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Sample records for 3kv 600a 4h-sic

  1. Kv1.3/Kv1.5 heteromeric channels compromise pharmacological responses in macrophages

    SciTech Connect

    Villalonga, Nuria; Escalada, Artur; Vicente, Ruben; Sanchez-Tillo, Ester; Celada, Antonio; Solsona, Carles; Felipe, Antonio . E-mail: afelipe@ub.edu

    2007-01-26

    Voltage-dependent K{sup +} (Kv) channels are involved in the immune response. Kv1.3 is highly expressed in activated macrophages and T-effector memory cells of autoimmune disease patients. Macrophages are actively involved in T-cell activation by cytokine production and antigen presentation. However, unlike T-cells, macrophages express Kv1.5, which is resistant to Kv1.3-drugs. We demonstrate that mononuclear phagocytes express different Kv1.3/Kv1.5 ratios, leading to biophysically and pharmacologically distinct channels. Therefore, Kv1.3-based treatments to alter physiological responses, such as proliferation and activation, are impaired by Kv1.5 expression. The presence of Kv1.5 in the macrophagic lineage should be taken into account when designing Kv1.3-based therapies.

  2. Catalytic properties of thimet oligopeptidase H600A mutant

    SciTech Connect

    Machado, Mauricio F.M.; Marcondes, Marcelo F.; Rioli, Vanessa; Ferro, Emer S.; Juliano, Maria A.; Juliano, Luiz; Oliveira, Vitor

    2010-04-02

    Thimet oligopeptidase (EC 3.4.24.15, TOP) is a metallo-oligopeptidase that participates in the intracellular metabolism of peptides. Predictions based on structurally analogous peptidases (Dcp and ACE-2) show that TOP can present a hinge-bend movement during substrate hydrolysis, what brings some residues closer to the substrate. One of these residues that in TOP crystallographic structure are far from the catalytic residues, but, moves toward the substrate considering this possible structural reorganization is His{sup 600}. In the present work, the role of His{sup 600} of TOP was investigated by site-directed mutagenesis. TOP H600A mutant was characterized through analysis of S{sub 1} and S{sub 1}' specificity, pH-activity profile and inhibition by JA-2. Results showed that TOP His{sup 600} residue makes important interactions with the substrate, supporting the prediction that His{sup 600} moves toward the substrate due to a hinge movement similar to the Dcp and ACE-2. Furthermore, the mutation H600A affected both K{sub m} and k{sub cat}, showing the importance of His{sup 600} for both substrate binding and/or product release from active site. Changes in the pH-profile may indicate also the participation of His{sup 600} in TOP catalysis, transferring a proton to the newly generated NH{sub 2}-terminus or helping Tyr{sup 605} and/or Tyr{sup 612} in the intermediate oxyanion stabilization.

  3. 75 FR 35824 - Agency Information Collection Activities: Forms I-600/I-600A, Extension of a Currently Approved...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-23

    ... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Forms I-600/I-600A, Extension of a Currently Approved Information Collection; Comment Request ACTION: 60-Day Notice of Information Collection Under Review: Forms I- 600/I-600A, Petition To Classify Orphan as...

  4. 75 FR 65499 - Agency Information Collection Activities: Form I-600/I-600A, Extension of a Currently Approved...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-25

    ... published in the Federal Register on June 23, 2010, at 75 FR 35824, allowing for a 60-day public comment... SECURITY U.S. Citizenship and Immigration Services Agency Information Collection Activities: Form I-600/ I-600A, Extension of a Currently Approved Information Collection; Comment Request ACTION: 30-Day...

  5. Repeatability and validity of the PowerRefractor and the Nidek AR600-A in an adult population with healthy eyes.

    PubMed

    Allen, Peter M; Radhakrishnan, Hema; O'Leary, Daniel J

    2003-03-01

    We assessed the repeatability and validity of the PowerRefractor and the Nidek AR-600A autorefractor. This is the first independent study conducted on adults to evaluate the performance of these instruments in a laboratory setting. Fifty subjects (23 males and 27 females) aged 16 to 61 years (mean, 37 +/- 12) participated in the study. The validity of the PowerRefractor and the Nidek autorefractor readings were determined by comparing them to subjective refraction. Measurements of refractive error were obtained from the two instruments on two separate occasions to assess their repeatability. The measured refractive error was converted into a dioptric power matrix for data analysis. No significant difference was found between the measurements obtained with the two instruments and the subjective refraction. The estimate of refractive error given by the two instruments was also found to be repeatable. In addition to measuring the refractive error, the PowerRefractor also offers the facility to measure eye position, pupil size, and dynamics of accommodation. We suggest some improvements to the PowerRefractor measurement technique to standardize its clinical use and to improve accuracy.

  6. Effect of ZnO nanoparticles in R290/R600a (50/50) based vapour compression refrigeration system added via lubricant oil on compressor suction and discharge characteristics

    NASA Astrophysics Data System (ADS)

    Kumar, Ravinder; Singh, Jagdev

    2016-10-01

    The primary source of energy consumption in a vapour compression refrigeration system is a compressor. The possibility of a reduction in the work of compression may leads to enhance the compressor suction and discharge characteristics and the overall performance of the refrigeration system. The present experimental investigation based upon the study of ZnO nanoparticles in a vapour compression refrigeration system using hydrocarbon blend R290/R600a (50/50) as a refrigerant. The zinc oxide nanoparticles are appended with system refrigerant via compressor lubricating oil. The results observed that by using different weight concentrations of nanoparticles in R290/R600a refrigeration system, both the compressor suction and discharge pressures and temperatures were reduced compared to conventional system. The viscosity of mineral oil with the addition of nanoparticles increases. The compressor energy consumption was reduced by 7.48 % using (0.2-1.0) wt% concentrations of nanoparticles. The COP of the refrigeration system has been increased by about 46 % with the addition of nanoparticles. Thus, the ZnO nanoparticles worked efficiently in the R290/R600a refrigeration system.

  7. Short- and Long-Term Dynamics of Gas Hydrate at GC600: A Gulf of Mexico Hydrocarbon Seep

    NASA Astrophysics Data System (ADS)

    MacDonald, I. R.; Johansen, C.; Silva, M.; Daneshgar, S.; Garcia-Pineda, O. G.; Shedd, W. W.

    2014-12-01

    The GC600 hydrocarbon seep is located at 1200 m in the northern Gulf of Mexico (GOM). Satellite data show it to be one of the most prolific sources of natural oil slicks in the entire GOM. We mapped its seafloor oil and gas vents with 3-D seismic, swath-bathymetry acoustics and submersible observations, documenting gas hydrate deposits, brine pools, benthic fauna, and authigenic carbonates. Geophysical profiles show subbottom locations of salt bodies and migration conduits. We deployed time-lapse imaging systems focused on individual vents to quantify release rates. Oil and gas flow upward along the flanks of an allochthonous salt body from source rocks at 10,000 m and migrate to the seafloor from faults emanating from the salt. Venting to the water column and surface consists of oily bubbles and occurs in two fields separated by ~1 km. The NW vent field (Megaplume) appears to be a more recent expression and hosts about three highly active vents; while the SE vent field (Birthday Candles) hosts more than 10 vents that are generally slower. We measured discharge rates of 2.6 cm3 s-1 and Megaplume and 0.09 cm3 s-1 at Birthday Candles. Although surface deposits of gas hydrate were evident at both vent fields, the Birthday Candles area featured dozens of conical mounds formed by gas hydrate that were dark brown due to large amounts of liquid oil perfused throughout the deposits. Large brine pools indicated gas hydrate formation at the seafloor. Venting occurred in horizontal fissures on the mounds, in which oil and hydrate combined to form short-lived chimneys and balloon-like structures. Ice worms (Hesiocaeca methanicola) were extremely abundant in burrows extending from the sediment into the gas hydrate. Proceeding farther to the SE, venting is reduced and absent, but surface carbonate deposits suggest relict gas hydrate mounds. We propose that the NW to SE trend at GC600 encompasses the progressive development of a biogeochemical filter that sequesters and mineralizes a very substantial portion of the source hydrocarbon prior to discharge into the water column.

  8. Ubiquitin-specific Protease 36 (USP36) Controls Neuronal Precursor Cell-expressed Developmentally Down-regulated 4-2 (Nedd4-2) Actions over the Neurotrophin Receptor TrkA and Potassium Voltage-gated Channels 7.2/3 (Kv7.2/3).

    PubMed

    Anta, Begoña; Martín-Rodríguez, Carlos; Gomis-Perez, Carolina; Calvo, Laura; López-Benito, Saray; Calderón-García, Andrés A; Vicente-García, Cristina; Villarroel, Álvaro; Arévalo, Juan C

    2016-09-01

    Ubiquitination of the TrkA neurotrophin receptor in response to NGF is critical in the regulation of TrkA activation and functions. TrkA is ubiquitinated, among other E3 ubiquitin ligases, by Nedd4-2. To understand mechanistically how TrkA ubiquitination is regulated, we performed a siRNA screening to identify deubiquitinating enzymes and found that USP36 acts as an important regulator of TrkA activation kinetics and ubiquitination. However, USP36 action on TrkA was indirect because it does not deubiquitinate TrkA. Instead, USP36 binds to Nedd4-2 and regulates the association of TrkA and Nedd4-2. In addition, depletion of USP36 increases TrkA·Nedd4-2 complex formation, whereas USP36 expression disrupts the complex, resulting in an enhancement or impairment of Nedd4-2-dependent TrkA ubiquitination, respectively. Moreover, USP36 depletion leads to enhanced total and surface TrkA expression that results in increased NGF-mediated TrkA activation and signaling that augments PC12 cell differentiation. USP36 actions extend beyond TrkA because the presence of USP36 interferes with Nedd4-2-dependent Kv7.2/3 channel regulation. Our results demonstrate that USP36 binds to and regulates the actions of Nedd4-2 over different substrates affecting their expression and functions.

  9. Ubiquitin-specific Protease 36 (USP36) Controls Neuronal Precursor Cell-expressed Developmentally Down-regulated 4-2 (Nedd4-2) Actions over the Neurotrophin Receptor TrkA and Potassium Voltage-gated Channels 7.2/3 (Kv7.2/3).

    PubMed

    Anta, Begoña; Martín-Rodríguez, Carlos; Gomis-Perez, Carolina; Calvo, Laura; López-Benito, Saray; Calderón-García, Andrés A; Vicente-García, Cristina; Villarroel, Álvaro; Arévalo, Juan C

    2016-09-01

    Ubiquitination of the TrkA neurotrophin receptor in response to NGF is critical in the regulation of TrkA activation and functions. TrkA is ubiquitinated, among other E3 ubiquitin ligases, by Nedd4-2. To understand mechanistically how TrkA ubiquitination is regulated, we performed a siRNA screening to identify deubiquitinating enzymes and found that USP36 acts as an important regulator of TrkA activation kinetics and ubiquitination. However, USP36 action on TrkA was indirect because it does not deubiquitinate TrkA. Instead, USP36 binds to Nedd4-2 and regulates the association of TrkA and Nedd4-2. In addition, depletion of USP36 increases TrkA·Nedd4-2 complex formation, whereas USP36 expression disrupts the complex, resulting in an enhancement or impairment of Nedd4-2-dependent TrkA ubiquitination, respectively. Moreover, USP36 depletion leads to enhanced total and surface TrkA expression that results in increased NGF-mediated TrkA activation and signaling that augments PC12 cell differentiation. USP36 actions extend beyond TrkA because the presence of USP36 interferes with Nedd4-2-dependent Kv7.2/3 channel regulation. Our results demonstrate that USP36 binds to and regulates the actions of Nedd4-2 over different substrates affecting their expression and functions. PMID:27445338

  10. 76 FR 22302 - Airworthiness Directives; Airbus Model A310 Series Airplanes; and Model A300 B4-600, A300 B4-600R...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-21

    ... products. That NPRM was published in the Federal Register on August 23, 2010 (75 FR 51698). That NPRM...'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will not have... bulletins were revised for minor changes such as deleting THS zeroing in job set-up and deleting the...

  11. Genome Sequence and Analysis of Escherichia coli MRE600, a Colicinogenic, Nonmotile Strain that Lacks RNase I and the Type I Methyltransferase, EcoKI

    PubMed Central

    Kurylo, Chad M.; Alexander, Noah; Dass, Randall A.; Parks, Matthew M.; Altman, Roger A.; Vincent, C. Theresa; Mason, Christopher E.; Blanchard, Scott C.

    2016-01-01

    Escherichia coli strain MRE600 was originally identified for its low RNase I activity and has therefore been widely adopted by the biomedical research community as a preferred source for the expression and purification of transfer RNAs and ribosomes. Despite its widespread use, surprisingly little information about its genome or genetic content exists. Here, we present the first de novo assembly and description of the MRE600 genome and epigenome. To provide context to these studies of MRE600, we include comparative analyses with E. coli K-12 MG1655 (K12). Pacific Biosciences Single Molecule, Real-Time sequencing reads were assembled into one large chromosome (4.83 Mb) and three smaller plasmids (89.1, 56.9, and 7.1 kb). Interestingly, the 7.1-kb plasmid possesses genes encoding a colicin E1 protein and its associated immunity protein. The MRE600 genome has a G + C content of 50.8% and contains a total of 5,181 genes, including 4,913 protein-encoding genes and 268 RNA genes. We identified 41,469 modified DNA bases (0.83% of total) and found that MRE600 lacks the gene for type I methyltransferase, EcoKI. Phylogenetic, taxonomic, and genetic analyses demonstrate that MRE600 is a divergent E. coli strain that displays features of the closely related genus, Shigella. Nevertheless, comparative analyses between MRE600 and E. coli K12 show that these two strains exhibit nearly identical ribosomal proteins, ribosomal RNAs, and highly homologous tRNA species. Substantiating prior suggestions that MRE600 lacks RNase I activity, the RNase I-encoding gene, rna, contains a single premature stop codon early in its open-reading frame. PMID:26802429

  12. 76 FR 1346 - Airworthiness Directives; Airbus Model A300, A300-600, A310, A318, A319, A320, A321, A330-300...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-10

    ... 12866, (2) Is not a ``significant rule'' under DOT Regulatory Policies and Procedures (44 FR 11034... Series Airplanes; and Model A330-201, A330-202, A330- 203, A330-223, A330-243 Airplanes AGENCY: Federal...-600 series airplanes, and Model A330-201, A330-202, A330-203, A330-223, A330-243 airplanes,...

  13. 75 FR 51698 - Airworthiness Directives; Airbus Model A310 Series Airplanes; and Model A300 B4-600, A300 B4-600R...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-23

    ... Policies and Procedures (44 FR 11034, February 26, 1979); and 3. Will not have a significant economic... Goodrich were fitted with an upper attachment gimbal having a thickness of 58 mm (2.28 in), which is... demonstration of the THSA upper attachment primary load path elements, only a gimbal having a thickness of...

  14. The ERTS-1 investigation (ER-600): A compendium of analysis results of the utility of ERTS-1 data for land resources management

    NASA Technical Reports Server (NTRS)

    Erb, R. B.

    1974-01-01

    The results of the ERTS-1 investigations conducted by the Earth Observations Division at the NASA Lyndon B. Johnson Space Center are summarized in this report, which is an overview of documents detailing individual investigations. Conventional image interpretation and computer-aided classification procedures were the two basic techniques used in analyzing the data for detecting, identifying, locating, and measuring surface features related to earth resources. Data from the ERTS-1 multispectral scanner system were useful for all applications studied, which included agriculture, coastal and estuarine analysis, forestry, range, land use and urban land use, and signature extension. Percentage classification accuracies are cited for the conventional and computer-aided techniques.

  15. Genome Sequence and Analysis of Escherichia coli MRE600, a Colicinogenic, Nonmotile Strain that Lacks RNase I and the Type I Methyltransferase, EcoKI.

    PubMed

    Kurylo, Chad M; Alexander, Noah; Dass, Randall A; Parks, Matthew M; Altman, Roger A; Vincent, C Theresa; Mason, Christopher E; Blanchard, Scott C

    2016-03-01

    Escherichia coli strain MRE600 was originally identified for its low RNase I activity and has therefore been widely adopted by the biomedical research community as a preferred source for the expression and purification of transfer RNAs and ribosomes. Despite its widespread use, surprisingly little information about its genome or genetic content exists. Here, we present the first de novo assembly and description of the MRE600 genome and epigenome. To provide context to these studies of MRE600, we include comparative analyses with E. coli K-12 MG1655 (K12). Pacific Biosciences Single Molecule, Real-Time sequencing reads were assembled into one large chromosome (4.83 Mb) and three smaller plasmids (89.1, 56.9, and 7.1 kb). Interestingly, the 7.1-kb plasmid possesses genes encoding a colicin E1 protein and its associated immunity protein. The MRE600 genome has a G + C content of 50.8% and contains a total of 5,181 genes, including 4,913 protein-encoding genes and 268 RNA genes. We identified 41,469 modified DNA bases (0.83% of total) and found that MRE600 lacks the gene for type I methyltransferase, EcoKI. Phylogenetic, taxonomic, and genetic analyses demonstrate that MRE600 is a divergent E. coli strain that displays features of the closely related genus, Shigella. Nevertheless, comparative analyses between MRE600 and E. coli K12 show that these two strains exhibit nearly identical ribosomal proteins, ribosomal RNAs, and highly homologous tRNA species. Substantiating prior suggestions that MRE600 lacks RNase I activity, the RNase I-encoding gene, rna, contains a single premature stop codon early in its open-reading frame. PMID:26802429

  16. Demonstration of the First 4H-SiC EUV Detector with Large Detection Area

    NASA Technical Reports Server (NTRS)

    Xin, Xiaobin; Yan, Feng; Koeth, Timothy W.; Hu, Jun; Zhao, Jian H.

    2005-01-01

    Ultraviolet (UV) and Extreme Ultraviolet (EUV) detectors are very attractive in astronomy, photolithography and biochemical applications. For EUV applications, most of the semiconductor detectors based on PN or PIN structures suffer from the very short penetration depth. Most of the carries are absorbed at the surface and recombined there due to the high surface recombination before reach the depletion region, resulting very low quantum efficiency. On the other hand, for Schottky structures, the active region starts from the surface and carriers generated from the surface can be efficiently collected. 4H-Sic has a bandgap of 3.26eV and is immune to visible light background noise. Also, 4H-Sic detectors usually have very good radiation hardness and very low noise, which is very important for space applications where the signal is very weak. The E W photodiodes presented in this paper are based on Schottky structures. Platinum (Pt) and Nickel (Ni) are selected as the Schottky contact metals, which have the highest electron work functions (5.65eV and 5.15eV, respectively) among all the known metals on 4H-Sic.

  17. 76 FR 47430 - Airworthiness Directives; Airbus Model A300 B4-600, A300 B4-600R, and A300 F4-600R Series...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-05

    ...: Hamilton Sundstrand (HS), the manufacturer of the RAT [ram air turbine], reported the failure during a wind... fastening screw on the RAT turbine cover during a wind tunnel test. After investigation, it has been... engine failure, or a total loss of normal electrical power generation, could result in loss of control...

  18. 76 FR 25259 - Airworthiness Directives; Airbus Model A300 B4-600, A300 B4-600R, and A300 F4-600R Series...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-04

    ...], reported the failure during a wind tunnel test of a balance weight fastening screw on the RAT turbine cover... balance weight fastening screw on the RAT turbine cover during a wind tunnel test. After investigation, it... double engine failure, or a total loss of normal electrical power generation, could result in loss...

  19. Results of tests in the NASA/LaRC 31-inch CFHT on an 0.010-scale model (32-OT) of the space shuttle configuration 3 to determine the RCS jet flowfield interaction effects on aerodynamic characteristics (IA60/0A105), volume 2

    NASA Technical Reports Server (NTRS)

    Thornton, D. E.

    1974-01-01

    Tests were conducted in the NASA Langley Research Center 31-inch continuous flow hypersonic wind tunnel from 14 February to 22 February 1974, to determine RCS jet interaction effect on the hypersonic aerodynamic and stability and control characteristics prior to RTLS abort separation. The model used was an 0.010-scale replica of the space shuttle vehicle configuration 3. Hypersonic stability data were obtained from tests at Mach 10.3 and dynamic pressure of 150 psf for the intergrated orbiter and external tank and the orbiter alone. RCS modes of pitch, yaw, and roll at free flight dynamic pressure simulation of 7, 20, and 50 psf were investigated. The effects of speedbrake, bodyflap, elevon, and aileron deflections were also investigated.

  20. Results of tests in the NASA/LaRC 31-inch CFHT on an 0.010-scale model (32-OT) of the space shuttle configuration 3 to determine the RCS jet flowfield interaction effects on aerodynamic characteristics (IA60/0A105), volume 1

    NASA Technical Reports Server (NTRS)

    Thornton, D. E.

    1974-01-01

    Tests were conducted in the 31-inch continuous Flow Hypersonic Wind Tunnel to determine RCS jet interaction effect on the hypersonic aerodynamic and stability and control characteristics prior to RTLS abort separation. The model used was an 0.010-scale replica of the Space Shuttle Vehicle Configuration 3. Hypersonic stability data were obtained from tests at Mach 10.3 and dynamic pressure of 150 psf for the integrated Orbiter and external tank and the Orbiter alone. RCS modes of pitch, yaw, and roll at free flight dynamic pressure simulation of 7, 20, and 50 psf were investigated. The effects of speedbrake, bodyflap, elevon, and airleron deflections were also investigated.

  1. Kv1.5 in the Immune System: the Good, the Bad, or the Ugly?

    PubMed Central

    Felipe, Antonio; Soler, Concepció; Comes, Núria

    2010-01-01

    For the last 20 years, knowledge of the physiological role of voltage-dependent potassium channels (Kv) in the immune system has grown exponentially. Leukocytes express a limited repertoire of Kv channels, which contribute to the membrane potential. These proteins are involved in the immune response and are therefore considered good pharmacological targets. Although there is a clear consensus about the physiological relevance of Kv1.3, the expression and the role of Kv1.5 are controversial. However, recent reports indicate that certain heteromeric Kv1.3/Kv1.5 associations may provide insight on Kv1.5. Here, we summarize what is known about this issue and highlight the role of Kv1.5 partnership interactions that could be responsible for this debate. The Kv1.3/Kv1.5 heterotetrameric composition of the channel and their possible differential associations with accessory regulatory proteins warrant further investigation. PMID:21423392

  2. Extended defects in 4H-silicon carbide homoepitaxial layers

    NASA Astrophysics Data System (ADS)

    Zhang, Xuan

    The purpose of this thesis is to study the structure of extended defects in 4H-SIC homoepitaxial layers, and to identify their nucleation mechanisms. Characteristics of basal plane dislocations in 4H-SiC epilayers were investigated in a comprehensive manner, including their morphologies, Burgers' vectors, positions, and correlation with the extended defects propagating from the substrate. Plan-view transmission x-ray topography was the major characterization technique used in this study. Complementary data was obtained by KOH etching and optical microscopy. Trace of glide was detected on every basal plane dislocation in the entire 3-inch epilayer. In the center area of the epi-wafer, the glide can extend to macroscopic distance and form edge-type dislocations at the epilayer/surface interface. During the motion, dislocation half loop arrays were found to nucleate at the growth front. The magnitude of the resolved shear stress was estimated based on the radius of curvature of the dislocation lines. It surpassed the critical resolved shear stress at the epitaxial growth temperature. The stress was identified to be compressive in the epilayer. Its origin was studied. Nitrogen-doping-difference-induced misfit strain was excluded as the source of the stress. The structures of two morphological defects, 'carrots' and 'arrows', were studied. Cross-section x-ray topography was used to image the structure of carrot defect in whole. The defect was found to nucleate at the epilayer/substrate interface on a threading screw dislocation propagating from the substrate. Its structure was mainly composed of a prismatic stacking fault and a Frank-type basal plane stacking fault. The arrow defect was found to be produced by a spheroid shape inclusion in the volume of the epilayer. Zone axis diffraction pattern under transmission electron microscope identified the nature of the inclusion as 3C-SIC. It was determined to nucleate at the substrate surface contaminations.

  3. Kv1.5 Association Modifies Kv1.3 Traffic and Membrane Localization*S⃞

    PubMed Central

    Vicente, Rubén; Villalonga, Núria; Calvo, Maria; Escalada, Artur; Solsona, Carles; Soler, Concepció; Tamkun, Michael M.; Felipe, Antonio

    2008-01-01

    Kv1.3 activity is determined by raft association. In addition to Kv1.3, leukocytes also express Kv1.5, and both channels control physiological responses. Because the oligomeric composition may modify the channel targeting to the membrane, we investigated heterotetrameric Kv1.3/Kv1.5 channel traffic and targeting in HEK cells. Kv1.3 and Kv1.5 generate multiple heterotetramers with differential surface expression according to the subunit composition. FRET analysis and pharmacology confirm the presence of functional hybrid channels. Raft association was evaluated by cholesterol depletion, caveolae colocalization, and lateral diffusion at the cell surface. Immunoprecipitation showed that both Kv1.3 and heteromeric channels associate with caveolar raft domains. However, homomeric Kv1.3 channels showed higher association with caveolin traffic. Moreover, FRAP analysis revealed higher mobility for hybrid Kv1.3/Kv1.5 than Kv1.3 homotetramers, suggesting that heteromers target to distinct surface microdomains. Studies with lipopolysaccharide-activated macrophages further supported that different physiological mechanisms govern Kv1.3 and Kv1.5 targeting to rafts. Our results implicate the traffic and localization of Kv1.3/Kv1.5 heteromers in the complex regulation of immune system cells. PMID:18218624

  4. Kolaviron was protective against sodium azide (NaN3) induced oxidative stress in the prefrontal cortex.

    PubMed

    Olajide, Olayemi J; Enaibe, Bernard U; Bankole, Oluwamolakun O; Akinola, Oluwole B; Laoye, Babafemi J; Ogundele, Olalekan M

    2016-02-01

    Kolaviron is a phytochemical isolated from Garcina kola (G. kola); a common oral masticatory agent in Nigeria (West Africa). It is a bioflavonoid used--as an antiviral, anti-inflammatory and antioxidant--in relieving the symptoms of several diseases and infections. In this study we have evaluated the neuroprotective and regenerative effect of kolaviron in neurons of the prefrontal cortex (Pfc) before or after exposure to sodium azide (NaN3) induced oxidative stress. Separate groups of animals were treated as follows; kolaviron (200 mg/Kg) for 21 days; kolaviron (200 mg/Kg for 21 days) followed by NaN3 treatment (20 mg/Kg for 5 days); NaN3 treatment (20 mg/Kg for 5 days) followed by kolaviron (200 mg/Kg for 21 days); 1 ml of corn-oil (21 days-vehicle); NaN3 treatment (20 mg/Kg for 5 days). Exploratory activity associated with Pfc function was assessed in the open field test (OFT) following which the microscopic anatomy of the prefrontal cortex was examined in histology (Haematoxylin and Eosin) and antigen retrieval Immunohistochemistry to show astroglia activation (GFAP), neuronal metabolism (NSE), cytoskeleton (NF) and cell cycle dysregulation (p53). Subsequently, we quantified the level of Glucose-6-phosphate dehydrogenase (G6PDH) and lactate dehydrogenase (LDH) in the brain tissue homogenate as a measure of stress-related glucose metabolism. Kolaviron (Kv) and Kolaviron/NaN3 treatment caused no prominent change in astroglia density and size while NaN3 and NaN3/Kv induced astroglia activation and scar formation (astrogliosis) in the Pfc when compared with the control. Similarly, Kolaviron and Kv/NaN3 did not alter NSE expression (glucose metabolism) while NaN3 and NaN3/Kv treatment increased cortical NSE expression; thus indicating stress related metabolism. Further studies on enzymes of glucose metabolism (G6PDH and LDH) showed that NaN3 increased LDH while kolaviron reduced LDH in the brain tissue homogenate (P < 0.001). In addition kolaviron treatment before (P

  5. 77 FR 65709 - Agency Information Collection Activities: Petition To Classify Orphan as an Immediate Relative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-30

    ... uses Form I-600 to determine whether a child alien is an eligible orphan. Form I-600A is used to... adult member (age 18 and older), who lives in the home of the prospective adoptive parent(s), except...

  6. KCNQ5 K(+) channels control hippocampal synaptic inhibition and fast network oscillations.

    PubMed

    Fidzinski, Pawel; Korotkova, Tatiana; Heidenreich, Matthias; Maier, Nikolaus; Schuetze, Sebastian; Kobler, Oliver; Zuschratter, Werner; Schmitz, Dietmar; Ponomarenko, Alexey; Jentsch, Thomas J

    2015-02-04

    KCNQ2 (Kv7.2) and KCNQ3 (Kv7.3) K(+) channels dampen neuronal excitability and their functional impairment may lead to epilepsy. Less is known about KCNQ5 (Kv7.5), which also displays wide expression in the brain. Here we show an unexpected role of KCNQ5 in dampening synaptic inhibition and shaping network synchronization in the hippocampus. KCNQ5 localizes to the postsynaptic site of inhibitory synapses on pyramidal cells and in interneurons. Kcnq5(dn/dn) mice lacking functional KCNQ5 channels display increased excitability of different classes of interneurons, enhanced phasic and tonic inhibition, and decreased electrical shunting of inhibitory postsynaptic currents. In vivo, loss of KCNQ5 function leads to reduced fast (gamma and ripple) hippocampal oscillations, altered gamma-rhythmic discharge of pyramidal cells and impaired spatial representations. Our work demonstrates that KCNQ5 controls excitability and function of hippocampal networks through modulation of synaptic inhibition.

  7. Measurements of ground motion and magnet vibrations at the APS

    SciTech Connect

    Shiltsev, V.

