIe Computer. Second Edition.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.

    This step-by-step guide to using AppleWorks V1.3 to construct database files for the Apple IIe computer covers (1) program loading; (2) selecting the add files to the desktop option; (3) naming the file; (4) the blinking block cursor; (5) naming categories or fields; (6) moving to insert data; (7) inserting data; (8) changing database file…

  20. Using AppleWorks V1.3 To Construct Word Processing Files for the Apple IIe Computer. Second Edition.

    ERIC Educational Resources Information Center

    Schlenker, Richard M.

    This step-by-step guide to using AppleWorks V1.3 to construct word processing files for the Apple IIe computer covers (1) program loading; (2) selecting the add files to the desktop option; (3) selecting a different disk; (4) selecting disk 2; (5) selecting the word processor option; (6) naming the file; (7) setting tabs; (8) selecting print…

  1. Early representation of shape by onset synchronization of border-ownership-selective cells in the V1-V2 network.

    PubMed

    Hatori, Yasuhiro; Sakai, Ko

    2014-04-01

    Construction of surface is a crucial step toward the representation of shape through the integration of local information. Physiological studies have reported that the primary visual cortex (V1) codes the medial axis (MA) that is a skeletal structure equidistant from nearby contours, suggesting the early representation of surface in V1. Although the neural basis of surface construction has not been clarified, the onset synchronization of border ownership (BO)-selective cells is a plausible candidate for the generation of surface. We investigated computationally the representation of surface in a biophysically detailed model of primate V1-V2 networks. The simulation results showed that the simultaneous arrival of signals from BO-selective cells evoked strong responses of V1 cells located around the MA. The simulation results lead to a prediction that the perception of the direction of figure (DOF) depends on the degree of synchronous presentation of contour. We conducted a psychophysical experiment and showed that the perception of the DOF is biased toward a highly synchronized contour. These results suggest a crucial role of the onset synchronization of BO-selective cells for the construction of early representation of shape. PMID:24695133

  2. Graded Ca²⁺/calmodulin-dependent coupling of voltage-gated CaV1.2 channels.

    PubMed

    Dixon, Rose E; Moreno, Claudia M; Yuan, Can; Opitz-Araya, Ximena; Binder, Marc D; Navedo, Manuel F; Santana, Luis F

    2015-01-01

    In the heart, reliable activation of Ca(2+) release from the sarcoplasmic reticulum during the plateau of the ventricular action potential requires synchronous opening of multiple CaV1.2 channels. Yet the mechanisms that coordinate this simultaneous opening during every heartbeat are unclear. Here, we demonstrate that CaV1.2 channels form clusters that undergo dynamic, reciprocal, allosteric interactions. This 'functional coupling' facilitates Ca(2+) influx by increasing activation of adjoined channels and occurs through C-terminal-to-C-terminal interactions. These interactions are initiated by binding of incoming Ca(2+) to calmodulin (CaM) and proceed through Ca(2+)/CaM binding to the CaV1.2 pre-IQ domain. Coupling fades as [Ca(2+)]i decreases, but persists longer than the current that evoked it, providing evidence for 'molecular memory'. Our findings suggest a model for CaV1.2 channel gating and Ca(2+)-influx amplification that unifies diverse observations about Ca(2+) signaling in the heart, and challenges the long-held view that voltage-gated channels open and close independently. PMID:25714924

  3. Graded Ca2+/calmodulin-dependent coupling of voltage-gated CaV1.2 channels

    PubMed Central

    Dixon, Rose E; Moreno, Claudia M; Yuan, Can; Opitz-Araya, Ximena; Binder, Marc D; Navedo, Manuel F; Santana, Luis F

    2015-01-01

    In the heart, reliable activation of Ca2+ release from the sarcoplasmic reticulum during the plateau of the ventricular action potential requires synchronous opening of multiple CaV1.2 channels. Yet the mechanisms that coordinate this simultaneous opening during every heartbeat are unclear. Here, we demonstrate that CaV1.2 channels form clusters that undergo dynamic, reciprocal, allosteric interactions. This ‘functional coupling’ facilitates Ca2+ influx by increasing activation of adjoined channels and occurs through C-terminal-to-C-terminal interactions. These interactions are initiated by binding of incoming Ca2+ to calmodulin (CaM) and proceed through Ca2+/CaM binding to the CaV1.2 pre-IQ domain. Coupling fades as [Ca2+]i decreases, but persists longer than the current that evoked it, providing evidence for ‘molecular memory’. Our findings suggest a model for CaV1.2 channel gating and Ca2+-influx amplification that unifies diverse observations about Ca2+ signaling in the heart, and challenges the long-held view that voltage-gated channels open and close independently. DOI: http://dx.doi.org/10.7554/eLife.05608.001 PMID:25714924

  4. V1 and V2b interneurons secure the alternating flexor-extensor motor activity mice require for limbed locomotion

    PubMed Central

    Zhang, Jingming; Lanuza, Guillermo M.; Britz, Olivier; Wang, Zhi; Siembab, Valerie C.; Zhang, Ying; Velasquez, Tomoko; Alvarez, Francisco J.; Frank, Eric; Goulding, Martyn

    2014-01-01

    SUMMARY The reciprocal activation of flexor and extensor muscles constitutes the fundamental mechanism that tetrapod vertebrates use for locomotion and limb-driven reflex behaviors. This aspect of motor coordination is controlled by inhibitory neurons in the spinal cord; however, the identity of the spinal interneurons that serve this function is not known. Here we show that the production of an alternating flexor-extensor motor rhythm depends on the composite activities of two classes of ventrally-located inhibitory neurons, V1 and V2b interneurons (INs). Abrogating V1 and V2b IN-derived neurotransmission in the isolated spinal cord results in a synchronous pattern of L2 flexor-related and L5 extensor-related locomotor activity. Mice lacking V1 and V2b inhibition are unable to articulate their limb joints and display marked deficits in limb-driven reflex movements. Taken together, these findings identify V1- and V2b-derived neurons as the core interneuronal components of the limb central pattern generator (CPG) that coordinate flexor-extensor motor activity. PMID:24698273

  5. V1 and v2b interneurons secure the alternating flexor-extensor motor activity mice require for limbed locomotion.

    PubMed

    Zhang, Jingming; Lanuza, Guillermo M; Britz, Olivier; Wang, Zhi; Siembab, Valerie C; Zhang, Ying; Velasquez, Tomoko; Alvarez, Francisco J; Frank, Eric; Goulding, Martyn

    2014-04-01

    Reciprocal activation of flexor and extensor muscles constitutes the fundamental mechanism that tetrapod vertebrates use for locomotion and limb-driven reflex behaviors. This aspect of motor coordination is controlled by inhibitory neurons in the spinal cord; however, the identity of the spinal interneurons that serve this function is not known. Here, we show that the production of an alternating flexor-extensor motor rhythm depends on the composite activities of two classes of ventrally located inhibitory neurons, V1 and V2b interneurons (INs). Abrogating V1 and V2b IN-derived neurotransmission in the isolated spinal cord results in a synchronous pattern of L2 flexor-related and L5 extensor-related locomotor activity. Mice lacking V1 and V2b inhibition are unable to articulate their limb joints and display marked deficits in limb-driven reflex movements. Taken together, these findings identify V1- and V2b-derived neurons as the core interneuronal components of the limb central pattern generator (CPG) that coordinate flexor-extensor motor activity. PMID:24698273

  6. CATS-ISS_L2O_N-M7.2-V1-03_05kmPro

    Atmospheric Science Data Center

    2016-04-27

    CATS-ISS_L2O_N-M7.2-V1-03_05kmPro Project Title:  CATS Discipline:  Clouds Aerosols Version:  ... and Order:  ASDC Order Tool Product Browse Tool:  CATS Order Tool OPeNDAP Access:  OPeNDAP Parameters:  ...

  7. CATS-ISS_L2O_N-M7.2-V1-03_05kmLay

    Atmospheric Science Data Center

    2016-04-27

    CATS-ISS_L2O_N-M7.2-V1-03_05kmLay Project Title:  CATS Discipline:  Clouds Aerosols Version:  ... and Order:  ASDC Order Tool Product Browse Tool:  CATS Order Tool OPeNDAP Access:  OPeNDAP Parameters:  ...

  8. CATS-ISS_L2O_D-M7.2-V1-03_05kmLay

    Atmospheric Science Data Center

    2016-04-27

    CATS-ISS_L2O_D-M7.2-V1-03_05kmLay The Cloud-Aerosol Transport System (CATS) is a three wavelength, polarization-sensitive lidar that provides ... in the Earth's atmosphere. Project Title:  CATS Discipline:  Clouds Aerosols Version:  ...

  9. Molecular epidemiological analyses of Cryptosporidium parvum virus 1 (CSpV1), a symbiotic virus of Cryptosporidium parvum, in Japan.

    PubMed

    Murakoshi, Fumi; Ichikawa-Seki, Madoka; Aita, Junya; Yaita, Seiko; Kinami, Aiko; Fujimoto, Katsuhisa; Nishikawa, Yoshifumi; Murakami, Shin; Horimoto, Taisuke; Kato, Kentaro

    2016-01-01

    We show that Cryptosporidium parvum virus 1 (CSpV1), a member of the family Partitiviridae, genus Cryspovirus that can infect Cryptosporidium parvum, is a new candidate for high-resolution tool for tracing C. parvum. CSpV1 was detected in all C. parvum-positive samples tested. Phylogenetic analysis of dsRNA1 sequence from CSpV1 can distinguish infected areas of C. parvum on the national level. Sequences detected in samples from Iwate prefecture and other islands (Tanegashima, and Okinawa) belonged to a single clade. This system can differentiate the samples from Hokkaido and south part of Japan as well as from other countries. Samples from Iwate, Tanegashima, and Okinawa belonged to a single subclade, respectively. Therefore, the CSpV1 dsRNA sequences reflect the regional distribution of their host and have potential as a high-resolution tool to trace C. parvum IIaA15G2R1 subtype. PMID:26439535

  10. CATS-ISS_L2O_D-M7.2-V1-04_05kmLay

    Atmospheric Science Data Center

    2016-06-30

    CATS-ISS_L2O_D-M7.2-V1-04_05kmLay Project Title:  CATS Discipline:  Clouds Aerosols Version:  ... and Order:  ASDC Order Tool Product Browse Tool:  CATS Order Tool OPeNDAP Access:  OPeNDAP Parameters:  ...

  11. CATS-ISS_L2O_N-M7.2-V1-04_05kmPro

    Atmospheric Science Data Center

    2016-06-30

    CATS-ISS_L2O_N-M7.2-V1-04_05kmPro Project Title:  CATS Discipline:  Clouds Aerosols Version:  ... and Order:  ASDC Order Tool Product Browse Tool:  CATS Order Tool OPeNDAP Access:  OPeNDAP Parameters:  ...

  12. CATS-ISS_L2O_N-M7.2-V1-04_05kmLay

    Atmospheric Science Data Center

    2016-06-30

    CATS-ISS_L2O_N-M7.2-V1-04_05kmLay Project Title:  CATS Discipline:  Clouds Aerosols Version:  ... and Order:  ASDC Order Tool Product Browse Tool:  CATS Order Tool OPeNDAP Access:  OPeNDAP Parameters:  ...

  13. CATS-ISS_L2O_D-M7.2-V1-04_05kmPro

    Atmospheric Science Data Center

    2016-06-30

    CATS-ISS_L2O_D-M7.2-V1-04_05kmPro Project Title:  CATS Discipline:  Clouds Aerosols Version:  ... and Order:  ASDC Order Tool Product Browse Tool:  CATS Order Tool OPeNDAP Access:  OPeNDAP Parameters:  ...

  14. Release of Bet v 1 from birch pollen from 5 European countries. Results from the HIALINE study

    NASA Astrophysics Data System (ADS)

    Buters, Jeroen T. M.; Thibaudon, Michel; Smith, Matt; Kennedy, Roy; Rantio-Lehtimäki, Auli; Albertini, Roberto; Reese, Gerald; Weber, Bernhard; Galan, Carmen; Brandao, Rui; Antunes, Celia M.; Jäger, Siegfried; Berger, Uwe; Celenk, Sevcan; Grewling, Łukasz; Jackowiak, Bogdan; Sauliene, Ingrida; Weichenmeier, Ingrid; Pusch, Gudrun; Sarioglu, Hakan; Ueffing, Marius; Behrendt, Heidrun; Prank, Marje; Sofiev, Mikhail; Cecchi, Lorenzo; Hialine Working Group

    2012-08-01

    Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content of ambient air is unknown. We therefore monitored atmospheric concentrations of birch pollen grains and the matched major birch pollen allergen Bet v 1 simultaneously across Europe within the EU-funded project HIALINE (Health Impacts of Airborne Allergen Information Network). Pollen count was assessed with Hirst type pollen traps at 10 l min-1 at sites in France, United Kingdom, Germany, Italy and Finland. Allergen concentrations in ambient air were sampled at 800 l min-1 with a Chemvol® high-volume cascade impactor equipped with stages PM > 10 μm, 10 μm > PM > 2.5 μm, and in Germany also 2.5 μm > PM > 0.12 μm. The major birch pollen allergen Bet v 1 was determined with an allergen specific ELISA. Bet v 1 isoform patterns were analyzed by 2D-SDS-PAGE blots and mass spectrometric identification. Basophil activation was tested in an FcɛR1-humanized rat basophil cell line passively sensitized with serum of a birch pollen symptomatic patient. Compared to 10 previous years, 2009 was a representative birch pollen season for all stations. About 90% of the allergen was found in the PM > 10 μm fraction at all stations. Bet v 1 isoforms pattern did not vary substantially neither during ripening of pollen nor between different geographical locations. The average European allergen release from birch pollen was 3.2 pg Bet v 1/pollen and did not vary much between the European countries. However, in all countries a >10-fold difference in daily allergen release per pollen was measured which could be explained by long-range transport of pollen with a deviating allergen release. Basophil activation by ambient air extracts correlated better with airborne allergen than with pollen concentration. Although Bet v 1 is a mixture of different

  15. Release of Bet v 1 from birch pollen from 5 European countries. Results from the HIALINE study

    NASA Astrophysics Data System (ADS)

    The HIALINE working Group; Buters, Jeroen T. M.; Thibaudon, Michel; Smith, Matt; Kennedy, Roy; Rantio-Lehtimäki, Auli; Albertini, Roberto; Reese, Gerald; Weber, Bernhard; Galan, Carmen; Brandao, Rui; Antunes, Celia M.; Jäger, Siegfried; Berger, Uwe; Celenk, Sevcan; Grewling, Łukasz; Jackowiak, Bogdan; Sauliene, Ingrida; Weichenmeier, Ingrid; Pusch, Gudrun; Sarioglu, Hakan; Ueffing, Marius; Behrendt, Heidrun; Prank, Marje; Sofiev, Mikhail; Cecchi, Lorenzo

    2012-08-01

    Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content of ambient air is unknown. We therefore monitored atmospheric concentrations of birch pollen grains and the matched major birch pollen allergen Bet v 1 simultaneously across Europe within the EU-funded project HIALINE (Health Impacts of Airborne Allergen Information Network).Pollen count was assessed with Hirst type pollen traps at 10 l min-1 at sites in France, United Kingdom, Germany, Italy and Finland. Allergen concentrations in ambient air were sampled at 800 l min-1 with a Chemvol® high-volume cascade impactor equipped with stages PM > 10 μm, 10 μm > PM > 2.5 μm, and in Germany also 2.5 μm > PM > 0.12 μm. The major birch pollen allergen Bet v 1 was determined with an allergen specific ELISA. Bet v 1 isoform patterns were analyzed by 2D-SDS-PAGE blots and mass spectrometric identification. Basophil activation was tested in an FcɛR1-humanized rat basophil cell line passively sensitized with serum of a birch pollen symptomatic patient.Compared to 10 previous years, 2009 was a representative birch pollen season for all stations. About 90% of the allergen was found in the PM > 10 μm fraction at all stations. Bet v 1 isoforms pattern did not vary substantially neither during ripening of pollen nor between different geographical locations. The average European allergen release from birch pollen was 3.2 pg Bet v 1/pollen and did not vary much between the European countries. However, in all countries a >10-fold difference in daily allergen release per pollen was measured which could be explained by long-range transport of pollen with a deviating allergen release. Basophil activation by ambient air extracts correlated better with airborne allergen than with pollen concentration.Although Bet v 1 is a mixture of different

  16. The selective V1a receptor agonist selepressin (FE 202158) blocks vascular leak in ovine severe sepsis

    PubMed Central

    Wiśniewska, Halina; Traber, Lillian D.; Lin, ChiiDean; Fan, Juanjuan; Hawkins, Hal K.; Cox, Robert A.; Wiśniewski, Kazimierz; Schteingart, Claudio D.; Landry, Donald W.; Rivière, Pierre J.-M.; Traber, Daniel L.

    2014-01-01

    Objective To determine if the selective vasopressin type 1a receptor (V1aR) agonist selepressin (FE 202158) is as effective as the mixed V1a/V2 receptor (V1aR/V2R) agonist vasopressor hormone arginine vasopressin (AVP) when used as a titrated first-line vasopressor therapy in an ovine model of Pseudomonas aeruginosa pneumonia-induced severe sepsis. Design Prospective, randomized, controlled laboratory experiment. Setting University animal research facility. Subjects Forty-five chronically instrumented sheep. Interventions Sheep were anesthetized, insufflated with cooled cotton smoke via tracheostomy, and P. aeruginosa were instilled into their airways. They were then placed on assisted ventilation, awakened, and resuscitated with lactated Ringer's solution titrated to maintain hematocrit ± 3% from baseline levels. If, despite fluid management, mean arterial pressure (MAP) fell by > 10 mm Hg from baseline levels, a continuous i.v. infusion of AVP or selepressin was titrated to raise and maintain MAP within 10 mm Hg of baseline. Effects of combination treatment of selepressin with the selective V2R agonist desmopressin were similarly investigated. Measurements and Main Results In septic sheep, MAP fell by ~30 mm Hg, systemic vascular resistance index (SVRI) decreased by ~50%, and ~7 L of fluid were retained over 24 h; this fluid accumulation was partially reduced by AVP and almost completely blocked by selepressin; combined infusion of selepressin and desmopressin increased fluid accumulation to levels similar to AVP treatment. Conclusions Resuscitation with the selective V1aR agonist selepressin blocked vascular leak more effectively than the mixed V1aR/V2R agonist AVP because of its lack of agonist activity at the V2R. PMID:24674922

  17. Retinotopic patterns of background connectivity between V1 and fronto-parietal cortex are modulated by task demands

    PubMed Central

    Griffis, Joseph C.; Elkhetali, Abdurahman S.; Burge, Wesley K.; Chen, Richard H.; Visscher, Kristina M.

    2015-01-01

    Attention facilitates the processing of task-relevant visual information and suppresses interference from task-irrelevant information. Modulations of neural activity in visual cortex depend on attention, and likely result from signals originating in fronto-parietal and cingulo-opercular regions of cortex. Here, we tested the hypothesis that attentional facilitation of visual processing is accomplished in part by changes in how brain networks involved in attentional control interact with sectors of V1 that represent different retinal eccentricities. We measured the strength of background connectivity between fronto-parietal and cingulo-opercular regions with different eccentricity sectors in V1 using functional MRI data that were collected while participants performed tasks involving attention to either a centrally presented visual stimulus or a simultaneously presented auditory stimulus. We found that when the visual stimulus was attended, background connectivity between V1 and the left frontal eye fields (FEF), left intraparietal sulcus (IPS), and right IPS varied strongly across different eccentricity sectors in V1 so that foveal sectors were more strongly connected than peripheral sectors. This retinotopic gradient was weaker when the visual stimulus was ignored, indicating that it was driven by attentional effects. Greater task-driven differences between foveal and peripheral sectors in background connectivity to these regions were associated with better performance on the visual task and faster response times on correct trials. These findings are consistent with the notion that attention drives the configuration of task-specific functional pathways that enable the prioritized processing of task-relevant visual information, and show that the prioritization of visual information by attentional processes may be encoded in the retinotopic gradient of connectivty between V1 and fronto-parietal regions. PMID:26106320

  18. /sup 125/I)-(d(CH2)5, Sar7)AVP: a selective radioligand for V1 vasopressin receptors

    SciTech Connect

    Kelly, J.M.; Abrahams, J.M.; Phillips, P.A.; Mendelsohn, F.A.; Grzonka, Z.; Johnston, C.I.