    1996-09-01

    This article presents results of ground motion and magnet vibrations measurements at the Advanced Photon Source. The experiments were done over a wide, frequency range (0-05-100 Hz) with the use of SM-3KV-type seismic probes from the Budker Institute of Nuclear Physics (Russia). Spectral power densities of vertical and horizontal motions of the APS hall floor and quadrupoles on regular supports were obtained. Also investigated were magnet vibrations induced by designed cooling water flow and spectral characteristics of spatial correlation of the quadrupole vibrations at different sectors of the ring. The influence of personnel activity in the hall and traffic under the ring on the slow motion of storage ring elements were observed. Amplitudes of vibrations at the APS are compared with results of seismic measurements at some other accelerators.

  8. Action potential processing in a detailed Purkinje cell model reveals a critical role for axonal compartmentalization

    PubMed Central

    Masoli, Stefano; Solinas, Sergio; D'Angelo, Egidio

    2015-01-01

    The Purkinje cell (PC) is among the most complex neurons in the brain and plays a critical role for cerebellar functioning. PCs operate as fast pacemakers modulated by synaptic inputs but can switch from simple spikes to complex bursts and, in some conditions, show bistability. In contrast to original works emphasizing dendritic Ca-dependent mechanisms, recent experiments have supported a primary role for axonal Na-dependent processing, which could effectively regulate spike generation and transmission to deep cerebellar nuclei (DCN). In order to account for the numerous ionic mechanisms involved (at present including Nav1.6, Cav2.1, Cav3.1, Cav3.2, Cav3.3, Kv1.1, Kv1.5, Kv3.3, Kv3.4, Kv4.3, KCa1.1, KCa2.2, KCa3.1, Kir2.x, HCN1), we have elaborated a multicompartmental model incorporating available knowledge on localization and gating of PC ionic channels. The axon, including initial segment (AIS) and Ranvier nodes (RNs), proved critical to obtain appropriate pacemaking and firing frequency modulation. Simple spikes initiated in the AIS and protracted discharges were stabilized in the soma through Na-dependent mechanisms, while somato-dendritic Ca channels contributed to sustain pacemaking and to generate complex bursting at high discharge regimes. Bistability occurred only following Na and Ca channel down-regulation. In addition, specific properties in RNs K currents were required to limit spike transmission frequency along the axon. The model showed how organized electroresponsive functions could emerge from the molecular complexity of PCs and showed that the axon is fundamental to complement ionic channel compartmentalization enabling action potential processing and transmission of specific spike patterns to DCN. PMID:25759640

  9. The Redistribution of Drosophila Vesicular Monoamine Transporter Mutants from Synaptic Vesicles to Large Dense-Core Vesicles Impairs Amine-Dependent Behaviors

    PubMed Central

    Grygoruk, Anna; Chen, Audrey; Martin, Ciara A.; Lawal, Hakeem O.; Fei, Hao; Gutierrez, Gabriel; Biedermann, Traci; Najibi, Rod; Hadi, Richard; Chouhan, Amit K.; Murphy, Niall P.; Schweizer, Felix E.; Macleod, Gregory T.; Maidment, Nigel T.

    2014-01-01

    Monoamine neurotransmitters are stored in both synaptic vesicles (SVs), which are required for release at the synapse, and large dense-core vesicles (LDCVs), which mediate extrasynaptic release. The contributions of each type of vesicular release to specific behaviors are not known. To address this issue, we generated mutations in the C-terminal trafficking domain of the Drosophila vesicular monoamine transporter (DVMAT), which is required for the vesicular storage of monoamines in both SVs and LDCVs. Deletion of the terminal 23 aa (DVMAT-Δ3) reduced the rate of endocytosis and localization of DVMAT to SVs, but supported localization to LDCVs. An alanine substitution mutation in a tyrosine-based motif (DVMAT-Y600A) also reduced sorting to SVs and showed an endocytic deficit specific to aminergic nerve terminals. Redistribution of DVMAT-Y600A from SV to LDCV fractions was also enhanced in aminergic neurons. To determine how these changes might affect behavior, we expressed DVMAT-Δ3 and DVMAT-Y600A in a dVMAT null genetic background that lacks endogenous dVMAT activity. When expressed ubiquitously, DVMAT-Δ3 showed a specific deficit in female fertility, whereas DVMAT-Y600A rescued behavior similarly to DVMAT-wt. In contrast, when expressed more specifically in octopaminergic neurons, both DVMAT-Δ3 and DVMAT-Y600A failed to rescue female fertility, and DVMAT-Y600A showed deficits in larval locomotion. DVMAT-Y600A also showed more severe dominant effects than either DVMAT-wt or DVMAT-Δ3. We propose that these behavioral deficits result from the redistribution of DVMAT from SVs to LDCVs. By extension, our data suggest that the balance of amine release from SVs versus that from LDCVs is critical for the function of some aminergic circuits. PMID:24828646

  10. The redistribution of Drosophila vesicular monoamine transporter mutants from synaptic vesicles to large dense-core vesicles impairs amine-dependent behaviors.

    PubMed

    Grygoruk, Anna; Chen, Audrey; Martin, Ciara A; Lawal, Hakeem O; Fei, Hao; Gutierrez, Gabriel; Biedermann, Traci; Najibi, Rod; Hadi, Richard; Chouhan, Amit K; Murphy, Niall P; Schweizer, Felix E; Macleod, Gregory T; Maidment, Nigel T; Krantz, David E

    2014-05-14

    Monoamine neurotransmitters are stored in both synaptic vesicles (SVs), which are required for release at the synapse, and large dense-core vesicles (LDCVs), which mediate extrasynaptic release. The contributions of each type of vesicular release to specific behaviors are not known. To address this issue, we generated mutations in the C-terminal trafficking domain of the Drosophila vesicular monoamine transporter (DVMAT), which is required for the vesicular storage of monoamines in both SVs and LDCVs. Deletion of the terminal 23 aa (DVMAT-Δ3) reduced the rate of endocytosis and localization of DVMAT to SVs, but supported localization to LDCVs. An alanine substitution mutation in a tyrosine-based motif (DVMAT-Y600A) also reduced sorting to SVs and showed an endocytic deficit specific to aminergic nerve terminals. Redistribution of DVMAT-Y600A from SV to LDCV fractions was also enhanced in aminergic neurons. To determine how these changes might affect behavior, we expressed DVMAT-Δ3 and DVMAT-Y600A in a dVMAT null genetic background that lacks endogenous dVMAT activity. When expressed ubiquitously, DVMAT-Δ3 showed a specific deficit in female fertility, whereas DVMAT-Y600A rescued behavior similarly to DVMAT-wt. In contrast, when expressed more specifically in octopaminergic neurons, both DVMAT-Δ3 and DVMAT-Y600A failed to rescue female fertility, and DVMAT-Y600A showed deficits in larval locomotion. DVMAT-Y600A also showed more severe dominant effects than either DVMAT-wt or DVMAT-Δ3. We propose that these behavioral deficits result from the redistribution of DVMAT from SVs to LDCVs. By extension, our data suggest that the balance of amine release from SVs versus that from LDCVs is critical for the function of some aminergic circuits. PMID:24828646

  11. Effects of Adding Nanoparticles on Boiling and Condensing Heat Transfer inside a horizontal round tube

    NASA Astrophysics Data System (ADS)

    Sheikholeslami, Mohsen; Sadoughi, Mohammadkazem; Shariatmadar, Hamed; Akhavan-Behabadi, Mohammad Ali

    2015-11-01

    An experimental investigation is performed on heat transfer evaluation of a nano-refrigerant flow during condensation and evaporation inside a horizontal round tube. Experiments are carried out for three working fluid types including: i) pure refrigerant (R600a); ii) refrigerant/lubricant (R600a/oil); and iii) nano-refrigerant: refrigerant/lubricant/nanoparticles (R600a/oil/CuO). Nanoparticles are added to the lubricant and their mixture is mixed with pure refrigerant. Therefore, nano-refrigerants (R600a/oil/CuO) are prepared by dispersing CuO nanoparticles with different fractions of 0.5%, 1% and 1.5% in the baseline mixture (R600a/oil). Effects of different factors including vapor quality, mass flux, and nanoparticles on the heat transfer coefficient are examined for both of condensation and evaporation flows, separately. The results shows that maximum heat transfer augmentation of 79% and 83% are achieved by using the refrigerant/lubricant/nanoparticles mixture, in comparison with the pure refrigerant case in condensation and evaporation, respectively which are occurred for nano-refrigerant with 1.5% mass fraction in both of them.

  12. Regulation of voltage-gated potassium channels by PI(4,5)P2

    PubMed Central

    Kruse, Martin; Hammond, Gerald R.V.

    2012-01-01

    Phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) regulates activities of numerous ion channels including inwardly rectifying potassium (Kir) channels, KCNQ, TRP, and voltage-gated calcium channels. Several studies suggest that voltage-gated potassium (KV) channels might be regulated by PI(4,5)P2. Wide expression of KV channels in different cells suggests that such regulation could have broad physiological consequences. To study regulation of KV channels by PI(4,5)P2, we have coexpressed several of them in tsA-201 cells with a G protein–coupled receptor (M1R), a voltage-sensitive lipid 5-phosphatase (Dr-VSP), or an engineered fusion protein carrying both lipid 4-phosphatase and 5-phosphatase activity (pseudojanin). These tools deplete PI(4,5)P2 with application of muscarinic agonists, depolarization, or rapamycin, respectively. PI(4,5)P2 at the plasma membrane was monitored by Förster resonance energy transfer (FRET) from PH probes of PLCδ1 simultaneously with whole-cell recordings. Activation of Dr-VSP or recruitment of pseudojanin inhibited KV7.1, KV7.2/7.3, and Kir2.1 channel current by 90–95%. Activation of M1R inhibited KV7.2/7.3 current similarly. With these tools, we tested for potential PI(4,5)P2 regulation of activity of KV1.1/KVβ1.1, KV1.3, KV1.4, and KV1.5/KVβ1.3, KV2.1, KV3.4, KV4.2, KV4.3 (with different KChIPs and DPP6-s), and hERG/KCNE2. Interestingly, we found a substantial removal of inactivation for KV1.1/KVβ1.1 and KV3.4, resulting in up-regulation of current density upon activation of M1R but no changes in activity upon activating only VSP or pseudojanin. The other channels tested except possibly hERG showed no alteration in activity in any of the assays we used. In conclusion, a depletion of PI(4,5)P2 at the plasma membrane by enzymes does not seem to influence activity of most tested KV channels, whereas it does strongly inhibit members of the KV7 and Kir families. PMID:22851677

  13. Molecular expression and pharmacological evidence for a functional role of kv7 channel subtypes in Guinea pig urinary bladder smooth muscle.

    PubMed

    Afeli, Serge A Y; Malysz, John; Petkov, Georgi V

    2013-01-01

    Voltage-gated Kv7 (KCNQ) channels are emerging as essential regulators of smooth muscle excitability and contractility. However, their physiological role in detrusor smooth muscle (DSM) remains to be elucidated. Here, we explored the molecular expression and function of Kv7 channel subtypes in guinea pig DSM by RT-PCR, qRT-PCR, immunohistochemistry, electrophysiology, and isometric tension recordings. In whole DSM tissue, mRNAs for all Kv7 channel subtypes were detected in a rank order: Kv7.1~Kv7.2Kv7.3~Kv7.5Kv7.4. In contrast, freshly-isolated DSM cells showed mRNA expression of: Kv7.1~Kv7.2Kv7.5Kv7.3~Kv7.4. Immunohistochemical confocal microscopy analyses of DSM, conducted by using co-labeling of Kv7 channel subtype-specific antibodies and α-smooth muscle actin, detected protein expression for all Kv7 channel subtypes, except for the Kv7.4, in DSM cells. L-364373 (R-L3), a Kv7.1 channel activator, and retigabine, a Kv7.2-7.5 channel activator, inhibited spontaneous phasic contractions and the 10-Hz electrical field stimulation (EFS)-induced contractions of DSM isolated strips. Linopiridine and XE991, two pan-Kv7 (effective at Kv7.1-Kv7.5 subtypes) channel inhibitors, had opposite effects increasing DSM spontaneous phasic and 10 Hz EFS-induced contractions. EFS-induced DSM contractions generated by a wide range of stimulation frequencies were decreased by L-364373 (10 µM) or retigabine (10 µM), and increased by XE991 (10 µM). Retigabine (10 µM) induced hyperpolarization and inhibited spontaneous action potentials in freshly-isolated DSM cells. In summary, Kv7 channel subtypes are expressed at mRNA and protein levels in guinea pig DSM cells. Their pharmacological modulation can control DSM contractility and excitability; therefore, Kv7 channel subtypes provide potential novel therapeutic targets for urinary bladder dysfunction.

  14. Correlation between potassium channel expression and sensitivity to drug-induced cell death in tumor cell lines.

    PubMed

    Leanza, Luigi; O'Reilly, Paul; Doyle, Anne; Venturini, Elisa; Zoratti, Mario; Szegezdi, Eva; Szabo, Ildiko

    2014-01-01

    Plasma membrane (PM) and mitochondrial (mt) ion channels - particularly potassium channels - became oncological targets soon after the discovery that they are involved both in the regulation of proliferation and apoptosis. Some members of the Kv Shaker family, namely Kv1.1, Kv1.3, Kv1.5 and Kv11.1 (Herg), and the intermediate-conductance calcium-activated potassium KCa3.1 (IK) channels have been shown to contribute to apoptosis in various cell lines. Kv1.3, Kv1.5 and IK are located in the plasma membrane but also in the mitochondrial inner membrane, where they participate in apoptotic signalling. Interestingly, an altered protein expression of some of the channels mentioned above has been reported in neoplastic cell lines/tissues, but a systematic quantification addressing the protein expression of the above potassium channels in tumor cell lines of different origin has not been carried out yet. In the present study we investigated whether expression of specific potassium channels, at the mRNA and protein level, can be correlated with cell sensitivity to various apoptotic stimuli, including chemotherapeutic drugs, in a panel of cancer cell lines. The results show correlation between the protein expression of the Kv1.1 and Kv1.3 channels and susceptibility to death upon treatment with staurosporine, C2-ceramide and cisplatin. Furthermore, we investigated the correlation between Kv channel expression and sensitivity to three distinct membrane-permeant Kv1.3 inhibitors, since these drugs have recently been shown to be able to induce apoptosis and also reduce tumor volume in an in vivo model. Higher protein expression of Kv1.3 significantly correlated with lower cell survival upon treatment with clofazimine, one of the Kv1.3 inhibitors. These results suggest that expression of Kv1.1 and Kv1.3 sensitizes tumour cells of various origins to cytotoxins. Data reported in this work regarding potassium channel protein expression in different cancer cell lines may be exploited

  15. A calibration of detectors and gratings between 100 and 600 Angstroms

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.

    1975-01-01

    Calibration and efficiency measurements of magnetic electron multipliers, diffraction gratings, and photocathodes over the wavelength range 100 to 600 A are reported. For some of the measurements it was found necessary to use the synchrotron radiation from a storage ring. Measurements of grating efficiencies, the polarization produced by diffraction gratings, and the photoelectric yields of various photocathodes are included.

  16. 49 CFR 529.5 - Requirements for intermediate manufacturers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... accordance with 40 CFR part 600. (2) If neither the intermediate manufacturer of an incomplete automobile nor... with 40 CFR part 600. (4) The intermediate manufacturer shall attach to the incomplete automobile in accordance with 40 CFR part 600 a fuel economy label identical to the label that is required under this...

  17. 49 CFR 529.6 - Requirements for final-stage manufacturers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... automobile in accordance with 40 CFR part 600. (2) If the final-stage manufacturer places the portion of the... automobile in accordance with 40 CFR part 600. (3) The final-stage manufacturer shall attach to the completed automobile in accordance with 40 CFR part 600 a fuel economy label identical to the label that is...

  18. Child Labor Amendments of 1991. Joint Hearing on S.600 To Amend the Fair Labor Standards Act of 1938 To Improve Enforcement of the Child Labor Provisions of Such Act, and for Other Purposes, before the Subcommittee on Labor and Subcommittee on Children, Family, Drugs and Alcoholism of the Committee on Labor and Human Resources. United States Senate, One Hundred Second Congress, First Session.

    ERIC Educational Resources Information Center

    Congress of the U.S., Washington, DC. Senate Committee on Labor and Human Resources.

    A joint hearing was held to consider S. 600, a U.S. Senate bill designed to help educate the public about federal child labor laws and strengthen enforcement of child labor laws through an amendment to the Fair Labor Standards Act of 1938. Senator Howard M. Metzenbaum presided. The hearings were called because of sporadic enforcement of inadequate…

  19. 14 CFR 221.180 - Requirements for electronic filing of tariffs.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the filer may bring its computer down between 6:00 a.m. and 6:00 p.m. Eastern Standard Time or Eastern Daylight Saving Time, as the case may be, on Sundays, when necessary, for maintenance or for operational... the Department (as may be required from time to time) one or more CRT devices and printers...

  20. 14 CFR 221.180 - Requirements for electronic filing of tariffs.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... the filer may bring its computer down between 6:00 a.m. and 6:00 p.m. Eastern Standard Time or Eastern Daylight Saving Time, as the case may be, on Sundays, when necessary, for maintenance or for operational... the Department (as may be required from time to time) one or more CRT devices and printers...

  1. 10 CFR 455.140 - Approval of applications from institutions and coordinating agencies for technical assistance and...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... specified in the DOE Financial Assistance Rules (10 CFR part 600), a grantee shall request prior written... 10 Energy 3 2012-01-01 2012-01-01 false Approval of applications from institutions and coordinating agencies for technical assistance and energy conservation measures. 455.140 Section 455.140...

  2. 78 FR 5828 - Agency Information Collection Activities: Petition To Classify Orphan as an Immediate Relative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-28

    ..., at 77 FR 65709, allowing for a 60-day public comment period. USCIS did receive two comments in... uses Form I-600 to determine whether a child alien is an eligible orphan. Form I-600A is used to... adult member (age 18 and older), who lives in the home of the prospective adoptive parent(s), except...

  3. 14 CFR 93.226 - Allocation of slots in low-demand periods.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... available less than 5 days per week. (2) Any time period for which a slot is available for less than a full season. (3) For LaGuardia and Washington National Airports: (i) 6:00 a.m.-6:59 a.m. (ii) 10:00...

  4. 49 CFR 529.5 - Requirements for intermediate manufacturers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... accordance with 40 CFR part 600. (2) If neither the intermediate manufacturer of an incomplete automobile nor... with 40 CFR part 600. (4) The intermediate manufacturer shall attach to the incomplete automobile in accordance with 40 CFR part 600 a fuel economy label identical to the label that is required under this...

  5. 49 CFR 529.6 - Requirements for final-stage manufacturers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... automobile in accordance with 40 CFR part 600. (2) If the final-stage manufacturer places the portion of the... automobile in accordance with 40 CFR part 600. (3) The final-stage manufacturer shall attach to the completed automobile in accordance with 40 CFR part 600 a fuel economy label identical to the label that is...

  6. 26 CFR 1.174-4 - Treatment as deferred expenses.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... section 165 and the regulations thereunder for rules relating to the treatment of losses resulting from... expenditures are first realized. On January 1, 1955, N Corporation also purchased for $57,600 a building having... the period. Fifty percent of the building's facilities are to be used in connection with the...

  7. A Study in Child Care (Case Study from Volume II-A): "A Rolls-Royce of Day Care." Day Care Programs Reprint Series.

    ERIC Educational Resources Information Center

    O'Farrell, Brigid

    The Amalgamated Day Care Center is an independent trust established through a collective bargaining agreement between the Amalgamated Clothing Workers of America, AFL-CIO, and the employers of the garment industry. The free center, open from 6:00 a.m. to 6:00 p.m., is located near the Chicago garment industries to minimize transportation problems…

  8. 7 CFR 58.43 - Fees for inspection, grading, and sampling.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... performed between 6:00 p.m. and 6:00 a.m., for the time required to perform the service calculated to the nearest 15-minute period, including the time required for preparation of certificates and reports and the travel time of the inspector or grader in connection with the performance of the service. A...

  9. 75 FR 29740 - Office of Elementary and Secondary Education; Overview Information; Gulf Coast Recovery Grant...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-27

    ... electronically using e-Application, accessible through the Department's e-Grants Web site at: http://e-grants.ed... begin the application process. The hours of operation of the e-Grants Web site are 6:00 a.m. Monday...; Notice Inviting Applications for New Awards for Fiscal Year (FY) 2010 Catalog of Federal...

  10. 75 FR 1757 - Office of Special Education and Rehabilitative Services (OSERS); Overview Information; National...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-13

    ...-Application, accessible through the Department's e-Grants Web site at: http://e-grants.ed.gov . We will reject... application process. The hours of operation of the e-Grants Web site are 6:00 a.m. Monday until 7:00 p.m... performance reports, which include information on NIDRR programs, are available on the Department's Web...

  11. 10 CFR 602.14 - Fee.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Fee. 602.14 Section 602.14 Energy DEPARTMENT OF ENERGY....14 Fee. (a) Notwithstanding 10 CFR part 600, a fee may be paid, in appropriate circumstances, to a recipient that is a small business concern, as qualified under the criteria and size standards of 13...

  12. 10 CFR 605.15 - Fee.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Fee. 605.15 Section 605.15 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS THE OFFICE OF ENERGY RESEARCH FINANCIAL ASSISTANCE PROGRAM § 605.15 Fee. (a) Notwithstanding 10 CFR part 600, a fee may be paid, in appropriate circumstances, to a...

  13. 10 CFR 602.14 - Fee.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Fee. 602.14 Section 602.14 Energy DEPARTMENT OF ENERGY....14 Fee. (a) Notwithstanding 10 CFR part 600, a fee may be paid, in appropriate circumstances, to a recipient that is a small business concern, as qualified under the criteria and size standards of 13...

  14. 10 CFR 605.15 - Fee.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Fee. 605.15 Section 605.15 Energy DEPARTMENT OF ENERGY (CONTINUED) ASSISTANCE REGULATIONS THE OFFICE OF ENERGY RESEARCH FINANCIAL ASSISTANCE PROGRAM § 605.15 Fee. (a) Notwithstanding 10 CFR part 600, a fee may be paid, in appropriate circumstances, to a...

  15. The Relationship between Job Satisfaction and Selected Demographics and Teacher Retention

    ERIC Educational Resources Information Center

    Claybon, Karen M.

    2008-01-01

    According to the Texas State Board of Education in 2002, 60% of teachers in Texas classrooms quit the profession after only five years in the classroom. In 1998-99, Texas filled over 63,000 teaching positions. Most vacant positions resulted from existing teachers retiring (11,000) or leaving the profession (46,600). A recent study in Texas…

  16. 10 CFR 605.15 - Fee.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... acquired with DOE funds vests in the recipient (10 CFR part 600). (d) Notwithstanding 10 CFR part 600, any.... (a) Notwithstanding 10 CFR part 600, a fee may be paid, in appropriate circumstances, to a recipient... size standards in 13 CFR part 121. In addition, the application must state the amount of fee...

  17. 10 CFR 602.14 - Fee.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... payments are provided; and/or (ii) Title to property acquired with DOE funds vests in the recipient (10 CFR....14 Fee. (a) Notwithstanding 10 CFR part 600, a fee may be paid, in appropriate circumstances, to a... concern qualified under the criteria and size standards in 13 CFR part 121. In addition, the...

  18. 10 CFR 602.14 - Fee.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ....14 Fee. (a) Notwithstanding 10 CFR part 600, a fee may be paid, in appropriate circumstances, to a recipient that is a small business concern, as qualified under the criteria and size standards of 13 CFR... generally be appropriate.) Fees shall not be paid to other entities except as a deviation from 10 CFR...

  19. Deficiency of the miR-29a/b-1 cluster leads to ataxic features and cerebellar alterations in mice.

    PubMed

    Papadopoulou, Aikaterini S; Serneels, Lutgarde; Achsel, Tilmann; Mandemakers, Wim; Callaerts-Vegh, Zsuzsanna; Dooley, James; Lau, Pierre; Ayoubi, Torik; Radaelli, Enrico; Spinazzi, Marco; Neumann, Melanie; Hébert, Sébastien S; Silahtaroglu, Asli; Liston, Adrian; D'Hooge, Rudi; Glatzel, Markus; De Strooper, Bart

    2015-01-01

    miR-29 is expressed strongly in the brain and alterations in expression have been linked to several neurological disorders. To further explore the function of this miRNA in the brain, we generated miR-29a/b-1 knockout animals. Knockout mice develop a progressive disorder characterized by locomotor impairment and ataxia. The different members of the miR-29 family are strongly expressed in neurons of the olfactory bulb, the hippocampus and in the Purkinje cells of the cerebellum. Morphological analysis showed that Purkinje cells are smaller and display less dendritic arborisation compared to their wildtype littermates. In addition, a decreased number of parallel fibers form synapses on the Purkinje cells. We identified several mRNAs significantly up-regulated in the absence of the miR-29a/b-1 cluster. At the protein level, however, the voltage-gated potassium channel Kcnc3 (Kv3.3) was significantly up-regulated in the cerebella of the miR-29a/b knockout mice. Dysregulation of KCNC3 expression may contribute to the ataxic phenotype. PMID:25315682

  20. Serum- and glucocorticoid-inducible kinase 1 in the regulation of renal and extrarenal potassium transport.

    PubMed

    Lang, Florian; Vallon, Volker

    2012-02-01

    Serum- and glucocorticoid inducible-kinase 1 (SGK1) is an early gene transcriptionally upregulated by cell stress such as cell shrinkage and hypoxia and several hormones including gluco- and mineralocorticoids. It is activated by insulin and growth factors. SGK1 is a powerful regulator of a wide variety of channels and transporters. The present review describes the role of SGK1 in the regulation of potassium (K(+)) channels, K(+) transporters and K(+) homeostasis. SGK1-regulated K(+) channels include renal outer medullary K+ channel, Kv1.3, Kv1.5, KCNE1/KCNQ1, KCNQ4 and, via regulation of calcium (Ca(2+)) entry, Ca(2+)-sensitive K(+) channels. SGK1-sensitive transporters include sodium-potassium-chloride cotransporter 2 and sodium/potassium-adenosine triphosphatase. SGK1-dependent regulation of K(+) channels and K(+) transport contributes to the stimulation of renal K(+) excretion following high K(+) intake, to insulin-induced cellular K(+) uptake and hypokalemia, to inhibition of insulin release by glucocorticoids, to stimulation of mast cell degranulation and gastric acid secretion, and to cardiac repolarization. Thus, SGK1 has a profound effect on K(+) homeostasis and on a multitude of K(+)-sensitive cellular functions. PMID:22038256

  1. Environmentally-induced discharge transient coupling to spacecraft

    NASA Technical Reports Server (NTRS)

    Viswanathan, R.; Barbay, G.; Stevens, N. J.

    1985-01-01

    The Hughes SCREENS (Space Craft Response to Environments of Space) technique was applied to generic spin and 3-axis stabilized spacecraft models. It involved the NASCAP modeling for surface charging and lumped element modeling for transients coupling into a spacecraft. A differential voltage between antenna and spun shelf of approx. 400 V and current of 12 A resulted from discharge at antenna for the spinner and approx. 3 kv and 0.3 A from a discharge at solar panels for the 3-axis stabilized Spacecraft. A typical interface circuit response was analyzed to show that the transients would couple into the Spacecraft System through ground points, which are most vulnerable. A compilation and review was performed on 15 years of available data from electron and ion current collection phenomena. Empirical models were developed to match data and compared with flight data of Pix-1 and Pix-2 mission. It was found that large space power systems would float negative and discharge if operated at or above 300 V. Several recommendations are given to improve the models and to apply them to large space systems.

  2. Fundamental evaluation of LSI`s using anisotropic reactive ion etching

    SciTech Connect

    Sanada, M.; Suzuki, S.; Numaziri, T.; Omata, T.; Yoshida, N.

    1995-12-31

    An electrical and physical evaluation of CMOS LSI`s with multiple-metal layers exposed using a reactive ion etcher (RIE), is described. Anisotropic etching is executed using a parallel plate type reactive ion etcher with 3KV/mm sheath voltage grade and a CF4/02 gas mixture. The formation of small vertical protrusions, known as ``RIE grass``, on the Si-surface is prevented by using a Teflon plate and aluminum foil which covers over the cathode plate and LSI package, except for the LSI chip, itself. High density CMOS LSI`s with 0.5{micro}m design rules and three metal layers, each of which is composed of a sandwiched structure of aluminum between refractory metals (Ti, TiN), are used for an electrical and physical evaluation. Three important results, exhibiting no degradation of transistor characteristics, are discussed: a 10% speed up in circuit operation resulting from removing the isolation layer, a complex change of leakage current value resulting from very small RIE grass, and a change of metal line constitution resulting from removal of the upper refractory metal layer. The absence of transistor degradation shows that RIE is an effective tool for exposing multiple layers of metal lines of LSI`s without destroying any of the electrical functionality of a device. This technique is applied to the failure analysis of a CMOS LSI having an underlying pattern defect. By using an electron beam tester, the complete analysis is executed.

  3. Controllable parabolic lensed liquid-core optical fiber by using electrostatic force.

    PubMed

    Tang, Chun Yin; Zhang, Xuming; Chai, Yang; Hui, Long; Tao, Lili; Tsang, Yuen H

    2014-08-25

    For typical optical fiber system, an external lens accessory set is required to adjust the optical path of output light, which however is limited by the fixed parameter of the lens accessory setup. Considering spherical aberration in the imaging process and its small focusable spot size, a complicated lens combination is required to compensate the aberration. This paper has demonstrated a unique method to fabricate liquid-core lensed fibers by filling water and NOA61 respectively into hollow Teflon AF fibers and silicate fiber, the radius of curvature of the liquid lens can be controlled by adjusting the applied voltage on the core liquid and even parabolic shape lens can be produced with enough applied voltage. The experiment has successfully demonstrated a variation of focal length from 0.628 mm to 0.111 mm responding to the change of applied voltage from 0V to 3.2KV (L = 2mm) for the Teflon AF fiber, as well as a variation of focal length from 0.274 mm to 0.08 mm responding to the change of applied voltage from 0V to 3KV (L = 2mm) for the silicate fiber. Further simulation shows that the focused spot size can be reduced to 2 µm by adjusting the refractive index and fiber geometry. Solid state parabolic lensed fiber can be produced after NOA61 is solidified by the UV curing.