    1989-01-01

    Arginine8-vasopressin (AVP) acts on vascular and hepatic V1 receptors to influence blood pressure and glycogenolysis respectively. We have radioiodinated the AVP V1 receptor antagonist, (1-(beta-mercapto-beta, beta-cyclopentamethylenepropionic-acid), 7-sarcosine, 8-arginine) vasopressin ((d(CH2)5, Sar7)AVP) and determined its receptor-binding properties in rat liver and kidney plasma membranes. The binding was of high affinity to single classes of receptors (liver: Kd = 3.0 nM and Bmax = 530 +/- 10 fmol/mg protein, kidney: Kd = 0.5 +/- 0.9 nM and Bmax = 11 +/- 8 fmol/mg protein). Competition of (125I)-(d(CH2)5, Sar7)AVP binding by unlabelled AVP analogues gave the following order of potency in both tissues, consistent with that expected for binding to a V1 receptor: (d(CH2)5, Tyr(Me)2)AVP greater than AVP greater than (d(CH2)5, D-Ile2, Ile4) AVP greater than DDAVP. No degradation of (125I)-(d(CH2)5, Sar7)AVP during incubation or storage was detected by HPLC analysis. We have used (125I)-(d(CH2)5, Sar7)AVP and in vitro autoradiography to demonstrate its use in localizing brain AVP receptors. These studies suggest that (125I)-(d(CH2)5, Sar7)AVP is a suitable selective radioligand for labelling V1 receptors and will provide a valuable tool for the study of the localization and regulation of AVP V1 receptors in tissues and in receptor isolation.

  19. Panulirus argus virus 1 (PaV1) infection prevalence and risk factors in a Mexican lobster fishery employing casitas.

    PubMed

    Huchin-Mian, Juan Pablo; Rodríguez-Canul, Rossanna; Briones-Fourzán, Patricia; Lozano-Álvarez, Enrique

    2013-12-12

    In Bahía de la Ascensión in Mexico, the Caribbean spiny lobster Panulirus argus fishery is based on extensive use of artificial shelters (casitas) that can harbor both juveniles and adults of this highly gregarious species. There is concern that the use of casitas might increase contact transmission of Panulirus argus virus 1 (PaV1). However, a previous study found no evidence for lobster crowding within casitas influencing the prevalence of clinical PaV1 disease, although differences in clinical prevalence were noted between different bay environments. To investigate this more closely, 683 lobsters were sampled from casitas in 2 zones in this bay (Vigía Chico, a shallow low-vegetation zone, and Punta Allen, a deeper dense-vegetation zone) previously found to have the lowest and highest prevalence, respectively, of observed clinical signs. When hemolymph collected from these lobsters was tested by PCR, the prevalence of PaV1 infection was found to be significantly lower in Vigía Chico relative to Punta Allen irrespective of season or the size, sex, or presence of shell injuries on lobsters. Among 714 large commercial-catch lobsters collected throughout the bay, the prevalence of infection was low irrespective of year or sex. For all lobsters tested, the sensitivity (0.510) at which PaV1 infection was detected by observed clinical signs was about half that determined by PCR, but the specificity of clinical signs was absolute (1), indicating that a simple 2× correction factor can be used to accurately estimate PaV1 infection prevalence based on more easily conducted visual assessments of lobsters. PMID:24334351

  20. A FORTRAN-90 Low-Energy Electron Diffraction program (LEED90 v1.1)

    NASA Astrophysics Data System (ADS)

    Blanco-Rey, Maria; de Andres, Pedro; Held, Georg; King, David A.

    2004-08-01

    We describe a FORTRAN-90 program to compute low-energy electron diffraction I(V) curves. Plane-waves and layer doubling are used to compute the inter-layer multiple-scattering, while the intra-layer multiple-scattering is computed in the standard way expanding the wavefield on a basis of spherical waves. The program is kept as general as possible, in order to allow testing different parts of multiple-scattering calculations. In particular, it can handle non-diagonal t-matrices describing the scattering of non-spherical potentials, anisotropic vibrations, anharmonicity, etc. The program does not use old FORTRAN flavours, and has been written keeping in mind the advantage for parallelism brought forward by FORTRAN-90. Program summaryTitle of program: LEED90 Catalogue number: ADUE Program summary URL:http://cpc.sc.qub.ac.uk/summaries/ADUE Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland. Computers: Alpha ev6-21264 (700 MHz) and Pentium-IV. Operating system: Digital UNIX V5.0 and Linux (Red Hat 8.0). Programming language: FORTRAN-90/95 (Compaq True64 compiler, and Intel Fortran Compiler 7.0 for Linux). High-speed storage required for the test run: minimum 64 Mbytes, it can grow to more depending on the system considered. Disk storage required: None No. of bits in a word: 64 and 32 No. of lines in distributed program, including test data, etc.: 17 953 No. of bytes in distributed program, including test data, etc.: 100 051 Distribution format: tar.gz Nature of problem: We describe the FORTRAN-90 program LEED90 (v1.1) to compute dynamical I(V) curves using layer-doubling. The program has been designed to be able to take, as an option, input from non-diagonal t-matrix, e.g., representing a molecule, temperature corrections for anisotropic/anharmonic vibrations, or non-spherical muffin-tin potentials. Method of solution: The intra-layer multiple-scattering problem is solved by adding self-consistently spherical wave amplitudes

  1. The V1 region of gp120 is preferentially selected during SIV/HIV transmission and is indispensable for envelope function and virus infection.

    PubMed

    Li, Yanpeng; Dittmer, Ulf; Wang, Yan; Song, Jiping; Sun, Binlian; Yang, Rongge

    2016-06-01

    A transmission bottleneck occurs during each human immunodeficiency virus (HIV) transmission event, which allows only a few viruses to establish new infection. However, the genetic characteristics of the transmitted viruses that are preferentially selected have not been fully elucidated. Here, we analyzed amino acids changes in the envelope protein during simian immunodeficiency virus (SIV)/HIV deep transmission history and current HIV evolution within the last 15-20 years. Our results confirmed that the V1V2 region of gp120 protein, particularly V1, was preferentially selected. A shorter V1 region was preferred during transmission history, while during epidemic, HIV may evolve to an expanded V1 region gradually and thus escape immune recognition. We then constructed different HIV-1 V1 mutants using different HIV-1 subtypes to elucidate the role of the V1 region in envelope function. We found that the V1 region, although highly variable, was indispensable for virus entry and infection, probably because V1 deletion mutants exhibited impaired processing of gp160 into mature gp120 and gp41. Additionally, the V1 region affected Env incorporation. These results indicated that the V1 region played a critical role in HIV transmission and infection. PMID:27117672

  2. Cytotoxic Nitrobenzoyloxy-substituted Sesquiterpenes from Spongederived Endozoic Fungus Aspergillus insulicola MD10-2.

    PubMed

    Zhao, Hong-Ying; Anbuchezhian, Ramasamy; Sun, Wei; Shao, Chang-Lun; Zhang, Feng-Li; Yin, Ying; Yu, Zhi-Sheng; Li, Zhi-Yong; Wang, Chang-Yun

    2016-01-01

    The emergence of drug resistance and spread of new infectious diseases necessitated the development of novel antibiotics. Marine sponge-associated fungi represent a reservoir of novel molecules with diverse biological potentials. In this study, we isolated five nitrobenzoyloxy-substituted sesquiterpenes 1-5 from the culture mycelia of an endozoic fungus Aspergillus insulicola MD10-2, obtained from the South China Sea sponge Cinachyrella australiensis. Compound 2 showed cytotoxicity against human lung cancer cell line H-460 with an IC50 value of 6.9 µM. Cytotoxicity of the acetylated derivatives (2a and 2b) of compound 2 decreased markedly, suggesting that the hydroxyl group contributed to the cytotoxic activity. Compound 5 was inactive against H-460, which implied the double bond at C-7 had an effect on cytotoxic activity as well. PMID:26696019

  3. 25 CFR 10.2 - Who is responsible for developing and maintaining the policies and standards for detention and...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... policies and standards for detention and holding facilities in Indian country? 10.2 Section 10.2 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAW AND ORDER INDIAN COUNTRY DETENTION FACILITIES... detention and holding facilities in Indian country? The Director, Office of Law Enforcement Services...

  4. Geology of the North Polar Region of Venus: Snegurochka Planitia (V-1) Quadrangle

    NASA Astrophysics Data System (ADS)

    Hurwitz, D. M.; Head, J. W.

    2008-09-01

    Introduction Geologic mapping of Snegurochka Planitia (V-1) reveals a complex stratigraphy of tectonic and volcanic features that can provide insight into the geologic history of Venus and Archean Earth [1,2] including 1) crustal thickening environments and processes, 2) the nature of diapirism, 3) the nature and origin of deformation belts, and 4) the origin and context of regional plains-forming volcanism. We present our progress in mapping the spatial and stratigraphic relationships of these features in the region surrounding the north pole of Venus. Mapping Results We have used full-resolution (75 m/pixel) images to produce a detailed map and stratigraphic column (Figures 1-3) in conjunction with the USGS mapping effort [3]. Eleven material units and two structural units have been identified and mapped similar to those identified in previous studies [e.g., 4- 5]. The material units include (from older to younger) tessera material (t), densely lineated plains material (pld), deformed and ridged plains material, both radar dark and radar bright (pdd, pbd), shield plains material (ps), plains material with dense concentrations of wrinkle ridges (rp), smooth radar dark plains material (pds), smooth radar bright plains material (pbs), lobate plains material (lop), edifice features (ed), and craters material (c). The structural features identified are wrinkle ridges (wr) and extensional lineaments (ext) that deform the mapped units. Material and Structural Units The tessera terrain is consistently the oldest material in the region and is characterized by high elevation, extensively deformed radar bright material that is embayed by younger plains units. The fractures that define this unit are generally hard to trace in detail, as many different fracture orientations are evident. In contrast, densely lineated plains material, while also generally characterized by high elevation and a rough surface texture, have a single primary orientation of fractures. These deformed

  5. Deformation characteristics of the rapidly solidified Al-8. 5% Fe-1. 2% V-1. 7% Si alloy

    SciTech Connect

    Hariprasad, S.; Sastry, S.M.L.; Jerina, K.L. )

    1993-08-15

    Dispersion strengthened Al-8.5% Fe-1.2% V-1.7% Si (8009) alloy containing 40-80 nm diameter dispersoids and exhibiting attractive elevated temperature strengths can be successfully produced by rapid solidification techniques such as Planar Flow Casting (PFC) and Atomized Melt Deposition (AMD). The grain sizes of alloys produced by PFC and AMD are typically O.5 to 1.0 [mu]m. Fine grain sized aluminum alloys have been found to exhibit plastic instabilities such as yield drop, formation of Lueder's bands and positive deviation from Hall-Petch relationship. The stress-strain behavior at room and elevated temperature of the fine grained dispersion strengthened Al-8.5% Fe-1.2% V-1.7% Si alloy produced by PFC and the AMD processes was determined with the objective of delineating the effect of fine grain size on the deformation behavior.

  6. Morphological Substrates for Parallel Streams of Corticogeniculate Feedback Originating in Both V1 and V2 of the Macaque Monkey.

    PubMed

    Briggs, Farran; Kiley, Caitlin W; Callaway, Edward M; Usrey, W Martin

    2016-04-20

    Corticothalamic circuits are essential for reciprocal information exchange between the thalamus and cerebral cortex. Nevertheless, the role of corticothalamic circuits in sensory processing remains a mystery. In the visual system, afferents from retina to the lateral geniculate nucleus (LGN) and from LGN to primary visual cortex (V1) are organized into functionally distinct parallel processing streams. Physiological evidence suggests corticogeniculate feedback may be organized into parallel streams; however, little is known about the diversity of corticogeniculate neurons, their local computations, or the structure-function relationship among corticogeniculate neurons. We used a virus-mediated approach to label and reconstruct the complete dendritic and local axonal arbors of identified corticogeniculate neurons in the macaque monkey. Our results reveal morphological substrates for parallel streams of corticogeniculate feedback based on distinct classes of neurons in V1 and V2. These results support the hypothesis that distinct populations of feedback neurons provide independent and unique information to the LGN. PMID:27041497

  7. Secondary structure, stability and tetramerisation of recombinant K(V)1.1 potassium channel cytoplasmic N-terminal fragment.

    PubMed

    Abbott, G W; Bloemendal, M; Van Stokkum, I H; Mercer, E A; Miller, R T; Sewing, S; Wolters, M; Pongs, O; Srai, S K

    1997-08-15

    The recombinant N-terminal fragment (amino acids 14-162) of a tetrameric voltage-gated potassium channel (K(V)1.1) has been studied using spectroscopic techniques. Evidence is presented that it forms a tetramer in aqueous solution, whereas when solubilised in 1% Triton X-100 it remains monomeric. The secondary structure content of both monomeric and tetrameric K(V)1.1 N-terminal fragment has been estimated from FTIR and CD spectroscopy to be 20-25% alpha-helix, 20-25% beta-sheet, 20% turns and 30-40% random coil. Solubilisation of the protein in detergent is shown by hydrogen-deuterium exchange analysis to alter tertiary structure rather than secondary structure and this may be the determining factor in tetramerisation ability. Using molecular modelling we propose a supersecondary structure consisting of two structural domains. PMID:9300810

  8. DCPT v1.0 - New particle tracker for modeling transport in dual-continuum - User's Manual

    SciTech Connect

    Pan, Lehua; Liu, Hui Hai; Cushey, Mark; Bodvarsson, Gudmundur

    2001-04-01

    DCPT (Dual-Continuum Particle Tracker) V1.0 is a new software for simulating solute transport in the subsurface. It is based on the random-walk method for modeling transport processes such as advection, dispersion/diffusion, linear sorption, radioactive decay, and fracture-matrix mass exchange (in fractured porous media). The user shall provide flow-field and other parameters in the form of input files. In Comparison to several analytical and numerical solutions for a number of test cases, DCPT shows excellent performance in both accuracy and efficiency. This report serves as a user's manual of DCPT V1.0. It includes theoretical basis, numerical methods, software structure, input/output description, and examples.

  9. Analgesic Effects of GpTx-1, PF-04856264 and CNV1014802 in a Mouse Model of NaV1.7-Mediated Pain.

    PubMed

    Deuis, Jennifer R; Wingerd, Joshua S; Winter, Zoltan; Durek, Thomas; Dekan, Zoltan; Sousa, Silmara R; Zimmermann, Katharina; Hoffmann, Tali; Weidner, Christian; Nassar, Mohammed A; Alewood, Paul F; Lewis, Richard J; Vetter, Irina

    2016-03-01

    Loss-of-function mutations of Na(V)1.7 lead to congenital insensitivity to pain, a rare condition resulting in individuals who are otherwise normal except for the inability to sense pain, making pharmacological inhibition of Na(V)1.7 a promising therapeutic strategy for the treatment of pain. We characterized a novel mouse model of Na(V)1.7-mediated pain based on intraplantar injection of the scorpion toxin OD1, which is suitable for rapid in vivo profiling of Na(V)1.7 inhibitors. Intraplantar injection of OD1 caused spontaneous pain behaviors, which were reversed by co-injection with Na(V)1.7 inhibitors and significantly reduced in Na(V)1.7(-/-) mice. To validate the use of the model for profiling Na(V)1.7 inhibitors, we determined the Na(V) selectivity and tested the efficacy of the reported Na(V)1.7 inhibitors GpTx-1, PF-04856264 and CNV1014802 (raxatrigine). GpTx-1 selectively inhibited Na(V)1.7 and was effective when co-administered with OD1, but lacked efficacy when delivered systemically. PF-04856264 state-dependently and selectively inhibited Na(V)1.7 and significantly reduced OD1-induced spontaneous pain when delivered locally and systemically. CNV1014802 state-dependently, but non-selectively, inhibited Na(V) channels and was only effective in the OD1 model when delivered systemically. Our novel model of Na(V)1.7-mediated pain based on intraplantar injection of OD1 is thus suitable for the rapid in vivo characterization of the analgesic efficacy of Na(V)1.7 inhibitors. PMID:26999206

  10. Analgesic Effects of GpTx-1, PF-04856264 and CNV1014802 in a Mouse Model of NaV1.7-Mediated Pain

    PubMed Central

    Deuis, Jennifer R.; Wingerd, Joshua S.; Winter, Zoltan; Durek, Thomas; Dekan, Zoltan; Sousa, Silmara R.; Zimmermann, Katharina; Hoffmann, Tali; Weidner, Christian; Nassar, Mohammed A.; Alewood, Paul F.; Lewis, Richard J.; Vetter, Irina

    2016-01-01

    Loss-of-function mutations of NaV1.7 lead to congenital insensitivity to pain, a rare condition resulting in individuals who are otherwise normal except for the inability to sense pain, making pharmacological inhibition of NaV1.7 a promising therapeutic strategy for the treatment of pain. We characterized a novel mouse model of NaV1.7-mediated pain based on intraplantar injection of the scorpion toxin OD1, which is suitable for rapid in vivo profiling of NaV1.7 inhibitors. Intraplantar injection of OD1 caused spontaneous pain behaviors, which were reversed by co-injection with NaV1.7 inhibitors and significantly reduced in NaV1.7−/− mice. To validate the use of the model for profiling NaV1.7 inhibitors, we determined the NaV selectivity and tested the efficacy of the reported NaV1.7 inhibitors GpTx-1, PF-04856264 and CNV1014802 (raxatrigine). GpTx-1 selectively inhibited NaV1.7 and was effective when co-administered with OD1, but lacked efficacy when delivered systemically. PF-04856264 state-dependently and selectively inhibited NaV1.7 and significantly reduced OD1-induced spontaneous pain when delivered locally and systemically. CNV1014802 state-dependently, but non-selectively, inhibited NaV channels and was only effective in the OD1 model when delivered systemically. Our novel model of NaV1.7-mediated pain based on intraplantar injection of OD1 is thus suitable for the rapid in vivo characterization of the analgesic efficacy of NaV1.7 inhibitors. PMID:26999206

  11. Engineering, purification and applications of His-tagged recombinant antibody fragments with specificity for the major birch pollen allergen, bet v1.

    PubMed

    Flicker, S; Laffer, S; Steinberger, P; Alhani, B; Zhu, Y; Laukkanen, M L; Keinänen, K; Kraft, D; Valenta, R

    2000-01-01

    Type I allergy, an immunodisorder affecting almost 20% of the population worldwide, is based on the production of IgE antibodies against per se harmless allergens. We report the expression of hexahistidine-tagged antibody fragments (Fabs) with specificity for Bet v1, the major birch pollen allergen, in Escherichia coli. The cDNA coding for the heavy chain fragment of a mouse monoclonal anti-Bet v1 antibody, Bip 1, was engineered by PCR to contain a hexahistidine-encoding 3' end. The modified Bip1 heavy chain cDNA was co-expressed in E. coli XL-1 Blue with the Bip 1 light chain cDNA using the combinatorial plasmid pComb3H. His-tagged recombinant (r) Bip 1 Fabs were isolated by nickel affinity chromatography and rBip 1 Fabs without His-tag were purified via affinity to rBet v1. rBip 1 Fabs with and without His-tag bound specifically to rBet v1 and, like Bet v1 -specific human serum IgE and rabbit-anti rBet v1 antibodies, cross-reacted with Bet v1-related allergens in other plant-species (alder, oak, hazelnut). We demonstrate the usefulness of His-tagged rBip 1 Fabs (1) for the identification of pollen samples containing Bet v 1 by particle blotting, (2) forthe detection of Bet v1-specific IgE antibodies in human serum samples by sandwich ELISA and (3) for the quantification of Bet v1 in solution. Based on these examples we suggest to use rBip 1 Fabs for the detection of Bet v1 and Bet v1-related allergens in natural allergen sources for allergy prevention, as well as for the standardization of natural allergen extracts produced for diagnosis and immunotherapy of birch pollen allergy. PMID:10722049

  12. The Impact of Nitration on the Structure and Immunogenicity of the Major Birch Pollen Allergen Bet v 1.0101

    PubMed Central

    Ackaert, Chloé; Kofler, Stefan; Horejs-Hoeck, Jutta; Zulehner, Nora; Asam, Claudia; von Grafenstein, Susanne; Fuchs, Julian E.; Briza, Peter; Liedl, Klaus R.; Bohle, Barbara; Ferreira, Fátima; Brandstetter, Hans; Oostingh, Gertie J.; Duschl, Albert

    2014-01-01

    Allergy prevalence has increased in industrialized countries. One contributing factor could be pollution, which can cause nitration of allergens exogenously (in the air) or endogenously (in inflamed lung tissue). We investigated the impact of nitration on both the structural and immunological behavior of the major birch pollen allergen Bet v 1.0101 to determine whether nitration might be a factor in the increased incidence of allergy. Bet v 1.0101 was nitrated with tetranitromethane. Immune effects were assessed by measuring the proliferation of specific T-cell lines (TCLs) upon stimulation with different concentrations of nitrated and unmodified allergen, and by measurement of cytokine release of monocyte-derived dendritic cells (moDCs) and primary DCs (primDCs) stimulated with nitrated versus unmodified allergen. HPLC-MS, crystallography, gel electrophoresis, amino acid analysis, size exclusion chromatography and molecular dynamics simulation were performed to characterize structural changes after nitration of the allergen. The proliferation of specific TCLs was higher upon stimulation with the nitrated allergen in comparison to the unmodified allergen. An important structural consequence of nitration was oligomerization. Moreover, analysis of the crystal structure of nitrated Bet v 1.0101 showed that amino acid residue Y83, located in the hydrophobic cavity, was nitrated to 100%. Both moDCs and primDCs showed decreased production of TH1-priming cytokines, thus favoring a TH2 response. These results implicate that nitration of Bet v 1.0101 might be a contributing factor to the observed increase in birch pollen allergy, and emphasize the importance of protein modifications in understanding the molecular basis of allergenicity. PMID:25126882

  13. Salt-induced sympathoexcitation involves vasopressin V1a receptor activation in the paraventricular nucleus of the hypothalamus.

    PubMed

    Ribeiro, Natalia; Panizza, Helena do Nascimento; Santos, Karoline Martins Dos; Ferreira-Neto, Hildebrando C; Antunes, Vagner Roberto

    2015-12-01

    A high-salt diet can lead to hydromineral imbalance and increases in plasma sodium and osmolality. It is recognized as one of the major contributing factors for cardiovascular diseases such as hypertension. The paraventricular nucleus (PVN) plays a pivotal role in osmotically driven sympathoexcitation and high blood pressure, the precise mechanisms of which are not fully understood. Recent evidence indicates that AVP released from magnocellular neurons might be involved in this process. Using a combination of in vivo and in situ studies, we sought to investigate whether AVP, acting on PVN neurons, can change mean arterial pressure (MAP) and sympathetic nerve activity (SNA) in euhydrated male rats. Furthermore, we wanted to determine whether V1a receptors on PVN neurons would be involved in salt-induced sympathoexcitation and hypertension. In rats, 4 days of salt loading (NaCl 2%) elicited a significant increase in plasma osmolality (39 ± 7 mosmol/kgH2O), an increase in MAP (26 ± 2 mmHg, P < 0.001), and sympathoexcitation compared with euhydrated rats. Microinjection of AVP into the PVN of conscious euhydrated animals (100 nl, 3 μM) elicited a pressor response (14 ± 2 mmHg) and a significant increase in lumbar SNA (100 nl, 1 mM) (19 ± 5%). Pretreatment with a V1a receptor antagonist, microinjected bilaterally into the PVN of salt-loaded animals, elicited a decrease in lumbar SNA (-14 ± 5%) and MAP (-19 ± 5 mmHg), when compared with the euhydrated group. Our findings show that AVP plays an important role in modulating the salt-induced sympathoexcitation and high blood pressure, via V1a receptors, within the PVN of male rats. As such, V1a receptors in the PVN might contribute to neurogenic hypertension in individuals consuming a high-salt diet. PMID:26354848

  14. Callosally projecting neurons in the macaque monkey V1/V2 border are enriched in nonphosphorylated neurofilament protein

    NASA Technical Reports Server (NTRS)

    Hof, P. R.; Ungerleider, L. G.; Adams, M. M.; Webster, M. J.; Gattass, R.; Blumberg, D. M.; Morrison, J. H.; Bloom, F. E. (Principal Investigator)

    1997-01-01

    Previous immunohistochemical studies combined with retrograde tracing in macaque monkeys have demonstrated that corticocortical projections can be differentiated by their content of neurofilament protein. The present study analyzed the distribution of nonphosphorylated neurofilament protein in callosally projecting neurons located at the V1/V2 border. All of the retrogradely labeled neurons were located in layer III at the V1/V2 border and at an immediately adjacent zone of area V2. A quantitative analysis showed that the vast majority (almost 95%) of these interhemispheric projection neurons contain neurofilament protein immunoreactivity. This observation differs from data obtained in other sets of callosal connections, including homotypical interhemispheric projections in the prefrontal, temporal, and parietal association cortices, that were found to contain uniformly low proportions of neurofilament protein-immunoreactive neurons. Comparably, highly variable proportions of neurofilament protein-containing neurons have been reported in intrahemispheric corticocortical pathways, including feedforward and feedback visual connections. These results indicate that neurofilament protein is a prominent neurochemical feature that identifies a particular population of interhemispheric projection neurons at the V1/V2 border and suggest that this biochemical attribute may be critical for the function of this subset of callosal neurons.

  15. The unexpected structure of the designed protein Octarellin V.1 forms a challenge for protein structure prediction tools.

    PubMed

    Figueroa, Maximiliano; Sleutel, Mike; Vandevenne, Marylene; Parvizi, Gregory; Attout, Sophie; Jacquin, Olivier; Vandenameele, Julie; Fischer, Axel W; Damblon, Christian; Goormaghtigh, Erik; Valerio-Lepiniec, Marie; Urvoas, Agathe; Durand, Dominique; Pardon, Els; Steyaert, Jan; Minard, Philippe; Maes, Dominique; Meiler, Jens; Matagne, André; Martial, Joseph A; Van de Weerdt, Cécile

    2016-07-01

    Despite impressive successes in protein design, designing a well-folded protein of more 100 amino acids de novo remains a formidable challenge. Exploiting the promising biophysical features of the artificial protein Octarellin V, we improved this protein by directed evolution, thus creating a more stable and soluble protein: Octarellin V.1. Next, we obtained crystals of Octarellin V.1 in complex with crystallization chaperons and determined the tertiary structure. The experimental structure of Octarellin V.1 differs from its in silico design: the (αβα) sandwich architecture bears some resemblance to a Rossman-like fold instead of the intended TIM-barrel fold. This surprising result gave us a unique and attractive opportunity to test the state of the art in protein structure prediction, using this artificial protein free of any natural selection. We tested 13 automated webservers for protein structure prediction and found none of them to predict the actual structure. More than 50% of them predicted a TIM-barrel fold, i.e. the structure we set out to design more than 10years ago. In addition, local software runs that are human operated can sample a structure similar to the experimental one but fail in selecting it, suggesting that the scoring and ranking functions should be improved. We propose that artificial proteins could be used as tools to test the accuracy of protein structure prediction algorithms, because their lack of evolutionary pressure and unique sequences features. PMID:27181418

  16. The spatial summation characteristics of three categories of V1 neurons differing in non-classical receptive field modulation properties.

    PubMed

    Chen, Ke; Song, Xue-Mei; Dai, Zheng-Qiang; Yin, Jiao-Jiao; Xu, Xing-Zhen; Li, Chao-Yi

    2014-03-01

    The spatial summation of excitation and inhibition determines the final output of neurons in the cat V1. To characterize the spatial extent of the excitatory classical receptive field (CRF) and inhibitory non-classical receptive field (nCRF) areas, we examined the spatial summation properties of 169 neurons in cat V1 at high (20-90%) and low (5-15%) stimulus contrasts. Three categories were classified based on the difference in the contrast dependency of the surround suppression. We discovered that the three categories significantly differed in CRF size, peak firing rate, and the proportion of simple/complex cell number. The classification of simple and complex cells was determined at both high and low contrasts. While the majority of V1 neurons had stable modulation ratios in their responses, 10 cells (6.2%) in our sample crossed the classification boundary under different stimulus contrasts. No significant difference was found in the size of the CRF between simple and complex cells. Further comparisons in each category determined that the CRFs for complex cells were significantly larger than those for simple cells in category type I neurons, with no significant differences between simple and complex cells in category type II and type III neurons. In addition, complex cells have higher peak firing rates than simple cells. PMID:24508921

  17. Parallel processing of face and house stimuli by V1 and specialized visual areas: a magnetoencephalographic (MEG) study

    PubMed Central

    Shigihara, Yoshihito; Zeki, Semir

    2014-01-01

    We used easily distinguishable stimuli of faces and houses constituted from straight lines, with the aim of learning whether they activate V1 on the one hand, and the specialized areas that are critical for the processing of faces and houses on the other, with similar latencies. Eighteen subjects took part in the experiment, which used magnetoencephalography (MEG) coupled to analytical methods to detect the time course of the earliest responses which these stimuli provoke in these cortical areas. Both categories of stimuli activated V1 and areas of the visual cortex outside it at around 40 ms after stimulus onset, and the amplitude elicited by face stimuli was significantly larger than that elicited by house stimuli. These results suggest that “low-level” and “high-level” features of form stimuli are processed in parallel by V1 and visual areas outside it. Taken together with our previous results on the processing of simple geometric forms (Shgihara and Zeki, 2013; Shigihara and Zeki, 2014), the present ones reinforce the conclusion that parallel processing is an important component in the strategy used by the brain to process and construct forms. PMID:25426050

  18. Prdm12 specifies V1 interneurons through cross-repressive interactions with Dbx1 and Nkx6 genes in Xenopus

    PubMed Central

    Thélie, Aurore; Desiderio, Simon; Hanotel, Julie; Quigley, Ian; Van Driessche, Benoit; Rodari, Anthony; Borromeo, Mark D.; Kricha, Sadia; Lahaye, François; Croce, Jenifer; Cerda-Moya, Gustavo; Ordoño Fernandez, Jesús; Bolle, Barbara; Lewis, Katharine E.; Sander, Maike; Pierani, Alessandra; Schubert, Michael; Johnson, Jane E.; Kintner, Christopher R.; Pieler, Tomas; Van Lint, Carine; Henningfeld, Kristine A.; Bellefroid, Eric J.; Van Campenhout, Claude

    2015-01-01

    V1 interneurons are inhibitory neurons that play an essential role in vertebrate locomotion. The molecular mechanisms underlying their genesis remain, however, largely undefined. Here, we show that the transcription factor Prdm12 is selectively expressed in p1 progenitors of the hindbrain and spinal cord in the frog embryo, and that a similar restricted expression profile is observed in the nerve cord of other vertebrates as well as of the cephalochordate amphioxus. Using frog, chick and mice, we analyzed the regulation of Prdm12 and found that its expression in the caudal neural tube is dependent on retinoic acid and Pax6, and that it is restricted to p1 progenitors, due to the repressive action of Dbx1 and Nkx6-1/2 expressed in the adjacent p0 and p2 domains. Functional studies in the frog, including genome-wide identification of its targets by RNA-seq and ChIP-Seq, reveal that vertebrate Prdm12 proteins act as a general determinant of V1 cell fate, at least in part, by directly repressing Dbx1 and Nkx6 genes. This probably occurs by recruiting the methyltransferase G9a, an activity that is not displayed by the amphioxus Prdm12 protein. Together, these findings indicate that Prdm12 promotes V1 interneurons through cross-repressive interactions with Dbx1 and Nkx6 genes, and suggest that this function might have only been acquired after the split of the vertebrate and cephalochordate lineages. PMID:26443638

  19. Biophysical characterization data of the artificial protein Octarellin V.1 and binding test with its X-ray helpers.

    PubMed

    Figueroa, Maximiliano; Vandenameele, Julie; Goormaghtigh, Erik; Valerio-Lepiniec, Marie; Minard, Philippe; Matagne, André; Van de Weerdt, Cécile

    2016-09-01

    The artificial protein Octarellin V.1 (http://dx.doi.org/10.1016/j.jsb.2016.05.004[1]) was obtained through a direct evolution process over the de novo designed Octarellin V (http://dx.doi.org/10.1016/S0022-2836(02)01206-8[2]). The protein has been characterized by circular dichroism and fluorescence techniques, in order to obtain data related to its thermo and chemical stability. Moreover, the data for the secondary structure content studied by circular dichroism and infra red techniques is reported for the Octarellin V and V.1. Two crystallization helpers, nanobodies (http://dx.doi.org/10.1038/nprot.2014.039[3]) and αRep (http://dx.doi.org/10.1016/j.jmb.2010.09.048[4]), have been used to create stable complexes. Here we present the data obtained of the binding characterization of the Octarellin V.1 with the crystallization helpers by isothermal titration calorimetry. PMID:27547801

  20. Early Posttransplant Isolated v1 Lesion Does Not Need to Be Treated and Does Not Lead to Increased Fibrosis

    PubMed Central

    Moinuddin, Irfan; Thajudeen, Bijin; Sussman, Amy; Madhrira, Machaiah; Bracamonte, Erika; Popovtzer, Mordecai; Kadambi, Pradeep V.

    2016-01-01

    Acute vascular rejection (AVR) is characterized by intimal arteritis in addition to tubulitis and interstitial inflammation. It is associated with a poorer prognosis compared to tubulointerstitial rejection (AIR) and AVR is associated with a higher rate of graft loss than AIR. The prognosis and treatment of arteritis without tubulitis and interstitial inflammation (isolated v1 lesion) are still controversial. We report a case of a patient who had a biopsy of the kidney allograft for evaluation of slow graft function. The biopsy revealed an isolated v1 lesion. However, we chose not to augment immunosuppression. The patient's kidney allograft function improved over time with close monitoring. Repeat biopsy a year later showed no evidence of endothelialitis and relatively unchanged fibrosis and no other abnormalities. Although it is suggested that most cases of isolated v1 lesions will respond to corticosteroids or T cell depleting therapies, some cases will improve with conservative management. Further studies are needed to determine which cases could be managed conservatively. PMID:27293950

  1. Quantitative inference of population response properties across eccentricity from motion-induced maps in macaque V1

    PubMed Central

    Chen, Ming; Wu, Si; Lu, Haidong D.; Roe, Anna W.

    2013-01-01

    Interpreting population responses in the primary visual cortex (V1) remains a challenge especially with the advent of techniques measuring activations of large cortical areas simultaneously with high precision. For successful interpretation, a quantitatively precise model prediction is of great importance. In this study, we investigate how accurate a spatiotemporal filter (STF) model predicts average response profiles to coherently drifting random dot motion obtained by optical imaging of intrinsic signals in V1 of anesthetized macaques. We establish that orientation difference maps, obtained by subtracting orthogonal axis-of-motion, invert with increasing drift speeds, consistent with the motion streak effect. Consistent with perception, the speed at which the map inverts (the critical speed) depends on cortical eccentricity and systematically increases from foveal to parafoveal. We report that critical speeds and response maps to drifting motion are excellently reproduced by the STF model. Our study thus suggests that the STF model is quantitatively accurate enough to be used as a first model of choice for interpreting responses obtained with intrinsic imaging methods in V1. We show further that this good quantitative correspondence opens the possibility to infer otherwise not easily accessible population receptive field properties from responses to complex stimuli, such as drifting random dot motions. PMID:23197457

  2. Spatial and temporal characteristics of V1 microstimulation during chronic implantation of a microelectrode array in a behaving macaque

    NASA Astrophysics Data System (ADS)

    Davis, T. S.; Parker, R. A.; House, P. A.; Bagley, E.; Wendelken, S.; Normann, R. A.; Greger, B.

    2012-12-01

    Objective. It has been hypothesized that a vision prosthesis capable of evoking useful visual percepts can be based upon electrically stimulating the primary visual cortex (V1) of a blind human subject via penetrating microelectrode arrays. As a continuation of earlier work, we examined several spatial and temporal characteristics of V1 microstimulation. Approach. An array of 100 penetrating microelectrodes was chronically implanted in V1 of a behaving macaque monkey. Microstimulation thresholds were measured using a two-alternative forced choice detection task. Relative locations of electrically-evoked percepts were measured using a memory saccade-to-target task. Main results. The principal finding was that two years after implantation we were able to evoke behavioural responses to electric stimulation across the spatial extent of the array using groups of contiguous electrodes. Consistent responses to stimulation were evoked at an average threshold current per electrode of 204 ± 49 µA (mean ± std) for groups of four electrodes and 91 ± 25 µA for groups of nine electrodes. Saccades to electrically-evoked percepts using groups of nine electrodes showed that the animal could discriminate spatially distinct percepts with groups having an average separation of 1.6 ± 0.3 mm (mean ± std) in cortex and 1.0° ± 0.2° in visual space. Significance. These results demonstrate chronic perceptual functionality and provide evidence for the feasibility of a cortically-based vision prosthesis for the blind using penetrating microelectrodes.

  3. prdm12b specifies the p1 progenitor domain and reveals a role for V1 interneurons in swim movements.

    PubMed

    Zannino, Denise A; Downes, Gerald B; Sagerström, Charles G

    2014-06-15

    Proper functioning of the vertebrate central nervous system requires the precise positioning of many neuronal cell types. This positioning is established during early embryogenesis when gene regulatory networks pattern the neural tube along its anteroposterior and dorsoventral axes. Dorsoventral patterning of the embryonic neural tube gives rise to multiple progenitor cell domains that go on to differentiate unique classes of neurons and glia. While the genetic program is reasonably well understood for some lineages, such as ventrally derived motor neurons and glia, other lineages are much less characterized. Here we show that prdm12b, a member of the PR domain containing-family of transcriptional regulators, is expressed in the p1 progenitor domain of the zebrafish neural tube in response to Sonic Hedgehog signaling. We find that disruption of prdm12b function leads to dorsal expansion of nkx6.1 expression and loss of p1-derived eng1b-expressing V1 interneurons, while the adjacent p0 and p2 domains are unaffected. We also demonstrate that prdm12b-deficient fish exhibit an abnormal touch-evoked escape response with excessive body contractions and a prolonged response time, as well as an inability to coordinate swimming movements, thereby revealing a functional role for V1 interneurons in locomotor circuits. We conclude that prdm12b is required for V1 interneuron specification and that these neurons control swimming movements in zebrafish. PMID:24631215

  4. MATISSE-v1.5 and MATISSE-v2.0: new developments and comparison with MIRAMER measurements

    NASA Astrophysics Data System (ADS)

    Simoneau, Pierre; Caillault, Karine; Fauqueux, Sandrine; Huet, Thierry; Labarre, Luc; Malherbe, Claire; Rosier, Bernard

    2009-05-01

    MATISSE is a background scene generator developed for the computation of natural background spectral radiance images and useful atmospheric radiatives quantities (radiance and transmission along a line of sight, local illumination, solar irradiance ...). The spectral bandwidth ranges from 0.4 to 14 μm. Natural backgrounds include atmosphere (taking into account spatial variability), low and high altitude clouds, sea and land. The current version MATISSE-v1.5 can be run on SUN and IBM workstations as well as on PC under Windows and Linux environment. An IHM developed under Java environment is also implemented. MATISSE-v2.0 recovers all the MATISSE-v1.5 functionalities, and includes a new sea surface radiance model depending on wind speed, wind direction and the fetch value. The release of this new version in planned for April 2009. This paper gives a description of MATISSE-v1.5 and MATISSE-v2.0 and shows preliminary comparison results between generated images and measured images during the MIRAMER campaign, which hold in May 2008 in the Mediterranean Sea.