  4. Combinatorial augmentation of voltage-gated KCNQ potassium channels by chemical openers

    PubMed Central

    Xiong, Qiaojie; Sun, Haiyan; Zhang, Yangming; Nan, Fajun; Li, Min

    2008-01-01

    Noninactivating potassium current formed by KCNQ2 (Kv7.2) and KCNQ3 (Kv7.3) subunits resembles neuronal M-currents which are activated by voltage and play a critical role in controlling membrane excitability. Activation of voltage-gated potassium channels by a chemical opener is uncommon. Therefore, the mechanisms of action are worthy further investigation. Retigabine and zinc pyrithione are two activators for KCNQ channels but their molecular interactions with KCNQ channel remain largely elusive. Here we report that retigabine and zinc pyrithione recognize two different sites of KCNQ2 channels. Their agonistic actions are noncompetitive and allow for simultaneous binding of two different activators on the same channel complex, hence giving rise to combinatorial potentiation with characteristic properties of both openers. Examining their effects on mutant channels, we showed zinc pyrithione is capable of opening nonconductive channels and coapplication of zinc pyrithione and retigabine could restore a disease mutant channel similar to wild type. Our results indicate two independent activator binding sites present in KCNQ channels. The resultant combinatorial potentiation by multiple synthetic chemical openers indicates that KCNQ channels are accessible to various types and combinations of pharmacological regulation. PMID:18272489

  5. State-dependent inactivation of the Kv3 potassium channel.

    PubMed Central

    Marom, S; Levitan, I B

    1994-01-01

    Inactivation of Kv3 (Kv1.3) delayed rectifier potassium channels was studied in the Xenopus oocyte expression system. These channels inactivate slowly during a long depolarizing pulse. In addition, inactivation accumulates in response to a series of short depolarizing pulses (cumulative inactivation), although no significant inactivation occurs within each short pulse. The extent of cumulative inactivation does not depend on the voltage during the depolarizing pulse, but it does vary in a biphasic manner as a function of the interpulse duration. Furthermore, the rate of cumulative inactivation is influenced by changing the rate of deactivation. These data are consistent with a model in which Kv3 channel inactivation is a state-dependent and voltage-independent process. Macroscopic and single channel experiments indicate that inactivation can occur from a closed (silent) state before channel opening. That is, channels need not open to inactivate. The transition that leads to the inactivated state from the silent state is, in fact, severalfold faster then the observed inactivation of current during long depolarizing pulses. Long pulse-induced inactivation appears to be slow, because its rate is limited by the probability that channels are in the open state, rather than in the silent state from which they can inactivate. External potassium and external calcium ions alter the rates of cumulative and long pulse-induced inactivation, suggesting that antagonistic potassium and calcium binding steps are involved in the normal gating of the channel. PMID:7948675

  6. Apollo 16 far-ultraviolet imagery and spectra of the Large Magellanic Cloud

    NASA Technical Reports Server (NTRS)

    Page, T.; Carruthers, G. R.

    1976-01-01

    The Large Magellanic Cloud was observed by the far ultraviolet camera spectrograph from the lunar surface during the Apollo 16 mission 22 April 1972. Images were obtained with about 3 arc min resolution, in the 1,050 to 1,600 and 1,250 to 1,600 A wavelength ranges, of nearly the entire LMC. Spectra were also obtained in the 1,050 to 1,600 and 900 to 1,600 A ranges along a strip 1/4 deg wide (determined by the instrument's grid collimator) passing across the LMC. The images and spectra have been scanned with a PDS microdensitometer, and isodensity contour plots have been prepared using the Univac 1108 computer.

  7. The investigation of O and N2 densities from the OSO-7 extreme UV data

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The results of solar radiation observations in the extreme ultra-violet spectrum from 200 A to 600 A made by the OSO-7 Satellite were studied. The results of the influence of attenuation by the atmosphere in the 250 to 500 km altitude range are presented. Using published molecular absorption cross-sections at 304 A and 256 A, the Jaccia atmospheric model is validated, and shows that a mean exospheric of 1050 K is appropriate for the sunset data.

  8. Soil surface potentials induced by ITAIPU HVDC ground return current. Part II - Measurements

    SciTech Connect

    Caroli, C.E.; Santos, N.; Kovarsky, D.; Marques, M.A.M. )

    1988-07-01

    The method used for the measurement of the potential curves in the soil surface is presented, together with its results, obtained at different electrode current levels (100A, 600A, 1500A and 2300A). Circuits and instrumentation used are also presented, as well as notes on measurement noise and on the overall precision obtained. The results are finally also presented in the form of equipotential curves.

  9. Running Shanghai Soft x-ray FEL with the EEHG scheme

    SciTech Connect

    Xiang, D; Stupakov, G.; /SLAC

    2008-12-18

    With the nominal beam parameters (beam energy: 0.84 GeV, slice energy spread: 168 keV, peak current: 600 A, normalized emittance: 2 mm mrad) of the Shanghai soft X-ray Free Electron Laser (SXFEL) project, we show that using the echo-enabled harmonic generation (EEHG) scheme, 9 nm coherent soft x-ray with peak power exceeding 400 MW can be generated directly from the 270 nm seeding laser.

  10. 8 CFR 204.300 - Scope of this subpart.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... date, as defined in 8 CFR 204.301. (b) Orphan cases. On or after the Convention effective date, no Form I-600A or I-600 may be filed under section 101(b)(1)(F) of the Act and 8 CFR 204.3 in relation to...-600 was filed before the Convention effective date, the case will continue to be governed by 8 CFR...

  11. Experimental investigation of the performance of a single-stage auto-cascade refrigerator

    NASA Astrophysics Data System (ADS)

    Rui, Shengjun; Zhang, Hua; Zhang, Bohan; Wen, Dongsheng

    2016-01-01

    Auto-refrigerating cascade (ARC) systems possess many advantages comparing with traditional cascade refrigeration systems. This work proposed a novel ternary mixture, R600a/R23/R14, for ARC systems for 190 K applications. The performance of the ternary mixture and the influences of compositional ratio and bypass scheme were assessed in a modified domestic cooler. The results demonstrated the feasibility of the proposed R600a/R23/R14 ternary mixture as an environmental benign alternative for ARC systems. The performance varied little within a certain composition range and a mass ratio of 35/30/35 for R600a/R23/R14 mixture was recommended. It also showed that the two bypass schemes, which can regulate more effectively the refrigerant compositions, were better than the conventional hot-gas bypass approach. The variation of the evaporator temperature suggested the presence of local dryout at high heat loads (i.e., larger than the design value), which should be carefully prevented.

  12. Modulation of Kv7 potassium channels by a novel opener pyrazolo[1,5-a]pyrimidin-7(4H)-one compound QO-58

    PubMed Central

    Zhang, F; Mi, Y; Qi, JL; Li, JW; Si, M; Guan, BC; Du, XN; An, HL; Zhang, HL

    2013-01-01

    Background and Purpose Modulation of Kv7/M channel function represents a relatively new strategy to treat neuronal excitability disorders such as epilepsy and neuropathic pain. We designed and synthesized a novel series of pyrazolo[1,5-a] pyrimidin-7(4H)-one compounds, which activate Kv7 channels. Here, we characterized the effects of the lead compound, QO-58, on Kv7 channels and investigated its mechanism of action. Experimental Approach A perforated whole-cell patch technique was used to record Kv7 currents expressed in mammalian cell lines and M-type currents from rat dorsal root ganglion neurons. The effects of QO-58 in a rat model of neuropathic pain, chronic constriction injury (CCI) of the sciatic nerve, were also examined. Key Results QO-58 increased the current amplitudes, shifted the voltage-dependent activation curve in a more negative direction and slowed the deactivation of Kv7.2/Kv7.3 currents. QO-58 activated Kv7.1, Kv7.2, Kv7.4 and Kv7.3/Kv7.5 channels with a more selective effect on Kv7.2 and Kv7.4, but little effect on Kv7.3. The mechanism of QO-58's activation of Kv7 channels was clearly distinct from that used by retigabine. A chain of amino acids, Val224Val225Tyr226, in Kv7.2 was important for QO-58 activation of this channel. QO-58 enhanced native neuronal M currents, resulting in depression of evoked action potentials. QO-58 also elevated the pain threshold of neuropathic pain in the sciatic nerve CCI model. Conclusions and Implications The results indicate that QO-58 is a potent modulator of Kv7 channels with a mechanism of action different from those of known Kv7 openers. Hence, QO-58 shows potential as a treatment for diseases associated with neuronal hyperexcitability. PMID:23013484

  13. PreImplantation factor prevents atherosclerosis via its immunomodulatory effects without affecting serum lipids.

    PubMed

    Chen, Yung Chih; Rivera, Jennifer; Fitzgerald, Melissa; Hausding, Christian; Ying, Ya-Lan; Wang, Xiaowei; Todorova, Krassimira; Hayrabedyan, Soren; Barnea, Eytan R; Peter, Karlheinz

    2016-05-01

    PreImplantation factor (PIF) is a 15-amino acid peptide endogenously secreted by viable embryos, regulating/enabling maternal (host) acceptance/tolerance to the "invading" embryo (allograft) all-while preserving maternal immunity to fight infections. Such attributes make PIF a potential therapeutic agent for chronic inflammatory diseases. We investigated whether PIF's immunomodulatory properties prevent progression of atherosclerosis in the hyper-cholesterolaemic ApoE-deficient murine model. Male, high-fat diet fed, ApoE-deficient (ApoE-/-) mice were administered either PBS, scrambled PIF (0.3-3 mg/kg) or PIF (0.3-3 mg/kg) for seven weeks. After treatment, PIF (3 mg/kg)-treated ApoE-/- mice displayed significantly reduced atherosclerosis lesion burden in the aortic sinus and aortic arch, without any effect on lipid profile. PIF also caused a significant reduction in infiltration of macrophages, decreased expression of pro-inflammatory adhesion molecules, cytokines and chemokines in the plaque, and reduced circulating IFN-γ levels. PIF preferentially binds to monocytes/neutrophils. In vitro, PIF attenuated monocyte migration (MCP-1-induced chemotaxis assay) and in vivo in LPS peritonitis model. Also PIF prevented leukocyte extravasation (peritonitis thioglycollate-induced model), demonstrating that PIF exerts its effect in part by modulation of monocyte function. Inhibition of the potassium channel KCNAB3 (Kv1.3) and of the insulin degrading enzyme (IDE) was demonstrated as potential mechanism of PIF's immunomodulatory effects. In conclusion, PIF regulates/lowers inflammation and prevents atherosclerosis development without affecting circulating lipids. Overall our findings establish PIF as a strong immunomodulatory drug candidate for atherosclerosis therapy.

  14. Inter-study variability of preclinical in vivo safety studies and translational exposure–QTc relationships – a PKPD meta-analysis

    PubMed Central

    Gotta, V; Cools, F; van Ammel, K; Gallacher, D J; Visser, S A G; Sannajust, F; Morissette, P; Danhof, M; van der Graaf, P H

    2015-01-01

    Background and Purpose Preclinical cardiovascular safety studies (CVS) have been compared between facilities with respect to their sensitivity to detect drug-induced QTc prolongation (ΔQTc). Little is known about the consistency of quantitative ΔQTc predictions that are relevant for translation to humans. Experimental Approach We derived typical ΔQTc predictions at therapeutic exposure (ΔQTcTHER) with 95% confidence intervals (95%CI) for 3 Kv11.1 (hERG) channel blockers (moxifloxacin, dofetilide and sotalol) from a total of 14 CVS with variable designs in the conscious dog. Population pharmacokinetic-pharmacodynamic (PKPD) analysis of each study was followed by a meta-analysis (pooling 2–6 studies including 10–32 dogs per compound) to derive meta-predictions of typical ΔQTcTHER. Meta-predictions were used as a reference to evaluate the consistency of study predictions and to relate results to those found in the clinical literature. Key Results The 95%CIs of study-predicted ΔQTcTHER comprised in 13 out of 14 cases the meta-prediction. Overall inter-study variability (mean deviation from meta-prediction at upper level of therapeutic exposure) was 30% (range: 1–69%). Meta-ΔQTcTHER predictions for moxifloxacin, dofetilide and sotalol overlapped with reported clinical QTc prolongation when expressed as %-prolongation from baseline. Conclusions and Implications Consistent exposure-ΔQTc predictions were obtained from single preclinical dog studies of highly variable designs by systematic PKPD analysis, which is suitable for translational purposes. The good preclinical–clinical pharmacodynamic correlations obtained suggest that such an analysis should be more routinely applied to increase the informative and predictive value of results obtained from animal experiments. PMID:26076100

  15. Transient outward potassium current, ‘Ito’, phenotypes in the mammalian left ventricle: underlying molecular, cellular and biophysical mechanisms

    PubMed Central

    Patel, Sangita P; Campbell, Donald L

    2005-01-01

    At least two functionally distinct transient outward K+ current (Ito) phenotypes can exist across the free wall of the left ventricle (LV). Based upon their voltage-dependent kinetics of recovery from inactivation, these two phenotypes are designated ‘Ito,fast’ (recovery time constants on the order of tens of milliseconds) and ‘Ito,slow’ (recovery time constants on the order of thousands of milliseconds). Depending upon species, either Ito,fast, Ito,slow or both current phenotypes may be expressed in the LV free wall. The expression gradients of these two Ito phenotypes across the LV free wall are typically heterogeneous and, depending upon species, may consist of functional phenotypic gradients of both Ito,fast and Ito,slow and/or density gradients of either phenotype. We review the present evidence (molecular, biophysical, electrophysiological and pharmacological) for Kv4.2/4.3 α subunits underlying LV Ito,fast and Kv1.4 α subunits underlying LV Ito,slow and speculate upon the potential roles of each of these currents in determining frequency-dependent action potential characteristics of LV subepicardial versus subendocardial myocytes in different species. We also review the possible functional implications of (i) ancillary subunits that regulate Kv1.4 and Kv4.2/4.3 (Kvβ subunits, DPPs), (ii) KChIP2 isoforms, (iii) spider toxin-mediated block of Kv4.2/4.3 (Heteropoda toxins, phrixotoxins), and (iv) potential mechanisms of modulation of Ito,fast and Ito,slow by cellular redox state, [Ca2+]i and kinase-mediated phosphorylation. Ito phenotypic activation and state-dependent gating models and molecular structure–function relationships are also discussed. PMID:15831535

  16. PreImplantation factor prevents atherosclerosis via its immunomodulatory effects without affecting serum lipids.

    PubMed

    Chen, Yung Chih; Rivera, Jennifer; Fitzgerald, Melissa; Hausding, Christian; Ying, Ya-Lan; Wang, Xiaowei; Todorova, Krassimira; Hayrabedyan, Soren; Barnea, Eytan R; Peter, Karlheinz

    2016-05-01

    PreImplantation factor (PIF) is a 15-amino acid peptide endogenously secreted by viable embryos, regulating/enabling maternal (host) acceptance/tolerance to the "invading" embryo (allograft) all-while preserving maternal immunity to fight infections. Such attributes make PIF a potential therapeutic agent for chronic inflammatory diseases. We investigated whether PIF's immunomodulatory properties prevent progression of atherosclerosis in the hyper-cholesterolaemic ApoE-deficient murine model. Male, high-fat diet fed, ApoE-deficient (ApoE-/-) mice were administered either PBS, scrambled PIF (0.3-3 mg/kg) or PIF (0.3-3 mg/kg) for seven weeks. After treatment, PIF (3 mg/kg)-treated ApoE-/- mice displayed significantly reduced atherosclerosis lesion burden in the aortic sinus and aortic arch, without any effect on lipid profile. PIF also caused a significant reduction in infiltration of macrophages, decreased expression of pro-inflammatory adhesion molecules, cytokines and chemokines in the plaque, and reduced circulating IFN-γ levels. PIF preferentially binds to monocytes/neutrophils. In vitro, PIF attenuated monocyte migration (MCP-1-induced chemotaxis assay) and in vivo in LPS peritonitis model. Also PIF prevented leukocyte extravasation (peritonitis thioglycollate-induced model), demonstrating that PIF exerts its effect in part by modulation of monocyte function. Inhibition of the potassium channel KCNAB3 (Kv1.3) and of the insulin degrading enzyme (IDE) was demonstrated as potential mechanism of PIF's immunomodulatory effects. In conclusion, PIF regulates/lowers inflammation and prevents atherosclerosis development without affecting circulating lipids. Overall our findings establish PIF as a strong immunomodulatory drug candidate for atherosclerosis therapy. PMID:26842698

  17. SU-E-T-89: Comprehensive Quality Assurance Phantom for the Small Animal Radiation Research Platform

    SciTech Connect

    Jermoumi, M; Ngwa, W; Korideck, H; Zygmanski, P; Berbeco, R; Makrigiorgos, G; Cormack, R

    2014-06-01

    Purpose: Use of Small Animal Radiation Research Platform (SARRP) systems for conducting state-of-the-art image guided radiotherapy (IGRT) research on small animals has become more common over the past years. The purpose of this work is to develop and test the suitability and performance of a comprehensive quality assurance (QA) phantom for the SARRP. Methods: A QA phantom was developed for carrying out daily, monthly and annual QA tasks including imaging, dosimetry and treatment planning system (TPS) performance evaluation of the SARRP. The QA phantom consists of nine (60×60×5 mm3) KV-energy tissue equivalent solid water slabs that can be employed for annual dosimetry QA with film. Three of the top slabs are replaceable with ones incorporating Mosfets or OSLDs arranged in a quincunx pattern, or a slab drilled to accommodate an ion chamber insert. These top slabs are designed to facilitate routine daily and monthly QA tasks such as output constancy, isocenter congruency test, treatment planning system (TPS) QA, etc. One slab is designed with inserts for image QA. A prototype of the phantom was applied to test the performance of the imaging, planning and treatment delivery systems. Results: Output constancy test results showed daily variations within 3%. For isocenter congruency test, the phantom could be used to detect 0.3 mm deviations of the CBCT isocenter from the radiation isocenter. Using the Mosfet in phantom as target, the difference between TPS calculations and measurements was within 5%. Image-quality parameters could also be assessed in terms of geometric accuracy, CT number accuracy, linearity, noise and image uniformity, etc. Conclusion: The developed phantom can be employed as a simple tool for comprehensive performance evaluation of the SARRP. The study provides a reference for development of a comprehensive quality assurance program for the SARRP, with proposed tolerances and frequency of required tests.

  18. Ginsenoside Rg3, a Gating Modifier of EAG Family K+ Channels.

    PubMed

    Wu, Wei; Gardner, Alison; Sachse, Frank B; Sanguinetti, Michael C

    2016-10-01

    Ginsenoside 20(S)-Rg3 (Rg3) is a steroid glycoside that induces human ether-à-go-go-related gene type 1 (hERG1, Kv11.1) channels to activate at more negative potentials and to deactivate more slowly than normal. However, it is unknown whether this action is unique to hERG1 channels. Here we compare and contrast the mechanisms of actions of Rg3 on hERG1 with three other members of the ether-à-go-go (EAG) K(+) channel gene family, including EAG1 (Kv10.1), ERG3 (Kv11.3), and ELK1 (Kv12.1). All four channel types were heterologously expressed in Xenopus laevis oocytes, and K(+) currents were measured using the two-microelectrode voltage-clamp technique. At a maximally effective concentration, Rg3 shifted the half-point of voltage-dependent activation of currents by -14 mV for ERG1 (EC50 = 414 nM), -20 mV for ERG3 (EC50 = 374 nM), -28 mV for EAG1 (EC50 = 1.18 μM), and more than -100 mV for ELK1 (EC50 = 197 nM) channels. Rg3 also induced slowing of ERG1, ERG3, and ELK1 channel deactivation and accelerated the rate of EAG1 channel activation. A Markov model was developed to simulate gating and the effects of Rg3 on the voltage dependence of activation of hELK1 channels. Understanding the mechanism underlying the action of Rg3 may facilitate the development of more potent and selective EAG family channel activators as therapies for cardiovascular and neural disorders. PMID:27502018

  19. Regulation of Shaker-type potassium channels by hypoxia. Oxygen-sensitive K+ channels in PC12 cells.

    PubMed

    Conforti, L; Millhorn, D E

    2000-01-01

    Little is known about the molecular composition of the O2-sensitive K+ (Ko2) channels. The possibility that these channels belong to the Shaker subfamily (Kv1) of voltage-dependent K+ (Kv) channels has been raised in pulmonary artery (PA) smooth muscle cells. Numerous findings suggest that the Ko2 channel in PC12 cells is a Kv1 channel, formed by the Kv1.2 alpha subunit. The Ko2 channel in PC12 cells is a slow-inactivating voltage-dependent K+ channel of 20 pS conductance. Other Kv channels, also expressed in PC12 cells, are not inhibited by hypoxia. Selective up-regulation by chronic hypoxia of the Kv1.2 alpha subunit expression correlates with an increase O2-sensitivity of the K+ current. Other Kv1 alpha subunit genes encoding slow-inactivating Kv channels, such as Kv1.3, Kv2.1, Kv3.1 and Kv3.2 are not modulated by chronic hypoxia. The Ko2 current in PC12 cells is blocked by 5 mM externally applied tetraethylammonium chloride (TEA) and by charydbotoxin (CTX). The responses of the Kv1.2 K+ channel to hypoxia have been studied in the Xenopus oocytes and compared to those of Kv2.1, also proposed as Ko2 channel in PA smooth muscle cells. Two-electrode voltage clamp experiments show that hypoxia induces inhibition of K+ current amplitude only in oocytes injected with Kv1.2 cRNA. These data indicate that Kv1.2 K+ channels are inhibited by hypoxia. PMID:10849667

  20. New pyrimido-indole compound CD-160130 preferentially inhibits the KV11.1B isoform and produces antileukemic effects without cardiotoxicity.

    PubMed

    Gasparoli, Luca; D'Amico, Massimo; Masselli, Marika; Pillozzi, Serena; Caves, Rachel; Khuwaileh, Rawan; Tiedke, Wolfgang; Mugridge, Kenneth; Pratesi, Alessandro; Mitcheson, John S; Basso, Giuseppe; Becchetti, Andrea; Arcangeli, Annarosa

    2015-02-01

    KV11.1 (hERG1) channels are often overexpressed in human cancers. In leukemias, KV11.1 regulates pro-survival signals that promote resistance to chemotherapy, raising the possibility that inhibitors of KV11.1 could be therapeutically beneficial. However, because of the role of KV11.1 in cardiac repolarization, blocking these channels may cause cardiac arrhythmias. We show that CD-160130, a novel pyrimido-indole compound, blocks KV11.1 channels with a higher efficacy for the KV11.1 isoform B, in which the IC50 (1.8 μM) was approximately 10-fold lower than observed in KV11.1 isoform A. At this concentration, CD-160130 also had minor effects on Kir2.1, KV 1.3, Kv1.5, and KCa3.1. In vitro, CD-160130 induced leukemia cell apoptosis, and could overcome bone marrow mesenchymal stromal cell (MSC)-induced chemoresistance. This effect was caused by interference with the survival signaling pathways triggered by MSCs. In vivo, CD-160130 produced an antileukemic activity, stronger than that caused by cytarabine. Consistent with its atypical target specificity, CD-160130 did not bind to the main binding site of the arrhythmogenic KV11.1 blockers (the Phe656 pore residue). Importantly, in guinea pigs CD-160130 produced neither alteration of the cardiac action potential shape in dissociated cardiomyocytes nor any lengthening of the QT interval in vivo. Moreover, CD-160130 had no myelotoxicity on human bone marrow-derived cells. Therefore, CD-160130 is a promising first-in-class compound to attempt oncologic therapy without cardiotoxicity, based on targeting KV11.1. Because leukemia and cardiac cells tend to express different ratios of the A and B KV11.1 isoforms, the pharmacological properties of CD-160130 may depend, at least in part, on isoform specificity. PMID:25411366

  1. Kv1.3 channel blockade enhances the phagocytic function of RAW264.7 macrophages.

    PubMed

    Zhu, Hong; Yan, Li; Gu, JingLi; Hao, Wei; Cao, JiMin

    2015-09-01

    This study aimed to comprehend the largely unknown role of voltage-gated potassium channel 1.3 (Kv1.3) in the phagocytic function of macrophages. We found that blocking of the Kv1.3 channel with 100 pmol L(-1) Stichodactyla helianthus neurotoxin (ShK) enhanced the phagocytic capacities of both resting and lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages in the chicken erythrocyte system. In the fluorescein isothiocyanate (FITC)-labeled Escherichia coli k-12 system, ShK increased the phagocytic capacities of resting RAW264.7 cells, but not of the LPS-stimulated cells, as LPS alone stimulated almost saturated phagocytosis of the macrophages. ShK increased the nitric oxide (NO) production in LPS-activated cells, but not in resting RAW264.7 cells. There was no effect of ShK alone on the cytokine secretions in resting RAW264.7 cells, but it suppressed IL-1β secretion in LPS-stimulated RAW264.7 cells. At a concentration of 100 pmol L(-1), ShK did not affect the viability of the tested cells. Kv1.3 was expressed in RAW264.7 cells; this expression was downregulated by LPS, but significantly upregulated by disrupting caveolin-dependent endocytosis with filipin III. In addition, cytochalasin D, an inhibitor of actin polymerization, did not affect the Kv1.3 expression. Thus, blocking of the Kv1.3 channel enhances the phagocytic capacity and NO production of this cell line. Our results suggest that Kv1.3 channel serves as a negative regulator of phagocytosis in macrophages and can therefore be a potential target in the treatment of macrophage dysfunction. PMID:26354506

  2. Texture, residual strain, and plastic deformation around scratches in alloy 600 using synchrotron x-ray Laue micro-diffraction.

    SciTech Connect

    Suominen Fuller, M. L.; Klassen, R. J.; McIntyre, N. S.; Gerson, A. R.; Ramamurthy, S.; King, P. J.; Liu, W.; Univ. of Western Ontario; Univ. of South Australia; Babcock & Wilcox Canada

    2008-01-01

    Deformation around two scratches in Alloy 600 (A600) was studied nondestructively using synchrotron Laue differential aperture X-ray microscopy. The orientation of grains and elastic strain distribution around the scratches were measured. A complex residual deviatoric elastic strain state was found to exist around the scratches. Heavy plastic deformation was observed up to a distance of 20 {micro}m from the scratches. In the region 20-30 {micro}m from the scratches the diffraction spots were heavily streaked and split indicating misoriented dislocation cell structures.

  3. Two phenylalanines in the C-terminus of Epstein-Barr virus Rta protein reciprocally modulate its DNA binding and transactivation function

    SciTech Connect

    Chen, L.-W.; Raghavan, Vineetha; Chang, Pey-Jium; Shedd, Duane; Heston, Lee; Delecluse, Henri-Jacques; Miller, George

    2009-04-10

    The Rta (R transactivator) protein plays an essential role in the Epstein-Barr viral (EBV) lytic cascade. Rta activates viral gene expression by several mechanisms including direct and indirect binding to target viral promoters, synergy with EBV ZEBRA protein, and stimulation of cellular signaling pathways. We previously found that Rta proteins with C-terminal truncations of 30 aa were markedly enhanced in their capacity to bind DNA (Chen, L.W., Chang, P.J., Delecluse, H.J., and Miller, G., (2005). Marked variation in response of consensus binding elements for the Rta protein of Epstein-Barr virus. J. Virol. 79(15), 9635-9650.). Here we show that two phenylalanines (F600 and F605) in the C-terminus of Rta play a crucial role in mediating this DNA binding inhibitory function. Amino acids 555 to 605 of Rta constitute a functional DNA binding inhibitory sequence (DBIS) that markedly decreased DNA binding when transferred to a minimal DNA binding domain of Rta (aa 1-350). Alanine substitution mutants, F600A/F605A, abolished activity of the DBIS. F600 and F605 are located in the transcriptional activation domain of Rta. Alanine substitutions, F600A/F605A, decreased transcriptional activation by Rta protein, whereas aromatic substitutions, such as F600Y/F605Y or F600W/F605W, partially restored transcriptional activation. Full-length Rta protein with F600A/F605A mutations were enhanced in DNA binding compared to wild-type, whereas Rta proteins with F600Y/F605Y or F600W/F605W substitutions were, like wild-type Rta, relatively poor DNA binders. GAL4 (1-147)/Rta (416-605) fusion proteins with F600A/F605A mutations were diminished in transcriptional activation, relative to GAL4/Rta chimeras without such mutations. The results suggest that, in the context of a larger DBIS, F600 and F605 play a role in the reciprocal regulation of DNA binding and transcriptional activation by Rta. Regulation of DNA binding by Rta is likely to be important in controlling its different modes of

  4. Development of radiation tolerant components for the Quench Protection System at CERN

    NASA Astrophysics Data System (ADS)

    Bitterling, O.; Denz, R.; Steckert, J.; Uznanski, S.

    2016-01-01

    This paper describes the results of irradiation campaigns with the high resolution Analog to Digital Converter (ADC) ADS1281. This ADC will be used as part of a revised quench detection circuit for the 600 A corrector magnets at the CERN Large Hadron Collider (LHC) . To verify the radiation tolerance of the ADC an irradiation campaign using a proton beam, applying doses up to 3,4 kGy was conducted. The resulting data and an analysis of the found failure modes is discussed in this paper. Several mitigation measures are described that allow to reduce the error rate to levels acceptable for operation as part of the LHC QPS.