  5. prdm12b specifies the p1 progenitor domain and reveals a role for V1 interneurons in swim movements

    PubMed Central

    Zannino, Denise A.; Downes, Gerald B.; Sagerström, Charles G.

    2014-01-01

    Proper functioning of the vertebrate central nervous system requires the precise positioning of many neuronal cell types. This positioning is established during early embryogenesis when gene regulatory networks pattern the neural tube along its anteroposterior and dorsoventral axes. Dorsoventral patterning of the embryonic neural tube gives rise to multiple progenitor cell domains that go on to differentiate unique classes of neurons and glia. While the genetic program is reasonably well understood for some lineages, such as ventrally derived motor neurons and glia, other lineages are much less characterized. Here we show that prdm12b, a member of the PR domain containing-family of transcriptional regulators, is expressed in the p1 progenitor domain of the zebrafish neural tube in response to Sonic Hedgehog signaling. We find that disruption of prdm12b function leads to dorsal expansion of nkx6.1 expression and loss of p1-derived eng1b-expressing V1 interneurons, while the adjacent p0 and p2 domains are unaffected. We also demonstrate that prdm12b-deficient fish exhibit an abnormal touch-evoked escape response with excessive body contractions and a prolonged response time, as well as an inability to coordinate swimming movements, thereby revealing a functional role for V1 interneurons in locomotor circuits. We conclude that prdm12b is required for V1 interneuron specification and that these neurons control swimming movements in zebrafish. PMID:24631215

  6. Thermopower analysis of the electronic structure around the metal-insulator transition in V1-xWxO2

    NASA Astrophysics Data System (ADS)

    Katase, Takayoshi; Endo, Kenji; Ohta, Hiromichi

    2014-10-01

    The electronic structure across the metal-insulator (MI) transition of electron-doped V1-xWxO2 epitaxial films (x =0-0.06) grown on α-Al2O3 substrates was studied by means of thermopower (S) measurements. Significant increase of |S | values accompanied by MI transition was observed, and the transition temperatures of S (TS) decreased with x in a good linear relation with MI transition temperatures. |S| values of V1-xWxO2 films at T>TS were constant at low values of 23μVK-1 independently of x, which reflects a metallic electronic structure, whereas those at TV1-xWxO2 films have insulating electronic structures with a parabolic density of state around the conduction band bottom.

  7. Prdm12 specifies V1 interneurons through cross-repressive interactions with Dbx1 and Nkx6 genes in Xenopus.

    PubMed

    Thélie, Aurore; Desiderio, Simon; Hanotel, Julie; Quigley, Ian; Van Driessche, Benoit; Rodari, Anthony; Borromeo, Mark D; Kricha, Sadia; Lahaye, François; Croce, Jenifer; Cerda-Moya, Gustavo; Ordoño Fernandez, Jesús; Bolle, Barbara; Lewis, Katharine E; Sander, Maike; Pierani, Alessandra; Schubert, Michael; Johnson, Jane E; Kintner, Christopher R; Pieler, Tomas; Van Lint, Carine; Henningfeld, Kristine A; Bellefroid, Eric J; Van Campenhout, Claude

    2015-10-01

    V1 interneurons are inhibitory neurons that play an essential role in vertebrate locomotion. The molecular mechanisms underlying their genesis remain, however, largely undefined. Here, we show that the transcription factor Prdm12 is selectively expressed in p1 progenitors of the hindbrain and spinal cord in the frog embryo, and that a similar restricted expression profile is observed in the nerve cord of other vertebrates as well as of the cephalochordate amphioxus. Using frog, chick and mice, we analyzed the regulation of Prdm12 and found that its expression in the caudal neural tube is dependent on retinoic acid and Pax6, and that it is restricted to p1 progenitors, due to the repressive action of Dbx1 and Nkx6-1/2 expressed in the adjacent p0 and p2 domains. Functional studies in the frog, including genome-wide identification of its targets by RNA-seq and ChIP-Seq, reveal that vertebrate Prdm12 proteins act as a general determinant of V1 cell fate, at least in part, by directly repressing Dbx1 and Nkx6 genes. This probably occurs by recruiting the methyltransferase G9a, an activity that is not displayed by the amphioxus Prdm12 protein. Together, these findings indicate that Prdm12 promotes V1 interneurons through cross-repressive interactions with Dbx1 and Nkx6 genes, and suggest that this function might have only been acquired after the split of the vertebrate and cephalochordate lineages. PMID:26443638

  8. Engineering potent and selective analogues of GpTx-1, a tarantula venom peptide antagonist of the Na(V)1.7 sodium channel.

    PubMed

    Murray, Justin K; Ligutti, Joseph; Liu, Dong; Zou, Anruo; Poppe, Leszek; Li, Hongyan; Andrews, Kristin L; Moyer, Bryan D; McDonough, Stefan I; Favreau, Philippe; Stöcklin, Reto; Miranda, Les P

    2015-03-12

    NaV1.7 is a voltage-gated sodium ion channel implicated by human genetic evidence as a therapeutic target for the treatment of pain. Screening fractionated venom from the tarantula Grammostola porteri led to the identification of a 34-residue peptide, termed GpTx-1, with potent activity on NaV1.7 (IC50 = 10 nM) and promising selectivity against key NaV subtypes (20× and 1000× over NaV1.4 and NaV1.5, respectively). NMR structural analysis of the chemically synthesized three disulfide peptide was consistent with an inhibitory cystine knot motif. Alanine scanning of GpTx-1 revealed that residues Trp(29), Lys(31), and Phe(34) near the C-terminus are critical for potent NaV1.7 antagonist activity. Substitution of Ala for Phe at position 5 conferred 300-fold selectivity against NaV1.4. A structure-guided campaign afforded additive improvements in potency and NaV subtype selectivity, culminating in the design of [Ala5,Phe6,Leu26,Arg28]GpTx-1 with a NaV1.7 IC50 value of 1.6 nM and >1000× selectivity against NaV1.4 and NaV1.5. PMID:25658507

  9. Synthesis, crystal structure, and spectral studies of 10-(2-Benzothiazolylazo)-9-phenanthrol

    SciTech Connect

    Davydov, V. V.; Sokol, V. I.; Polyanskaya, N. A.; Linko, R. V. Ryabov, M. A.; Sergienko, V. S.

    2012-03-15

    10-(2-Benzothiazolylazo)-9-phenanthrol (L) is prepared by a reaction of 2-hydrazinobenzothiazol with 9,10-phenanthrenequinone. The crystal and molecular structure of the L{center_dot}CHCl{sub 3} solvate is determined by X-ray diffraction. The data of the X-ray diffraction study, as well as IR, {sup 1}H NMR, and electronic absorption spectra, indicate that in the crystal state and solutions the L molecule exists in the form of a quinohydrazone tautomer (b) (s-trans, cis) stabilized by the intramolecular N{sub 2}-HN{sub 2} Horizontal-Ellipsis O1 hydrogen bond. The 'mobile' H atom is located at the N2 atom of the azo group. The benzothiazolyl and phenanthrenequinone fragments are nearly coplanar. Spectroscopic criteria for the state of L in various media are determined based on the data of IR, {sup 1}H NMR, and electronic absorption spectroscopy and the results of the Pariser-Parr-Pople quantum-chemical calculations.

  10. Confirmation of immuno-reactivity of the recombinant major birch pollen allergen Bet v 1a by affinity-CIEF.

    PubMed

    Dullnig, Verena; Weiss, Richard; Amon, Sabine; Rizzi, Andreas; Stutz, Hanno

    2009-07-01

    Affinity-CIEF has been applied to characterize a recombinant product of the major birch pollen allergen Betula verrucosa isoform 1a (Bet v 1a) immuno-chemically. For this purpose mAbs of the IgG-type have been produced in-lab from two murine hybridoma lines, specified as clones 2 and 5.1. Both IgG clones were characterized by SDS-PAGE, MALDI-TOF-MS and CIEF. The purified IgG solutions had to be dialysed against 10 mmol/L phosphate (pH 7.4) to prevent IgG precipitation and to ensure appropriate CIEF separation. Both tested monoclonal IgGs (mIgGs) comprised four constituents covering pI ranges of 6.98-7.09 and 6.78-7.03 for clones 2 and 5.1 with major peaks at pI 7.09 and 7.03, respectively. When increasing amounts of Bet v 1a (pI 4.95) were incubated with 2.0 mumol/L mIgG, novel peaks were progressively induced in a pI range slightly more acidic than the focusing region of mIgGs. These peaks grew on the expense of original mIgG peaks. All pI values were calculated using two pI marker compounds with a repeatability of better than 0.03 units. New peaks represent complexes between Bet v 1a and mIgG either of 1:1 or of 2:1 binding stoichiometry. At a molar ratio of 2:1, saturation of both IgG paratopes with allergen (Ag) molecules was achieved as indicated by unbound Bet v 1a. The current CIEF approach addresses the proof of single epitope integrity in the course of immuno-chemical characterization of Bet v 1a. Contrary to traditional immunoassays, affinity CIEF allows for a distinction and relative quantification of mAbs, Ag-antibody complexes and Ag variants coexisting in one sample. PMID:19621361

  11. MEGAHIT v1.0: A fast and scalable metagenome assembler driven by advanced methodologies and community practices.

    PubMed

    Li, Dinghua; Luo, Ruibang; Liu, Chi-Man; Leung, Chi-Ming; Ting, Hing-Fung; Sadakane, Kunihiko; Yamashita, Hiroshi; Lam, Tak-Wah

    2016-06-01

    The study of metagenomics has been much benefited from low-cost and high-throughput sequencing technologies, yet the tremendous amount of data generated make analysis like de novo assembly to consume too much computational resources. In late 2014 we released MEGAHIT v0.1 (together with a brief note of Li et al. (2015) [1]), which is the first NGS metagenome assembler that can assemble genome sequences from metagenomic datasets of hundreds of Giga base-pairs (bp) in a time- and memory-efficient manner on a single server. The core of MEGAHIT is an efficient parallel algorithm for constructing succinct de Bruijn Graphs (SdBG), implemented on a graphical processing unit (GPU). The software has been well received by the assembly community, and there is interest in how to adapt the algorithms to integrate popular assembly practices so as to improve the assembly quality, as well as how to speed up the software using better CPU-based algorithms (instead of GPU). In this paper we first describe the details of the core algorithms in MEGAHIT v0.1, and then we show the new modules to upgrade MEGAHIT to version v1.0, which gives better assembly quality, runs faster and uses less memory. For the Iowa Prairie Soil dataset (252Gbp after quality trimming), the assembly quality of MEGAHIT v1.0, when compared with v0.1, has a significant improvement, namely, 36% increase in assembly size and 23% in N50. More interestingly, MEGAHIT v1.0 is no slower than before (even running with the extra modules). This is primarily due to a new CPU-based algorithm for SdBG construction that is faster and requires less memory. Using CPU only, MEGAHIT v1.0 can assemble the Iowa Prairie Soil sample in about 43h, reducing the running time of v0.1 by at least 25% and memory usage by up to 50%. MEGAHIT v1.0, exhibiting a smaller memory footprint, can process even larger datasets. The Kansas Prairie Soil sample (484Gbp), the largest publicly available dataset, can now be assembled using no more than 500GB

  12. Identification of Low-Confidence Regions in the Pig Reference Genome (Sscrofa10.2).

    PubMed

    Warr, Amanda; Robert, Christelle; Hume, David; Archibald, Alan L; Deeb, Nader; Watson, Mick

    2015-01-01

    Many applications of high throughput sequencing rely on the availability of an accurate reference genome. Variant calling often produces large data sets that cannot be realistically validated and which may contain large numbers of false-positives. Errors in the reference assembly increase the number of false-positives. While resources are available to aid in the filtering of variants from human data, for other species these do not yet exist and strict filtering techniques must be employed which are more likely to exclude true-positives. This work assesses the accuracy of the pig reference genome (Sscrofa10.2) using whole genome sequencing reads from the Duroc sow whose genome the assembly was based on. Indicators of structural variation including high regional coverage, unexpected insert sizes, improper pairing and homozygous variants were used to identify low quality (LQ) regions of the assembly. Low coverage (LC) regions were also identified and analyzed separately. The LQ regions covered 13.85% of the genome, the LC regions covered 26.6% of the genome and combined (LQLC) they covered 33.07% of the genome. Over half of dbSNP variants were located in the LQLC regions. Of copy number variable regions identified in a previous study, 86.3% were located in the LQLC regions. The regions were also enriched for gene predictions from RNA-seq data with 42.98% falling in the LQLC regions. Excluding variants in the LQ, LC, or LQLC from future analyses will help reduce the number of false-positive variant calls. Researchers using WGS data should be aware that the current pig reference genome does not give an accurate representation of the copy number of alleles in the original Duroc sow's genome. PMID:26640477

  13. Simultaneous VLBA polarimetric observations of the v={1,2} J=1-0 and v=1, J=2-1 SiO maser emission toward VY CMa II: component-level polarization analysis.

    NASA Astrophysics Data System (ADS)

    Richter, L.; Kemball, A.; Jonas, J.

    2016-06-01

    This paper presents a component-level comparison of the polarized v=1 J =1-0, v=2 J=1-0 and v=1 J=2-1 SiO maser emission towards the supergiant star VY CMa at milliarcsecond-scale, as observed using the VLBA at λ = 7mm and λ = 3mm. An earlier paper considered overall maser morphology and constraints on SiO maser excitation and pumping derived from these data. The goal of the current paper is to use the measured polarization properties of individual co-spatial components detected across multiple transitions to provide constraints on several competing theories for the transport of polarized maser emission. This approach minimizes the significant effects of spatial blending. We present several diagnostic tests designed to distinguish key features of competing theoretical models for maser polarization. The number of coincident features is limited by sensitivity however, particularly in the v=1 J=2-1 transition at 86 GHz, and deeper observations are needed. Preliminary conclusions based on the current data provide some support for: i) spin-independent solutions for linear polarization; ii) the influence of geometry on the distribution of fractional linear polarization with intensity; and, iii) π/2 rotations in linear polarization position angle arising from transitions across the Van Vleck angle (sin 2θ = 2/3) between the maser line-of-sight and magnetic field. There is weaker evidence for several enumerated non-Zeeman explanations for circular polarization. The expected 2:1 ratio in circular polarization between J=1-0 and J=2-1 predicted by standard Zeeman theory cannot unfortunately be tested conclusively due to insufficient coincident components.

  14. Simultaneous VLBA polarimetric observations of the v = {1,2} J = 1-0 and v = 1, J = 2-1 SiO maser emission towards VY CMa II: component-level polarization analysis

    NASA Astrophysics Data System (ADS)

    Richter, L.; Kemball, A.; Jonas, J.

    2016-09-01

    This paper presents a component-level comparison of the polarized v = 1 J = 1-0, v = 2 J = 1-0 and v = 1 J = 2-1 SiO maser emission towards the supergiant star VY CMa at milliarcsecond-scale, as observed using the Very Long Baseline Array at λ = 7 and 3 mm. An earlier paper considered overall maser morphology and constraints on SiO maser excitation and pumping derived from these data. The goal of the current paper is to use the measured polarization properties of individual co-spatial components detected across multiple transitions to provide constraints on several competing theories for the transport of polarized maser emission. This approach minimizes the significant effects of spatial blending. We present several diagnostic tests designed to distinguish key features of competing theoretical models for maser polarization. The number of coincident features is limited by sensitivity however, particularly in the v = 1 J = 2-1 transition at 86 GHz, and deeper observations are needed. Preliminary conclusions based on the current data provide some support for: (i) spin-independent solutions for linear polarization; (ii) the influence of geometry on the distribution of fractional linear polarization with intensity; and, (iii) π/2 rotations in linear polarization position angle arising from transitions across the Van Vleck angle (sin 2θ = 2/3) between the maser line of sight and magnetic field. There is weaker evidence for several enumerated non-Zeeman explanations for circular polarization. The expected 2:1 ratio in circular polarization between J = 1-0 and J = 2-1 predicted by standard Zeeman theory cannot unfortunately be tested conclusively due to insufficient coincident components.

  15. Structural basis for the modulation of the neuronal voltage-gated sodium channel NaV1.6 by calmodulin.

    PubMed

    Reddy Chichili, Vishnu Priyanka; Xiao, Yucheng; Seetharaman, J; Cummins, Theodore R; Sivaraman, J

    2013-01-01

    The neuronal-voltage gated sodium channel (VGSC), Na(V)1.6, plays an important role in propagating action potentials along myelinated axons. Calmodulin (CaM) is known to modulate the inactivation kinetics of Na(V)1.6 by interacting with its IQ motif. Here we report the crystal structure of apo-CaM:Na(V)1.6IQ motif, along with functional studies. The IQ motif of Na(V)1.6 adopts an α-helical conformation in its interaction with the C-lobe of CaM. CaM uses different residues to interact with Na(V)1.6IQ motif depending on the presence or absence of Ca²⁺. Three residues from Na(V)1.6, Arg1902, Tyr1904 and Arg1905 were identified as the key common interacting residues in both the presence and absence of Ca²⁺. Substitution of Arg1902 and Tyr1904 with alanine showed a reduced rate of Na(V)1.6 inactivation in electrophysiological experiments in vivo. Compared with other CaM:Na(V) complexes, our results reveal a different mode of interaction for CaM:Na(V)1.6 and provides structural insight into the isoform-specific modulation of VGSCs. PMID:23942337

  16. Conditional forebrain deletion of the L-type calcium channel Ca V 1.2 disrupts remote spatial memories in mice.

    PubMed

    White, Jessica A; McKinney, Brandon C; John, Manorama C; Powers, Patricia A; Kamp, Timothy J; Murphy, Geoffrey G

    2008-01-01

    To determine whether L-type voltage-gated calcium channels (L-VGCCs) are required for remote memory consolidation, we generated conditional knockout mice in which the L-VGCC isoform Ca(V)1.2 was postnatally deleted in the hippocampus and cortex. In the Morris water maze, both Ca(V)1.2 conditional knockout mice (Ca(V)1.2(cKO)) and control littermates displayed a marked decrease in escape latencies and performed equally well on probe trials administered during training. In distinct contrast to their performance during training, Ca(V)1.2(cKO) mice exhibited significant impairments in spatial memory when examined 30 d after training, suggesting that Ca(V)1.2 plays a critical role in consolidation of remote spatial memories. PMID:18174367

  17. Animation of natural scene by virtual eye-movements evokes high precision and low noise in V1 neurons

    PubMed Central

    Baudot, Pierre; Levy, Manuel; Marre, Olivier; Monier, Cyril; Pananceau, Marc; Frégnac, Yves

    2013-01-01

    Synaptic noise is thought to be a limiting factor for computational efficiency in the brain. In visual cortex (V1), ongoing activity is present in vivo, and spiking responses to simple stimuli are highly unreliable across trials. Stimulus statistics used to plot receptive fields, however, are quite different from those experienced during natural visuomotor exploration. We recorded V1 neurons intracellularly in the anaesthetized and paralyzed cat and compared their spiking and synaptic responses to full field natural images animated by simulated eye-movements to those evoked by simpler (grating) or higher dimensionality statistics (dense noise). In most cells, natural scene animation was the only condition where high temporal precision (in the 10–20 ms range) was maintained during sparse and reliable activity. At the subthreshold level, irregular but highly reproducible membrane potential dynamics were observed, even during long (several 100 ms) “spike-less” periods. We showed that both the spatial structure of natural scenes and the temporal dynamics of eye-movements increase the signal-to-noise ratio by a non-linear amplification of the signal combined with a reduction of the subthreshold contextual noise. These data support the view that the sparsening and the time precision of the neural code in V1 may depend primarily on three factors: (1) broadband input spectrum: the bandwidth must be rich enough for recruiting optimally the diversity of spatial and time constants during recurrent processing; (2) tight temporal interplay of excitation and inhibition: conductance measurements demonstrate that natural scene statistics narrow selectively the duration of the spiking opportunity window during which the balance between excitation and inhibition changes transiently and reversibly; (3) signal energy in the lower frequency band: a minimal level of power is needed below 10 Hz to reach consistently the spiking threshold, a situation rarely reached with visual

  18. Animation of natural scene by virtual eye-movements evokes high precision and low noise in V1 neurons.

    PubMed

    Baudot, Pierre; Levy, Manuel; Marre, Olivier; Monier, Cyril; Pananceau, Marc; Frégnac, Yves

    2013-01-01

    Synaptic noise is thought to be a limiting factor for computational efficiency in the brain. In visual cortex (V1), ongoing activity is present in vivo, and spiking responses to simple stimuli are highly unreliable across trials. Stimulus statistics used to plot receptive fields, however, are quite different from those experienced during natural visuomotor exploration. We recorded V1 neurons intracellularly in the anaesthetized and paralyzed cat and compared their spiking and synaptic responses to full field natural images animated by simulated eye-movements to those evoked by simpler (grating) or higher dimensionality statistics (dense noise). In most cells, natural scene animation was the only condition where high temporal precision (in the 10-20 ms range) was maintained during sparse and reliable activity. At the subthreshold level, irregular but highly reproducible membrane potential dynamics were observed, even during long (several 100 ms) "spike-less" periods. We showed that both the spatial structure of natural scenes and the temporal dynamics of eye-movements increase the signal-to-noise ratio by a non-linear amplification of the signal combined with a reduction of the subthreshold contextual noise. These data support the view that the sparsening and the time precision of the neural code in V1 may depend primarily on three factors: (1) broadband input spectrum: the bandwidth must be rich enough for recruiting optimally the diversity of spatial and time constants during recurrent processing; (2) tight temporal interplay of excitation and inhibition: conductance measurements demonstrate that natural scene statistics narrow selectively the duration of the spiking opportunity window during which the balance between excitation and inhibition changes transiently and reversibly; (3) signal energy in the lower frequency band: a minimal level of power is needed below 10 Hz to reach consistently the spiking threshold, a situation rarely reached with visual dense

  19. The LBB methodology application results performed on the safety related piping of NPP V-1 in Jaslovske Bohunice

    SciTech Connect

    Kupca, L.; Beno, P.

    1997-04-01

    A broad overview of the leak before break (LBB) application to the Slovakian V-1 nuclear power plant is presented in the paper. LBB was applied to the primary cooling circuit and surge lines of both WWER 440 type units, and also used to assess the integrity of safety related piping in the feed water and main steam systems. Experiments and calculations performed included analyses of stresses, material mechanical properties, corrosion, fatigue damage, stability of heavy component supports, water hammer, and leak rates. A list of analysis results and recommendations are included in the paper.

  20. Enhancement of the Two-Dimensional Conduction Electron Zeeman Energy Near v=1 by Optical Dynamic Nuclear Polarization

    SciTech Connect

    Bowers, C.R.; Reno, J.L.; Simmons, J.A.; Vitkalov, S.A.

    1998-11-06

    Enhancement of the Zeeman energy of 2D conduction electrons near v = 1 by optical dynamic nuclear polarization (lINP), as observed by the Overhauser shift of the transport detected electron spin resonance, is measured quantitatively for the first time in GaAs/AIGaAs mukiquantum wells. The NMR signal enhancement is obtained under similar conditions in the same sample, allowing the hyperke coupling constant of 3.7T between between the nuclei and 2D conduction electrons to be measured for the first time. The potential to suppress the Zeeman energy by optical DNP is discussed in the context of its potential influence on Skyrmion formation.

  1. Experimental and computational evidence for an essential role of NaV1.6 in spike initiation at stretch-sensitive colorectal afferent endings

    PubMed Central

    Zhu, Yi; La, Jun-Ho; Wills, Zachary P.; Gebhart, G. F.

    2015-01-01

    Stretch-sensitive afferents comprise ∼33% of the pelvic nerve innervation of mouse colorectum, which are activated by colorectal distension and encode visceral nociception. Stretch-sensitive colorectal afferent endings respond tonically to stepped or ramped colorectal stretch, whereas dissociated colorectal dorsal root ganglion neurons generally fail to spike repetitively upon stepped current stimulation. The present study investigated this difference in the neural encoding characteristics between the soma and afferent ending using pharmacological approaches in an in vitro mouse colon-nerve preparation and complementary computational simulations. Immunohistological staining and Western blots revealed the presence of voltage-gated sodium channel (NaV) 1.6 and NaV1.7 at sensory neuronal endings in mouse colorectal tissue. Responses of stretch-sensitive colorectal afferent endings were significantly reduced by targeting NaV1.6 using selective antagonists (μ-conotoxin GIIIa and μ-conotoxin PIIIa) or tetrodotoxin. In contrast, neither selective NaV1.8 (A803467) nor NaV1.7 (ProTX-II) antagonists attenuated afferent responses to stretch. Computational simulation of a colorectal afferent ending that incorporated independent Markov models for NaV1.6 and NaV1.7, respectively, recapitulated the experimental findings, suggesting a necessary role for NaV1.6 in encoding tonic spiking by stretch-sensitive afferents. In addition, computational simulation of a dorsal root ganglion soma showed that, by adding a NaV1.6 conductance, a single-spiking neuron was converted into a tonic spiking one. These results suggest a mechanism/channel to explain the difference in neural encoding characteristics between afferent somata and sensory endings, likely caused by differential expression of ion channels (e.g., NaV1.6) at different parts of the neuron. PMID:25652923

  2. Targeting Atp6v1c1 Prevents Inflammation and Bone Erosion Caused by Periodontitis and Reveals Its Critical Function in Osteoimmunology

    PubMed Central

    Wang, Lin; Lu, Yun; Li, Qian; Zhu, Zheng; Shao, Jian-Zhong; Chen, Wei

    2015-01-01

    Periodontal disease (Periodontitis) is a serious disease that affects a majority of adult Americans and is associated with other systemic diseases, including diabetes, rheumatoid arthritis, and other inflammatory diseases. While great efforts have been devoted toward understanding the pathogenesis of periodontitis, there remains a pressing need for developing potent therapeutic strategies for targeting this pervasive and destructive disease. In this study, we utilized novel adeno-associated virus (AAV)-mediated Atp6v1c1 knockdown gene therapy to treat bone erosion and inflammatory caused by periodontitis in mouse model. Atp6v1c1 is a subunit of the V-ATPase complex and regulator of the assembly of the V0 and V1 domains of the V-ATPase complex. We demonstrated previously that Atp6v1c1 has an essential function in osteoclast mediated bone resorption. We hypothesized that Atp6v1c1 may be an ideal target to prevent the bone erosion and inflammation caused by periodontitis. To test the hypothesis, we employed AAV RNAi knockdown of Atp6v1c1 gene expression to prevent bone erosion and gingival inflammation simultaneously. We found that lesion-specific injection of AAV-shRNA-Atp6v1c1 into the periodontal disease lesions protected against bone erosion (>85%) and gingival inflammation caused by P. gingivalis W50 infection. AAV-mediated Atp6v1c1 knockdown dramatically reduced osteoclast numbers and inhibited the infiltration of dendritic cells and macrophages in the bacteria-induced inflammatory lesions in periodontitis. Silencing of Atp6v1c1 expression also prevented the expressions of osteoclast-related genes and pro-inflammatory cytokine genes. Our data suggests that AAV-shRNA-Atp6v1c1 treatment can significantly attenuate the bone erosion and inflammation caused by periodontitis, indicating the dual function of AAV-shRNA-Atp6v1c1 as an inhibitor of bone erosion mediated by osteoclasts, and as an inhibitor of inflammation through down-regulation of pro

  3. Quantification of Early Stages of Cortical Reorganization of the Topographic Map of V1 Following Retinal Lesions in Monkeys

    PubMed Central

    Botelho, Eliã P.; Ceriatte, Cecília; Soares, Juliana G.M.; Gattass, Ricardo; Fiorani, Mario

    2014-01-01

    We quantified the capacity for reorganization of the topographic representation of area V1 in adult monkeys. Bias-free automated mapping methods were used to delineate receptive fields (RFs) of an array of neuronal clusters prior to, and up to 6 h following retinal lesions. Monocular lesions caused a significant reorganization of the topographic map in this area, both inside and outside the cortical lesion projection zone (LPZ). Small flashed stimuli revealed responses up to 0.85 mm inside the boundaries of the LPZ, with RFs representing regions of undamaged retina immediately surrounding the lesion. In contrast, long moving bars that spanned the scotoma resulting from the lesion revealed responsive units up to 1.87 mm inside the LPZ, with RFs representing interpolated responses in this region. This reorganization is present immediately after monocular retinal lesioning. Both stimuli showed a similar and significant (5-fold) increase of the RF scatter in the LPZ, 0.56 mm (median), compared with the undamaged retina, 0.12 mm. Our results reveal an array of preexisting subthreshold functional connections of up to 2 mm in V1, which can be rapidly mobilized independently from the differential qualitative reorganization elicited by each stimulus. PMID:23010747

  4. Vasotocin neurons and septal V1a-like receptors potently modulate songbird flocking and responses to novelty.

    PubMed

    Kelly, Aubrey M; Kingsbury, Marcy A; Hoffbuhr, Kristin; Schrock, Sara E; Waxman, Brandon; Kabelik, David; Thompson, Richmond R; Goodson, James L

    2011-06-01

    Previous comparisons of territorial and gregarious finches (family Estrildidae) suggest the hypothesis that arginine vasotocin (VT) neurons in the medial bed nucleus of the stria terminalis (BSTm) and V(1a)-like receptors in the lateral septum (LS) promote flocking behavior. Consistent with this hypothesis, we now show that intraseptal infusions of a V(1a) antagonist in male zebra finches (Taeniopygia guttata) reduce gregariousness (preference for a group of 10 versus 2 conspecific males), but have no effect on the amount of time that subjects spend in close proximity to other birds ("contact time"). The antagonist also produces a profound increase in anxiety-like behavior, as exhibited by an increased latency to feed in a novelty-suppressed feeding test. Bilateral knockdown of VT production in the BSTm using LNA-modified antisense oligonucleotides likewise produces increases in anxiety-like behavior and a potent reduction in gregariousness, relative to subjects receiving scrambled oligonucleotides. The antisense oligonucleotides also produced a modest increase in contact time, irrespective of group size. Together, these combined experiments provide clear evidence that endogenous VT promotes preferences for larger flock sizes, and does so in a manner that is coupled to general anxiolysis. Given that homologous peptide circuitry of the BSTm-LS is found across all tetrapod vertebrate classes, these findings may be predictive for other highly gregarious species. PMID:21295577

  5. Characterization of the honeybee AmNaV1 channel and tools to assess the toxicity of insecticides.

    PubMed

    Gosselin-Badaroudine, Pascal; Moreau, Adrien; Delemotte, Lucie; Cens, Thierry; Collet, Claude; Rousset, Matthieu; Charnet, Pierre; Klein, Michael L; Chahine, Mohamed

    2015-01-01

    Pollination is important for both agriculture and biodiversity. For a significant number of plants, this process is highly, and sometimes exclusively, dependent on the pollination activity of honeybees. The large numbers of honeybee colony losses reported in recent years have been attributed to colony collapse disorder. Various hypotheses, including pesticide overuse, have been suggested to explain the disorder. Using the Xenopus oocytes expression system and two microelectrode voltage-clamp, we report the functional expression and the molecular, biophysical, and pharmacological characterization of the western honeybee's sodium channel (Apis Mellifera NaV1). The NaV1 channel is the primary target for pyrethroid insecticides in insect pests. We further report that the honeybee's channel is also sensitive to permethrin and fenvalerate, respectively type I and type II pyrethroid insecticides. Molecular docking of these insecticides revealed a binding site that is similar to sites previously identified in other insects. We describe in vitro and in silico tools that can be used to test chemical compounds. Our findings could be used to assess the risks that current and next generation pesticides pose to honeybee populations. PMID:26202396

  6. Dependence of chromatic responses in V1 on visual field eccentricity and spatial frequency: an fMRI study.

    PubMed

    D'Souza, Dany V; Auer, Tibor; Frahm, Jens; Strasburger, Hans; Lee, Barry B

    2016-03-01

    Psychophysical sensitivity to red-green chromatic modulation decreases with visual eccentricity, compared to sensitivity to luminance modulation, even after appropriate stimulus scaling. This is likely to occur at a central, rather than a retinal, site. Blood-oxygenation-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) responses to stimuli designed to separately stimulate different afferent channels' [red-green, luminance, and short-wavelength (S)-cone] circular gratings were recorded as a function of visual eccentricity (±10  deg) and spatial frequency (SF) in human primary visual cortex (V1) and further visual areas (V2v, V3v). In V1, the SF tuning of BOLD fMRI responses became coarser with eccentricity. For red-green and luminance gratings, similar SF tuning curves were found at all eccentricities. The pattern for S-cone modulation differed, with SF tuning changing more slowly with eccentricity than for the other two modalities. This may be due to the different retinal distribution with eccentricity of this receptor type. A similar pattern held in V2v and V3v. This would suggest that transformation or spatial filtering of the chromatic (red-green) signal occurs beyond these areas. PMID:26974942

  7. Characterization of the honeybee AmNaV1 channel and tools to assess the toxicity of insecticides

    PubMed Central

    Gosselin-Badaroudine, Pascal; Moreau, Adrien; Delemotte, Lucie; Cens, Thierry; Collet, Claude; Rousset, Matthieu; Charnet, Pierre; Klein, Michael L.; Chahine, Mohamed

    2015-01-01

    Pollination is important for both agriculture and biodiversity. For a significant number of plants, this process is highly, and sometimes exclusively, dependent on the pollination activity of honeybees. The large numbers of honeybee colony losses reported in recent years have been attributed to colony collapse disorder. Various hypotheses, including pesticide overuse, have been suggested to explain the disorder. Using the Xenopus oocytes expression system and two microelectrode voltage-clamp, we report the functional expression and the molecular, biophysical, and pharmacological characterization of the western honeybee’s sodium channel (Apis Mellifera NaV1). The NaV1 channel is the primary target for pyrethroid insecticides in insect pests. We further report that the honeybee’s channel is also sensitive to permethrin and fenvalerate, respectively type I and type II pyrethroid insecticides. Molecular docking of these insecticides revealed a binding site that is similar to sites previously identified in other insects. We describe in vitro and in silico tools that can be used to test chemical compounds. Our findings could be used to assess the risks that current and next generation pesticides pose to honeybee populations. PMID:26202396

  8. Informational constraints on interceptive actions of elite football goalkeepers in 1v1 dyads during competitive performance.

    PubMed

    Shafizadeh, Mohsen; Davids, Keith; Correia, Vanda; Wheat, Jonathan; Hizan, Hazuan

    2016-09-01

    The aim of this study was to examine whether perceptual variables can provide informational constraints for the goalkeepers to intercept the ball successfully in 1v1 dyads. Video images of 42 actions (1v1 in direct shots) were selected randomly from different matches and divided into conceded goals (n = 20) and saved actions (n = 22) to investigate interceptive actions of 20 goalkeepers in the English Premier League in season 2013-2014. Time to Contact (TTC) of the closing distance gap between shooter and goalkeeper was obtained by digitising actions in the 18-yard penalty box. Statistical analyses revealed that, in sequences of play resulting in an intercepted shot at goal, goalkeepers closed down outfield players in the X axis, whereas when a goal was conceded, there was a significantly delayed movement by goalkeepers toward the shooters in this plane. The results of canonical correlations showed that a decreasing distance between a shooter and goalkeeper, and accompanied reduction in relative interpersonal velocity followed a temporal pattern. Findings of this study showed how perception of key informational constraints on dyadic system relations, such as TTC, interpersonal distance and relative velocity, constrain elite goalkeepers' interceptive actions, playing an important role in successful performance. PMID:26652039

  9. The role of attention in figure-ground segregation in areas V1 and V4 of the visual cortex.

    PubMed

    Poort, Jasper; Raudies, Florian; Wannig, Aurel; Lamme, Victor A F; Neumann, Heiko; Roelfsema, Pieter R

    2012-07-12

    Our visual system segments images into objects and background. Figure-ground segregation relies on the detection of feature discontinuities that signal boundaries between the figures and the background and on a complementary region-filling process that groups together image regions with similar features. The neuronal mechanisms for these processes are not well understood and it is unknown how they depend on visual attention. We measured neuronal activity in V1 and V4 in a task where monkeys either made an eye movement to texture-defined figures or ignored them. V1 activity predicted the timing and the direction of the saccade if the figures were task relevant. We found that boundary detection is an early process that depends little on attention, whereas region filling occurs later and is facilitated by visual attention, which acts in an object-based manner. Our findings are explained by a model with local, bottom-up computations for boundary detection and feedback processing for region filling. PMID:22794268

  10. Validation of CESAR Thermal-hydraulic Module of ASTEC V1.2 Code on BETHSY Experiments

    NASA Astrophysics Data System (ADS)

    Tregoures, Nicolas; Bandini, Giacomino; Foucher, Laurent; Fleurot, Joëlle; Meloni, Paride

    The ASTEC V1 system code is being jointly developed by the French Institut de Radioprotection et Sûreté Nucléaire (IRSN) and the German Gesellschaft für Anlagen und ReaktorSicherheit (GRS) to address severe accident sequences in a nuclear power plant. Thermal-hydraulics in primary and secondary system is addressed by the CESAR module. The aim of this paper is to present the validation of the CESAR module, from the ASTEC V1.2 version, on the basis of well instrumented and qualified integral experiments carried out in the BETHSY facility (CEA, France), which simulates a French 900 MWe PWR reactor. Three tests have been thoroughly investigated with CESAR: the loss of coolant 9.1b test (OECD ISP N° 27), the loss of feedwater 5.2e test, and the multiple steam generator tube rupture 4.3b test. In the present paper, the results of the code for the three analyzed tests are presented in comparison with the experimental data. The thermal-hydraulic behavior of the BETHSY facility during the transient phase is well reproduced by CESAR: the occurrence of major events and the time evolution of main thermal-hydraulic parameters of both primary and secondary circuits are well predicted.