  5. New full vector data from Visigothic remains in Zamora

    NASA Astrophysics Data System (ADS)

    Molina-Cardin, Alberto; Osete, María Luisa; Sastre, José Carlos

    2016-04-01

    Samples from five combustion structures, three bricks and a roof tile from the Visigothic archaeological site of El Castillón, located in Zamora (Spain) have been analysed. Thellier thermal demagnetization has been carried out obtaining both directional and palaeointensity data between 5th and 7th centuries. The effect of cooling rate and anisotropy of thermoremanent magnetization have also been investigated, the former being especially important even in directional results. The new palaeointensity data obtained are in agreement with other Iberian data for the epoch and do not show a second palaeointensity relative maximum suggested around 600 A.D. in Western Europe despite in Eastern Europe it is well registered.

  6. Measurements of material properties for solar cells. [aluminum film and KAPTON

    NASA Technical Reports Server (NTRS)

    Castle, J. G., Jr.

    1978-01-01

    Measurements on two candidate materials for space flight are reported. The observed optical transmittance of aluminum films vapor deposited on fused quartz showed anomalously high transmittance thru 400 A and 600 A and showed an effective skin depth of 110 A in the latter part of the 1000 A thickness. KAPTON films are shown by their optical transmission spectra to have an energy gap for electron excitation of approximately 2.5 eV, which value depends on the thickness as manufactured. The resistance of KAPTON film to ionizing radiation is described by their optical spectra and their electron spin resonance spectra.

  7. Electrically pumped 1.3 microm room-temperature InAs/GaAs quantum dot lasers on Si substrates by metal-mediated wafer bonding and layer transfer.

    PubMed

    Tanabe, Katsuaki; Guimard, Denis; Bordel, Damien; Iwamoto, Satoshi; Arakawa, Yasuhiko

    2010-05-10

    An electrically pumped InAs/GaAs quantum dot laser on a Si substrate has been demonstrated. The double-hetero laser structure was grown on a GaAs substrate by metal-organic chemical vapor deposition and layer-transferred onto a Si substrate by GaAs/Si wafer bonding mediated by a 380-nm-thick Au-Ge-Ni alloy layer. This broad-area Fabry-Perot laser exhibits InAs quantum dot ground state lasing at 1.31 microm at room temperature with a threshold current density of 600 A/cm(2).

  8. Transmissive metallic contact for amorphous silicon solar cells

    DOEpatents

    Madan, A.

    1984-11-29

    A transmissive metallic contact for amorphous silicon semiconductors includes a thin layer of metal, such as aluminum or other low work function metal, coated on the amorphous silicon with an antireflective layer coated on the metal. A transparent substrate, such as glass, is positioned on the light reflective layer. The metallic layer is preferably thin enough to transmit at least 50% of light incident thereon, yet thick enough to conduct electricity. The antireflection layer is preferably a transparent material that has a refractive index in the range of 1.8 to 2.2 and is approximately 550A to 600A thick.

  9. A Novel Pan-Negative-Gating Modulator of KCa2/3 Channels, Fluoro-Di-Benzoate, RA-2, Inhibits Endothelium-Derived Hyperpolarization–Type Relaxation in Coronary Artery and Produces Bradycardia In Vivo

    PubMed Central

    Oliván-Viguera, Aida; Valero, Marta Sofía; Coleman, Nicole; Brown, Brandon M.; Laría, Celia; Divina Murillo, María; Gálvez, José A.; Díaz-de-Villegas, María D.; Wulff, Heike; Badorrey, Ramón

    2015-01-01

    Small/intermediate conductance KCa channels (KCa2/3) are Ca2+/calmodulin regulated K+ channels that produce membrane hyperpolarization and shape neurologic, epithelial, cardiovascular, and immunologic functions. Moreover, they emerged as therapeutic targets to treat cardiovascular disease, chronic inflammation, and some cancers. Here, we aimed to generate a new pharmacophore for negative-gating modulation of KCa2/3 channels. We synthesized a series of mono- and dibenzoates and identified three dibenzoates [1,3-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate) (RA-2), 1,2-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate), and 1,4-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate)] with inhibitory efficacy as determined by patch clamp. Among them, RA-2 was the most drug-like and inhibited human KCa3.1 with an IC50 of 17 nM and all three human KCa2 subtypes with similar potencies. RA-2 at 100 nM right-shifted the KCa3.1 concentration-response curve for Ca2+ activation. The positive-gating modulator naphtho[1,2-d]thiazol-2-ylamine (SKA-31) reversed channel inhibition at nanomolar RA-2 concentrations. RA-2 had no considerable blocking effects on distantly related large-conductance KCa1.1, Kv1.2/1.3, Kv7.4, hERG, or inwardly rectifying K+ channels. In isometric myography on porcine coronary arteries, RA-2 inhibited bradykinin-induced endothelium-derived hyperpolarization (EDH)–type relaxation in U46619-precontracted rings. Blood pressure telemetry in mice showed that intraperitoneal application of RA-2 (≤100 mg/kg) did not increase blood pressure or cause gross behavioral deficits. However, RA-2 decreased heart rate by ≈145 beats per minute, which was not seen in KCa3.1−/− mice. In conclusion, we identified the KCa2/3–negative-gating modulator, RA-2, as a new pharmacophore with nanomolar potency. RA-2 may be of use to generate structurally new types of negative-gating modulators that could help to define the physiologic and pathomechanistic

  10. A novel pan-negative-gating modulator of KCa2/3 channels, fluoro-di-benzoate, RA-2, inhibits endothelium-derived hyperpolarization-type relaxation in coronary artery and produces bradycardia in vivo.

    PubMed

    Oliván-Viguera, Aida; Valero, Marta Sofía; Coleman, Nicole; Brown, Brandon M; Laría, Celia; Murillo, María Divina; Gálvez, José A; Díaz-de-Villegas, María D; Wulff, Heike; Badorrey, Ramón; Köhler, Ralf

    2015-02-01

    Small/intermediate conductance KCa channels (KCa2/3) are Ca(2+)/calmodulin regulated K(+) channels that produce membrane hyperpolarization and shape neurologic, epithelial, cardiovascular, and immunologic functions. Moreover, they emerged as therapeutic targets to treat cardiovascular disease, chronic inflammation, and some cancers. Here, we aimed to generate a new pharmacophore for negative-gating modulation of KCa2/3 channels. We synthesized a series of mono- and dibenzoates and identified three dibenzoates [1,3-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate) (RA-2), 1,2-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate), and 1,4-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate)] with inhibitory efficacy as determined by patch clamp. Among them, RA-2 was the most drug-like and inhibited human KCa3.1 with an IC50 of 17 nM and all three human KCa2 subtypes with similar potencies. RA-2 at 100 nM right-shifted the KCa3.1 concentration-response curve for Ca(2+) activation. The positive-gating modulator naphtho[1,2-d]thiazol-2-ylamine (SKA-31) reversed channel inhibition at nanomolar RA-2 concentrations. RA-2 had no considerable blocking effects on distantly related large-conductance KCa1.1, Kv1.2/1.3, Kv7.4, hERG, or inwardly rectifying K(+) channels. In isometric myography on porcine coronary arteries, RA-2 inhibited bradykinin-induced endothelium-derived hyperpolarization (EDH)-type relaxation in U46619-precontracted rings. Blood pressure telemetry in mice showed that intraperitoneal application of RA-2 (≤100 mg/kg) did not increase blood pressure or cause gross behavioral deficits. However, RA-2 decreased heart rate by ≈145 beats per minute, which was not seen in KCa3.1(-/-) mice. In conclusion, we identified the KCa2/3-negative-gating modulator, RA-2, as a new pharmacophore with nanomolar potency. RA-2 may be of use to generate structurally new types of negative-gating modulators that could help to define the physiologic and pathomechanistic

  11. Mitochondrial Ultrastructure and Glucose Signaling Pathways Attributed to the Kv1.3 Ion Channel

    PubMed Central

    Kovach, Christopher P.; Al Koborssy, Dolly; Huang, Zhenbo; Chelette, Brandon M.; Fadool, James M.; Fadool, Debra A.

    2016-01-01

    Gene-targeted deletion of the potassium channel Kv1.3 (Kv1.3−∕−) results in “Super-smeller” mice with a sensory phenotype that includes an increased olfactory ability linked to changes in olfactory circuitry, increased abundance of olfactory cilia, and increased expression of odorant receptors and the G-protein, Golf. Kv1.3−∕− mice also have a metabolic phenotype including lower body weight and decreased adiposity, increased total energy expenditure (TEE), increased locomotor activity, and resistance to both diet- and genetic-induced obesity. We explored two cellular aspects to elucidate the mechanism by which loss of Kv1.3 channel in the olfactory bulb (OB) may enhance glucose utilization and metabolic rate. First, using in situ hybridization we find that Kv1.3 and the insulin-dependent glucose transporter type 4 (GLUT4) are co-localized to the mitral cell layer of the OB. Disruption of Kv1.3 conduction via construction of a pore mutation (W386F Kv1.3) was sufficient to independently translocate GLUT4 to the plasma membrane in HEK 293 cells. Because olfactory sensory perception and the maintenance of action potential (AP) firing frequency by mitral cells of the OB is highly energy demanding and Kv1.3 is also expressed in mitochondria, we next explored the structure of this organelle in mitral cells. We challenged wildtype (WT) and Kv1.3−∕− male mice with a moderately high-fat diet (MHF, 31.8 % kcal fat) for 4 months and then examined OB ultrastructure using transmission electron microscopy. In WT mice, mitochondria were significantly enlarged following diet-induced obesity (DIO) and there were fewer mitochondria, likely due to mitophagy. Interestingly, mitochondria were significantly smaller in Kv1.3−∕− mice compared with that of WT mice. Similar to their metabolic resistance to DIO, the Kv1.3−∕− mice had unchanged mitochondria in terms of cross sectional area and abundance following a challenge with modified diet. We are very

  12. A novel pan-negative-gating modulator of KCa2/3 channels, fluoro-di-benzoate, RA-2, inhibits endothelium-derived hyperpolarization-type relaxation in coronary artery and produces bradycardia in vivo.

    PubMed

    Oliván-Viguera, Aida; Valero, Marta Sofía; Coleman, Nicole; Brown, Brandon M; Laría, Celia; Murillo, María Divina; Gálvez, José A; Díaz-de-Villegas, María D; Wulff, Heike; Badorrey, Ramón; Köhler, Ralf

    2015-02-01

    Small/intermediate conductance KCa channels (KCa2/3) are Ca(2+)/calmodulin regulated K(+) channels that produce membrane hyperpolarization and shape neurologic, epithelial, cardiovascular, and immunologic functions. Moreover, they emerged as therapeutic targets to treat cardiovascular disease, chronic inflammation, and some cancers. Here, we aimed to generate a new pharmacophore for negative-gating modulation of KCa2/3 channels. We synthesized a series of mono- and dibenzoates and identified three dibenzoates [1,3-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate) (RA-2), 1,2-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate), and 1,4-phenylenebis(methylene) bis(3-fluoro-4-hydroxybenzoate)] with inhibitory efficacy as determined by patch clamp. Among them, RA-2 was the most drug-like and inhibited human KCa3.1 with an IC50 of 17 nM and all three human KCa2 subtypes with similar potencies. RA-2 at 100 nM right-shifted the KCa3.1 concentration-response curve for Ca(2+) activation. The positive-gating modulator naphtho[1,2-d]thiazol-2-ylamine (SKA-31) reversed channel inhibition at nanomolar RA-2 concentrations. RA-2 had no considerable blocking effects on distantly related large-conductance KCa1.1, Kv1.2/1.3, Kv7.4, hERG, or inwardly rectifying K(+) channels. In isometric myography on porcine coronary arteries, RA-2 inhibited bradykinin-induced endothelium-derived hyperpolarization (EDH)-type relaxation in U46619-precontracted rings. Blood pressure telemetry in mice showed that intraperitoneal application of RA-2 (≤100 mg/kg) did not increase blood pressure or cause gross behavioral deficits. However, RA-2 decreased heart rate by ≈145 beats per minute, which was not seen in KCa3.1(-/-) mice. In conclusion, we identified the KCa2/3-negative-gating modulator, RA-2, as a new pharmacophore with nanomolar potency. RA-2 may be of use to generate structurally new types of negative-gating modulators that could help to define the physiologic and pathomechanistic

  13. Mitochondrial Ultrastructure and Glucose Signaling Pathways Attributed to the Kv1.3 Ion Channel.

    PubMed

    Kovach, Christopher P; Al Koborssy, Dolly; Huang, Zhenbo; Chelette, Brandon M; Fadool, James M; Fadool, Debra A

    2016-01-01

    Gene-targeted deletion of the potassium channel Kv1.3 (Kv1.3(-∕-)) results in "Super-smeller" mice with a sensory phenotype that includes an increased olfactory ability linked to changes in olfactory circuitry, increased abundance of olfactory cilia, and increased expression of odorant receptors and the G-protein, Golf. Kv1.3(-∕-) mice also have a metabolic phenotype including lower body weight and decreased adiposity, increased total energy expenditure (TEE), increased locomotor activity, and resistance to both diet- and genetic-induced obesity. We explored two cellular aspects to elucidate the mechanism by which loss of Kv1.3 channel in the olfactory bulb (OB) may enhance glucose utilization and metabolic rate. First, using in situ hybridization we find that Kv1.3 and the insulin-dependent glucose transporter type 4 (GLUT4) are co-localized to the mitral cell layer of the OB. Disruption of Kv1.3 conduction via construction of a pore mutation (W386F Kv1.3) was sufficient to independently translocate GLUT4 to the plasma membrane in HEK 293 cells. Because olfactory sensory perception and the maintenance of action potential (AP) firing frequency by mitral cells of the OB is highly energy demanding and Kv1.3 is also expressed in mitochondria, we next explored the structure of this organelle in mitral cells. We challenged wildtype (WT) and Kv1.3(-∕-) male mice with a moderately high-fat diet (MHF, 31.8 % kcal fat) for 4 months and then examined OB ultrastructure using transmission electron microscopy. In WT mice, mitochondria were significantly enlarged following diet-induced obesity (DIO) and there were fewer mitochondria, likely due to mitophagy. Interestingly, mitochondria were significantly smaller in Kv1.3(-∕-) mice compared with that of WT mice. Similar to their metabolic resistance to DIO, the Kv1.3(-∕-) mice had unchanged mitochondria in terms of cross sectional area and abundance following a challenge with modified diet. We are very interested to

  14. IA Channels Encoded by Kv1.4 and Kv4.2 Regulate Circadian Period of PER2 Expression in the Suprachiasmatic Nucleus.

    PubMed

    Granados-Fuentes, Daniel; Hermanstyne, Tracey O; Carrasquillo, Yarimar; Nerbonne, Jeanne M; Herzog, Erik D

    2015-10-01

    Neurons in the suprachiasmatic nucleus (SCN), the master circadian pacemaker in mammals, display daily rhythms in electrical activity with more depolarized resting potentials and higher firing rates during the day than at night. Although these daily variations in the electrical properties of SCN neurons are required for circadian rhythms in physiology and behavior, the mechanisms linking changes in neuronal excitability to the molecular clock are not known. Recently, we reported that mice deficient for either Kcna4 (Kv1.4(-/-)) or Kcnd2 (Kv4.2(-/-); but not Kcnd3, Kv4.3(-/-)), voltage-gated K(+) (Kv) channel pore-forming subunits that encode subthreshold, rapidly activating, and inactivating K(+) currents (IA), have shortened (0.5 h) circadian periods in SCN firing and in locomotor activity compared with wild-type (WT) mice. In the experiments here, we used a mouse (Per2(Luc)) line engineered with a bioluminescent reporter construct, PERIOD2::LUCIFERASE (PER2::LUC), replacing the endogenous Per2 locus, to test the hypothesis that the loss of Kv1.4- or Kv4.2-encoded IA channels also modifies circadian rhythms in the expression of the clock protein PERIOD2 (PER2). We found that SCN explants from Kv1.4(-/-)Per2(Luc) and Kv4.2(-/-) Per2(Luc), but not Kv4.3(-/-)Per2(Luc), mice have significantly shorter (by approximately 0.5 h) circadian periods in PER2 rhythms, compared with explants from Per2(Luc) mice, revealing that the membrane properties of SCN neurons feedback to regulate clock (PER2) expression. The combined loss of both Kv1.4- and Kv4.2-encoded IA channels in Kv1.4(-/-)/Kv4.2(-/-)Per2(Luc) SCN explants did not result in any further alterations in PER2 rhythms. Interestingly, however, mice lacking both Kv1.4 and Kv4.2 show a striking (approximately 1.8 h) advance in their daily activity onset in a light cycle compared with WT mice, suggesting additional roles for Kv1.4- and Kv4.2-encoded IA channels in controlling the light-dependent responses of neurons within

  15. Lithospheric Structure In Russian Karelia From Small-aperture Array Data

    NASA Astrophysics Data System (ADS)

    Riznitchenko, O.; Sanina, I.; Aleshin, I.; Kosarev, G.; Sstwg

    Mobile small-aperture array RUKSA in Hautavaara - Petrozavodsk region of Rus- sian Karelia - operated as part of SVEKALAPKO (EUROPROBE) experiment in September- October 1999. The region is characterised by complicated tectonic setting and modern tectonic activity. It is the junction zone between exposed Archaean, Sve- cofennian and Phanerozoic crustal segments. The array consisted of six vertical and three 3-component loggers with analogue preliminary amplifiers connected by cable lines to digital recording system. Loggers were positioned on symmetric concentric rings with the outer ring diameter 640 m and the inner ring diameter 300 m. Dy- namic range of the analogue recorders SM-3KV is 120 dB. The sampling rate is 100 Hz. About 100 seismic events of different origin were recorded during experiment, including the largest earthquakes of 1999 in Turkey, Taiwan, and Greece. The qual- ity of records is extremely high. The array data were used for analysis of coherency, scattering and polarization properties of signal and microseism noise. The RUKSA records demonstrate remarkable coherency of teleseismic signal within the frequency band of 0.2-5 Hz. The level of microseism noise is very low compared to other small- aperture array sites. Polarisation analysis of the first P pulses for teleseismic waves re- vealed regular azimuth dependence of P wave azimuth and incidence angle deviations. Three-component records of teleseismic signals were processed with "receiver func- tion" method (Kind et. al, 1995). Previously this approach was used in regional-scale studies for broad-band record analysis. This study presents the first positive result of application of the method to short-period array data. Position of the main boundaries in the upper lithosphere under the array, inferred from "receiver function" analysis, coincides well with results of complex geological and geophysical study including re- flection surveys. Field work and data processing were supported by the INTAS

  16. New positive Ca2+-activated K+ channel gating modulators with selectivity for KCa3.1.

    PubMed

    Coleman, Nichole; Brown, Brandon M; Oliván-Viguera, Aida; Singh, Vikrant; Olmstead, Marilyn M; Valero, Marta Sofia; Köhler, Ralf; Wulff, Heike

    2014-09-01

    Small-conductance (KCa2) and intermediate-conductance (KCa3.1) calcium-activated K(+) channels are voltage-independent and share a common calcium/calmodulin-mediated gating mechanism. Existing positive gating modulators like EBIO, NS309, or SKA-31 activate both KCa2 and KCa3.1 channels with similar potency or, as in the case of CyPPA and NS13001, selectively activate KCa2.2 and KCa2.3 channels. We performed a structure-activity relationship (SAR) study with the aim of optimizing the benzothiazole pharmacophore of SKA-31 toward KCa3.1 selectivity. We identified SKA-111 (5-methylnaphtho[1,2-d]thiazol-2-amine), which displays 123-fold selectivity for KCa3.1 (EC50 111 ± 27 nM) over KCa2.3 (EC50 13.7 ± 6.9 μM), and SKA-121 (5-methylnaphtho[2,1-d]oxazol-2-amine), which displays 41-fold selectivity for KCa3.1 (EC50 109 nM ± 14 nM) over KCa2.3 (EC50 4.4 ± 1.6 μM). Both compounds are 200- to 400-fold selective over representative KV (KV1.3, KV2.1, KV3.1, and KV11.1), NaV (NaV1.2, NaV1.4, NaV1.5, and NaV1.7), as well as CaV1.2 channels. SKA-121 is a typical positive-gating modulator and shifts the calcium-concentration response curve of KCa3.1 to the left. In blood pressure telemetry experiments, SKA-121 (100 mg/kg i.p.) significantly lowered mean arterial blood pressure in normotensive and hypertensive wild-type but not in KCa3.1(-/-) mice. SKA-111, which was found in pharmacokinetic experiments to have a much longer half-life and to be much more brain penetrant than SKA-121, not only lowered blood pressure but also drastically reduced heart rate, presumably through cardiac and neuronal KCa2 activation when dosed at 100 mg/kg. In conclusion, with SKA-121, we generated a KCa3.1-specific positive gating modulator suitable for further exploring the therapeutical potential of KCa3.1 activation.

  17. New Positive Ca2+-Activated K+ Channel Gating Modulators with Selectivity for KCa3.1

    PubMed Central

    Coleman, Nichole; Brown, Brandon M.; Oliván-Viguera, Aida; Singh, Vikrant; Olmstead, Marilyn M.; Valero, Marta Sofia; Köhler, Ralf

    2014-01-01

    Small-conductance (KCa2) and intermediate-conductance (KCa3.1) calcium-activated K+ channels are voltage-independent and share a common calcium/calmodulin-mediated gating mechanism. Existing positive gating modulators like EBIO, NS309, or SKA-31 activate both KCa2 and KCa3.1 channels with similar potency or, as in the case of CyPPA and NS13001, selectively activate KCa2.2 and KCa2.3 channels. We performed a structure-activity relationship (SAR) study with the aim of optimizing the benzothiazole pharmacophore of SKA-31 toward KCa3.1 selectivity. We identified SKA-111 (5-methylnaphtho[1,2-d]thiazol-2-amine), which displays 123-fold selectivity for KCa3.1 (EC50 111 ± 27 nM) over KCa2.3 (EC50 13.7 ± 6.9 μM), and SKA-121 (5-methylnaphtho[2,1-d]oxazol-2-amine), which displays 41-fold selectivity for KCa3.1 (EC50 109 nM ± 14 nM) over KCa2.3 (EC50 4.4 ± 1.6 μM). Both compounds are 200- to 400-fold selective over representative KV (KV1.3, KV2.1, KV3.1, and KV11.1), NaV (NaV1.2, NaV1.4, NaV1.5, and NaV1.7), as well as CaV1.2 channels. SKA-121 is a typical positive-gating modulator and shifts the calcium-concentration response curve of KCa3.1 to the left. In blood pressure telemetry experiments, SKA-121 (100 mg/kg i.p.) significantly lowered mean arterial blood pressure in normotensive and hypertensive wild-type but not in KCa3.1−/− mice. SKA-111, which was found in pharmacokinetic experiments to have a much longer half-life and to be much more brain penetrant than SKA-121, not only lowered blood pressure but also drastically reduced heart rate, presumably through cardiac and neuronal KCa2 activation when dosed at 100 mg/kg. In conclusion, with SKA-121, we generated a KCa3.1-specific positive gating modulator suitable for further exploring the therapeutical potential of KCa3.1 activation. PMID:24958817

  18. Expression of delayed rectifier potassium channels and their possible roles in proliferation of human gastric cancer cells.

    PubMed

    Lan, Mei; Shi, Yongquan; Han, Zheyi; Hao, Zhiming; Pan, Yanglin; Liu, Na; Guo, Changcun; Hong, Liu; Wang, Jun; Qiao, Taidong; Fan, Daiming

    2005-12-01

    Voltage-gated potassium (Kv) channels have been reported to be involved in the proliferation of many types of cells, including tumor cells. The overexpression of the Kv channels and related channel activity are involved in the neoplastic process. Our previous study has shown the existence of delayed rectifier potassium (I(K)) current in gastric cancer cells SGC7901. However, the expression and function of most delayed rectifier potassium (K(D)) channel subunits in gastric cancer cells are not completely resolved. Here we examine expression of K(D) channel subunits in Kv1-Kv3 families in immortalized gastric epithelial cells GES and various gastric cancer cells (including AGS, KATOIII, MKN28, MKN45, MGC803, SGC7901, SGC7901/ADR and SGC7901/VCR), and their roles in cell proliferation. RT-PCR analysis reveals that all cell lines examined express Kv1.3, Kv1.5, Kv1.6, Kv2.1 and Kv2.2. However, Kv1.2 and Kv3.2 genes are barely detectable in any given cancer cell lines. Kv1.5 protein, high mRNA levels in all cell lines examined, is also expressed in some cancer cells lines and more frequently detected in gastric cancer tissues. Downregulation of the expression of Kv1.5 in SGC7901 with RNA interference significantly inhibited the proliferation and tumorigenicity of SGC7901 cells. Moreover, in Ca(2+)-containing rather than Ca(2+)-free medium, KCl (50mM) stimulated a rapid increase in the concentration of cytosolic calcium in empty vector transfected cells that was blocked by verapamil. Likewise, decrease the expression of Kv1.5 with short interfering RNA also blocked the depolarization-induced influx of Ca(2+). This finding suggests that more than one kind of K(D) channel subunits are expressed in various gastric cancer cell lines. Kv1.5 may be involved in tumor cells proliferation by controlling Ca(2+) entry, and the interference of K(D) channels expression and/or activity could provide a novel strategy to reverse the malignant phenotype of gastric cancer cells. PMID

  19. Thermodynamic analysis of hydrocarbon refrigerants-based ethylene BOG re-liquefaction system

    NASA Astrophysics Data System (ADS)

    Beladjine, Boumedienne M.; Ouadha, Ahmed; Addad, Yacine

    2016-07-01

    The present study aims to make a thermodynamic analysis of an ethylene cascade re-liquefaction system that consists of the following two subsystems: a liquefaction cycle using ethylene as the working fluid and a refrigeration cycle operating with a hydrocarbon refrigerant. The hydrocarbon refrigerants considered are propane (R290), butane (R600), isobutane (R600a), and propylene (R1270). A computer program written in FORTRAN is developed to compute parameters for characteristic points of the cycles and the system's performance, which is determined and analyzed using numerical solutions for the refrigerant condensation temperature, temperature in tank, and temperature difference in the cascade condenser. Results show that R600a gives the best performance, followed by (in order) R600, R290, and R1270. Furthermore, it is found that an increase in tank temperature improves system performance but that an increase in refrigerant condensation temperature causes deterioration. In addition, it is found that running the system at a low temperature difference in the cascade condenser is advantageous.

  20. Thermodynamic analysis of hydrocarbon refrigerants-based ethylene BOG re-liquefaction system

    NASA Astrophysics Data System (ADS)

    Beladjine, Boumedienne M.; Ouadha, Ahmed; Addad, Yacine

    2016-09-01

    The present study aims to make a thermodynamic analysis of an ethylene cascade re-liquefaction system that consists of the following two subsystems: a liquefaction cycle using ethylene as the working fluid and a refrigeration cycle operating with a hydrocarbon refrigerant. The hydrocarbon refrigerants considered are propane (R290), butane (R600), isobutane (R600a), and propylene (R1270). A computer program written in FORTRAN is developed to compute parameters for characteristic points of the cycles and the system's performance, which is determined and analyzed using numerical solutions for the refrigerant condensation temperature, temperature in tank, and temperature difference in the cascade condenser. Results show that R600a gives the best performance, followed by (in order) R600, R290, and R1270. Furthermore, it is found that an increase in tank temperature improves system performance but that an increase in refrigerant condensation temperature causes deterioration. In addition, it is found that running the system at a low temperature difference in the cascade condenser is advantageous.

  1. Experimental study on heat transfer performance of pulsating heat pipe with refrigerants

    NASA Astrophysics Data System (ADS)

    Wang, Xingyu; Jia, Li

    2016-10-01

    The effects of different refrigerants on heat transfer performance of pulsating heat pipe (PHP) are investigated experimentally. The working temperature of pulsating heat pipe is kept in the range of 20°C-50°C. The startup time of the pulsating heat pipe with refrigerants can be shorter than 4 min, when heating power is in the range of 10W?100W. The startup time decreases with heating power. Thermal resistances of PHP with filling ratio 20.55% were obviously larger than those with other filling ratios. Thermal resistance of the PHP with R134a is much smaller than that with R404A and R600a. It indicates that the heat transfer ability of R134a is better. In addition, a correlation to predict thermal resistance of PHP with refrigerants was suggested.

  2. Influence of environmental and meteorological factors on the biting activity of Leptoconops noei and Leptoconops irritans (Diptera: Ceratopogonidae) in Italy.

    PubMed

    Carrieri, Marco; Montemurro, Eustachio; Valentino, Salvatore Vito; Bellini, Romeo

    2011-03-01

    The flight activity of Leptoconops irritans and L. noei was studied on the Jonian-Lucanian coast of southern Italy, using CO2-baited traps. The flight of the females lasted from 6:00 a.m. to 8:40 p.m., with L. irritans being active in the morning hours while L. noei peaked around 6:00 p.m. Based on a stepwise regression analysis, temperature, RH, solar radiation, trap proximity to larval habitats, and the time of the day seemed to have little influence on the biting cycle of the 2 biting midges. Only a shift in wind direction appeared to influence female dispersion, resulting into population fluctuations of both species.

  3. A compact and continuously driven supersonic plasma and neutral sourcea)

    NASA Astrophysics Data System (ADS)

    Asai, T.; Itagaki, H.; Numasawa, H.; Terashima, Y.; Hirano, Y.; Hirose, A.

    2010-10-01

    A compact and repetitively driven plasma source has been developed by utilizing a magnetized coaxial plasma gun (MCPG) for diagnostics requiring deep penetration of a large amount of neutral flux. The system consists of a MCPG 95mm in length with a DN16 ConFlat connection port and an insulated gate bipolar transistor (IGBT) inverter power unit. The power supply consists of an array of eight IGBT units and is able to switch the discharge on and off at up to 10 kV and 600 A with a maximum repetitive frequency of 10 kHz. Multiple short duration discharge pulses maximize acceleration efficiency of the plasmoid. In the case of a 10 kHz operating frequency, helium-plasmoids in the velocity range of 20 km/s can be achieved.