  11. Structural basis for diverse N-glycan recognition by HIV-1-neutralizing V1-V2-directed antibody PG16

    SciTech Connect

    Pancera, Marie; Shahzad-ul-Hussan, Syed; Doria-Rose, Nicole A.; McLellan, Jason S.; Bailer, Robert T.; Dai, Kaifan; Loesgen, Sandra; Louder, Mark K.; Staupe, Ryan P.; Yang, Yongping; Zhang, Baoshan; Parks, Robert; Eudailey, Joshua; Lloyd, Krissey E.; Blinn, Julie; Alam, S. Munir; Haynes, Barton F.; Amin, Mohammed N.; Wang, Lai-Xi; Burton, Dennis R.; Koff, Wayne C.; Nabel, Gary J.; Mascola, John R.; Bewley, Carole A; Kwong, Peter D.

    2013-08-05

    HIV-1 uses a diverse N-linked-glycan shield to evade recognition by antibody. Select human antibodies, such as the clonally related PG9 and PG16, recognize glycopeptide epitopes in the HIV-1 V1–V2 region and penetrate this shield, but their ability to accommodate diverse glycans is unclear. Here we report the structure of antibody PG16 bound to a scaffolded V1–V2, showing an epitope comprising both high mannose–type and complex-type N-linked glycans. We combined structure, NMR and mutagenesis analyses to characterize glycan recognition by PG9 and PG16. Three PG16-specific residues, arginine, serine and histidine (RSH), were critical for binding sialic acid on complex-type glycans, and introduction of these residues into PG9 produced a chimeric antibody with enhanced HIV-1 neutralization. Although HIV-1–glycan diversity facilitates evasion, antibody somatic diversity can overcome this and can provide clues to guide the design of modified antibodies with enhanced neutralization.

  12. Norcoclaurine Synthase Is a Member of the Pathogenesis-Related 10/Bet v1 Protein Family[W

    PubMed Central

    Lee, Eun-Jeong; Facchini, Peter

    2010-01-01

    Norcoclaurine synthase (NCS) catalyzes the first committed step in the biosynthesis of benzylisoquinoline alkaloids (BIAs). NCS from Thalictrum flavum (Tf NCS), Papaver somniferum (Ps NCS1 and Ps NCS2), and Coptis japonica (Cj PR10A) share substantial identity with pathogen-related 10 (PR10) and Bet v1 proteins, whose functions are not well understood. A distinct enzyme (Cj NCS1) with similarity to 2-oxoglutarate–dependent dioxygenases was suggested as the bona fide NCS in C. japonica. Here, we validate the exclusive role of PR10/Bet v1-type NCS enzymes in BIA metabolism. Immunolocalization of Ps NCS2 revealed its cell type–specific occurrence in phloem sieve elements, which contain all other known BIA biosynthetic enzymes. In opium poppy, NCS transcripts and proteins were abundant in root and stem, but at low levels in leaf and carpel. Silencing of NCS in opium poppy profoundly reduced alkaloid levels compared with controls. Immunoprecipitation of NCS from total protein extracts of T. flavum cells resulted in a nearly complete attenuation of NCS activity. A Ps NCS2–green fluorescent protein fusion introduced by microprojectile bombardment into opium poppy cells initially localized to the endoplasmic reticulum but subsequently sorted to the vacuole. In our hands, Cj NCS1 did not catalyze the formation of (S)-norcoclaurine from dopamine and 4-hydroxyphenylacetaldehyde. PMID:21037103

  13. Areas V1 and V2 show microsaccade-related 3-4-Hz covariation in gamma power and frequency.

    PubMed

    Lowet, E; Roberts, M J; Bosman, C A; Fries, P; De Weerd, P

    2016-05-01

    Neuronal gamma-band synchronization (25-80 Hz) in visual cortex appears sustained and stable during prolonged visual stimulation when investigated with conventional averages across trials. However, recent studies in macaque visual cortex have used single-trial analyses to show that both power and frequency of gamma oscillations exhibit substantial moment-by-moment variation. This has raised the question of whether these apparently random variations might limit the functional role of gamma-band synchronization for neural processing. Here, we studied the moment-by-moment variation in gamma oscillation power and frequency, as well as inter-areal gamma synchronization, by simultaneously recording local field potentials in V1 and V2 of two macaque monkeys. We additionally analyzed electrocorticographic V1 data from a third monkey. Our analyses confirm that gamma-band synchronization is not stationary and sustained but undergoes moment-by-moment variations in power and frequency. However, those variations are neither random and nor a possible obstacle to neural communication. Instead, the gamma power and frequency variations are highly structured, shared between areas and shaped by a microsaccade-related 3-4-Hz theta rhythm. Our findings provide experimental support for the suggestion that cross-frequency coupling might structure and facilitate the information flow between brain regions. PMID:26547390

  14. Vasotocin Neurons and Septal V1a-like Receptors Potently Modulate Songbird Flocking and Responses to Novelty

    PubMed Central

    Kelly, Aubrey M.; Kingsbury, Marcy A.; Hoffbuhr, Kristin; Schrock, Sara E.; Waxman, Brandon; Kabelik, David; Thompson, Richmond R.; Goodson, James L.

    2011-01-01

    Previous comparisons of territorial and gregarious finches (family Estrildidae) suggest the hypothesis that arginine vasotocin (VT) neurons in the medial bed nucleus of the stria terminalis (BSTm) and V1a-like receptors in the lateral septum (LS) promote flocking behavior. Consistent with this hypothesis, we now show that intraseptal infusions of a V1a antagonist in male zebra finches (Taeniopygia guttata) reduce gregariousness (preference for a group of 10 versus 2 conspecific males), but have no effect on the amount of time that subjects spend in close proximity to other birds (“contact time”). The antagonist also produces a profound increase in anxiety-like behavior, as exhibited by an increased latency to feed in a novelty-suppressed feeding test. Bilateral knockdown of VT production in the BSTm using LNA-modified antisense oligonucleotides likewise produces increases in anxiety-like behavior and a potent reduction in gregariousness, relative to subjects receiving scrambled oligonucleotides. The antisense oligonucleotides also produced a modest increase in contact time (irrespective of group size). Together, these combined experiments provide clear evidence that endogenous VT promotes preferences for larger flock sizes, and does so in a manner that is coupled to general anxiolysis. Given that homologous peptide circuitry of the BSTm-LS is found across all tetrapod vertebrate classes, these findings may be predictive for other highly gregarious species. PMID:21295577

  15. Distinct functional organizations for processing different motion signals in V1, V2, and V4 of macaque.

    PubMed

    An, Xu; Gong, Hongliang; Qian, Liling; Wang, Xiaochun; Pan, Yanxia; Zhang, Xian; Yang, Yupeng; Wang, Wei

    2012-09-26

    Motion perception is qualitatively invariant across different objects and forms, namely, the same motion information can be conveyed by many different physical carriers, and it requires the processing of motion signals consisting of direction, speed, and axis or trajectory of motion defined by a moving object. Compared with the representation of orientation, the cortical processing of these different motion signals within the early ventral visual pathway of the primate remains poorly understood. Using drifting full-field noise stimuli and intrinsic optical imaging, along with cytochrome-oxidase staining, we found that the orientation domains in macaque V1, V2, and V4 that processed orientation signals also served to process motion signals associated with the axis and speed of motion. In contrast, direction domains within the thick stripes of V2 demonstrated preferences that were independent of motion speed. The population responses encoding the orientation and motion axis could be precisely reproduced by a spatiotemporal energy model. Thus, our observation of orientation domains with dual functions in V1, V2, and V4 directly support the notion that the linear representation of the temporal series of retinotopic activations may serve as another motion processing strategy in primate ventral visual pathway, contributing directly to fine form and motion analysis. Our findings further reveal that different types of motion information are differentially processed in parallel and segregated compartments within primate early visual cortices, before these motion features are fully combined in high-tier visual areas. PMID:23015427

  16. Performance of Passive Samplers Analyzed by Computer-Controlled Scanning Electron Microscopy to Measure PM10-2.5.

    PubMed

    Peters, Thomas M; Sawvel, Eric J; Willis, Robert; West, Roger R; Casuccio, Gary S

    2016-07-19

    We report on the precision and accuracy of measuring PM10-2.5 and its components with particles collected by passive aerosol samplers and analyzed by computer-controlled scanning electron microscopy with energy dispersive X-ray spectroscopy. Passive samplers were deployed for week-long intervals in triplicate and colocated with a federal reference method sampler at three sites and for 5 weeks in summer 2009 and 5 weeks in winter 2010 in Cleveland, OH. The limit of detection of the passive method for PM10-2.5 determined from blank analysis was 2.8 μg m(-3). Overall precision expressed as root-mean-square coefficient of variation (CVRMS) improved with increasing concentrations (37% for all samples, n = 30; 19% for PM10-2.5 > 10 μg m(-3), n = 9; and 10% for PM10-2.5 > 15 μg m(-3), n = 4). The linear regression of PM10-2.5 measured passively on that measured with the reference sampler exhibited an intercept not statistically different than zero (p = 0.46) and a slope not statistically different from unity (p = 0.92). Triplicates with high CVs (CV > 40%, n = 5) were attributed to low particle counts (and mass concentrations), spurious counts attributed to salt particles, and Al-rich particles. This work provides important quantitative observations that can help guide future development and use of passive samplers for measuring atmospheric particulate matter. PMID:27300163

  17. Molecular characterization of recombinant T1, a non-allergenic periwinkle (Catharanthus roseus) protein, with sequence similarity to the Bet v 1 plant allergen family.

    PubMed Central

    Laffer, Sylvia; Hamdi, Said; Lupinek, Christian; Sperr, Wolfgang R; Valent, Peter; Verdino, Petra; Keller, Walter; Grote, Monika; Hoffmann-Sommergruber, Karin; Scheiner, Otto; Kraft, Dietrich; Rideau, Marc; Valenta, Rudolf

    2003-01-01

    More than 25% of the population suffer from Type I allergy, an IgE-mediated hypersensitivity disease. Allergens with homology to the major birch ( Betula verrucosa ) pollen allergen, Bet v 1, belong to the most potent elicitors of IgE-mediated allergies. T1, a cytokinin-inducible cytoplasmic periwinkle ( Catharanthus roseus ) protein, with significant sequence similarity to members of the Bet v 1 plant allergen family, was expressed in Escherichia coli. Recombinant T1 (rT1) did not react with IgE antibodies from allergic patients, and failed to induce basophil histamine release and immediate-type skin reactions in Bet v 1-allergic patients. Antibodies raised against purified rT1 could be used for in situ localization of natural T1 by immunogold electron microscopy, but did not cross-react with most of the Bet v 1-related allergens. CD analysis showed significant differences regarding secondary structure and thermal denaturation behaviour between rT1 and recombinant Bet v 1, suggesting that these structural differences are responsible for the different allergenicity of the proteins. T1 represents a non-allergenic member of the Bet v 1 family that may be used to study structural requirements of allergenicity and to engineer hypo-allergenic plants by replacing Bet v 1-related allergens for primary prevention of allergy. PMID:12656672

  18. Mapping the conformational epitope of a neutralizing antibody (AcV1) directed against the AcMNPV GP64 protein

    SciTech Connect

    Zhou Jian; Blissard, Gary W. . E-mail: gwb1@cornell.edu

    2006-09-01

    The envelope glycoprotein GP64 of Autographa californica nucleopolyhedrovirus (AcMNPV) is necessary and sufficient for the acid-induced membrane fusion activity that is required for fusion of the budded virus (BV) envelope and the endosome membrane during virus entry. Infectivity of the budded virus (BV) is neutralized by AcV1, a monoclonal antibody (MAb) directed against GP64. Prior studies indicated that AcV1 recognizes a conformational epitope and does not inhibit virus attachment to the cell, but instead inhibits entry at a step following virus attachment. We found that AcV1 recognition of GP64 was lost upon exposure of GP64 to low pH (pH 4.5) and restored by returning GP64 to pH 6.2. In addition, the AcV1 epitope was lost upon denaturation of GP64 in SDS, but the AcV1 epitope was restored by refolding the protein in the absence of SDS. Using truncated GP64 proteins expressed in insect cells, we mapped the AcV1 epitope to a 24 amino acid region in the central variable domain of GP64. When sequences within the mapped AcV1 epitope were substituted with a c-Myc epitope and the resulting construct was used to replace wt GP64 in recombinant AcMNPV viruses, the modified GP64 protein appeared to function normally. However, an anti-c-Myc monoclonal antibody did not neutralize infectivity of those viruses. Because binding of the c-Myc MAb to the same site in the GP64 sequence did not result in neutralization, these studies suggest that AcV1 neutralization may result from a specific structural constraint caused by AcV1 binding and not simply by steric hindrance caused by antibody binding at this position in GP64.

  19. Analysis of epitope-specific immune responses induced by vaccination with structurally folded and unfolded recombinant Bet v 1 allergen derivatives in man.

    PubMed

    Pree, Ines; Reisinger, Jürgen; Focke, Margit; Vrtala, Susanne; Pauli, Gabrielle; van Hage, Marianne; Cromwell, Oliver; Gadermaier, Elisabeth; Egger, Cornelia; Reider, Norbert; Horak, Friedrich; Valenta, Rudolf; Niederberger, Verena

    2007-10-15

    Previously, we have constructed recombinant derivatives of the major birch pollen allergen, Bet v 1, with a more than 100-fold reduced ability to induce IgE-mediated allergic reactions. These derivatives differed from each other because the two recombinant Bet v 1 fragments represented unfolded molecules whereas the recombinant trimer resembled most of the structural fold of the Bet v 1 allergen. In this study, we analyzed the Ab (IgE, IgG subclass, IgA, IgM) response to Bet v 1, recombinant and synthetic Bet v 1-derived peptides in birch pollen allergic patients who had been vaccinated with the derivatives or adjuvant alone. Furthermore, we studied the induction of IgE-mediated skin responses in these patients using Bet v 1 and Bet v 1 fragments. Both types of vaccines induced a comparable IgG1 and IgG4 response against new sequential epitopes which overlap with the conformational IgE epitopes of Bet v 1. This response was 4- to 5-fold higher than that induced by immunotherapy with birch pollen extract. Trimer more than fragments induced also IgE responses against new epitopes and a transient increase in skin sensitivity to the fragments at the beginning of therapy. However, skin reactions to Bet v 1 tended to decrease one year after treatment in both actively treated groups. We demonstrate that vaccination with folded and unfolded recombinant allergen derivatives induces IgG Abs against new epitopes. These data may be important for the development of therapeutic as well as prophylactic vaccines based on recombinant allergens. PMID:17911617

  20. Frequent occurrence of T cell–mediated late reactions revealed by atopy patch testing with hypoallergenic rBet v 1 fragments

    PubMed Central

    Campana, Raffaela; Moritz, Katharina; Marth, Katharina; Neubauer, Angela; Huber, Hans; Henning, Rainer; Blatt, Katharina; Hoermann, Gregor; Brodie, Tess M.; Kaider, Alexandra; Valent, Peter; Sallusto, Federica; Wöhrl, Stefan; Valenta, Rudolf

    2015-01-01

    Background Late allergic reactions are common in the course of allergen-specific immunotherapy and even occur with allergy vaccines with reduced IgE reactivity. Objective We sought to study atopy patch test (APT) reactions and T-cell responses to the recombinant birch pollen allergen Bet v 1 and recombinant hypoallergenic T-cell epitope–containing Bet v 1 fragments in patients with birch pollen allergy with and without atopic dermatitis (AD). Methods A clinical study was conducted in 15 patients with birch pollen allergy with AD (group 1), 5 patients with birch pollen allergy without AD (group 2), 5 allergic patients without birch pollen allergy (group 3), and 5 nonallergic subjects (group 4) by performing skin prick tests and APTs with rBet v 1 and hypoallergenic rBet v 1 fragments. T-cell, cutaneous lymphocyte antigen (CLA)+ and CCR4+ T-cell and cytokine responses were studied by thymidine uptake, carboxyfluorescein diacetate succinimidyl ester staining, and Luminex technology, respectively. Results rBet v 1 and hypoallergenic rBet v 1 fragments induced APT reactions in not only most of the patients with birch pollen allergy with AD (11/15) but also in most of those without AD (4/5). Patients with birch pollen allergy with AD had higher Bet v 1–specific proliferation of CLA+ and CCR4+ T cells compared with patients with birch pollen allergy without AD. There were no differences in Bet v 1–specific CLA+ and CCR4+ proliferation and cytokine secretion in patients with and without APT reactions. Conclusion Hypoallergenic rBet v 1 fragments induce T cell–dependent late reactions not only in patients with birch pollen allergy with AD but also in those without AD, which can be determined based on APT results but not based on in vitro parameters. PMID:26518092

  1. Multiple roles for NaV1.9 in the activation of visceral afferents by noxious inflammatory, mechanical, and human disease–derived stimuli

    PubMed Central

    Hockley, James R.F.; Boundouki, George; Cibert-Goton, Vincent; McGuire, Cian; Yip, Ping K.; Chan, Christopher; Tranter, Michael; Wood, John N.; Nassar, Mohammed A.; Blackshaw, L. Ashley; Aziz, Qasim; Michael, Gregory J.; Baker, Mark D.; Winchester, Wendy J.; Knowles, Charles H.; Bulmer, David C.

    2014-01-01

    Chronic visceral pain affects millions of individuals worldwide and remains poorly understood, with current therapeutic options constrained by gastrointestinal adverse effects. Visceral pain is strongly associated with inflammation and distension of the gut. Here we report that the voltage-gated sodium channel subtype NaV1.9 is expressed in half of gut-projecting rodent dorsal root ganglia sensory neurons. We show that NaV1.9 is required for normal mechanosensation, for direct excitation and for sensitization of mouse colonic afferents by mediators from inflammatory bowel disease tissues, and by noxious inflammatory mediators individually. Excitatory responses to ATP or PGE2 were substantially reduced in NaV1.9−/− mice. Deletion of NaV1.9 substantially attenuates excitation and subsequent mechanical hypersensitivity after application of inflammatory soup (IS) (bradykinin, ATP, histamine, PGE2, and 5HT) to visceral nociceptors located in the serosa and mesentery. Responses to mechanical stimulation of mesenteric afferents were also reduced by loss of NaV1.9, and there was a rightward shift in stimulus–response function to ramp colonic distension. By contrast, responses to rapid, high-intensity phasic distension of the colon are initially unaffected; however, run-down of responses to repeat phasic distension were exacerbated in NaV1.9−/− afferents. Finally colonic afferent activation by supernatants derived from inflamed human tissue was greatly reduced in NaV1.9−/− mice. These results demonstrate that NaV1.9 is required for persistence of responses to intense mechanical stimulation, contributes to inflammatory mechanical hypersensitivity, and is essential for activation by noxious inflammatory mediators, including those from diseased human bowel. These observations indicate that NaV1.9 represents a high-value target for development of visceral analgesics. PMID:24972070

  2. Alcohol Withdrawal-Induced Seizure Susceptibility is Associated with an Upregulation of CaV1.3 Channels in the Rat Inferior Colliculus

    PubMed Central

    Akinfiresoye, Luli R.; Allard, Joanne S.; Lovinger, David M.