  4. A compact and continuously driven supersonic plasma and neutral source.

    PubMed

    Asai, T; Itagaki, H; Numasawa, H; Terashima, Y; Hirano, Y; Hirose, A

    2010-10-01

    A compact and repetitively driven plasma source has been developed by utilizing a magnetized coaxial plasma gun (MCPG) for diagnostics requiring deep penetration of a large amount of neutral flux. The system consists of a MCPG 95mm in length with a DN16 ConFlat connection port and an insulated gate bipolar transistor (IGBT) inverter power unit. The power supply consists of an array of eight IGBT units and is able to switch the discharge on and off at up to 10 kV and 600 A with a maximum repetitive frequency of 10 kHz. Multiple short duration discharge pulses maximize acceleration efficiency of the plasmoid. In the case of a 10 kHz operating frequency, helium-plasmoids in the velocity range of 20 km/s can be achieved.

  5. Assessment of Environmentally Friendly Refrigerants for Window Air Conditioners

    SciTech Connect

    Bansal, Pradeep; Shen, Bo

    2014-01-01

    This paper presents technical assessment of environmentally friendly refrigerants for window air conditioners that currently use refrigerant R410A for residential and commercial applications. The alternative refrigerants that are studied for its replacement include R32, R600a, R290, R1234yf, R1234ze and a mixture of R32 (90% molar concentration) and R125 (10% molar concentration). Baseline experiments were performed on a window unit charged with R410A. The ORNL Heat Pump Design Model was calibrated with the baseline data and was used to assess the comparative performance of the WAC with alternative refrigerants. The paper discusses the advantages and disadvantages of each refrigerants and their suitability for window air conditioners.

  6. Analysis of Environmentally Friendly Refrigerant Options for Window Air Conditioners

    DOE PAGES

    Bansal, Pradeep; Shen, Bo

    2015-03-12

    This paper presents a technical assessment of environmentally friendly refrigerants as alternatives to R410A for window air conditioners. The alternative refrigerants that are studied for its replacement include R32, a mixture of R32/R125 with 90%/10% molar concentration, R600a, R290, R1234yf, R1234ze and R134a. Baseline experiments were performed on a window unit charged with R410A. The heat pump design model (HPDM) was modified and calibrated with the baseline data and was used to evaluate the comparative performance of the WAC with alternative refrigerants. The paper discusses the advantages and disadvantages of each refrigerants and their suitability for window air conditioners. Amongmore » all the refrigerants studied, R32 offers the best efficiency and the lowest Global Warming Potential (GWP), and hence its use will result in the overall environmental friendliness.« less

  7. Analysis of Environmentally Friendly Refrigerant Options for Window Air Conditioners

    SciTech Connect

    Bansal, Pradeep; Shen, Bo

    2015-03-12

    This paper presents a technical assessment of environmentally friendly refrigerants as alternatives to R410A for window air conditioners. The alternative refrigerants that are studied for its replacement include R32, a mixture of R32/R125 with 90%/10% molar concentration, R600a, R290, R1234yf, R1234ze and R134a. Baseline experiments were performed on a window unit charged with R410A. The heat pump design model (HPDM) was modified and calibrated with the baseline data and was used to evaluate the comparative performance of the WAC with alternative refrigerants. The paper discusses the advantages and disadvantages of each refrigerants and their suitability for window air conditioners. Among all the refrigerants studied, R32 offers the best efficiency and the lowest Global Warming Potential (GWP), and hence its use will result in the overall environmental friendliness.

  8. Host preferences of Aedes trivittatus (Diptera: Culicidae) in central Iowa.

    PubMed

    Pinger, R R; Rowley, W A

    1975-09-01

    The vertebrate host preferences of Aedes trivittatus mosquitoes were studied to gain an insight into the possible hosts of trivittatus (TVT) virus (California encephalitis group) in Iowa. Engorged mosquitoes were collected with a Malaise trap and Dry Ice-baited CDC miniature light traps. The origin of mosquito blood meals was determined by the capillary tube precipitin test. Of 600 A. trivittatus blood meals tested, 409 (68.2%) reacted positively with anti-rabbit serum. The incidences of mosquitoes feeding on other vertebrate species ranged from 0.2% to 2.5%. The vertebrate host preferences of A. trivittatus suggest a close association between this mosquito species and the eastern cottontail rabbit (Sylvilagus floridanus) in central Iowa. Furthermore, the results indicate that the eastern cottontail rabbit may be an important host for TVT virus in Iowa.

  9. Intense extreme ultraviolet emission from the B star Epsilon Canis Majoris

    NASA Technical Reports Server (NTRS)

    Vallerga, John V.; Vedder, Peter W.; Welsh, Barry Y.

    1993-01-01

    We report the discovery of the brightest nonsolar source of EUV emission: the B2 II star Epsilon Canis Majoris. This source has been detected by the Extreme Ultraviolet Explorer satellite's all-sky photometric survey. It is approximately 30 times brighter at 600 A than the predicted emission from the hot white dwarf star HZ 43, previously believed to be the brightest EUV source. We have fitted a simple B star photospheric model to the observed broadband EUV fluxes to explain this emission. Assuming a stellar temperature of 25,000 K and a gravity (log g) of 3.3, we derive an interstellar hydrogen column density of 1.05 +/- 0.05 x 10 exp 18/sq cm over the 187 pc to the star. This corresponds to a line-of-sight number density of hydrogen, of 0.002/cu cm, which is comparable to values found in the rarefied Local Bubble region which surrounds the sun.

  10. Low-temperature photoluminescence studies of chemical-vapor-deposition-grown 3C-SiC on Si

    NASA Technical Reports Server (NTRS)

    Choyke, W. J.; Feng, Z. C.; Powell, J. A.

    1988-01-01

    Low-temperature photoluminescence studies of 26 cubic SiC films, ranging in thickness from 600 A to 25 microns, grown by CVD on (100)Si are presented. It is suggested that the G band near 1.90-1.92 eV and its phonon side bands G1 and G2 are related to dislocations and extended defects. Formulas for the band-gap shift due to an axial stress have been obtained and applied to the CVD 3C-SiC/Si system. The results indicate that a 1-3-micron transition layer greatly reduces the interface misfit strain, and that biaxial stress in the SiC/Si system depresses the intensity of the no-phonon line.

  11. Spectroscopic Analysis of Perfluoropolyether Lubricant Degradation During Boundary Lubrication

    NASA Technical Reports Server (NTRS)

    Herrera-Fierro, Pilar; Shogrin, Bradley A.; Jones, William R., Jr.

    1996-01-01

    The degradation of a branched perfluoropolyether (PFPE) under boundary lubrication conditions was studied using mu-FTIR and mu-Raman spectroscopies. Stainless steel (440C) discs coated with thin (600A), uniform films of the PFPE were tested in a ball-on-disc apparatus until various levels of friction coefficient were attained. Discs were then examined using the above techniques. When the friction coefficient surpassed the value obtained with an un-lubricated control, the lubricant film had either been physically displaced or partially transformed in to a 'friction polymer'. Infrared analysis of this 'friction polymer' indicated the presence of a polymeric fluorinated acid species (R(sub f)COOH). Raman spectroscopy indicated the presence of amorphous carbon in the wear track and in the friction polymer. Some reaction mechanisms are suggested to explain the results.

  12. An analytical model for liquid-anode and vapor-anode AMTEC converters

    SciTech Connect

    Tournier, Jean-Michel; El-Genk, Mohamed S.; Schuller, Michael; Hausgen, Paul

    1997-01-10

    This paper describes a lumped analytical model of liquid-anode single-tube and vapor-anode multi-tube AMTEC cells. The model results agreed well with experimental data for Mo, NbN and TiN electrodes. Results showed that Mo and NbN electrodes exhibit high B values between 400 and 600 A.K{sup 1/2}/Pa.m{sup 2}, and have the potential for peak power densities slightly above 1 W/cm{sup 2}, with efficiencies as high as 28%. In contrast, TiN electrodes have lower temperature-independent exchange currents, between 120 and 135 A.K{sup 1/2}/Pa.m{sup 2}, lower peak power densities between 0.5 and 0.75 W/cm{sup 2}, and efficiencies below 24% at a BASE temperature of 1200 K. These values of B compare well with that reported by other investigators.

  13. A Superconducting Solenoid for Heavy Ion Beam Focusing

    NASA Astrophysics Data System (ADS)

    Kim, J. W.; Kubo, Toshiyuki; Kawaguchi, Takeo; Imai, Yoshio; Minato, Tsuneaki; Seo, Kazutaka

    1997-05-01

    A superconducting solenoid has been constructed to use as a final focusing element at the entrance of the projectile fragment separator RIPS (T. Kubo et al, Nucl. Instr. & Meth. B70 (1992) 309) at RIKEN. The design field on axis is 6 tesla, the average current density being 9,600 A/cm^2. The overall coil length is 1.1 meter, and the coil is divided into three sections of equal length to ease winding and possibly to distribute the stored energy. A major feature of the magnet is that cooling is conductive without LHe involved, using a cryocooler directly attached onto the coil. The solenoid is currently being tested, and the test results will be presented. After magnet testing, the solenoid will be installed in the beamline. The results of beam experiment will also be presented, along with calculation results with TRANSPORT.

  14. Nurses' perception of the first hour of the morning shift (6.00-7.00 a.m.) in a German hospital.

    PubMed

    Bauer, I

    1993-06-01

    Morning shifts in Germany usually start at 6.00 a.m. Apart from the well-known effects of shiftwork on health and family/social life, the early rising time poses additional problems. Part of a study on the first hour of the morning shift is described in this paper. Thirteen nurses on a female surgical and on a male medical ward were interviewed using a semi-structured interview guide. The findings were obtained through phenomenological analysis. Seven themes emerged from the results: (a) the impact of rising early on the individual, (b) the detrimental effect of alternating shifts on well-being, (c) disturbances to personal life, (d) the rationale for early start, (e) consequences for patients, (f) suggestions for change, and (g) increased risk of leaving the job. The findings suggest that the early start puts nurses under considerable stress. Tradition rules the time-oriented and ritualized way of organizing work. Further extensive research is recommended.

  15. Absolute spectrophotometry in M31 and M32

    NASA Technical Reports Server (NTRS)

    Oke, J. B.; Schwarzschild, M.

    1974-01-01

    For a number of places in the bulge of M31 and for two places in M32 photometric scans from 3300 A to 10,600 A have been obtained with the multichannel spectrometer on the 5-meter Hale telescope. The scans show that in both objects the color temperature (particularly shortwards of 5000 A) decreases towards the center and that the strength of the CN bands increases towards the center in both objects in agreement with earlier observations. The new data can all be interpreted in terms of an increase of heavy element abundance towards the center in both objects by a factor probably less than 2 and by an excess of heavy elements in M31 compared to M32 by a factor probably greater than 2, in qualitative agreement with earlier conclusions.

  16. 3000 Horsepower super conductive field acyclic motor

    SciTech Connect

    Marshall, R.

    1983-05-01

    A 3000 hp acyclic motor was assembled and tested utilizing superconducting field coils. The magnet assembly is designed as a quadrupole magnet, utilizing a multifilamentary niobium titanium superconductor. Each magnet coil is 18 inches in diameter and 10 inches long, and operates at rated current of 200 amperes, providing 5.8 tesla in the bore of the coils in the motor configuration. The average winding current density is 10,600 A/cm/sup 2/. The acyclic motor is of a drum-type design with liquid metal current collectors, and is designed to model full-scale machinery for ship propulsion applications. Laboratory test data verified the electrical and electromagnetic design to be within three percent of the calculated values.

  17. Photographic film as a detector for solar X-ray/XUV astronomical applications

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.

    1985-01-01

    The characteristics of several films as detectors for solar soft X-ray (3-100 A) and XUV (100-600 A) radiation are discussed. The properties of soft-X-ray-sensitive films like the SO-212 make them useful for the glancing-incidence X-ray telescopes. Used for the MSFC X-Ray Telescope during the Skylab mission (at the wavelengths of 8.34 and 15.4 A), the SO-212 film functioned as a photon detector, achieving spatial resolution of 2.2 arc sec. Other high-resolution soft-X-ray-sensitive films include SO-242 and 101-07. For XUV detection, the SC-5, SC-7, 104-07, and 101-07 films are recommended.

  18. Study to determine the existence of an azeotropic R-22 `drop-in` substitute

    SciTech Connect

    Kim, M.S.; Morrison, G.; Mulroy, W.J.; Didion, D.A.

    1996-03-01

    The reduction in chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) production and the scheduled phase-out of these ozone depleting refrigerants requires the development and determination of environmentally safe refrigerants for use in heat pumps, water chillers, air conditioners, and refrigerators. Azeotropic mixtures are attractive as alternative refrigerants because they behave very nearly as pure materials. A simple correlative scheme that allows one to judge whether or not an azeotrope is likely in a binary refrigerant mixture is discussed. This paper presents laboratory and computer simulation model evaluation of two of the azeotropic refrigerant mixtures which are identified, HFC-134a (1,1,1,2-tetrafluoroethane) with R-C290 (Propane) and HFC-134a with R-600a (Isobutane), in a generic heat pump apparatus. A third azeotropes mixture, HFC-134a with R-C290 (Cyclopropane) is examined by computer simulation only.

  19. 600 kV modulator design for the SLAC Next Linear Collider Test Accelerator

    SciTech Connect

    Harris, K.; de Lamare, J.; Nesterov, V.; Cassel, R.

    1992-07-01

    Preliminary design for the SLAC Next Linear Collider Test Accelerator (NLCTA) requires a pulse power source to produce a 600 kV, 600 A, 1.4 {mu}s, 0.1% flat top pulse with rise and fall times of approximately 100 ns to power an X-Band klystron with a microperveance of 1.25 at {approx} 100 MW peak RF power. The design goals for the modulator, including those previously listed, are peak modulator pulse power of 340 MW operating at 120 Hz. A three-stage darlington pulse-forming network, which produces a >100 kV, 1.4 {mu}s pulse, is coupled to the klystron load through a 6:1 pulse transformer. Careful consideration of the transformer leakage inductance, klystron capacitance, system layout, and component choice is necessary to produce the very fast rise and fall times at 600 kV operating continuously at 120 Hz.

  20. Upgrade of the gas flow control system of the resistive current leads of the LHC inner triplet magnets: Simulation and experimental validation

    SciTech Connect

    Perin, A.; Casas-Cubillos, J.; Pezzetti, M.; Almeida, M.

    2014-01-29

    The 600 A and 120 A circuits of the inner triplet magnets of the Large Hadron Collider are powered by resistive gas cooled current leads. The current solution for controlling the gas flow of these leads has shown severe operability limitations. In order to allow a more precise and more reliable control of the cooling gas flow, new flowmeters will be installed during the first long shutdown of the LHC. Because of the high level of radiation in the area next to the current leads, the flowmeters will be installed in shielded areas located up to 50 m away from the current leads. The control valves being located next to the current leads, this configuration leads to long piping between the valves and the flowmeters. In order to determine its dynamic behaviour, the proposed system was simulated with a numerical model and validated with experimental measurements performed on a dedicated test bench.

  1. Upgrade of the gas flow control system of the resistive current leads of the LHC inner triplet magnets: Simulation and experimental validation

    NASA Astrophysics Data System (ADS)

    Perin, A.; Almeida, M.; Casas-Cubillos, J.; Pezzetti, M.

    2014-01-01

    The 600 A and 120 A circuits of the inner triplet magnets of the Large Hadron Collider are powered by resistive gas cooled current leads. The current solution for controlling the gas flow of these leads has shown severe operability limitations. In order to allow a more precise and more reliable control of the cooling gas flow, new flowmeters will be installed during the first long shutdown of the LHC. Because of the high level of radiation in the area next to the current leads, the flowmeters will be installed in shielded areas located up to 50 m away from the current leads. The control valves being located next to the current leads, this configuration leads to long piping between the valves and the flowmeters. In order to determine its dynamic behaviour, the proposed system was simulated with a numerical model and validated with experimental measurements performed on a dedicated test bench.

  2. Compressible and incompressible fluid seals: Influence on rotordynamic response and stability

    NASA Technical Reports Server (NTRS)

    Thames, Howard D.

    1992-01-01

    The flow field inside a whirling annular seal operating a Reynolds numbers of 12,000 and 24,000 and a Taylor number of 6,600 was measured. The rotor was mounted eccentric (50 percent) upon the facilities shaft which resulted in a circular orbit at a whirl ratio of 1.0. Three papers which summarize the work were written and are presented. Addition measurements were performed for the annular seal operating at an eccentricity ratio of 10 percent for Re = 24,000 and Ta = 6,600. A labyrinth seal was also installed into the facility and operated at an eccentricity ratio of 50 percent at the same Reynolds and Taylor numbers. These data are currently being reduced and analyzed.

  3. Tough, processable semi-interpenetrating polymer networks from monomer reactants

    NASA Technical Reports Server (NTRS)

    Pater, Ruth H. (Inventor)

    1994-01-01

    A high temperature semi-interpenetrating polymer network (semi-IPN) was developed which had significantly improved processability, damage tolerance, and mechanical performance, when compared to the commercial Thermid materials. This simultaneous semi-IPN was prepared by mixing the monomer precursors of Thermid AL-600 (a thermoset) and NR-150B2 (a thermoplastic) and allowing the monomers to react randomly upon heating. This reaction occurs at a rate which decreases the flow and broadens the processing window. Upon heating at a higher temperature, there is an increase in flow. Because of the improved flow properties, broadened processing window and enhanced toughness, high strength polymer matrix composites, adhesives and molded articles can now be prepared from the acetylene end-capped polyimides which were previously inherently brittle and difficult to process.

  4. Crystallization of heavy metal fluoride glasses

    NASA Technical Reports Server (NTRS)

    Bansal, Narottam P.; Bruce, Allan J.; Doremus, R. H.; Moynihan, C. T.

    1984-01-01

    The kinetics of crystallization of a number of fluorozirconate glasses were studied using isothermal and dynamic differential scanning calorimetry and X-ray diffraction. The addition of the fluorides LiF, NaF, AlF3, LaF3 to a base glass composition of ZrF4-BaF2 reduced the tendency to crystallize, probably by modifying the viscosity-temperature relation. ZrF4-BaF2-LaF3-AlF3-NaF glass was the most stable against devitrification and perhaps is the best composition for optical fibers with low scattering loss. Some glasses first crystallize out into metastable beta-BaZr2F10 and beta-BaZrF6 phases, which transform into the most stable alpha-phases when heated to higher temperatures. The size of the crystallites was estimated to be about 600 A from X-ray diffraction.

  5. Evidence of melatonin synthesis in the ram reproductive tract.

    PubMed

    Gonzalez-Arto, M; Hamilton, T R dos S; Gallego, M; Gaspar-Torrubia, E; Aguilar, D; Serrano-Blesa, E; Abecia, J A; Pérez-Pé, R; Muiño-Blanco, T; Cebrián-Pérez, J A; Casao, A

    2016-01-01

    Melatonin is a ubiquitous molecule found in a wide range of fluids, one of them being ram seminal plasma, in which it can reach higher concentrations than those found in blood, suggesting an extrapineal secretion by the reproductive tract. In order to identify the source of the melatonin found in ram seminal plasma, we first tried to determine whether the melatonin levels were maintained during the day. For this purpose, melatonin concentrations were measured in seminal plasma obtained from first ejaculates of six rams at 6:00 a.m. in total darkness, at 10:00 a.m. and at 14:00 p.m. The melatonin concentration was higher (p < 0.05) in ejaculates collected at 6:00 a.m. than at 10:00 and 14:00. There was no statistical difference between the latter. To further corroborate an extrapineal secretion of melatonin, the presence of the two key enzymes involved in melatonin synthesis, arylalkylamine-N-acetyltransferase (AANAT) and N-acetylserotonin-O-methyltransferase (ASMT) was analyzed by RT-PCR, q-PCR and Western-blot in ram testes, epididymis, and accessory glands. The RT-PCR showed the presence of the m-RNA codifying both AANAT and ASTM in all the tissues under study, but the q-PCR and Western-blot revealed that gene expression of these enzymes was significantly higher in the testis (p < 0.05). Immunohistochemistry confirmed the presence of AANAT and ASMT in the testis and revealed that they were found in the Leydig cells, spermatocytes, and spermatids. Also, measurable levels of melatonin were found in testicular tissue and the tail of the epididymis. In conclusion, our study indicates that the testes are one of the likely sources of the high levels of melatonin found in ram seminal plasma, at least during the day. PMID:26742835

  6. Record current density of 344 A mm-2 at 4.2 K and 17 T in CORC® accelerator magnet cables

    NASA Astrophysics Data System (ADS)

    van der Laan, D. C.; Weiss, J. D.; Noyes, P.; Trociewitz, U. P.; Godeke, A.; Abraimov, D.; Larbalestier, D. C.

    2016-05-01

    One of the biggest challenges in developing conductor on round core (CORC®) magnet cables for use in the next generation of accelerator magnets is raising their engineering current density J E to approach 600 A mm-2 at 20 T, while maintaining their flexibility. One route to increase J E could be to add more RE-Ba2Cu3O7-δ coated conductors to the cable, but this would increase the cable size and reduce its flexibility. The preferred route to higher J E is a reduction in diameter of the CORC® cable, while maintaining the number of tapes wound into the cable. The availability of very thin tapes containing substrates of 30 μm thickness enabled us to wind a 5.1 mm diameter CORC® cable from 50 coated conductors, while maintaining a tape critical current I c of about 97% after cabling. The cable I c was 7030 A at 4.2 K in a background field of 17 T, corresponding to a J E of 344 A mm-2, which is the highest performance of any CORC® cable so far. The magnetic field dependence allowed us to extrapolate the cable performance to 20 T to predict an I c of 5654 A and a J E of 309 A mm-2. The results clearly show that rapid progress is being made on overcoming the J E hurdle for use of CORC® cables in the next generation of accelerator magnets. Further optimization of the cable layout will likely increase J E towards 600 A mm-2 at 20 T in the near future, while further reduction in cable size will also make them even more flexible.

  7. Differences between Weekday and Weekend Air Pollutant Levels in Atlanta; Baltimore; Chicago; Dallas-Fort Worth; Denver; Houston; New York; Phoenix; Washington, DC; and Surrounding Areas

    SciTech Connect

    Blanchard, C. L.; Tanenbaum, S.; Lawson, D. R.

    2008-12-01

    We evaluated day-of-week differences in mean concentrations of ozone (O3) precursors (nitric oxide NO), nitrogen oxides NOx, carbon monoxide CO, and volatile organic compounds VOCs at monitoring sites in 23 states comprising seven geographic focus areas over the period 1998- 2003. Data for VOC measurements were available for six metropolitan areas in five regions. We used Wednesdays to represent weekdays and Sundays to represent weekends; we also analyzed Saturdays. At many sites, NO, NOx, and CO mean concentrations decreased at all individual hours from 6:00 a.m. to 3:00 p.m. on Sundays compared with corresponding Wednesday means. Statistically significant (p 0.01) weekend decreases in ambient concentrations were observed for 92% of NOx sites, 89% of CO sites, and 23% of VOC sites. Nine-hour (6:00 a.m. to 3:00 p.m.) mean concentrations of NO, NOx, CO, and VOCs declined by 65, 49, 28, and 19%, respectively, from Wednesdays to Sundays (median site responses). Despite the large reductions in ambient NOx and moderate reductions in ambient CO and VOC concentrations on weekends, ozone and particulate matter (PM) nitrate did not exhibit large changes from weekdays to weekends. The median differences between Wednesday and Sunday mean ozone concentrations at all monitoring sites ranged from 3% higher on Sundays for peak 8-hr concentrations determined from all monitoring days to 3.8% lower on Sundays for peak 1-hr concentrations on extreme-ozone days. Eighty-three percent of the sites did not show statistically significant differences between Wednesday and weekend mean concentrations of peak ozone. Statistically significant weekend ozone decreases occurred at 6% of the sites and significant increases occurred at 11% of the sites. Average PM nitrate concentrations were 2.6% lower on Sundays than on Wednesdays. Statistically significant Sunday PM nitrate decreases occurred at one site and significant increases occurred at seven sites.

  8. Evidence of melatonin synthesis in the ram reproductive tract.

    PubMed

    Gonzalez-Arto, M; Hamilton, T R dos S; Gallego, M; Gaspar-Torrubia, E; Aguilar, D; Serrano-Blesa, E; Abecia, J A; Pérez-Pé, R; Muiño-Blanco, T; Cebrián-Pérez, J A; Casao, A

    2016-01-01

    Melatonin is a ubiquitous molecule found in a wide range of fluids, one of them being ram seminal plasma, in which it can reach higher concentrations than those found in blood, suggesting an extrapineal secretion by the reproductive tract. In order to identify the source of the melatonin found in ram seminal plasma, we first tried to determine whether the melatonin levels were maintained during the day. For this purpose, melatonin concentrations were measured in seminal plasma obtained from first ejaculates of six rams at 6:00 a.m. in total darkness, at 10:00 a.m. and at 14:00 p.m. The melatonin concentration was higher (p < 0.05) in ejaculates collected at 6:00 a.m. than at 10:00 and 14:00. There was no statistical difference between the latter. To further corroborate an extrapineal secretion of melatonin, the presence of the two key enzymes involved in melatonin synthesis, arylalkylamine-N-acetyltransferase (AANAT) and N-acetylserotonin-O-methyltransferase (ASMT) was analyzed by RT-PCR, q-PCR and Western-blot in ram testes, epididymis, and accessory glands. The RT-PCR showed the presence of the m-RNA codifying both AANAT and ASTM in all the tissues under study, but the q-PCR and Western-blot revealed that gene expression of these enzymes was significantly higher in the testis (p < 0.05). Immunohistochemistry confirmed the presence of AANAT and ASMT in the testis and revealed that they were found in the Leydig cells, spermatocytes, and spermatids. Also, measurable levels of melatonin were found in testicular tissue and the tail of the epididymis. In conclusion, our study indicates that the testes are one of the likely sources of the high levels of melatonin found in ram seminal plasma, at least during the day.

  9. Global distribution of beryllium isotopes in deep ocean water as derived from Fe-Mn crusts

    USGS Publications Warehouse

    Von Blanckenburg, F.; O'Nions, R. K.; Belshaw, N.S.; Gibb, A.; Hein, J.R.

    1996-01-01

    The direct measurement of the ratio of cosmogenic 10Be (T1/2 = 1.5 Ma) to stable terrigenously sourced 9Be in deep seawater or marine deposits can be used to trace water mass movements and to quantify the incorporation of trace metals into the deep sea. In this study a SIMS-based technique has been used to determine the 10Be/9Be ratios of the outermost millimetre of hydrogenetic ferromanganese crusts from the worlds oceans. 10Be/9Be ratios, time-corrected for radioactive decay of cosmogenic 10Be using 234U/ 238U, are in good agreement with AMS measurements of modern deep seawater. Ratios are relatively low in the North and equatorial Atlantic samples (0.4-0.5 ?? 10-7). In the Southwest Atlantic ratios increase up to 1 ?? 10-7, they vary between 0.7 and 1.0 ?? 10-7 in Indian Ocean samples, and have a near constant value of 1.1 ?? 0.2 ?? 10-7 for all Pacific samples. If the residence time of 10Be (??10Be) in deep water is constant globally, then the observed variations in 10Be/9Be ratios could be caused by accumulation of 10Be in deep water as it flows and ages along the conveyor, following a transient depletion upon its formation in the Northern Atlantic. In this view both 10Be and 9Be reach local steady-state concentration in Pacific deep water and the global ??10Be ??? 600 a. An alternative possibility is that the Be isotope abundances are controlled by local scavenging. For this scenario ??10Be would vary according to local particle concentration and would ??? 600 a in the central Pacific, but ??10Be ??? 230 a in the Atlantic. Mass balance considerations indicate that hydrothermal additions of 9Be to the oceans are negligible and that the dissolved riverine source is also small. Furthermore, aeolian dust input of 9Be appears insufficient to provide the dissolved Be inventory. The dissolution of only a small proportion (2%) of river-derived particulates could in principle supply the observed seawater Be content. If true, ocean margins would be the sites for 9Be

  10. NR4A nuclear receptors mediate carnitine palmitoyltransferase 1A gene expression by the rexinoid HX600

    SciTech Connect

    Ishizawa, Michiyasu; Kagechika, Hiroyuki; Makishima, Makoto

    2012-02-24

    Highlights: Black-Right-Pointing-Pointer The function of RXR heterodimers with NR4 receptors remains unknown. Black-Right-Pointing-Pointer The RXR ligand HX600 induces expression of carnitine palmitoyltransferase 1A (CPT1A). Black-Right-Pointing-Pointer HX600-induced CPT1A expression is mediated by the NR4 receptors, Nur77 and NURR1. Black-Right-Pointing-Pointer CPT1A induction by HX600 is not mediated by de novo protein synthesis. Black-Right-Pointing-Pointer CPT1A could be a target of the Nur77-RXR and NURR1-RXR heterodimers. -- Abstract: Retinoid X receptors (RXRs) are members of the nuclear receptor superfamily and can be activated by 9-cis retinoic acid (9CRA). RXRs form homodimers and heterodimers with other nuclear receptors such as the retinoic acid receptor and NR4 subfamily nuclear receptors, Nur77 and NURR1. Potential physiological roles of the Nur77-RXR and NURR1-RXR heterodimers have not been elucidated. In this study, we identified a gene regulated by these heterodimers utilizing HX600, a selective RXR agonist for Nur77-RXR and NURR1-RXR. While 9CRA induced many genes, including RAR-target genes, HX600 effectively induced only carnitine palmitoyltransferase 1A (CPT1A) in human teratocarcinoma NT2/D1 cells, which express RXR{alpha}, Nur77 and NURR1. HX600 also increased CPT1A expression in human embryonic kidney (HEK) 293 cells and hepatocyte-derived HepG2 cells. Although HX600 induced CPT1A less effectively than 9CRA, overexpression of Nur77 or NURR1 increased the HX600 response to levels similar to 9CRA in NT2/D1 and HEK293 cells. A dominant-negative form of Nur77 or NURR1 repressed the induction of CPT1A by HX600. A protein synthesis inhibitor did not alter HX600-dependent CPT1A induction. Thus, the rexinoid HX600 directly induces expression of CPT1A through a Nur77 or NURR1-mediated mechanism. CPT1A, a gene involved in fatty acid {beta}-oxidation, could be a target of RXR-NR4 receptor heterodimers.