    2015-01-01

    Background: We previously reported increased current density through L-type voltage-gated Ca2+ (CaV1) channels in inferior colliculus (IC) neurons during alcohol withdrawal. However, the molecular correlate of this increased CaV1 current is currently unknown. Methods: Rats received three daily doses of ethanol every 8 hours for 4 consecutive days; control rats received vehicle. The IC was dissected at various time intervals following alcohol withdrawal, and the mRNA and protein levels of the CaV1.3 and CaV1.2 α1 subunits were measured. In separate experiments, rats were tested for their susceptibility to alcohol withdrawal–induced seizures (AWS) 3, 24, and 48 hours after alcohol withdrawal. Results: In the alcohol-treated group, AWS were observed 24 hours after withdrawal; no seizures were observed at 3 or 48 hours. No seizures were observed at any time in the control-treated rats. Compared to control-treated rats, the mRNA level of the CaV1.3 α1 subunit was increased 1.4-fold, 1.9-fold, and 1.3-fold at 3, 24, and 48 hours, respectively. In contrast, the mRNA level of the CaV1.2 α1 subunit increased 1.5-fold and 1.4-fold at 24 and 48 hours, respectively. At 24 hours, Western blot analyses revealed that the levels of the CaV1.3 and CaV1.2 α1 subunits increased by 52% and 32%, respectively, 24 hours after alcohol withdrawal. In contrast, the CaV1.2 and CaV1.3 α1 subunits were not altered at either 3 or 48 hours during alcohol withdrawal. Conclusions: Expression of the CaV1.3 α1 subunit increased in parallel with AWS development, suggesting that altered L-type CaV1.3 channel expression is an important feature of AWS pathogenesis. PMID:25556199

  3. V1/V2 Neutralizing Epitope is Conserved in Divergent Non-M Groups of HIV-1

    PubMed Central

    Morgand, Marion; Bouvin-Pley, Mélanie; Plantier, Jean-Christophe; Moreau, Alain; Alessandri, Elodie; Simon, François; Pace, Craig S.; Pancera, Marie; Ho, David D.; Poignard, Pascal; Bjorkman, Pamela J.; Mouquet, Hugo; Nussenzweig, Michel C.; Kwong, Peter D.; Baty, Daniel; Chames, Patrick; Braibant, Martine

    2016-01-01

    Background: Highly potent broadly neutralizing monoclonal antibodies (bNAbs) have been obtained from individuals infected by HIV-1 group M variants. We analyzed the cross-group neutralization potency of these bNAbs toward non-M primary isolates (PI). Material and Methods: The sensitivity to neutralization was analyzed in a neutralization assay using TZM-bl cells. Twenty-three bNAbs were used, including reagents targeting the CD4-binding site, the N160 glycan-V1/V2 site, the N332 glycan-V3 site, the membrane proximal external region of gp41, and complex epitopes spanning both env subunits. Two bispecific antibodies that combine the inhibitory activity of an anti-CD4 with that of PG9 or PG16 bNAbs were included in the study (PG9-iMab and PG16-iMab). Results: Cross-group neutralization was observed only with the bNAbs targeting the N160 glycan-V1/V2 site. Four group O PIs, 1 group N PI, and the group P PI were neutralized by PG9 and/or PG16 or PGT145 at low concentrations (0.04–9.39 μg/mL). None of the non-M PIs was neutralized by the bNAbs targeting other regions at the highest concentration tested, except 10E8 that neutralized weakly 2 group N PIs and 35O22 that neutralized 1 group O PI. The bispecific bNAbs neutralized very efficiently all the non-M PIs with IC50 below 1 μg/mL, except 2 group O strains. Conclusion: The N160 glycan-V1/V2 site is the most conserved neutralizing site within the 4 groups of HIV-1. This makes it an interesting target for the development of HIV vaccine immunogens. The corresponding bNAbs may be useful for immunotherapeutic strategies in patients infected by non-M variants. PMID:26413851

  4. Development and basic evaluation of a prognostic aerosol scheme (v1) in the CNRM Climate Model CNRM-CM6

    NASA Astrophysics Data System (ADS)

    Michou, M.; Nabat, P.; Saint-Martin, D.

    2015-03-01

    We have implemented a prognostic aerosol scheme (v1) in CNRM-CM6, the climate model of CNRM-GAME and CERFACS, based upon the GEMS/MACC aerosol module of the ECMWF operational forecast model. This scheme describes the physical evolution of the five main types of aerosols, namely black carbon, organic matter, sulfate, desert dust and sea salt. In this work, we describe the characteristics of our implementation, for instance, taking into consideration a different dust scheme or boosting biomass burning emissions by a factor of 2, as well as the evaluation performed on simulation output. The simulations consist of time slice simulations for 2004 conditions and transient runs over the 1993-2012 period, and are either free-running or nudged towards the ERA-Interim Reanalysis. Evaluation data sets include several satellite instrument AOD (aerosol optical depth) products (i.e., MODIS Aqua classic and Deep-Blue products, MISR and CALIOP products), as well as ground-based AERONET data and the derived AERONET climatology, MAC-v1. The uncertainty of aerosol-type seasonal AOD due to model internal variability is low over large parts of the globe, and the characteristics of a nudged simulation reflect those of a free-running simulation. In contrast, the impact of the new dust scheme is large, with modelled dust AODs from simulations with the new dust scheme close to observations. Overall patterns and seasonal cycles of the total AOD are well depicted with, however, a systematic low bias over oceans. The comparison to the fractional MAC-v1 AOD climatology shows disagreements mostly over continents, while that to AERONET sites outlines the capability of the model to reproduce monthly climatologies under very diverse dominant aerosol types. Here again, underestimation of the total AOD appears in several cases, sometimes linked to insufficient efficiency of the aerosol transport away from the aerosol sources. Analysis of monthly time series at 166 AERONET sites shows, in general

  5. A Selective V1A Receptor Agonist, Selepressin, Is Superior to Arginine Vasopressin and to Norepinephrine in Ovine Septic Shock*

    PubMed Central

    He, Xinrong; Su, Fuhong; Taccone, Fabio Silvio; Laporte, Régent; Kjølbye, Anne Louise; Zhang, Jing; Xie, Keliang; Moussa, Mouhamed Djahoum; Reinheimer, Torsten Michael

    2016-01-01

    Objective: Selective vasopressin V1A receptor agonists may have advantages over arginine vasopressin in the treatment of septic shock. We compared the effects of selepressin, a selective V1A receptor agonist, arginine vasopressin, and norepinephrine on hemodynamics, organ function, and survival in an ovine septic shock model. Design: Randomized animal study. Setting: University hospital animal research laboratory. Subjects: Forty-six adult female sheep. Interventions: Fecal peritonitis was induced in the anesthetized, mechanically ventilated, fluid-resuscitated sheep, and they were randomized in two successive phases. Three late-intervention groups (each n = 6) received IV selepressin (1 pmol/kg/min), arginine vasopressin (0.25 pmol [0.1 mU]/kg/min), or norepinephrine (3 nmol [0.5 μg]/kg/min) when mean arterial pressure remained less than 70 mm Hg despite fluid challenge; study drugs were thereafter titrated to keep mean arterial pressure at 70–80 mm Hg. Three early-intervention groups (each n = 7) received selepressin, arginine vasopressin, or norepinephrine at the same initial infusion rates as for the late intervention, but already when mean arterial pressure had decreased by 10% from baseline; doses were then titrated as for the late intervention. A control group (n = 7) received saline. All animals were observed until death or for a maximum of 30 hours. Measurements and Main Results: In addition to hemodynamic and organ function assessment, plasma interleukin-6 and nitrite/nitrate levels were measured. In the late-intervention groups, selepressin delayed the decrease in mean arterial pressure and was associated with lower lung wet/dry weight ratios than in the other two groups. In the early-intervention groups, selepressin maintained mean arterial pressure and cardiac index better than arginine vasopressin or norepinephrine, slowed the increase in blood lactate levels, and was associated with less lung edema, lower cumulative fluid balance, and lower

  6. MULTI-SITE EVALUATIONS OF CANDIDATE METHODOLOGIES FOR DETERMINING COARSE PARTICULATE (PM 10-2.5) CONCENTRATIONS: AUGUST 2005 UPDATED REPORT REGARDING SECOND-GENERATION AND NEW PM 10-2.5 SAMPLERS

    EPA Science Inventory

    Multi-site field studies were conducted to evaluate the performance of sampling methods for measuring the coarse fraction of PM10 (PM10 2.5) in ambient air. The field studies involved the use of both time-integrated filter-based and direct continuous methods. Despite operationa...

  7. MOSSPATCH V1

    2001-01-31

    This program reduces the data from one-dimensional laser beam arrays from kSA MOS program, k-Space Associates, Ann Arbor, MI. Initial data is recorded without headers in 38 columns, with one row of data per acquisition per laser beam tracked. MOSS Patch can merge several data files together, filters out beam overlaps, and reduces the data. The final data is graphed and saved in a tab-delimited column format with headers that can be plotted in anymore » graphing software.« less

  8. BALTRIM v.1

    SciTech Connect

    Gaffney, Thomas M.

    1999-02-01

    BalTrim is an Excel(R) spreadsheet designed to calculate the inertial mass properties and ballast trim weight for either an assembled reentry vehicle (RV) or reentry body (RB). With this application, the user enters known mass properties and global coordinates for each subcomponent of the assembly, and BalTrim calculates the mass properties of the total assembly. Then, using the assembly mass properties, BalTrim calculates the necessary amount of ballast trim weight required to dynamically and statically balance the assembly mass properties. The final mass properties and trim ballast weight calculated with BalTrim agree with physicaly measured values.

  9. Ideals generated by traces in the algebra of symplectic reflections {H_{1,{v_{1,}}{v_2}}}( {{I_2}( {2m} )} )

    NASA Astrophysics Data System (ADS)

    Konstein, S. E.; Tyutin, I. V.

    2016-05-01

    The associative algebra of symplectic reflections H: = {H_{1,{v_{1,}}{v_2}}}( {{I_2}( {2m} )} ) based on the group generated by the root system I 2(2m) depends on two parameters, ν 1 and ν 2. For each value of these parameters, the algebra admits an m-dimensional space of traces. A trace tr is said to be degenerate if the corresponding symmetric bilinear form B tr( x, y) = tr( xy) is degenerate. We find all values of the parameters ν 1 and ν 2 for which the space of traces contains degenerate traces and the algebra H consequently has a two-sided ideal. It turns out that a linear combination of degenerate traces is also a degenerate trace. For the ν 1 and ν 2 values corresponding to degenerate traces, we find the dimensions of the space of degenerate traces.

  10. Rotational mechanism of Enterococcus hirae V1-ATPase by crystal-structure and single-molecule analyses.

    PubMed

    Iino, Ryota; Ueno, Hiroshi; Minagawa, Yoshihiro; Suzuki, Kano; Murata, Takeshi

    2015-04-01

    In ion-transporting rotary ATPases, the mechanical rotation of inner rotor subunits against other stator subunits in the complex mediates conversion of chemical free energy from ATP hydrolysis into electrochemical potential by pumping ions across the cell membrane. To fully understand the rotational mechanism of energy conversion, it is essential to analyze a target sample by multiple advanced methods that differ in spatiotemporal resolutions and sample environments. Here, we describe such a strategy applied to the water-soluble V1 moiety of Enterococcus hirae V-ATPase; this strategy involves integration of crystal structure studies and single-molecule analysis of rotary dynamics and torque generation. In addition, we describe our current model of the chemo-mechanical coupling scheme obtained by this approach, as well as future prospects. PMID:25796033

  11. CaV1.2/CaV3.x channels mediate divergent vasomotor responses in human cerebral arteries.

    PubMed

    Harraz, Osama F; Visser, Frank; Brett, Suzanne E; Goldman, Daniel; Zechariah, Anil; Hashad, Ahmed M; Menon, Bijoy K; Watson, Tim; Starreveld, Yves; Welsh, Donald G

    2015-05-01

    The regulation of arterial tone is critical in the spatial and temporal control of cerebral blood flow. Voltage-gated Ca(2+) (CaV) channels are key regulators of excitation-contraction coupling in arterial smooth muscle, and thereby of arterial tone. Although L- and T-type CaV channels have been identified in rodent smooth muscle, little is known about the expression and function of specific CaV subtypes in human arteries. Here, we determined which CaV subtypes are present in human cerebral arteries and defined their roles in determining arterial tone. Quantitative polymerase chain reaction and Western blot analysis, respectively, identified mRNA and protein for L- and T-type channels in smooth muscle of cerebral arteries harvested from patients undergoing resection surgery. Analogous to rodents, CaV1.2 (L-type) and CaV3.2 (T-type) α1 subunits were expressed in human cerebral arterial smooth muscle; intriguingly, the CaV3.1 (T-type) subtype present in rodents was replaced with a different T-type isoform, CaV3.3, in humans. Using established pharmacological and electrophysiological tools, we separated and characterized the unique profiles of Ca(2+) channel subtypes. Pressurized vessel myography identified a key role for CaV1.2 and CaV3.3 channels in mediating cerebral arterial constriction, with the former and latter predominating at higher and lower intraluminal pressures, respectively. In contrast, CaV3.2 antagonized arterial tone through downstream regulation of the large-conductance Ca(2+)-activated K(+) channel. Computational analysis indicated that each Ca(2+) channel subtype will uniquely contribute to the dynamic regulation of cerebral blood flow. In conclusion, this study documents the expression of three distinct Ca(2+) channel subtypes in human cerebral arteries and further shows how they act together to orchestrate arterial tone. PMID:25918359

  12. Dynamic causal modelling of eye movements during pursuit: Confirming precision-encoding in V1 using MEG.

    PubMed

    Adams, Rick A; Bauer, Markus; Pinotsis, Dimitris; Friston, Karl J

    2016-05-15

    This paper shows that it is possible to estimate the subjective precision (inverse variance) of Bayesian beliefs during oculomotor pursuit. Subjects viewed a sinusoidal target, with or without random fluctuations in its motion. Eye trajectories and magnetoencephalographic (MEG) data were recorded concurrently. The target was periodically occluded, such that its reappearance caused a visual evoked response field (ERF). Dynamic causal modelling (DCM) was used to fit models of eye trajectories and the ERFs. The DCM for pursuit was based on predictive coding and active inference, and predicts subjects' eye movements based on their (subjective) Bayesian beliefs about target (and eye) motion. The precisions of these hierarchical beliefs can be inferred from behavioural (pursuit) data. The DCM for MEG data used an established biophysical model of neuronal activity that includes parameters for the gain of superficial pyramidal cells, which is thought to encode precision at the neuronal level. Previous studies (using DCM of pursuit data) suggest that noisy target motion increases subjective precision at the sensory level: i.e., subjects attend more to the target's sensory attributes. We compared (noisy motion-induced) changes in the synaptic gain based on the modelling of MEG data to changes in subjective precision estimated using the pursuit data. We demonstrate that imprecise target motion increases the gain of superficial pyramidal cells in V1 (across subjects). Furthermore, increases in sensory precision - inferred by our behavioural DCM - correlate with the increase in gain in V1, across subjects. This is a step towards a fully integrated model of brain computations, cortical responses and behaviour that may provide a useful clinical tool in conditions like schizophrenia. PMID:26921713

  13. Measurement of vibrational energy transfer of OH (A2S+,v'=1?0) in low-pressure flames

    NASA Astrophysics Data System (ADS)

    Hartlieb, A. T.; Markus, D.; Kreutner, W.; Kohse-Höinghaus, K.

    1997-07-01

    Vibrational energy transfer (VET) and electronic quenching of OH (A2D+) was measured in a low-pressure H2/O2 flame for three rotational levels of OH (v'=1). Rate coefficients for collisions with H2O and N2 were determined. At 1600 K, kVET (N2) is (in 10-11 cm3s-1) 10.1DŽ, 6.1ǃ.8, and 3.8ǃ.3 for N'=0, 5, and 13, respectively. The kVET (H2O) is <1.1ǃ.8. The kQ (N2) is <2.4NJ for both vibrational levels. The kQ (H2O) in v'=1 is 59.1Lj.5, 54.7Lj.4, and 54.9Lj.6 for N'=0, 5, and 13, respectively, and, determined indirectly, 74.6ᆞ.4, 70.6ᆞ.3, and 63.4lj.3 for N'=0, 5, and 13 in v'=0. A multi-level model of OH population dynamics, which is being developed for the quantitative simulation of experimental LIF spectra, was extended to include VET. It was attempted to simulate state-to-state-specific VET coefficients for N2 collisions. From these simulations it appears that angular momentum conservation does not determine the N dependence of the vibrational relaxation step.

  14. An Internally Consistent Dataset of δ13C-DIC in the North Atlantic Ocean - NAC13v1

    NASA Astrophysics Data System (ADS)

    Becker, Meike; Andersen, Nils; Erlenkeuser, Helmut; Humphreys, Matthew. P.; Tanhua, Toste; Körtzinger, Arne

    2016-03-01

    The stable carbon isotope composition of dissolved inorganic carbon (δ13C-DIC) can be used to quantify fluxes within the carbon system. For example, knowing the δ13C-DIC signature of the inorganic carbon pool can help to describe the exchange between ocean and atmosphere as well as the amount of anthropogenic carbon in the water column. The measurements can also be used for evaluating modeled carbon fluxes, for making basin wide estimates, studying seasonal and interannual variability or decadal trends in interior ocean biogeochemistry. For all these purposes, it is not only important to have a sufficient amount of data, but these data must also be internally consistent and of high quality. In this study, we present a δ13C-DIC dataset for the North Atlantic, which has undergone secondary quality control. The data originate from oceanographic research cruises between 1981 and 2012. During a primary quality control step based on simple range tests obviously bad data were flagged. In a second quality control step, biases between measurements from different cruises were quantified through a crossover analysis using nearby data of the respective cruises and absolute values of biased cruises were adjusted in the data product. the crossover analysis was possible for 22 of the 29 cruises in our dataset and adjustments were applied to 10 of these. The internal accuracy of this dataset is 0.017 ‰. The dataset is available via CDIAC at http://cdiac.ornl.gov/oceans/ndp_096/NAC13v1.html, doi: 10.3334/CDIAC/OTG.NAC13v1.

  15. Dynamic causal modelling of eye movements during pursuit: Confirming precision-encoding in V1 using MEG

    PubMed Central

    Adams, Rick A.; Bauer, Markus; Pinotsis, Dimitris; Friston, Karl J.

    2016-01-01

    This paper shows that it is possible to estimate the subjective precision (inverse variance) of Bayesian beliefs during oculomotor pursuit. Subjects viewed a sinusoidal target, with or without random fluctuations in its motion. Eye trajectories and magnetoencephalographic (MEG) data were recorded concurrently. The target was periodically occluded, such that its reappearance caused a visual evoked response field (ERF). Dynamic causal modelling (DCM) was used to fit models of eye trajectories and the ERFs. The DCM for pursuit was based on predictive coding and active inference, and predicts subjects' eye movements based on their (subjective) Bayesian beliefs about target (and eye) motion. The precisions of these hierarchical beliefs can be inferred from behavioural (pursuit) data. The DCM for MEG data used an established biophysical model of neuronal activity that includes parameters for the gain of superficial pyramidal cells, which is thought to encode precision at the neuronal level. Previous studies (using DCM of pursuit data) suggest that noisy target motion increases subjective precision at the sensory level: i.e., subjects attend more to the target's sensory attributes. We compared (noisy motion-induced) changes in the synaptic gain based on the modelling of MEG data to changes in subjective precision estimated using the pursuit data. We demonstrate that imprecise target motion increases the gain of superficial pyramidal cells in V1 (across subjects). Furthermore, increases in sensory precision – inferred by our behavioural DCM – correlate with the increase in gain in V1, across subjects. This is a step towards a fully integrated model of brain computations, cortical responses and behaviour that may provide a useful clinical tool in conditions like schizophrenia. PMID:26921713

  16. Discovery of Aryl Sulfonamides as Isoform-Selective Inhibitors of NaV1.7 with Efficacy in Rodent Pain Models.

    PubMed

    Focken, Thilo; Liu, Shifeng; Chahal, Navjot; Dauphinais, Maxim; Grimwood, Michael E; Chowdhury, Sultan; Hemeon, Ivan; Bichler, Paul; Bogucki, David; Waldbrook, Matthew; Bankar, Girish; Sojo, Luis E; Young, Clint; Lin, Sophia; Shuart, Noah; Kwan, Rainbow; Pang, Jodie; Chang, Jae H; Safina, Brian S; Sutherlin, Daniel P; Johnson, J P; Dehnhardt, Christoph M; Mansour, Tarek S; Oballa, Renata M; Cohen, Charles J; Robinette, C Lee

    2016-03-10

    We report on a novel series of aryl sulfonamides that act as nanomolar potent, isoform-selective inhibitors of the human sodium channel hNaV1.7. The optimization of these inhibitors is described. We aimed to improve potency against hNaV1.7 while minimizing off-target safety concerns and generated compound 3. This agent displayed significant analgesic effects in rodent models of acute and inflammatory pain and demonstrated that binding to the voltage sensor domain 4 site of NaV1.7 leads to an analgesic effect in vivo. Our findings corroborate the importance of hNaV1.7 as a drug target for the treatment of pain. PMID:26985315

  17. Seven novel modulators of the analgesic target NaV 1.7 uncovered using a high-throughput venom-based discovery approach

    PubMed Central

    Klint, Julie K; Smith, Jennifer J; Vetter, Irina; Rupasinghe, Darshani B; Er, Sing Yan; Senff, Sebastian; Herzig, Volker; Mobli, Mehdi; Lewis, Richard J; Bosmans, Frank; King, Glenn F

    2015-01-01

    Background and Purpose Chronic pain is a serious worldwide health issue, with current analgesics having limited efficacy and dose-limiting side effects. Humans with loss-of-function mutations in the voltage-gated sodium channel NaV1.7 (hNaV1.7) are indifferent to pain, making hNaV1.7 a promising target for analgesic development. Since spider venoms are replete with NaV channel modulators, we examined their potential as a source of hNaV1.7 inhibitors. Experimental Approach We developed a high-throughput fluorescent-based assay to screen spider venoms against hNaV1.7 and isolate ‘hit’ peptides. To examine the binding site of these peptides, we constructed a panel of chimeric channels in which the S3b-S4 paddle motif from each voltage sensor domain of hNaV1.7 was transplanted into the homotetrameric KV2.1 channel. Key Results We screened 205 spider venoms and found that 40% contain at least one inhibitor of hNaV1.7. By deconvoluting ‘hit’ venoms, we discovered seven novel members of the NaSpTx family 1. One of these peptides, Hd1a (peptide μ-TRTX-Hd1a from venom of the spider Haplopelma doriae), inhibited hNaV1.7 with a high level of selectivity over all other subtypes, except hNaV1.1. We showed that Hd1a is a gating modifier that inhibits hNaV1.7 by interacting with the S3b-S4 paddle motif in channel domain II. The structure of Hd1a, determined using heteronuclear NMR, contains an inhibitor cystine knot motif that is likely to confer high levels of chemical, thermal and biological stability. Conclusion and Implications Our data indicate that spider venoms are a rich natural source of hNaV1.7 inhibitors that might be useful leads for the development of novel analgesics. PMID:25754331

  18. V1a- and V2-type vasopressin receptors mediate vasopressin-induced Ca2+ responses in isolated rat supraoptic neurones

    PubMed Central

    Gouzènes, Laurent; Sabatier, Nancy; Richard, Philippe; Moos, Françoise C; Dayanithi, Govindan

    1999-01-01

    The pharmacological profile of receptors activated by vasopressin (AVP) in freshly dissociated supraoptic magnocellular neurones was investigated using specific V1a- and V2-type AVP receptor agonists and antagonists. In 97 % of AVP-responding neurones (1–3000 nm) V1a or V2 receptor type agonists (F-180 and dDAVP, respectively) elicited dose-dependent [Ca2+]i transients that were suppressed by removal of external Ca2+. The [Ca2+]i response induced by 1 μm F-180 or dDAVP was selectively blocked by 10 nm of V1a and V2 antagonists (SR 49059 and SR 121463A, respectively). The response to V1a agonist was maintained in the presence of the V2 antagonist, and the V2 agonist-induced response persisted in the presence of the V1a antagonist. The [Ca2+]i response induced by 1 μm AVP was partially (61 %) blocked by 10 nm SR 121463A. This blockade was increased by a further 31 % with the addition of 10 nm SR 49059. Similarly, the AVP-induced response was partially (47 %) decreased by SR 49059, and a further inhibition of 33 % was achieved in the presence of SR 121463A. We demonstrate that AVP acts on the magnocellular neurones via two distinct types of AVP receptors that exhibit the pharmacological profiles of V1a and V2 types. However, since V2 receptor mRNA is not expressed in the supraoptic nucleus (SON), and since V1b receptor transcripts are observed in the SON, we propose that the V2 receptor agonist and antagonist act on a ‘V2-like’ receptor or a new type of AVP receptor that remains to be elucidated. The possibility that V2 ligands act on the V1b receptor cannot be excluded. PMID:10358117

  19. Arginine vasotocin V1a2 receptor and GnRH-I co-localize in preoptic neurons of the sex changing grouper, Epinephelus adscensionis.

    PubMed

    Kline, Richard J; Holt, G Joan; Khan, Izhar A

    2016-01-01

    The arginine vasotocin/vasopressin (AVT/AVP) and gonadotropin releasing hormone (GnRH) systems are known to control sexual behaviors and reproduction, respectively, in different vertebrate groups. However, a direct functional connection between these two neuroendocrine systems has not been demonstrated for any vertebrate species. Therefore, the objective of this research was to test the hypothesis that AVT acts on the GnRH system via an AVT V1a receptor in a sex changing grouper species, the rock hind, Epinephelus adscensionis. AVT V1a2 receptors were co-localized with GnRH-I on neurons in the preoptic anterior hypothalamus identifying a structural linkage between the AVT system and GnRH-I. Transcripts for avt, gnrh-I, and two AVT receptor subtypes (v1a1 and v1a2) were isolated and characterized for E. adscensionis and their expression was measured in males and females by q-RT-PCR. Translation of V1a-type cDNA sequences revealed two distinct forms of the AVT V1a receptor in E. adscensionis brain similar to those reported for other species. The observation of significantly higher gnrh-I mRNA in the POA+H of rock hind males as compared to females suggests differential regulation of the gnrh-I transcripts in the two sexes of this protogynous species. In male E. adscensionis, but not in females, a negative relationship was seen between plasma 11-ketotestosterone (11-KT) and the v1a1 receptor mRNA levels in the POA+H, while a positive trend was observed between 11-KT and v1a2 receptor mRNA levels, indicating that these receptor forms may be differentially regulated. PMID:26361870

  20. The primary circuit materials properties results analysis performed on archive material used in NPP V-1 and Kola NPP Units 1 and 2

    SciTech Connect

    Kupca, L.; Beno, P.

    1997-04-01

    A very brief summary is provided of a primary circuit piping material properties analysis. The analysis was performed for the Bohunice V-1 reactor and the Kola-1 and -2 reactors. Assessment was performed on Bohunice V-1 archive materials and primary piping material cut from the Kola units after 100,000 hours of operation. Main research program tasks included analysis of mechanical properties, corrosion stability, and microstructural properties. Analysis results are not provided.

  1. μ-Conotoxins that differentially block sodium channels NaV1.1 through 1.8 identify those responsible for action potentials in sciatic nerve

    PubMed Central

    Wilson, Michael J.; Yoshikami, Doju; Azam, Layla; Gajewiak, Joanna; Olivera, Baldomero M.; Bulaj, Grzegorz; Zhang, Min-Min

    2011-01-01

    Voltage-gated sodium channels (VGSCs) are important for action potentials. There are seven major isoforms of the pore-forming and gate-bearing α-subunit (NaV1) of VGSCs in mammalian neurons, and a given neuron can express more than one isoform. Five of the neuronal isoforms, NaV1.1, 1.2, 1.3, 1.6, and 1.7, are exquisitely sensitive to tetrodotoxin (TTX), and a functional differentiation of these presents a serious challenge. Here, we examined a panel of 11 μ-conopeptides for their ability to block rodent NaV1.1 through 1.8 expressed in Xenopus oocytes. Although none blocked NaV1.8, a TTX-resistant isoform, the resulting “activity matrix” revealed that the panel could readily discriminate between the members of all pair-wise combinations of the tested isoforms. To examine the identities of endogenous VGSCs, a subset of the panel was tested on A- and C-compound action potentials recorded from isolated preparations of rat sciatic nerve. The results show that the major subtypes in the corresponding A- and C-fibers were NaV1.6 and 1.7, respectively. Ruled out as major players in both fiber types were NaV1.1, 1.2, and 1.3. These results are consistent with immunohistochemical findings of others. To our awareness this is the first report describing a qualitative pharmacological survey of TTX-sensitive NaV1 isoforms responsible for propagating action potentials in peripheral nerve. The panel of μ-conopeptides should be useful in identifying the functional contributions of NaV1 isoforms in other preparations. PMID:21652775

  2. The yptV1 gene encodes a small G-protein in the green alga Volvox carteri: gene structure and properties of the gene product.

    PubMed

    Fabry, S; Nass, N; Huber, H; Palme, K; Jaenicke, L; Schmitt, R

    1992-09-10

    Small G-proteins encoded by ras-like genes are ubiquitous in eukaryotic cells. These G-proteins are believed to play a role in central processes, such as signal transduction, cell differentiation and membrane vesicle transport. By screening genomic and cDNA libraries of the colonial alga, Volvox carteri f. nagariensis, with ypt DNA probes from Zea mays, we have identified the first member of a ypt gene family, yptV1, within a green alga. The 1538-bp yptV1 gene of V. carteri consists of nine exons and eight introns and has three potential polyadenylation sites 210, 420 and 500 bp downstream from the UGA stop codon. The derived 203-amino-acid polypeptide, YptV1, exhibits 81% similarity with Ypt1 from mouse, with the corresponding genes sharing four identical intron positions. Recombinant YptV1 (reYptV1) produced in Escherichia coli retains the ability to bind GTP after SDS-PAGE and immobilization on nitrocellulose. Immunological studies using polyclonal antibodies against reYptV1 indicate that the protein is present in the membrane fraction of a V. carteri extract and is expressed throughout the whole life-cycle of the alga. Similar to other Ras-like proteins, YptV1 contains two conserved C-terminal cysteine residues suggesting post-translational modification(s), such as isoprenylation or palmitoylation, required for membrane anchoring. The presumptive role of YptV1 in cytoplasmic vesicle transport is briefly discussed. PMID:1511889

  3. Sustained inhibition of the NaV1.7 sodium channel by engineered dimers of the domain II binding peptide GpTx-1.

    PubMed

    Murray, Justin K; Biswas, Kaustav; Holder, J Ryan; Zou, Anruo; Ligutti, Joseph; Liu, Dong; Poppe, Leszek; Andrews, Kristin L; Lin, Fen-Fen; Meng, Shi-Yuan; Moyer, Bryan D; McDonough, Stefan I; Miranda, Les P

    2015-11-01

    Many efforts are underway to develop selective inhibitors of the voltage-gated sodium channel NaV1.7 as new analgesics. Thus far, however, in vitro selectivity has proved difficult for small molecules, and peptides generally lack appropriate pharmacokinetic properties. We previously identified the NaV1.7 inhibitory peptide GpTx-1 from tarantula venom and optimized its potency and selectivity via structure-guided analoging. To further understand GpTx-1 binding to NaV1.7, we have mapped the binding site to transmembrane segments 1-4 of the second pseudosubunit internal repeat (commonly referred to as Site 4) using NaV1.5/NaV1.7 chimeric protein constructs. We also report that select GpTx-1 amino acid residues apparently not contacting NaV1.7 can be derivatized with a hydrophilic polymer without adversely affecting peptide potency. Homodimerization of GpTx-1 with a bifunctional polyethylene glycol (PEG) linker resulted in a compound with increased potency and a significantly reduced off-rate, demonstrating the ability to modulate the function and properties of GpTx-1 by linking to additional molecules. PMID:26112439

  4. MP-V1 from the Venom of Social Wasp Vespula vulgaris Is a de Novo Type of Mastoparan that Displays Superior Antimicrobial Activities.

    PubMed

    Kim, Yangseon; Son, Minky; Noh, Eun-Young; Kim, Soonok; Kim, Changmu; Yeo, Joo-Hong; Park, Chanin; Lee, Keun Woo; Bang, Woo Young

    2016-01-01

    Mastoparans from the venom of social wasps have attracted considerable attention as effective antibiotic candidates. In this study, mastoparan V1 (MP-V1) from Vespula vulgaris was first disclosed to have a peptide amino acid sequence distinct from typical mastoparans and its biochemical properties and antimicrobial effects were compared with those of typical mastoparans MP-L, -X(V) and -B. Circular dichroism (CD) spectroscopy revealed that MP-V1 and -X(V) form more stable α-helical conformations in lipid membrane-like environments than MP-L and -B. In parallel, these two also showed more effective antimicrobial activities against the pathogens than did MP-L and -B. Although MP-V1 had a less stable α-helical conformation than MP-X(V), it showed stronger antimicrobial effects against Streptococcus mutans and Salmonella enterica than MP-X(V). In the meantime, analysis of hemolytic activity revealed a range of doses (~50 μM) that exhibited little potent cytotoxicity on human erythrocytes. Finally, the atypical MP-V1 peptide amino acid sequence provided important clues to understanding its antimicrobial mechanism from a structural perspective. Therefore, it has been concluded that MP-V1 is a de novo type of mastoparan with superior antimicrobial activities against both pathogenic bacteria and fungi, which may be useful in developing multipurpose antimicrobial drugs against infectious diseases. PMID:27104500

  5. Divergent biophysical properties, gating mechanisms, and possible functions of the two skeletal muscle CaV1.1 calcium channel splice variants

    PubMed Central

    Tuluc, Petronel; Flucher, Bernhard E.

    2014-01-01

    Voltage-gated calcium channels are multi-subunit protein complexes that specifically allow calcium ions to enter the cell in response to membrane depolarization. But, for many years it seemed that the skeletal muscle calcium channel CaV1.1 is the exception. The classical splice variant CaV1.1a activates slowly, has a very small current amplitude and poor voltage sensitivity. In fact adult muscle fibers work perfectly well even in the absence of calcium influx. Recently a new splice variant of the skeletal muscle calcium channel CaV1.1e has been characterized. The lack of the 19 amino acid exon 29 in this splice variant results in a rapidly activating calcium channel with high current amplitude and good voltage sensitivity. CaV1.1e is the dominant channel in embryonic muscle, where the expression of this high calcium-conducting CaV1.1 isoform readily explains developmental processes depending on L-type calcium currents. Moreover, the availability of these two structurally similar but functionally distinct channel variants facilitates the analysis of the molecular mechanisms underlying the unique current properties of the classical CaV1.1a channel. PMID:22057633

  6. Discovery of a selective NaV1.7 inhibitor from centipede venom with analgesic efficacy exceeding morphine in rodent pain models.

    PubMed

    Yang, Shilong; Xiao, Yao; Kang, Di; Liu, Jie; Li, Yuan; Undheim, Eivind A B; Klint, Julie K; Rong, Mingqiang; Lai, Ren; King, Glenn F

    2013-10-22

    Loss-of-function mutations in the human voltage-gated sodium channel NaV1.7 result in a congenital indifference to pain. Selective inhibitors of NaV1.7 are therefore likely to be powerful analgesics for treating a broad range of pain conditions. Herein we describe the identification of µ-SLPTX-Ssm6a, a unique 46-residue peptide from centipede venom that potently inhibits NaV1.7 with an IC50 of ∼25 nM. µ-SLPTX-Ssm6a has more than 150-fold selectivity for NaV1.7 over all other human NaV subtypes, with the exception of NaV1.2, for which the selectivity is 32-fold. µ-SLPTX-Ssm6a contains three disulfide bonds with a unique connectivity pattern, and it has no significant sequence homology with any previously characterized peptide or protein. µ-SLPTX-Ssm6a proved to be a more potent analgesic than morphine in a rodent model of chemical-induced pain, and it was equipotent with morphine in rodent models of thermal and acid-induced pain. This study establishes µ-SPTX-Ssm6a as a promising lead molecule for the development of novel analgesics targeting NaV1.7, which might be suitable for treating a wide range of human pain pathologies. PMID:24082113

  7. Targeting of protein phosphatases PP2A and PP2B to the C-terminus of the L-type calcium channel Ca v1.2.

    PubMed

    Xu, Hui; Ginsburg, Kenneth S; Hall, Duane D; Zimmermann, Maike; Stein, Ivar S; Zhang, Mingxu; Tandan, Samvit; Hill, Joseph A; Horne, Mary C; Bers, Donald; Hell, Johannes W

    2010-12-01

    The L-type Ca(2+) channel Ca(v)1.2 forms macromolecular signaling complexes that comprise the β(2) adrenergic receptor, trimeric G(s) protein, adenylyl cyclase, and cAMP-dependent protein kinase (PKA) for efficient signaling in heart and brain. The protein phosphatases PP2A and PP2B are part of this complex. PP2A counteracts increase in Ca(v)1.2 channel activity by PKA and other protein kinases, whereas PP2B can either augment or decrease Ca(v)1.2 currents in cardiomyocytes depending on the precise experimental conditions. We found that PP2A binds to two regions in the C-terminus of the central, pore-forming α(1) subunit of Ca(v)1.2: one region spans residues 1795-1818 and the other residues 1965-1971. PP2B binds immediately downstream of residue 1971. Injection of a peptide that contained residues 1965-1971 and displaced PP2A but not PP2B from endogenous Ca(v)1.2 increased basal and isoproterenol-stimulated L-type Ca(2+) currents in acutely isolated cardiomyocytes. Together with our biochemical data, these physiological results indicate that anchoring of PP2A at this site of Ca(v)1.2 in the heart negatively regulates cardiac L-type currents, likely by counterbalancing basal and stimulated phosphorylation that is mediated by PKA and possibly other kinases. PMID:21053940

  8. Scotoma analysis of 10-2 visual field testing with a white target in screening for hydroxychloroquine retinopathy

    PubMed Central

    Browning, David J; Lee, Chong

    2015-01-01

    Objective To quantify the variability of scotomas detected by 10-2 visual field (VF) testing in patients taking hydroxychloroquine without and with retinopathy. Design Retrospective review of clinical charts and visual fields. Subjects Twenty-one patients taking hydroxychloroquine without retinopathy, and nine patients taking hydroxychloroquine and one patient taking chloroquine with retinopathy. Methods Retinopathy was defined by annular scotomas on 10-2 VF testing with corroborative spectral domain optical coherence tomographic outer retinal changes and multifocal electroretinographic changes leading to cessation of hydroxychloroquine or chloroquine. Location and depth of scotoma points on 10-2 VF testing were recorded and their fates followed in serial, reliable 10-2 VFs performed with a white target over time. Main outcome measures Number of scotoma points and locations, percentage of persistent scotoma points, size of scotomas, location of scotomas, and percentage of scotomas deepening. Results A median of five, interquartile range (IQR) 3–8 scotoma points per VF occurred in patients without retinopathy. A median of 86%, IQR 63%–100% of these points resolve on the subsequent field. For patients with retinopathy, a median of 22%, IQR 10%–59% resolve. The median percentage of scotoma points in the zone 2–8 degrees from fixation in eyes with retinopathy was 79%, IQR 68%–85% compared to 60%, IQR 54%–75% in eyes without retinopathy (P=0.0094). Single-point scotomas were more common in eyes without than with retinopathy. Scotomas consisting of more than four contiguous scotoma points were generally indicative of retinopathy. Conclusion Point scotomas are common and variable in 10-2 VF testing with a white target for hydroxychloroquine retinopathy in subjects without retinopathy. The annular zone 2 to 8 degrees from fixation was useful for distinguishing the significance of scotoma points. Scotomas with more contiguous scotoma points were more often

  9. Comparing microbial and chemical kinetics for modelling soil organic carbon decomposition using the DecoChem v1.0 and DecoBio v1.0 models