  11. Type B accident investigation board report of the July 2, 1997 curium intake by shredder operator at Building 513 Lawrence Livermore National Laboratory, Livermore, California. Final report

    SciTech Connect

    1997-08-01

    On July 2, 1997 at approximately 6:00 A.M., two operators (Workers 1 and 2), wearing approved personal protective equipment (PPE), began a shredding operation of HEPA filters for volume reduction in Building 513 (B-513) at Lawrence Livermore National Laboratory (LLNL). The waste requisitions indicated they were shredding filters containing {le} 1 {micro}Ci of americium-241 (Am-241). A third operator (Worker 3) provided support to the shredder operators in the shredding area (hot area) from a room that was adjacent to the shredding area (cold area). At Approximately 8:00 A.M., a fourth operator (Worker 4) relieved Worker 2 in the shredding operation. Sometime between 8:30 A.M. and 9:00 A.M., Worker 3 left the cold area to make a phone call and set off a hand and foot counter in Building 514. Upon discovering the contamination, the shredding operation was stopped and surveys were conducted in the shredder area. Surveys conducted on the workers found significant levels of contamination on their PPE and the exterior of their respirator cartridges. An exit survey of Worker 1 was conducted at approximately 10:05 A.M., and found contamination on his PPE, as well as on the exterior and interior of his respirator. Contamination was also found on his face, chest, back of neck, hair, knees, and mustache. A nose blow indicated significant contamination, which was later determined to be curium-244.

  12. X-ray Laue micro diffraction and neutron diffraction analysis of residual elastic strains and plastic deformation in a 1% uniaxial tensile tested nickel alloy 600 sample

    SciTech Connect

    Chao, Jing; Mark, Alison; Fuller, Marina; Barabash, Rozaliya; McIntyre, Stewart; Holt, Richard A.; Klassen, Robert; Liu, W.

    2009-01-01

    The magnitude and distribution of elastic strain for a nickel alloy 600 (A600) sample that had been subjected to uniaxial tensile stress were measured by micro Laue diffraction (MLD) and neutron diffraction techniques. For a sample that had been dimensionally strained by 1%, both MLD and neutron diffraction data indicated that the global residual elastic strain was on the order of 10{sup -4}, however the micro-diffraction data indicated considerable grain-to-grain variability amongst individual components of the residual strain tensor. A more precise comparison was done by finding those grains in the MLD map that had appropriate oriented in the specific directions matching those used in the neutron measurements and the strains were found to agree within the uncertainty. Large variations in strain values across the grains were noted during the MLD measurements which are reflected in the uncertainties. This is a possible explanation for the large uncertainty in the average strains measured from multiple grains during neutron diffraction.

  13. TO THE CENTENARY OF A. F. IOFFE: Global hydrodynamics of the sun

    NASA Astrophysics Data System (ADS)

    Monin, A. S.

    1980-09-01

    CONTENTS Introduction 594 1. The sun as a whole 595 a) Dimensions 596 b) Rotation 596 c) Radiation 596 d) Atmosphere 596 1. Photosphere 596 2. Chromosphere 597 3. Corona 598 e) Interior 598 1. Solar neutrinos 599 2. Convection zone 599 2. Phenomena in the solar atmosphere 600 a) Sunspots 600 b) Magnetic fields of spots 601 c) Faculae 602 d) Chromospherie flares 602 e) Prominences 603 f) Coronal streamers and holes 603 g) Centers of activity 604 h) Solar magnetic field 604 3. Rotation of the sun 604 a) Observational data 604 b) Rotation of the solar wind 606 c) Oblateness 606 d) Hydrodynamics of the differential rotation 607 e) Reynolds stresses 608 f) Hypothesis of an anisotropic viscosity 609 g) Equations for the second moments 610 h) Numerical simulations 611 4. The solar cycle 612 a) Wolf numbers 612 b) Sporer'slaw 612 c) Hale-Nicholson laws 613 d) Waldmeier eruption hypothesis 613 e) Relaxation nature of the solar cycle 613 f) Maunder minimum 614 g) Babcock model 615 h) Leighton's equations 616 i) Hydromagnetic dynamos 617 References 618

  14. Raman-scattering and optical studies of argon-etched GaAs surfaces

    SciTech Connect

    Feng, G.F.; Zallen, R. ); Epp, J.M.; Dillard, J.G. )

    1991-04-15

    We have studied the structual damage in low-energy argon-ion-bombarded (ion-etched) GaAs using Raman scattering and ultraviolet reflectivity. When combined with post-bombardment sequential chemical etching, the Raman results reveal a graded depth profile of the damage layer, with a nearly linear damage dropoff with depth. The total damage-layer thickness is about 600 A for high-fluence bombardment with 3.89-keV Ar{sup +} ions. The spectral effects produced by argon etching are very different from those produced by high-energy ion implantation. The longitudinal-optic Raman line seen for argon-etched GaAs is not shifted and broadened as in ion-implanted GaAs. More striking are the results of the reflectivity measurements. For argon-etched GaAs, the electronic interband peaks are both broadened and strongly red shifted relative to the crystal peaks; for ion-implanted GaAs, only the broadening occurs. Distinct nanocrystals, which account for the effects seen in ion-implanted GaAs, are evidently absent in argon-etched GaAs. Instead, the damage layer caused by argon etching appears to be characterized by a very high density of point defects, which previous work suggests may be arsenic vacancies.

  15. Practical applications of SiC-MOSFETs and further developments

    NASA Astrophysics Data System (ADS)

    Furuhashi, Masayuki; Tomohisa, Shingo; Kuroiwa, Takeharu; Yamakawa, Satoshi

    2016-03-01

    The next generation power modules using SiC-MOSFETs have been developed for over ten years. From our successful results, we have released SiC power modules which have been used in railway vehicles, industrial machines and home appliances, etc. Low on-resistance 3.3 kV SiC-MOSFETs have been realized by JFET doping and they demonstrated a loss reduction of 55% in a traction inverter compared to a conventional system. In the case of a 1.2 kV MOSFET, a 1 cm2 die verified that it can control a large current of over 600 A. For home appliances, we reduce the trade-off between the threshold voltage and channel mobility by a new gate oxide process. High threshold voltage SiC-MOSFETs having a low on-resistance contribute to the low cost installation of SiC-MOSFETs into air conditioners and achieved a loss reduction of 45% in DC converters. For further reduction of conduction loss, we investigated new structures and technologies. Trench SiC-MOSFETs having a bottom p-well verify lower on-resistance and a larger SCSOA than those of planar MOSFETs. The optimization of the dopant concentration in the drift layer and a reduction of wafer thickness verified the reduction of on-resistance. They are expected to contribute to a lower power loss.

  16. Role of calcium in the interaction of alpha and beta adrenoceptor-mediated renin release in isolated, constant pressure perfused rabbit kidneys.

    PubMed

    Opgenorth, T J; Zehr, J E

    1983-10-01

    These experiments were designed to study the role of calcium in the modulation of renin secretion by alpha and beta adrenoceptors. Rabbit kidneys were isolated and single-pass perfused with a modified Ringer's solution. Renal perfusion pressure was precisely controlled by an electronic servocontrol system. Tubular events were minimized by ligation of the ureter before initiating the studies. Under these conditions the predominant factor modifying renin secretion was assumed to originate directly on the juxtaglomerular cells. Isoproterenol infused at 0.1, 0.5, 1.0 and 5.0 nM/min/g of kidney weight increased renin secretion in a dose-dependent manner whereas phenylephrine infused at identical molar doses did not. In addition, phenylephrine (5.0 nM/min/g of kidney weight) blocked the usual response to isoproterenol. Removal of calcium from the perfusing medium had no effect on either the response to isoproterenol or the lack of a response to phenylephrine. On the other hand, when calcium is removed from the perfusate or when D-600, a calcium channel blocker, is added to calcium-containing medium, phenylephrine failed to block the usual response to isoproterenol. We conclude that the suppression of beta adrenoceptor stimulation of renin release by alpha adrenoceptor agonists is calcium dependent by a final mechanism as yet undefined, but probably involving movement of calcium into the juxtaglomerular cells.

  17. Imaging extreme ultraviolet spectrometer employing a single toroidal diffraction grating: the initial evaluation.

    PubMed

    Huber, M C; Timothy, J G; Morgan, J S; Lemaitre, G; Tondello, G; Jannitti, E; Scarin, P

    1988-08-15

    A high-efficiency extreme ultraviolet (EUV) imaging spectrometer has been constructed and tested. The spectrometer employs a concave toroidal grating illuminated at normal incidence in a Rowland circle mounting and has only one reflecting surface. The toroidal grating has been fabricated by a new technique employing an elastically deformable submaster grating which is replicated in a spherical form and then mechanically distorted to produce the desired aspect ratio of the toroidal surface for stigmatic imaging over the selected wavelength range. The fixed toroidal grating used in the spectrometer is then replicated from this surface. Photographic tests and initial photoelectric tests with a 2-D pulse-counting detector system have verified the image quality of the toroidal grating at wavelengths near 600 A. The results of these initial tests are described in detail, and the basic designs of two instruments which could employ the imaging spectrometer for astrophysical investigations in space are briefly described, namely, a high-resolution EUV spectroheliometer for studies of the solar chromosphere, transition region, and corona and an EUV spectroscopic telescope for studies of nonsolar objects. PMID:20539406

  18. Convection due to an unstable density difference across a permeable membrane

    NASA Astrophysics Data System (ADS)

    Puthenveettil, Baburaj A.; Arakeri, Jaywant H.

    We study natural convection driven by unstable concentration differences of sodium chloride (NaCl) across a horizontal permeable membrane at Rayleigh numbers (Ra) of 1010 to 1011 and Schmidt number (Sc)=600. A layer of brine lies over a layer of distilled water, separated by the membrane, in square-cross-section tanks. The membrane is permeable enough to allow a small flow across it at higher driving potentials. Based on the predominant mode of transport across the membrane, three regimes of convection, namely an advection regime, a diffusion regime and a combined regime, are identified. The near-membrane flow in all the regimes consists of sheet plumes formed from the unstable layers of fluid near the membrane. In the advection regime observed at higher concentration differences (Bb) show a common log-normal probability density function at all Ra. We propose a phenomenology which predicts /line{lambda}_b sqrt{Z_w Z_{V_i}}, where Zw and Z_{V_i} are, respectively, the near-wall length scales in Rayleighnard convection (RBC) and due to the advection velocity. In the combined regime, which occurs at intermediate values of C/2)4/3. At lower driving potentials, in the diffusion regime, the flux scaling is similar to that in turbulent RBC.

  19. Improved superconducting magnet wire

    DOEpatents

    Schuller, I.K.; Ketterson, J.B.

    1983-08-16

    This invention is directed to a superconducting tape or wire composed of alternating layers of copper and a niobium-containing superconductor such as niobium of NbTi, Nb/sub 3/Sn or Nb/sub 3/Ge. In general, each layer of the niobium-containing superconductor has a thickness in the range of about 0.05 to 1.5 times its coherence length (which for Nb/sub 3/Si is 41 A) with each copper layer having a thickness in the range of about 170 to 600 A. With the use of very thin layers of the niobium composition having a thickness within the desired range, the critical field (H/sub c/) may be increased by factors of 2 to 4. Also, the thin layers of the superconductor permit the resulting tape or wire to exhibit suitable ductility for winding on a magnet core. These compositions are also characterized by relatively high values of critical temperature and therefore will exhibit a combination of useful properties as superconductors.

  20. Electromagnetic pulse-induced current measurement device

    NASA Astrophysics Data System (ADS)

    Gandhi, Om P.; Chen, Jin Y.

    1991-08-01

    To develop safety guidelines for exposure to high fields associated with an electromagnetic pulse (EMP), it is necessary to devise techniques that would measure the peak current induced in the human body. The main focus of this project was to design, fabricate, and test a portable, self-contained stand-on device that would measure and hold the peak current and the integrated change Q. The design specifications of the EMP-Induced Current Measurement Device are as follows: rise time of the current pulse, 5 ns; peak current, 20-600 A; charge Q, 0-20 microcoulombs. The device uses a stand-on parallel-plate bilayer sensor and fast high-frequency circuit that are well-shielded against spurious responses to high incident fields. Since the polarity of the incident peak electric field of the EMP may be either positive or negative, the induced peak current can also be positive or negative. Therefore, the device is designed to respond to either of these polarities and measure and hold both the peak current and the integrated charge which are simultaneously displayed on two separate 3-1/2 digit displays. The prototype device has been preliminarily tested with the EMP's generated at the Air Force Weapons Laboratory (ALECS facility) at Kirtland AFB, New Mexico.

  1. Bacteriophage Infecting the Myxobacterium Chondrococcus columnaris

    PubMed Central

    Kingsbury, David T.; Ordal, Erling J.

    1966-01-01

    Kingsbury, David T. (University of Washington, Seattle), and Erling J. Ordal. Bacteriophage infecting the myxobacterium Chondrococcus columnaris. J. Bacteriol. 91:1327–1332. 1966.—During a series of screening experiments, seven bacteriophages which infect the pathogenic myxobacterium Chondrococcus columnaris were isolated. Of these, one was chosen for detailed study. This phage has a wide host range among strains of C. columnaris, but does not infect other myxobacterial species tested. Morphologically, this phage resembles coliphage T2, though it is smaller. It has a head diameter of 600 A, a tail length of 1,000 A, and a tail width of 200 A. The head is attached to the tail by a well-defined neck. The turbid plaques produced by this phage are similar in appearance to those produced by coliphage λ, and average 1 mm in diameter. The phage has a latent period of 100 min, a rise period of an additional 90 min, and a burst size of 23. Calcium ions at a concentration of 0.004 m are required for adsorption. This requirement cannot be met by substitution of magnesium ions. A purified preparation of 2 × 1012 phage particles was extracted with phenol, and the nucleic acid was identified as deoxyribonucleic acid (DNA). Base ratios of the phage DNA and the DNA of two propagating strains were similar. Streptomycin at a concentration of 70 μg/ml inhibits phage infection at an early stage, probably by inhibiting injection of the phage DNA. Images PMID:5929758

  2. The underground electromagnetic pulse: Four representative models

    SciTech Connect

    Wouters, L.F.

    1989-06-01

    I describe four phenomenological models by which an underground nuclear explosion may generate electromagnetic pulses: Compton current asymmetry (or ''Compton dipole''); Uphole conductor currents (or ''casing currents''); Diamagnetic cavity plasma (or ''magnetic bubble''); and Large-scale ground motion (or ''magneto-acoustic wave''). I outline the corresponding analytic exercises and summarize the principal results of the computations. I used a 10-kt contained explosion as the fiducial case. Each analytic sequence developed an equivalent source dipole and calculated signal waveforms at representative ground-surface locations. As a comparative summary, the Compton dipole generates a peak source current moment of about 12,000 A/center dot/m in the submicrosecond time domain. The casing-current source model obtains an equivalent peak moment of about 2 /times/ 10/sup 5/ A/center dot/m in the 10- to 30-/mu/s domain. The magnetic bubble produces a magnetic dipole moment of about 7 /times/ 10/sup 6/ A/center dot/m/sup 2/, characterized by a 30-ms time structure. Finally, the magneto-acoustic wave corresponds to a magnetic dipole moment of about 600 A/center dot/m/sup 2/, with a waveform showing 0.5-s periodicities. 8 refs., 35 figs., 7 tabs.

  3. Lambda Front Propagation in the Superfluid Helium Contained in the External Auxiliary Bus-Bar Line of the LHC

    NASA Astrophysics Data System (ADS)

    Capatina, O.; Poncet, A.; Skoczen, B.

    2004-06-01

    The array of the corrector magnets of the LHC arc, associated with the main and some dispersion suppressor quadrupoles are powered by a special line routed inside the cryostat, running alongside the cold mass of the half-cell. This line, composed of a 50 mm diameter stainless steel tube fixed to the cold mass, houses the superconducting multi-wire cable(s) carrying the 600 A and 6 kA current to the corrector magnets and special quadrupoles. It is cooled down to 1.9 K with pressurized superfluid helium provided by links to the cold-mass placed at regular intervals (one half-cell). The paper is focused on the process of sub-cooling the long channel from 4.5 K down to 1.9 K, including the propagation of the lambda front along the pipeline. The mechanism of sub-cooling is based on a zone of phase transformation traveling along the channel, with the heat transport both in helium and in the copper wires. A new 2-D model, including the radial heat exchange between copper and He II, has been used to study the process. A clamped temperature problem with a jump-like variable section of the channel has been solved. The model has been applied to the analysis of recovery of the line after a quench in the main magnets. A comparison with the measurements in the LHC prototype cell (String 2) is shown.

  4. A visualization instrument to investigate the mechanical-electro properties of high temperature superconducting tapes under multi-fields

    NASA Astrophysics Data System (ADS)

    Liu, Wei; Zhang, Xingyi; Liu, Cong; Zhang, Wentao; Zhou, Jun; Zhou, YouHe

    2016-07-01

    We construct a visible instrument to study the mechanical-electro behaviors of high temperature superconducting tape as a function of magnetic field, strain, and temperature. This apparatus is directly cooled by a commercial Gifford-McMahon cryocooler. The minimum temperature of sample can be 8.75 K. A proportion integration differentiation temperature control is used, which is capable of producing continuous variation of specimen temperature from 8.75 K to 300 K with an optional temperature sweep rate. We use an external loading device to stretch the superconducting tape quasi-statically with the maximum tension strain of 20%. A superconducting magnet manufactured by the NbTi strand is applied to provide magnetic field up to 5 T with a homogeneous range of 110 mm. The maximum fluctuation of the magnetic field is less than 1%. We design a kind of superconducting lead composed of YBa2Cu3O7-x coated conductor and beryllium copper alloy (BeCu) to transfer DC to the superconducting sample with the maximum value of 600 A. Most notably, this apparatus allows in situ observation of the electromagnetic property of superconducting tape using the classical magnetic-optical imaging.

  5. Fabrication of a Short-Period Nb3Sn Superconducting Undulator

    SciTech Connect

    Dietderich, Daniel; Dietderich, Daniel; Godeke, Arno; Prestemon, Soren; Pipersky, Paul T.; Liggins, Nate L.; Higley, Hugh C.; Marks, Steve; Schlueter, Ross D.

    2007-06-01

    Lawrence Berkeley National Laboratory develops high-field Nb{sub 3}Sn magnets for HEP applications. In the past few years, this experience has been extended to the design and fabrication of undulator magnets. Some undulator applications require devices that can operate in the presence of a heat load from a beam. The use of Nb{sub 3}Sn permits operation of a device at both a marginally higher temperature (5-8K) and a higher J{sub c}, compared to NbTi devices, without requiring a larger magnetic gap. A half-undulator device consisting of 6 periods (12 coil packs) of 14.5 mm period was designed, wound, reacted, potted and tested. It reached the short sample current limit of 717A in 4 quenches. The non-Cu Jc of the strand was over 7,600 A/mm{sup 2} and the Cu current density at quench was over 8,000 A/mm{sup 2}. Magnetic field models show that if a complete device was fabricated with the same parameters one could obtain beam fields of 1.1 T and 1.6 T for pole gaps of 8 mm and 6 mm, respectively.

  6. Assessment of E-coding practices and costs in Massachusetts hospitals.

    PubMed Central

    Ozonoff, V V; Tan-Torres, S; Barber, C W

    1993-01-01

    Hospital discharge data are a potentially useful information resource for documenting the epidemiology of nonfatal injuries. However, hospitals often do not include E-codes that identify external causes of injury in discharge abstracts. One barrier has been assumed to be the cost of assigning E-codes to medical records. Directors of medical records at hospitals in Massachusetts were surveyed to assess the validity of a cost-assessment study by Rivara and coworkers and to determine what resources they would need to E-code all injury discharges. According to Rivara's estimates, injury coding an additional 500 hospital discharges would entail a continuing cost to each hospital of about $600 a year. More than half of the survey's 101 respondents believed that the estimates were accurate, 16 percent believed that the estimates were inaccurate, and 27 percent were unable to assess the potential costs. Among the resources needed to E-code all injury-related discharges, respondents most often cited training for those who assign the codes and the approval of the hospital administration. Only 20 percent of the respondents cited needs directly related to ongoing costs. The perception by hospitals of the cost of E-coding, frequently cited as a major barrier to the use of hospital discharge data as an injury surveillance source, did not emerge in this survey as an overriding concern. PMID:8210261

  7. Beam Dynamics Experiments in Support of Relativistic Klystrons

    SciTech Connect

    Houck, T; Lidia, S

    2001-06-03

    Experiments to study beam dynamics for Relativistic Klystrons (RK) are being performed with a 1-MeV, 600-A induction accelerator beam. The RK is a RF Power source based on induction accelerator technology and conventional resonant output structures. Capable of generating 100's of MW/m at frequencies up to K-band, the RK has been proposed as a driver for a future linear collider in one version of a Two-Beam Accelerator. A critical feasibility issue remaining to be demonstrated is suppression of the transverse instability of the drive beam. This kiloampere beam must transit about a hundred resonance output structures and many hundreds of induction accelerator cavities for the RK to achieve competitive efficiency and cost with respect to other proposed power sources. The RK's strong focusing used to contain the beam in the small aperture resonant structures, repetitive geometry, and reacceleration allow the resonant output structures to be spaced at a betatron phase advance of 360{sup o}. This phase advance (or any integral multiple of 180{sup o}) is beneficial in linear accelerators as the instability growth changes from exponential to linear. In our experiment the beam is contained in a solenoidal focusing channel, RF cavities are spaced every 60 cm, and growth in the transverse motion is measured as a function of phase advance. Details of the experiments and results are presented.

  8. A visualization instrument to investigate the mechanical-electro properties of high temperature superconducting tapes under multi-fields.

    PubMed

    Liu, Wei; Zhang, Xingyi; Liu, Cong; Zhang, Wentao; Zhou, Jun; Zhou, YouHe

    2016-07-01

    We construct a visible instrument to study the mechanical-electro behaviors of high temperature superconducting tape as a function of magnetic field, strain, and temperature. This apparatus is directly cooled by a commercial Gifford-McMahon cryocooler. The minimum temperature of sample can be 8.75 K. A proportion integration differentiation temperature control is used, which is capable of producing continuous variation of specimen temperature from 8.75 K to 300 K with an optional temperature sweep rate. We use an external loading device to stretch the superconducting tape quasi-statically with the maximum tension strain of 20%. A superconducting magnet manufactured by the NbTi strand is applied to provide magnetic field up to 5 T with a homogeneous range of 110 mm. The maximum fluctuation of the magnetic field is less than 1%. We design a kind of superconducting lead composed of YBa2Cu3O7-x coated conductor and beryllium copper alloy (BeCu) to transfer DC to the superconducting sample with the maximum value of 600 A. Most notably, this apparatus allows in situ observation of the electromagnetic property of superconducting tape using the classical magnetic-optical imaging.

  9. Characterisation of a grooved heat pipe with an anodised surface

    NASA Astrophysics Data System (ADS)

    Solomon, A. Brusly; Ram Kumar, A. M.; Ramachandran, K.; Pillai, B. C.; Senthil Kumar, C.; Sharifpur, Mohsen; Meyer, Josua P.

    2016-06-01

    A grooved heat pipe (GHP) is an important device for managing heat in space applications such as satellites and space stations, as it works efficiently in the absence of gravity. Apart from the above application, axial GHPs are used in many applications, such as electronic cooling units for temperature control and permafrost cooling. Improving the performance of GHPs is essential for better cooling and thermal management. In the present study, the effect of anodization on the heat transfer characteristics of a GHP is studied with R600a as a working fluid. In addition, the effects of fill ratio, inclination angle and heat inputs on the heat transfer performance of a GHP are studied. Furthermore, the effect of heat flux on dimensional numbers, such as the Webber, Bond, Kutateladze and condensation numbers, are studied. The inclination angle, heat input and fill ratio of GHPs are varied in the range of 0°-90°, 25-250 W and 10-70 % respectively. It is found that the above parameters have a significant effect on the performance of a GHP. Due to the anodisation, the maximum enhancement in heat transfer coefficient at the evaporator is 39 % for a 90° inclination at a heat flux of 11 kW/m2. The reported performance enhancement of a GHP may be due to the large numbers of nucleation sites created by the anodisation process and enhancement in the capillary force due to the coating.

  10. On the aggregate grid load imposed by battery health-conscious charging of plug-in hybrid electric vehicles

    NASA Astrophysics Data System (ADS)

    Bashash, Saeid; Moura, Scott J.; Fathy, Hosam K.

    2011-10-01

    This article examines the problem of estimating the aggregate load imposed on the power grid by the battery health-conscious charging of plug-in hybrid electric vehicles (PHEVs). The article begins by generating a set of representative daily trips using (i) the National Household Travel Survey (NHTS) and (ii) a Markov chain model of both federal and naturalistic drive cycles. A multi-objective optimizer then uses each of these trips, together with PHEV powertrain and battery degradation models, to optimize both PHEV daily energy cost and battery degradation. The optimizer achieves this by varying (i) the amounts of charge obtained from the grid by each PHEV, and (ii) the timing of this charging. The article finally computes aggregate PHEV power demand by accumulating the charge patterns optimized for individual PHEV trips. The results of this aggregation process show a peak PHEV load in the early morning (between 5.00 and 6.00 a.m.), with approximately half of all PHEVs charging simultaneously. The ability to charge at work introduces smaller additional peaks in the aggregate load pattern. The article concludes by exploring the sensitivity of these results to the relative weighting of the two optimization objectives (energy cost and battery health), battery size, and electricity price.

  11. An analytical model for liquid-anode and vapor-anode AMTEC converters

    SciTech Connect

    Tournier, J.; El-Genk, M.S.; Schuller, M.; Hausgen, P.

    1997-01-01

    This paper describes a lumped analytical model of liquid-anode single-tube and vapor-anode multi-tube AMTEC cells. The model results agreed well with experimental data for Mo, NbN and TiN electrodes. Results showed that Mo and NbN electrodes exhibit high B values between 400 and 600A.K{sup 1/2}/Pa.m{sup 2}, and have the potential for peak power densities slightly above 1W/cm{sup 2}, with efficiencies as high as 28{percent}. In contrast, TiN electrodes have lower temperature-independent exchange currents, between 120 and 135A.K{sup 1/2}/Pa.m{sup 2}, lower peak power densities between 0.5 and 0.75W/cm{sup 2}, and efficiencies below 24{percent} at a BASE temperature of 1200 K. These values of B compare well with that reported by other investigators. {copyright} {ital 1997 American Institute of Physics.}

  12. Comparative study of heat transfer and pressure drop during flow boiling and flow condensation in minichannels

    NASA Astrophysics Data System (ADS)

    Mikielewicz, Dariusz; Andrzejczyk, Rafał; Jakubowska, Blanka; Mikielewicz, Jarosław

    2014-09-01

    In the paper a method developed earlier by authors is applied to calculations of pressure drop and heat transfer coefficient for flow boiling and also flow condensation for some recent data collected from literature for such fluids as R404a, R600a, R290, R32,R134a, R1234yf and other. The modification of interface shear stresses between flow boiling and flow condensation in annular flow structure are considered through incorporation of the so called blowing parameter. The shear stress between vapor phase and liquid phase is generally a function of nonisothermal effects. The mechanism of modification of shear stresses at the vapor-liquid interface has been presented in detail. In case of annular flow it contributes to thickening and thinning of the liquid film, which corresponds to condensation and boiling respectively. There is also a different influence of heat flux on the modification of shear stress in the bubbly flow structure, where it affects bubble nucleation. In that case the effect of applied heat flux is considered. As a result a modified form of the two-phase flow multiplier is obtained, in which the nonadiabatic effect is clearly pronounced.

  13. Superconductivity in dense MgB2 wires.

    PubMed

    Canfield, P C; Finnemore, D K; Bud'ko, S L; Ostenson, J E; Lapertot, G; Cunningham, C E; Petrovic, C

    2001-03-12

    MgB2 becomes superconducting just below 40 K. Whereas porous polycrystalline samples of MgB2 can be synthesized from boron powders, in this Letter we demonstrate that dense wires of MgB2 can be prepared by exposing boron filaments to Mg vapor. The resulting wires have a diameter of 160 microm, are better than 80% dense, and manifest the full chi = -1/4pi shielding in the superconducting state. Temperature-dependent resistivity measurements indicate that MgB2 is a highly conducting metal in the normal state with rho(40 K) = 0.38 microOmega cm. By using this value, an electronic mean-free path, l approximately 600 A can be estimated, indicating that MgB2 wires are well within the clean limit. Tc, Hc2(T), and Jc data indicate that MgB2 manifests comparable or better superconducting properties in dense wire form than it manifests as a sintered pellet.

  14. Solar thermal organic rankine cycle for micro-generation

    NASA Astrophysics Data System (ADS)

    Alkahli, N. A.; Abdullah, H.; Darus, A. N.; Jalaludin, A. F.

    2012-06-01

    The conceptual design of an Organic Rankine Cycle (ORC) driven by solar thermal energy is developed for the decentralized production of electricity of up to 50 kW. Conventional Rankine Cycle uses water as the working fluid whereas ORC uses organic compound as the working fluid and it is particularly suitable for low temperature applications. The ORC and the solar collector will be sized according to the solar flux distribution in the Republic of Yemen for the required power output of 50 kW. This will be a micro power generation system that consists of two cycles, the solar thermal cycle that harness solar energy and the power cycle, which is the ORC that generates electricity. As for the solar thermal cycle, heat transfer fluid (HTF) circulates the cycle while absorbing thermal energy from the sun through a parabolic trough collector and then storing it in a thermal storage to increase system efficiency and maintains system operation during low radiation. The heat is then transferred to the organic fluid in the ORC via a heat exchanger. The organic fluids to be used and analyzed in the ORC are hydrocarbons R600a and R290.

  15. Feasibility of drying system using waste heat as the heating source

    NASA Astrophysics Data System (ADS)

    Xie, M. N.; Shi, Y. L.; Chen, L. X.

    2016-08-01

    In this study, a wastewater heat pump system was proposed and its thermal performance was analyzed. The proposed system includes two evaporators: an air-source evaporator and a water-source evaporator. The air-source evaporator absorbs heat from the moist hot air which exhaust from the drying oven. The water-source evaporator absorbs heat from the waste water, while the waste water recovers heat from the mechanical energy, which was produced by cutting and polishing in stone production. The thermodynamic model was developed to evaluate the performance of the proposed system. The energetic analysis was carried out to investigate the influences of the temperature of fresh air. The results show significantly higher energy efficiency, compact-sized and energy-saving compared with the system which uses air as the heat source. Among the seven of alternative refrigerants (R152a, R123, R1234yf, R1234ze, R600a, R22 and R600) investigated, R123 was suggested to be used in this heat pump for its high heating efficiency, inflammable, very low ODP(Ozone Depletion Potential) and GWP(Global warming potential).

  16. RF sputtered silicon and hafnium nitrides as applied to 440C steel

    NASA Technical Reports Server (NTRS)

    Grill, A.; Aron, P. R.

    1984-01-01

    Silicon nitride and hafnium nitride coatings were deposited on oxidized and unoxidized 440C stainless steel substrates. Sputtering was done in mixtures of argon and nitrogen gases from pressed powder silicon nitride and from hafnium metal targets. The coatings and the interface between the coating and substrate were investigated by X-ray diffractometry, scanning electron microscopy, energy dispersive X-ray analysis and Auger electron spectroscopy. Oxide was found at all interfaces with an interface width of at least 600 A for the oxidized substrates and at least 300 A for the unoxidized substrates. Scratch test results demonstrate that the adhesion of hafnium nitride to both oxidized and unoxidized 440C is superior to that of silicon nitride. Oxidized 440C is found to have increased adhesion, to both nitrides, over that of unoxidized 440C. Coatings of both nitrides deposited at 8 mtorr were found to have increased adhesion to both oxidized and unoxidized 440C over those deposited at 20 mtorr.

  17. Triggering GaAs lock-on switches with laser diode arrays

    SciTech Connect

    Loubriel, G.M.; Buttram, M.T.; Helgeson, W.D.; McLaughlin, D.L.; O'Malley, M.W.; Zutavern, F.J. ); Rosen, A.; Stabile, P.J. )

    1990-01-01

    Laser diode arrays have been used to trigger GaAs Photoconducting Semiconductor Switches (PCSS) charged to voltages of up to 60 kV and conducting currents of 580 A. The driving forces behind the use of laser diode arrays are compactness, elimination of complicated optics, and the ability to run at high repetition rates. Laser diode arrays are compactness, elimination of complicated optics, and the ability to run at high repetition rates. Laser diode arrays can trigger GaAs at high fields as the result of a new switching mode (lock-on) with very high carrier number gain. We have achieved switching of up to 10 MW in a 60 {Omega} system, with a pulse rise time of 500 ps. At 1.2 MW we have achieved repetition rates of 1 kHz with switch rise time of 500 ps for 10{sup 5} shots. The laser diode array used for these experiments delivers a 166 W pulse. In a single shot mode we have switched 4 kA with a flash lamp pumped laser and 600 A with the 166 W array. 7 refs., 5 figs.

  18. The evaluation of a deformable diffraction grating for a stigmatic EUV spectroheliometer

    NASA Technical Reports Server (NTRS)

    Timothy, J. G.

    1987-01-01

    A high-efficiency, extreme ultraviolet (EUV) imaging spectrometer is constructed and tested. The spectrometer employs a concave toroidal grating illuminated at normal incidence in a Rowland circle mounting and has only one reflecting surface. The toroidal grating has been fabricated by a new technique employing an elastically-deformable sub-master grating replicated in a spherical form and then mechanically distorted to produce the desired aspect ratio of the toroidal surface for stigmatic imaging over the selected wavelength range. The fixed toroidal grating used in the spectrometer is then replicated from this surface. Photographic tests and initial photoelectric tests with a two-dimensional, pulse-counting detector system verify the image quality of the toroidal grating at wavelengths near 600 A. The results of these tests and the basic designs of two instruments which could employ the imaging spectrometer for astrophysical investigations in space are described; i.e., a high-resolution EUV spectroheliometer for studies of the solar chromosphere, transition region, and corona; and an EUV spectroscopic telescope for studies of non-solar objects.

  19. Recognizing cursive typewritten text using segmentation-free system.

    PubMed

    Khorsheed, Mohammad S

    2015-01-01

    Feature extraction plays an important role in text recognition as it aims to capture essential characteristics of the text image. Feature extraction algorithms widely range between robust and hard to extract features and noise sensitive and easy to extract features. Among those feature types are statistical features which are derived from the statistical distribution of the image pixels. This paper presents a novel method for feature extraction where simple statistical features are extracted from a one-pixel wide window that slides across the text line. The feature set is clustered in the feature space using vector quantization. The feature vector sequence is then injected to a classification engine for training and recognition purposes. The recognition system is applied to a data corpus which includes cursive Arabic text of more than 600 A4-size sheets typewritten in multiple computer-generated fonts. The system performance is compared to a previously published system from the literature with a similar engine but a different feature set. PMID:25961075

  20. The P600-as-P3 hypothesis revisited: single-trial analyses reveal that the late EEG positivity following linguistically deviant material is reaction time aligned.

    PubMed

    Sassenhagen, Jona; Schlesewsky, Matthias; Bornkessel-Schlesewsky, Ina

    2014-10-01

    The P600, a late positive ERP component following linguistically deviant stimuli, is commonly seen as indexing structural, high-level processes, e.g. of linguistic (re)analysis. It has also been identified with the P3 (P600-as-P3 hypothesis), which is thought to reflect a systemic neuromodulator release facilitating behavioural shifts and is usually response time aligned. We investigated single-trial alignment of the P600 to response, a critical prediction of the P600-as-P3 hypothesis. Participants heard sentences containing morphosyntactic and semantic violations and responded via a button press. The elicited P600 was perfectly response aligned, while an N400 following semantic deviations was stimulus aligned. This is, to our knowledge, the first single-trial analysis of language processing data using within-sentence behavioural responses as temporal covariates. Results support the P600-as-P3 perspective and thus constitute a step towards a neurophysiological grounding of language-related ERPs.

  1. CYTOPLASMIC INCLUSIONS RESEMBLING NUCLEOLI IN SYMPATHETIC NEURONS OF ADULT RATS

    PubMed Central

    Grillo, Mary A.

    1970-01-01

    A distinctive cytoplasmic inclusion consisting of a convoluted network of electron-opaque strands embedded in a less dense matrix was identified in the neurons, but not in the supporting cells, of rat sympathetic ganglia. This ball-like structure, designated "nematosome," measures ∼ 0.9 µ and lacks a limiting membrane. Its strands (diameter = 400–600 A) appear to be made of an entanglement of tightly packed filaments and particles ∼ 25–50 A thick. Cytochemical studies carried out with the light microscope suggest the presence of nonhistone proteins and some RNA. Usually only one such structure is present in a cell, and it appears to occur in most ganglion cells. Although they can be seen anywhere in the cell body, nematosomes are typically located in the perinuclear cytoplasm, where they are often associated with smooth-surfaced and coated vesicles. In fine structure and stainability, they bear a resemblance to the fibrous component of the nucleolus. Subsynaptic formations, which are a special feature of some of the synapses in sympathetic ganglia, appear similar to the threadlike elements in the nematosomes. The possibility that these three structures—nucleolus, nematosome, and subsynaptic formation—may be interrelated in origin and function is discussed. PMID:5458990

  2. A Green's function method for heavy ion beam transport

    NASA Technical Reports Server (NTRS)

    Shinn, J. L.; Wilson, J. W.; Schimmerling, W.; Shavers, M. R.; Miller, J.; Benton, E. V.; Frank, A. L.; Badavi, F. F.

    1995-01-01

    The use of Green's function has played a fundamental role in transport calculations for high-charge high-energy (HZE) ions. Two recent developments have greatly advanced the practical aspects of implementation of these methods. The first was the formulation of a closed-form solution as a multiple fragmentation perturbation series. The second was the effective summation of the closed-form solution through nonperturbative techniques. The nonperturbative methods have been recently extended to an inhomogeneous, two-layer transport media to simulate the lead scattering foil present in the Lawrence Berkeley Laboratories (LBL) biomedical beam line used for cancer therapy. Such inhomogeneous codes are necessary for astronaut shielding in space. The transport codes utilize the Langley Research Center atomic and nuclear database. Transport code and database evaluation are performed by comparison with experiments performed at the LBL Bevalac facility using 670 A MeV 20Ne and 600 A MeV 56Fe ion beams. The comparison with a time-of-flight and delta E detector measurement for the 20Ne beam and the plastic nuclear track detectors for 56Fe show agreement up to 35%-40% in water and aluminium targets, respectively.

  3. Computational insight into the catalytic implication of head/tail-first orientation of arachidonic acid in human 5-lipoxygenase: consequences for the positional specificity of oxygenation.

    PubMed

    Saura, Patricia; Maréchal, Jean-Didier; Masgrau, Laura; Lluch, José M; González-Lafont, Àngels

    2016-08-17

    In the present work we have combined homology modeling, protein-ligand dockings, quantum mechanics/molecular mechanics calculations and molecular dynamics simulations to generate human 5-lipoxygenase (5-LOX):arachidonic acid (AA) complexes consistent with the 5-lipoxygenating activity (which implies hydrogen abstraction at the C7 position). Our results suggest that both the holo and the apo forms of human Stable 5-LOX could accommodate AA in a productive form for 5-lipoxygenation. The former, in a tail-first orientation, with the AA carboxylate end interacting with Lys409, gives the desired structures with C7 close to the Fe-OH(-) cofactor and suitable barrier heights for H7 abstraction. Only when using the apo form structure, a head-first orientation with the AA carboxylate close to His600 (a residue recently proposed as essential for AA positioning) is obtained in the docking calculations. However, the calculated barrier heights for this head-first orientation are in principle consistent with 5-LOX specificity, but also with 12/8 regioselectivity. Finally, long MD simulations give support to the recent hypothesis that the Phe177 + Tyr181 pair needs to close the active site access during the chemical reaction, and suggest that in the case of a head-first orientation Phe177 may be the residue interacting with the AA carboxylate. PMID:27489112

  4. A visualization instrument to investigate the mechanical-electro properties of high temperature superconducting tapes under multi-fields.

    PubMed

    Liu, Wei; Zhang, Xingyi; Liu, Cong; Zhang, Wentao; Zhou, Jun; Zhou, YouHe

    2016-07-01

    We construct a visible instrument to study the mechanical-electro behaviors of high temperature superconducting tape as a function of magnetic field, strain, and temperature. This apparatus is directly cooled by a commercial Gifford-McMahon cryocooler. The minimum temperature of sample can be 8.75 K. A proportion integration differentiation temperature control is used, which is capable of producing continuous variation of specimen temperature from 8.75 K to 300 K with an optional temperature sweep rate. We use an external loading device to stretch the superconducting tape quasi-statically with the maximum tension strain of 20%. A superconducting magnet manufactured by the NbTi strand is applied to provide magnetic field up to 5 T with a homogeneous range of 110 mm. The maximum fluctuation of the magnetic field is less than 1%. We design a kind of superconducting lead composed of YBa2Cu3O7-x coated conductor and beryllium copper alloy (BeCu) to transfer DC to the superconducting sample with the maximum value of 600 A. Most notably, this apparatus allows in situ observation of the electromagnetic property of superconducting tape using the classical magnetic-optical imaging. PMID:27475594

  5. Short minority carrier lifetimes in highly nitrogen-doped 4H-SiC epilayers for suppression of the stacking fault formation in PiN diodes

    NASA Astrophysics Data System (ADS)

    Tawara, T.; Miyazawa, T.; Ryo, M.; Miyazato, M.; Fujimoto, T.; Takenaka, K.; Matsunaga, S.; Miyajima, M.; Otsuki, A.; Yonezawa, Y.; Kato, T.; Okumura, H.; Kimoto, T.; Tsuchida, H.

    2016-09-01

    We investigated the dependency of minority carrier lifetimes on the nitrogen concentration, temperature, and the injected carrier concentration for highly nitrogen-doped 4H-SiC epilayers. The minority carrier lifetimes greatly shortened when the nitrogen concentration exceeded 1018 cm-3 through enhancing direct band-to-band and Auger recombination and showed a slight variation in the temperature range from room temperature (RT) to 250 °C. The epilayer with a nitrogen concentration of 9.3 × 1018 cm-3 exhibited a very short minority carrier lifetime of 38 ns at RT and 43 ns at 250 °C. The short minority carrier lifetimes of the highly nitrogen-doped epilayer were confirmed to maintain the values even after the subsequent annealing of 1700 °C. 4H-SiC PiN diodes were fabricated by depositing a highly nitrogen-doped epilayer as a "recombination enhancing layer" between an n- drift layer free from basal plane dislocations and the substrate. The PiN diodes showed no formation of stacking faults and no increase in forward voltage during current conduction of 600 A/cm2 (DC), demonstrating that a highly nitrogen-doped buffer layer with a short minority carrier lifetime successfully suppresses the "bipolar degradation" phenomenon.

  6. Magnetic field structure evolution in rotating magnetic field plasmas

    SciTech Connect

    Petrov, Yuri; Yang Xiaokang; Huang, T.-S.

    2008-07-15

    A study of magnetic field structure evolution during 40-ms plasma discharge has been performed in a new device with 80 cm long/40 cm diameter cylindrical chamber, in which a plasma current I{sub p}{approx_equal}2 kA was driven and sustained by a rotating magnetic field. The main focus of the experiments is on how the changes in externally applied magnetic field affect the current profile and magnetic field in plasma. During plasma discharge, a pulse current was briefly fed to a magnetic coil located at the midplane (middle coil). The magnetic field in cross section of plasma was scanned with pickup probes. Two regimes were studied: without and with an external toroidal field (TF) produced by axial I{sub z} current. With a relatively small current (I{sub m} {<=} 600 A) in the middle coil, the plasma current is boosted up to 5 kA. The magnetic flux surfaces become extended along the axial Z direction, sometimes with the formation of doublet shape plasma. The regime without TF appears to be less stable, presumably due to the reversal of plasma current in central area of plasma column.

  7. Notes on the history of the Dr. Senckenbergische Anatomie in Frankfurt/Main. Part I. Development of student numbers, body procurement, and gross anatomy courses from 1914 to 2013.

    PubMed

    Brehm, Thomas Theo; Korf, Horst-Werner; Benzenhöfer, Udo; Schomerus, Christof; Wicht, Helmut

    2015-09-01

    Until recently, it was believed that all internal documentation regarding student affairs and body procurement of the Dr. Senckenbergische Anatomie concerning the time before March 1944 - when the building was destroyed during an Allied air raid - was lost. A few years ago, however, we discovered stacks of old documents in the current anatomy building. These documents permitted a reconstruction (1) of the history of body procurement, student numbers and course management from 1914 to 1944, as well as (2) some aspects of the building's history in the time immediately after its destruction that have hitherto not been documented. In this paper (Part I), we will deal with the organizational history of the Dr. Senckenbergische Anatomie from 1914 to 2013, placing special emphasis on the development of the student population and body procurement, as well as on the major changes that occurred in the gross anatomy labs of the last century. More than 30,000 students were trained in the Dr. Senckenbergische Anatomie over the last 100 years, and more than 3000 bodies have been received. The number of incoming bodies has remained quite stable in all these years and is, on average, approximately 32 per year. The number of students entering the gross anatomy lab during that period, however, rose from less than 100 to more than 600. A companion paper (Part II) deals with the years of the Third Reich (1933-1945) in more detail.

  8. A Green's function method for heavy ion beam transport.

    PubMed

    Shinn, J L; Wilson, J W; Schimmerling, W; Shavers, M R; Miller, J; Benton, E V; Frank, A L; Badavi, F F

    1995-08-01

    The use of Green's function has played a fundamental role in transport calculations for high-charge high-energy (HZE) ions. Two recent developments have greatly advanced the practical aspects of implementation of these methods. The first was the formulation of a closed-form solution as a multiple fragmentation perturbation series. The second was the effective summation of the closed-form solution through nonperturbative techniques. The nonperturbative methods have been recently extended to an inhomogeneous, two-layer transport media to simulate the lead scattering foil present in the Lawrence Berkeley Laboratories (LBL) biomedical beam line used for cancer therapy. Such inhomogeneous codes are necessary for astronaut shielding in space. The transport codes utilize the Langley Research Center atomic and nuclear database. Transport code and database evaluation are performed by comparison with experiments performed at the LBL Bevalac facility using 670 A MeV 20Ne and 600 A MeV 56Fe ion beams. The comparison with a time-of-flight and delta E detector measurement for the 20Ne beam and the plastic nuclear track detectors for 56Fe show agreement up to 35%-40% in water and aluminium targets, respectively. PMID:7480630

  9. Performance and energy saving analysis of a refrigerator using hydrocarbon mixture (HC-R134a) as working fluid

    NASA Astrophysics Data System (ADS)

    Mohtar, M. N.; Nasution, H.; Aziz, A. A.

    2015-12-01

    The use of hydrocarbon mixture as a working fluid in a refrigerator system is rarely explored. Almost all domestic refrigerators use hydroflourocarbon R134a (HFC-R134a) as refrigerants. In this study, hydrocarbon gas (HC-R134a) is used as the alternative refrigerant to replace HFC-R134a. It has a composition of R290 (56%), R600a (54.39%) and additive (0.1%wt) blended for the trials. The experiments were conducted with 105 g and 52.5 g refrigerant mass charge, subjected to internal heat load of 0, 1, 2, 3 and 4 kg respectively. The study investigates the coefficient of performance of the refrigerator (COPR) and energy consumption. The results show that the use of HC-R134a as the replaceable refrigerant can save energy ranging from 2.04% to 7.09%, as compared to the conventional HFC-R134a refrigerant. Naturally, the COPR improvement and temperature distribution using HC-R134a are much better than HFC-R134a

  10. Influence of uniaxial, biaxial and plane strain pre-straining on the dynamic tensile properties of high strength sheet steels

    NASA Astrophysics Data System (ADS)

    Larour, P.; Verleysen, P.; Bleck, W.

    2006-08-01

    The influence of pre-straining and microstructure on the dynamic properties of car body high strength steels has been investigated at room temperature. The mechanical properties of a dual phase steel DP600, a TRIP steel TRIP700 and an austenitic steel AISI 301LN2B (1.4318) have been determined performing high speed servohydraulic and split-Hopkinson bar tensile tests in the strain rate range from 0.005s-1 up to 950s-1. The pre-straining modes and levels, respectively 10% uniaxial, 10% plane strain and 5% biaxial pre-straining, have been chosen in this investigation according to industrial use. 10% plane strain pre-straining brings the highest increase of yield and tensile strength values. 5% biaxial and 10% uniaxial pre-straining have similar effect on strength properties. The austenitic steel presents a pronounced minimum for tensile strength values at around 1/s. A combination of adiabatic heating and exothermic γ to α' transformation produces some significant softening effects in the austenitic steel grade.

  11. First long-term application of squeezed states of light in a gravitational-wave observatory.

    PubMed

    Grote, H; Danzmann, K; Dooley, K L; Schnabel, R; Slutsky, J; Vahlbruch, H

    2013-05-01

    We report on the first long-term application of squeezed vacuum states of light to improve the shot-noise-limited sensitivity of a gravitational-wave observatory. In particular, squeezed vacuum was applied to the German-British detector GEO 600 during a period of three months from June to August 2011, when GEO 600 was performing an observational run together with the French-Italian Virgo detector. In a second period, the squeezing application continued for about 11 months from November 2011 to October 2012. During this time, squeezed vacuum was applied for 90.2% (205.2 days total) of the time that science-quality data were acquired with GEO 600. A sensitivity increase from squeezed vacuum application was observed broadband above 400 Hz. The time average of gain in sensitivity was 26% (2.0 dB), determined in the frequency band from 3.7 to 4.0 kHz. This corresponds to a factor of 2 increase in the observed volume of the Universe for sources in the kHz region (e.g., supernovae, magnetars). We introduce three new techniques to enable the long-term application of squeezed light, and show that the glitch rate of the detector did not increase from squeezing application. Squeezed vacuum states of light have arrived as a permanent application, capable of increasing the astrophysical reach of gravitational-wave detectors.

  12. Observation of Resonant Effects in Ultracold Collisions between Heteronuclear Feshbach Molecules

    NASA Astrophysics Data System (ADS)

    Ye, Xin; Wang, Fudong; Zhu, Bing; Guo, Mingyang; Lu, Bo; Wang, Dajun

    2016-05-01

    Magnetic field dependent dimer-dimer collisional losses are studied with ultracold 23 Na87 Rb Feshbach molecules. By ramping the magnetic field across the 347.8 G inter-species Feshbach resonance and removing residual atoms with a magnetic field gradient, ~ 8000 pure NaRb Feshbach molecules with a temperature below 1 μK are produced. By holding the pure molecule sample in a crossed optical dipole trap and measuring the time-dependent loss curves under different magnetic fields near the Feshbach resonance, the dimer-dimer loss rates with respect to the atomic scattering length a are mapped out. We observe a resonant feature at around a = 600a0 and a rising tail at above a = 1600a0 . This behavior resembles previous theoretical works on homonuclear Feshbach molecule, where resonant effects between dimer-dimer collisions tied to tetramer bound states were predicted. Our work shows the possibility of exploring four-body physics within a heteronuclear system. We are supported by Hong Kong RGC General Research Fund no. CUHK403813.

  13. Fatal accidents among car and truck drivers: effects of fatigue, age, and alcohol consumption.

    PubMed

    Summala, H; Mikkola, T

    1994-06-01

    Fatigue increases the risk of an accident if the driver, on recognizing symptoms of fatigue, does not stop driving. We studied whether a tendency to continue the current activity and complete the task especially affects younger drivers, who are more susceptible to motivational pressures at the wheel in general. The data consisted of Finnish in-depth studies on 586 single-vehicle and 1357 multiple-vehicle accidents in which at least one vehicle occupant died. When excluding alcohol-related cases, the results showed that, first, trailer-truck drivers who either fell asleep or were tired to a degree that contributed to the accident were younger than those involved in the other fatalities. For car drivers, the proportion of fatigue-related cases was approximately constant in each age group, but a variation was seen when studied according to the time of day of the accident, mainly resulting from two distinct peaks. The first was in young drivers 18 to 20 years old between midnight and 6:00 a.m. The other occurred in drivers 56 years and older during the late afternoon hours. These data also indicate that in terms of fatal accidents, fatigue and alcohol seem to be less of a problem for truckers than for car drivers. PMID:8070795

  14. Abundance ratios of oxygen, neon, and magnesium in solar active regions and flares: The FIP effect

    NASA Technical Reports Server (NTRS)

    Widing, K. G.; Feldman, U.

    1995-01-01

    Relative abundances of oxygen, neon, and magnesium have been derived for a sample of nine solar active regions, flares, and an erupting prominance by combining plots of the ion differential emission measures. The observations were photographed in the 300-600 A range by the Naval Research Laboratory (NRL) spectroheliograph on Skylab. Methods for deriving the Mg/Ne abundance ratio-which measures the separation between the low- first ionization potential (FIP) and high-FIP abundnace plateaus-have been described in previous papers. In this paper we describe the spectroscopic methods for deriving the O/Ne abundance ratio, which gives the ratio between two high-FIP elements. The plot of the O/Ne ratio versus the Mg/Ne ratio in the sample of nine Skylab events is shown. The variation in the Mg/Ne ratio by a factor of 6 is associated with a much smaller range in the O/Ne ratio. This is broadly consistent with the presence of the standard FIP pattern of abundances in the outer atmosphere of the Sun. However, a real change in the relative abundances of oxygen and neon by a factor of 1.5 cannot be excluded.

  15. Notes on the history of the Dr. Senckenbergische Anatomie in Frankfurt/Main. Part I. Development of student numbers, body procurement, and gross anatomy courses from 1914 to 2013.

    PubMed

    Brehm, Thomas Theo; Korf, Horst-Werner; Benzenhöfer, Udo; Schomerus, Christof; Wicht, Helmut

    2015-09-01

    Until recently, it was believed that all internal documentation regarding student affairs and body procurement of the Dr. Senckenbergische Anatomie concerning the time before March 1944 - when the building was destroyed during an Allied air raid - was lost. A few years ago, however, we discovered stacks of old documents in the current anatomy building. These documents permitted a reconstruction (1) of the history of body procurement, student numbers and course management from 1914 to 1944, as well as (2) some aspects of the building's history in the time immediately after its destruction that have hitherto not been documented. In this paper (Part I), we will deal with the organizational history of the Dr. Senckenbergische Anatomie from 1914 to 2013, placing special emphasis on the development of the student population and body procurement, as well as on the major changes that occurred in the gross anatomy labs of the last century. More than 30,000 students were trained in the Dr. Senckenbergische Anatomie over the last 100 years, and more than 3000 bodies have been received. The number of incoming bodies has remained quite stable in all these years and is, on average, approximately 32 per year. The number of students entering the gross anatomy lab during that period, however, rose from less than 100 to more than 600. A companion paper (Part II) deals with the years of the Third Reich (1933-1945) in more detail. PMID:26234698

  16. Generation of the first layers of a zirconia plasma sprayed coating: Correlation between splat layering and spraying parameters

    SciTech Connect

    Haddadi, A.; Nardou, F.; Grimaud, A.; Fauchais, P.

    1995-12-31

    Fused and crushed partially stabilized zirconia particles (8 wt % Y{sub 2}O{sub 3}) were plasma sprayed with an Ar-H{sub 2} plasma jet (45 slm Ar, 15 slm H{sub 2}, 600 A, nozzle i.d. 7 mm, internal injection). The study was devoted to the splat, beads and passes (maximum 8 passes) formation. The particles were sprayed on cast iron or stainless steel substrates at which temperature was kept as constant as possible either at 75 or at 350 C with the help of air jets either blown orthogonally to the plasma jet or to the substrate surface. The splat shape and morphology was examined by OM and image analysis, the beads and passes cross sections as well as fractured sections were examined by SEM and their phases determined by XRD. These examinations have shown the drastic influence of the substrate temperature on the splat shapes and contacts with underlying layers, columnar structure growth within one bead or one pass and macrocracks network within the beads and passes.

  17. Miniaturized pulsed CO2 laser with sealed electron source

    NASA Astrophysics Data System (ADS)

    Bychkov, Y. I.; Orlovskiy, V. M.; Osipov, V. V.; Poteryayev, A. G.

    1984-04-01

    A new miniature electron beam-controlled CO2 laser (the MIG-3) contains an electron accelerator, gas cell and DC supply in one large unit (0.22 x 0,16 x 0.7 m) and the accelerator power supply and laser control panel in a second smaller unit. The overall weight of the instrument in 30 kg. The electron beam is controlled by four vacuum diodes in parallel; a 180 KV pulse is fed to the vacuum diode inputs from a "NORA" series-produced X-ray source (the MIRA-3D) also is used). The total electron beam current from all diodes was 600 A following the foil with a half-height width of 10 ns. The lasing medium is CO2:N2 - 1:1 at 4.5 atm. The maximum stimulated emission pulse energy was 1 J with an efficiency of 8% when the pressure was 4 atm. With a pulse repetition rate of 4 Hz, the average power consumption of the unit was 100 W.

  18. Flight Calibration of the LROC Narrow Angle Camera

    NASA Astrophysics Data System (ADS)

    Humm, D. C.; Tschimmel, M.; Brylow, S. M.; Mahanti, P.; Tran, T. N.; Braden, S. E.; Wiseman, S.; Danton, J.; Eliason, E. M.; Robinson, M. S.

    2016-04-01

    Characterization and calibration are vital for instrument commanding and image interpretation in remote sensing. The Lunar Reconnaissance Orbiter Camera Narrow Angle Camera (LROC NAC) takes 500 Mpixel greyscale images of lunar scenes at 0.5 meters/pixel. It uses two nominally identical line scan cameras for a larger crosstrack field of view. Stray light, spatial crosstalk, and nonlinearity were characterized using flight images of the Earth and the lunar limb. These are important for imaging shadowed craters, studying ˜1 meter size objects, and photometry respectively. Background, nonlinearity, and flatfield corrections have been implemented in the calibration pipeline. An eight-column pattern in the background is corrected. The detector is linear for DN = 600--2000 but a signal-dependent additive correction is required and applied for DN<600. A predictive model of detector temperature and dark level was developed to command dark level offset. This avoids images with a cutoff at DN=0 and minimizes quantization error in companding. Absolute radiometric calibration is derived from comparison of NAC images with ground-based images taken with the Robotic Lunar Observatory (ROLO) at much lower spatial resolution but with the same photometric angles.

  19. Impact of pollution caused by uranium production on soil macrofauna.

    PubMed

    Gongalsky, Konstantin B

    2003-12-01

    Thirty years of mining and milling activities of the Priargunsky Mining-Chemical Production Company (South-Eastern Siberia, Russia) have resulted in an enrichment of uranium in adjacent steppe soils by a factor of up to 600. A number of attendant pollutants (thorium, arsenic and heavy metals) also have high concentrations in the soil. To estimate the effects of this pollution on soil-living macroinvertebrates, pitfall trapping and core sampling were applied. The element composition of four beetle species was analysed. Soil macroinvertebrates had 3-37 times lower abundance and biodiversity at the contaminated sites compared with the control. Ground beetle communities at the contaminated sites were reduced compared to the control site. The concentrations of uranium and arsenic in beetles collected at the contaminated sites were 2-41 and 2-26 times higher, respectively, than at the control site. There is strong evidence that the contamination caused by uranium production has severe negative biological effects on important groups of the soil food web.

  20. Current characteristics associated with hereditary angioedema attacks and treatment: the home infusion based patient experience.

    PubMed

    Tachdjian, Raffi; Banerji, Aleena; Guyer, Autumn; Morphew, Tricia

    2015-01-01

    This article presents a current perspective on the characteristics of hereditary angioedema (HAE) attacks and treatment as captured by a home infusion service. Retrospective data on 158 HAE patients who were enrolled in this acute treatment program were analyzed for factors surrounding an attack. The majority of patients had a high level of disease severity at baseline (88%), with a higher than expected likelihood of having a positive family history (87.8%). The most likely times for patients to call for home treatment were just before and during working hours (6:00 A.M.-5:00 P.M.). Eighty-three percent had more than one alternate mode of medication. Factors associated with a severe attack included an overall severe rating of HAE attacks in the previous year, an abdominal attack alone or a combination of peripheral and abdominal attacks versus a peripheral attack alone, and the use of two doses rather than one for treatment of the current attack. Average time to relief onset was 43.5 minutes. One dose of ecallantide was sufficient to treat the majority of attacks, and a second dose was needed in 23.6% of patients experiencing a severe attack. However, patients who reported both a severe attack rating during the previous year and experiencing only a peripheral current attack were more likely to experience a severe current attack. Acute treatment paradigms for HAE remain diverse. Understanding factors driving these decisions could help alleviate the overall burden of this disease and help overcome some of the challenges faced by the patients and their caretakers and improve their quality of life. Enhanced capture and analysis of prodromal factors in future studies should help us further alleviate the burden of this disease.

  1. An efficient method for Agrobacterium-mediated genetic transformation and plant regeneration in cumin (Cuminum cyminum L.).

    PubMed

    Pandey, Sonika; Mishra, Avinash; Patel, Manish Kumar; Jha, Bhavanath

    2013-09-01

    Cumin is an annual herbaceous medicinally important plant having diverse applications. An efficient and reproducible method of Agrobacterium-mediated genetic transformation was herein established for the first time. A direct regeneration method without callus induction was optimised using embryos as explant material in Gamborg's B5 medium supplemented with 0.5-μM 6-benzyladenine and 2.0-μM α-naphthalene acetic acid. About 1,020 embryos (a mean of 255 embryos per batch) were used for the optimisation of transformation conditions. These conditions were an Agrobacterium cell suspension of 0.6 OD600, a co-cultivation time of 72 h, 300-μM acetosyringone and wounding of explants using a razor blade. Pre-cultured elongated embryos were treated using optimised conditions. About 720 embryos (a mean of 180 embryos per batch) were used for transformation and 95 % embryos showed transient β-glucuronidase expression after co-cultivation. Putative transformed embryos were cultured on B5 medium for shoot proliferation and 21 regenerated plants were obtained after selection and allowed to root. T0 plantlets showed β-glucuronidase expression and gene integration was confirmed via PCR amplification of 0.96 and 1.28 kb fragments of the hygromycin-phosphotransferase II and β-glucuronidase genes, respectively. In this study, a transformation efficiency of 1.5 % was demonstrated and a total of 11 transgenic plants were obtained at the hardening stage, however, only four plants acclimatised during hardening. Gene copy number was analysed by Southern blot analysis of hardened plants and single-copy gene integration was observed. This is the first successful attempt of Agrobacterium-mediated genetic transformation of cumin.

  2. Effect of night time-intervals, height of traps and lunar phases on sand fly collection in a highly endemic area for canine leishmaniasis.

    PubMed

    Gaglio, Gabriella; Brianti, Emanuele; Napoli, Ettore; Falsone, Luigi; Dantas-Torres, Filipe; Tarallo, Viviana D; Otranto, Domenico; Giannetto, Salvatore

    2014-05-01

    The activity of phlebotomine sand flies was monitored in a sub-urban area of Sicily in order to acquire data on seasonality and to elucidate the effect of the night time-intervals, height of traps from ground and lunar phases on the abundance of the capture. The study was conducted in the farm of the University of Messina (Italy). Light traps were placed as in the following: biweekly, from dusk to dawn, and from May to November; for three consecutive nights from 18:00 to 6:00, with the net bag being changed every 2h; for 30 days, at different heights from 18:00 to 6:00. A total of five species (i.e., Phlebotomus perniciosus, Phlebotomus neglectus, Phlebotomus sergenti, Phlebotomus perfiliewi, and Sergentomyia minuta), three of which are proven vectors of Leishmania infantum, were captured. The most abundant species was P. perniciosus (73.3%) followed by S. minuta (23.3%). The highest number of phlebotomine sand flies was collected in August and September with a peak of collection recorded in the evening (i.e., from 20:01 to 22.00). The number of phlebotomine sand flies collected at 50cm above the ground was significantly higher (P=0.041) than that captured at 150cm. Results of this study shed light on the ecology of main phlebotomine species in the Mediterranean area, and on the influence of some factors, such as time and height of traps, on the light trap capture efficiency.

  3. Parallel molecular dynamics simulations of pressure-induced structural transformations in cadmium selenide nanocrystals

    NASA Astrophysics Data System (ADS)

    Lee, Nicholas Jabari Ouma

    Parallel molecular dynamics (MD) simulations are performed to investigate pressure-induced solid-to-solid structural phase transformations in cadmium selenide (CdSe) nanorods. The effects of the size and shape of nanorods on different aspects of structural phase transformations are studied. Simulations are based on interatomic potentials validated extensively by experiments. Simulations range from 105 to 106 atoms. These simulations are enabled by highly scalable algorithms executed on massively parallel Beowulf computing architectures. Pressure-induced structural transformations are studied using a hydrostatic pressure medium simulated by atoms interacting via Lennard-Jones potential. Four single-crystal CdSe nanorods, each 44A in diameter but varying in length, in the range between 44A and 600A, are studied independently in two sets of simulations. The first simulation is the downstroke simulation, where each rod is embedded in the pressure medium and subjected to increasing pressure during which it undergoes a forward transformation from a 4-fold coordinated wurtzite (WZ) crystal structure to a 6-fold coordinated rocksalt (RS) crystal structure. In the second so-called upstroke simulation, the pressure on the rods is decreased and a reverse transformation from 6-fold RS to a 4-fold coordinated phase is observed. The transformation pressure in the forward transformation depends on the nanorod size, with longer rods transforming at lower pressures close to the bulk transformation pressure. Spatially-resolved structural analyses, including pair-distributions, atomic-coordinations and bond-angle distributions, indicate nucleation begins at the surface of nanorods and spreads inward. The transformation results in a single RS domain, in agreement with experiments. The microscopic mechanism for transformation is observed to be the same as for bulk CdSe. A nanorod size dependency is also found in reverse structural transformations, with longer nanorods transforming more

  4. An implementation for the detection and analysis of negative peaks in an applied current signal across a silicon nanopore

    NASA Astrophysics Data System (ADS)

    Billo, Joseph A.; Asghar, Waseem; Iqbal, Samir M.

    2011-06-01

    Translocation of DNA through a silicon nanopore with an applied voltage bias causes the ionic current signal to spike sharply downward as molecules block the flow of ions through the pore. Proper processing of the sampled signal is paramount in obtaining accurate translocation kinetics from the negative peaks, but manual analysis is time-consuming. Here, an algorithm is reported that automates the process. It imports the signal from a tab-delimited text file, automatically zero-baselines, filters noise, detects negative peaks, and estimates each peak's start and end time. The imported signal is processed using a zero-overlap sampling window. Peaks are detected by comparison of the window's standard deviation to a threshold standard deviation in addition to a comparison against a peak magnitude threshold. Zero-baselining and noise removal is accomplished through calculation of the mean of non-peak window values. The start and end times of a peak are approximated by checking where the signal becomes positive on either side of the peak. The program then stores the magnitude, sample number, approximate start time, and approximate end time of each peak in a matrix. All these tasks are automatically done by the program, requiring only the following initial input from the user: window size, file path to sampled signal data file, standard deviation threshold, peak magnitude threshold, and sampling frequency of the sampled signal. Trials with signals from an 11-micron pore sampled at 100 kHz for 30 seconds yielded a high rate of successful peak detection with a magnitude threshold of 600, a standard deviation threshold of 1.25, and a window size of 100.

  5. Toxicity Data to Determine Refrigerant Concentration Limits

    SciTech Connect

    Calm, James M.

    2000-09-30

    This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant concentration limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL concentrations-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others in commercial or developmental status. Appendices provide profiles for the cited single-compound refrigerants and for R-500 and R-502 as well as narrative toxicity summaries for common refrigerants. The report includes an extensive set of references.

  6. Interferon gamma-activated human monocytes downregulate transferrin receptors and inhibit the intracellular multiplication of Legionella pneumophila by limiting the availability of iron.

    PubMed Central

    Byrd, T F; Horwitz, M A

    1989-01-01

    We have investigated the role of iron in the intracellular biology of Legionella pneumophila in human monocytes and in the effector arm of cell-mediated immune defense against this intracellular bacterial pathogen. To determine if L. pneumophila intracellular multiplication is iron dependent, we studied the effect of the iron chelator deferoxamine on L. pneumophila infection of monocytes. Deferoxamine at 15 microM completely inhibited L. pneumophila intracellular multiplication. The inhibitory effect of deferoxamine was reversed with equimolar iron-saturated transferrin but not apotransferrin. To examine the potential role of iron in monocyte activation, we investigated the influence of iron-saturated transferrin on L. pneumophila multiplication in IFN gamma-activated monocytes. Iron transferrin, but not apotransferrin, neutralized the capacity of activated monocytes to inhibit L. pneumophila multiplication. To explore a potential mechanism by which activated monocytes might limit the availability of intracellular iron, we examined transferrin receptor expression on nonactivated and activated monocytes cultured in vitro for 5 d. By fluorescence-activated flow cytometry, activated monocytes exhibited markedly fewer transferrin receptors than nonactivated monocytes. By Scatchard analysis of 125I-transferrin binding to monocytes, nonactivated monocytes had 38,300 +/- 12,700 (mean +/- SE) transferrin binding sites, whereas activated monocytes had 10,300 +/- 1,600, a reduction of 73%. Activated and nonactivated monocytes had a similar mean Kd (1.8 +/- 0.2 nM). This study demonstrates that (a) L. pneumophila intracellular multiplication is iron dependent; (b) activated monocytes inhibit L. pneumophila multiplication by limiting the availability of intracellular iron; and (c) transferrin receptors are downregulated on IFN gamma-activated monocytes. Images PMID:2496141

  7. Use of Special Sensor Microwave/Imager (SSM/I) for estimation of precipitation features in a semi-arid, mountain region: A case study of southwest Saudi Arabia

    SciTech Connect

    Mashat, A.S.

    1992-01-01

    The linear regression method was used to determine the degree of correlation between soil caused by rainfall and Special Sensor Microwave/Imager (SSM/I) brightness temperatures or combinations of two brightness temperatures. This study is concerned with the application of passive microwaves to soil moisture classifications in a semi-arid, mountain region. The southwest region of Saudi Arabia was chosen for this study. Two case studies were performed to investigate the response of SSM/I brightness temperatures to soil moisture. The first case study is at satellite ascending overpass time (about 6:00 a.m. local solar time), and the second case study is at satellite descending overpass time (about 6:00 p.m. local solar time). It is shown that brightness temperatures normalized with respect to ground temperature may be interpreted in terms of the soil moisture in the surface layer of the soil. Normalized brightness temperatures are not sensitive to soil moisture when precipitating clouds are present. The existence of precipitating clouds over the study area was determined through an examination of brightness temperatures at 8.5. GHz. It was found that the normalized brightness temperatures with respect to ground temperature responded to the change of the soil moisture caused by rainfall. The normalized brightness temperature in channel H19 with respect to ground temperature (H19/T) was the best single SSM/I channel to use for a surface soil moisture investigation at satellite descending overpass time, and the normalized brightness temperature in channel H37 with respect to ground temperature (H37/T) was the best single SSM/I channel to use for a surface soil moisture investigation at satellite ascending overpass time.

  8. Revisiting the destination ranking procedure in development of an Intervening Opportunities Model for public transit trip distribution

    NASA Astrophysics Data System (ADS)

    Nazem, Mohsen; Trépanier, Martin; Morency, Catherine

    2015-01-01

    An Enhanced Intervening Opportunities Model (EIOM) is developed for Public Transit (PT). This is a distribution supply dependent model, with single constraints on trip production for work trips during morning peak hours (6:00 a.m.-9:00 a.m.) within the Island of Montreal, Canada. Different data sets, including the 2008 Origin-Destination (OD) survey of the Greater Montreal Area, the 2006 Census of Canada, GTFS network data, along with the geographical data of the study area, are used. EIOM is a nonlinear model composed of socio-demographics, PT supply data and work location attributes. An enhanced destination ranking procedure is used to calculate the number of spatially cumulative opportunities, the basic variable of EIOM. For comparison, a Basic Intervening Opportunities Model (BIOM) is developed by using the basic destination ranking procedure. The main difference between EIOM and BIOM is in the destination ranking procedure: EIOM considers the maximization of a utility function composed of PT Level Of Service and number of opportunities at the destination, along with the OD trip duration, whereas BIOM is based on a destination ranking derived only from OD trip durations. Analysis confirmed that EIOM is more accurate than BIOM. This study presents a new tool for PT analysts, planners and policy makers to study the potential changes in PT trip patterns due to changes in socio-demographic characteristics, PT supply, and other factors. Also it opens new opportunities for the development of more accurate PT demand models with new emergent data such as smart card validations.

  9. Cultivation and Characterization of Cynara Cardunculus for Solid Biofuels Production in the Mediterranean Region

    PubMed Central

    Grammelis, Panagiotis; Malliopoulou, Anastasia; Basinas, Panagiotis; Danalatos, Nicholas G.

    2008-01-01

    Technical specifications of solid biofuels are continuously improved towards the development and promotion of their market. Efforts in the Greek market are limited, mainly due to the climate particularity of the region, which hinders the growth of suitable biofuels. Taking also into account the increased oil prices and the high inputs required to grow most annual crops in Greece, cardoon (Cynara cardunculus L.) is now considered the most important and promising sources for solid biofuel production in Greece in the immediate future. The reason is that cardoon is a perennial crop of Mediterranean origin, well adapted to the xerothermic conditions of southern Europe, which can be utilized particularly for solid biofuel production. This is due to its minimum production cost, as this perennial weed may perform high biomass productivity on most soils with modest or without any inputs of irrigation and agrochemicals. Within this framework, the present research work is focused on the planning and analysis of different land use scenarios involving this specific energy crop and the combustion behaviour characterization for the solid products. Such land use scenarios are based on quantitative estimates of the crop'sproduction potential under specific soil-climatic conditions as well as the inputs required for its realization in comparison to existing conventional crops. Concerning its decomposition behaviour, devolatilisation and char combustion tests were performed in a non-isothermal thermogravimetric analyser (TA Q600). A kinetic analysis was applied and accrued results were compared with data already available for other lignocellulosic materials. The thermogravimetric analysis showed that the decomposition process of cardoon follows the degradation of other lignocellulosic fuels, meeting high burnout rates. This research work concludes that Cynara cardunculus, under certain circumstances, can be used as a solid biofuel of acceptable quality. PMID:19325802

  10. Movements of wolves at the northern extreme of the species' range, including during four months of darkness

    USGS Publications Warehouse

    Mech, L.D.; Cluff, H.D.

    2011-01-01

    Information about wolf (Canis lupus) movements anywhere near the northern extreme of the species' range in the High Arctic (<75??N latitude) are lacking. There, wolves prey primarily on muskoxen (Ovibos moschatus) and must survive 4 months of 24 hr/day winter darkness and temperatures reaching -53 C. The extent to which wolves remain active and prey on muskoxen during the dark period are unknown, for the closest area where information is available about winter wolf movements is >2,250 km south. We studied a pack of ???20 wolves on Ellesmere Island, Nunavut, Canada (80??N latitude) from July 2009 through mid-April 2010 by collaring a lead wolf with a Global Positioning System (GPS)/Argos radio collar. The collar recorded the wolf's precise locations at 6:00 a.m. and 6:00 p.m. daily and transmitted the locations by satellite to our email. Straight-line distances between consecutive 12-hr locations varied between 0 and 76 km. Mean (SE) linear distance between consecutive locations (n = 554) was 11 (0.5) km. Total minimum distance traveled was 5,979 km, and total area covered was 6,640 km2, the largest wolf range reported. The wolf and presumably his pack once made a 263-km (straight-line distance) foray to the southeast during 19-28 January 2010, returning 29 January to 1 February at an average of 41 km/day straight-line distances between 12-hr locations. This study produced the first detailed movement information about any large mammal in the High Arctic, and the average movements during the dark period did not differ from those afterwards. Wolf movements during the dark period in the highest latitudes match those of the other seasons and generally those of wolves in lower latitudes, and, at least with the gross movements measurable by our methods, the 4-month period without direct sunlight produced little change in movements. ?? 2011 Mech, Cluff.

  11. Uncovering the Spectral Energy Distribution in Active Galaxies Using High Ionization Mid-Infrared Emission Lines

    NASA Technical Reports Server (NTRS)

    Melendez, M.; Kraemer, S. B.; Weaver, K. A.; Mushotzky, R. F.

    2011-01-01

    The shape of the spectral energy distribution of active galaxies in the EUV soft X-ray band (13.6 eV to 1 keV) is uncertain because obscuration by dust and gas can hamper our view of the continuum. To investigate the shape of the spectral energy distribution in this energy band, we have generated a set of photoionization models which reproduce the small dispersion found in correlations between high-ionization mid-infrared emission lines in a sample of hard X-ray selected AGN. Our calculations show that a broken power-law continuum model is sufficient to reproduce the [Ne V]14.32 microns/[Ne III], [Ne V]24.32 microns/[O IV]25.89 micron and [O IV] 25.89 microns/[Ne III] ratios, and does not require the addition of a "big bump" EUV model component. We constrain the EUV-soft X-ray slope, alpha(sub i), to be between 1.5 - 2.0 and derive a best fit of alpha(sub i) approx. 1.9 for Seyfert 1 galaxies, consistent with previous studies of intermediate redshift quasars. If we assume a blue bump model, most sources in our sample have derived temperatures between T(sub BB) = 10(exp 5.18) K to 10(exp 5.7) K, suggesting that the peak of this component spans a large range of energies extending from approx. (Lambda)600 A to > (Lambda)1900 A. In this case, the best fitting peak energy that matches the mid-infrared line ratios of Seyfert 1 galaxies occurs between approx. (Lambda)700-(Lambda)1000 A. Despite the fact that our results do not rule out the presence of an EUV bump, we conclude that our power-law model produces enough photons with energies > 4 Ry to generate the observed amount of mid-infrared emission in our sample of BAT AGN.

  12. Numerical simulation on level fluctuation in bloom casting mold with electromagnetic stirring

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Ni, H. W.; Li, Y.; Zhao, Z. F.

    2016-03-01

    Based on a 380mm × 280mm bloom caster mold, the level fluctuation of steel-slag interface in the mold was simulated by the VOF model of commercial software Fluent. The effects of current intensity and frequency of EMS (electromagnetic stirring) on the level fluctuation in the mold were studied. The results show that whether or not with EMS, the maximum level fluctuation site of the mold occurs in the vicinity of the submerged entry nozzle. Compared with casting without EMS, molten steel flows horizontally rotatably under the action of the electromagnetic force by electromagnetic stirring, so the impact depth of molten steel decreases, then the level fluctuation slightly reduces, and the maximum level fluctuation value in the wide direction and the narrow direction of the mold, reduce from 4.24mm and 4.14mm to 4.04mm and 3.73mm respectively. With increasing intensity and frequency of current, the mold level fluctuation rises and the distribution uniformity of the level fluctuating amplitude worsens. The maximum level fluctuation enlarges by 0.18mm with raising the current intensity from 450A to 550A, but it enlarges by 0.79mm with 600A current intensity. The maximum level fluctuation enlarges by 0.15mm with raising the current frequency from 1.5Hz to 2.0Hz, but it quickly enlarges by 0.78mm with 2.5Hz current frequency. When the current strength and frequency are not more than 550A and 2.0Hz, level fluctuations are 4.00mm or less, which can meet requirements for controlling the bloom surface quality.

  13. Extreme events in the sedimentary record of maar Lake Pavin: Implications for natural hazards assessment in the French Massif Central

    NASA Astrophysics Data System (ADS)

    Chassiot, Léo; Chapron, Emmanuel; Di Giovanni, Christian; Albéric, Patrick; Lajeunesse, Patrick; Lehours, Anne-Catherine; Meybeck, Michel

    2016-06-01

    A set of sedimentary cores, high resolution swath bathymetry and subbottom profiler data provides new insights on sedimentary processes in meromictic maar Lake Pavin, France. Three sedimentary environments (i.e., littoral, plateau and basin) have been identified in the lake from sediment composition using bulk organic geochemistry and the analysis of hydroacoustic images. Various forms of rapidly deposited layers (RDLs) have been identified and radiocarbon dated. An up to date stratigraphy of sedimentary events matching coeval RDLs across the lake is presented and illustrates a wide range of natural hazards linked to Lake Pavin during the last 2000 years. In AD 600, a sudden lake outburst triggered a slump deposit along with a 9 m lake-level drop that drove shifts in sedimentary organic matter composition. Outside the lake, outburst flood deposits have been described downstream and provide sedimentary evidence for this event. The lake-level drop also favored the generation of gravity reworking processes, as shown by (1) a regional earthquake-triggered large slope failure on the plateau connected to a mass-wasting deposit in the basin dated to AD 1300, and (2) a succession of turbidites in AD 1825 and AD 1860 contemporaneous to two historic earthquakes, suggesting that this lake is sensitive to earthquakes with a minimum epicentral intensity of V. Finally, past observations of lake water color changes in AD 1783 and AD 1936, similar to reports in other meromictic lakes, match iron-rich deposits identified in maar lake sediments and suggest that Lake Pavin could have undergone limnic eruptions.

  14. ‘MicroRNA Targets’, a new AthaMap web-tool for genome-wide identification of miRNA targets in Arabidopsis thaliana

    PubMed Central

    2012-01-01

    Background The AthaMap database generates a genome-wide map for putative transcription factor binding sites for A. thaliana. When analyzing transcriptional regulation using AthaMap it may be important to learn which genes are also post-transcriptionally regulated by inhibitory RNAs. Therefore, a unified database for transcriptional and post-transcriptional regulation will be highly useful for the analysis of gene expression regulation. Methods To identify putative microRNA target sites in the genome of A. thaliana, processed mature miRNAs from 243 annotated miRNA genes were used for screening with the psRNATarget web server. Positional information, target genes and the psRNATarget score for each target site were annotated to the AthaMap database. Furthermore, putative target sites for small RNAs from seven small RNA transcriptome datasets were used to determine small RNA target sites within the A. thaliana genome. Results Putative 41,965 genome wide miRNA target sites and 10,442 miRNA target genes were identified in the A. thaliana genome. Taken together with genes targeted by small RNAs from small RNA transcriptome datasets, a total of 16,600 A. thaliana genes are putatively regulated by inhibitory RNAs. A novel web-tool, ‘MicroRNA Targets’, was integrated into AthaMap which permits the identification of genes predicted to be regulated by selected miRNAs. The predicted target genes are displayed with positional information and the psRNATarget score of the target site. Furthermore, putative target sites of small RNAs from selected tissue datasets can be identified with the new ‘Small RNA Targets’ web-tool. Conclusions The integration of predicted miRNA and small RNA target sites with transcription factor binding sites will be useful for AthaMap-assisted gene expression analysis. URL: http://www.athamap.de/ PMID:22800758

  15. SDSS-IV MaNGA: Survey Design and Progress

    NASA Astrophysics Data System (ADS)

    Yan, Renbin; MaNGA Team

    2016-01-01

    The ongoing SDSS-IV/MaNGA Survey will obtain integral field spectroscopy at a resolution of R~2000 with a wavelength coverage from 3,600A to 10,300A for 10,000 nearby galaxies. Within each 3 degree diameter pointing of the 2.5m Sloan Telescope, we deploy 17 hexagonal fiber bundles with sizes ranging from 12 to 32 arcsec in diameter. The bundles are build with 2 arcsec fibers and have a 56% fill factor. During observations, we obtained sets of exposures at 3 different dither positions to achieve near-critical sampling of the effective point spread function, which has a FWHM about 2.5 arcsec, corresponding to 1-2 kpc for the majority of the galaxies targeted. The flux calibration is done using 12 additional mini-fiber-bundles targeting standard stars simultaneously with science targets, achieving a calibration accuracy better than 5% over 90% of the wavelength range. The target galaxies are selected to ensure uniform spatial coverage in units of effective radii for the majority of the galaxies while maximizing spatial resolution. About 2/3 of the sample is covered out to 1.5Re (primary sample) and 1/3 of the sample covered to 2.5Re (secondary sample). The sample is designed to have approximately equal representation from high and low mass galaxies while maintaining volume-limited selection at fixed absolute magnitudes. We obtain an average S/N of 4 per Angstrom in r-band continuum at a surface brightness of 23 AB arcsec-2. With spectral stacking in an elliptical annulus covering 1-1.5Re, our primary sample galaxies have a median S/N of ~60 per Angstrom in r-band.

  16. An efficient method for Agrobacterium-mediated genetic transformation and plant regeneration in cumin (Cuminum cyminum L.).

    PubMed

    Pandey, Sonika; Mishra, Avinash; Patel, Manish Kumar; Jha, Bhavanath

    2013-09-01

    Cumin is an annual herbaceous medicinally important plant having diverse applications. An efficient and reproducible method of Agrobacterium-mediated genetic transformation was herein established for the first time. A direct regeneration method without callus induction was optimised using embryos as explant material in Gamborg's B5 medium supplemented with 0.5-μM 6-benzyladenine and 2.0-μM α-naphthalene acetic acid. About 1,020 embryos (a mean of 255 embryos per batch) were used for the optimisation of transformation conditions. These conditions were an Agrobacterium cell suspension of 0.6 OD600, a co-cultivation time of 72 h, 300-μM acetosyringone and wounding of explants using a razor blade. Pre-cultured elongated embryos were treated using optimised conditions. About 720 embryos (a mean of 180 embryos per batch) were used for transformation and 95 % embryos showed transient β-glucuronidase expression after co-cultivation. Putative transformed embryos were cultured on B5 medium for shoot proliferation and 21 regenerated plants were obtained after selection and allowed to root. T0 plantlets showed β-glucuronidase expression and gene integration was confirmed via PCR amplification of 0.96 and 1.28 kb fragments of the hygromycin-phosphotransferase II and β-glucuronidase genes, respectively. In this study, a transformation efficiency of 1.5 % was demonstrated and a total of 11 transgenic plants were obtained at the hardening stage, however, only four plants acclimatised during hardening. Gene copy number was analysed by Southern blot analysis of hardened plants and single-copy gene integration was observed. This is the first successful attempt of Agrobacterium-mediated genetic transformation of cumin. PMID:23813408

  17. Clinical profile of patients diagnosed with leptospirosis after a typhoon: a multicenter study.

    PubMed

    Mendoza, Myrna T; Roxas, Evalyn A; Ginete, Joanne Kathleene; Alejandria, Marissa M; Roman, Arthur Dessi E; Leyritana, Katerina T; Penamora, Mary Ann D; Pineda, Cristina C

    2013-11-01

    This study described the clinical features and complications of leptospirosis among patients seen at nine tertiary hospitals from September 28 to November 30, 2009 after a heavy rainfall typhoon. The clinical findings of the confirmed cases were compared with the previous clinical studies on seasonal leptospirosis in the Philippines. Risk factors for complicated disease were also identified. Confirmed cases were based on any of the following: positive leptospiral cultures of blood or urine, single high leptospira microscopic agglutination test (MAT) titer of 1:1,600, a fourfold rise in MAT, and/or seroconversion. Of 670 patients with possible leptospirosis, 591 were probable by the WHO criteria, 259 (44%) were confirmed. Diagnosis was confirmed by MAT 176 (68%), by culture 57 (22%), and by MAT and culture 26 (10%). The mean age of the confirmed cases was 38.9 years (SD 14.3). The majority were males (82%) and had a history of wading in floodwaters (98%). The majority of the patients presented with nonspecific signs, with fever as the most common (98.5%). Other findings were myalgia (78.1%), malaise (74.9%), conjunctival suffusion (59.3%), oliguria (56.6%), diarrhea (39%), and jaundice (38%). Most of the patients presented with a moderate-to-severe form of leptospirosis (83%). Complications identified were renal failure (82%), pulmonary hemorrhage (8%), meningitis (5%), and myocarditis (4%). Mortality rate was 5%, mostly due to pulmonary hemorrhage. This study emphasizes the importance of public awareness and high index of suspicion among clinicians of leptospirosis during the monsoon months when flooding is common. Early recognition and detection of the disease should decrease morbidity and mortality.

  18. [The significance of malaria in the Western Roman Empire: A text passage in the Digesta].

    PubMed

    Hassl, Andreas R

    2008-01-01

    The significance of malaria for the decadence and the final fall of the Western Roman Empire is discussed controversially. It seems verisimilar that Central Europe was free of malaria at the end of the last ice age, and it is undisputed that the Apennine peninsula was a substantially depopulated, endemic malaria area around 600 A.D. The immigration of three of the four Plasmodium species infectious for man took place most likely at different era and with very different effects on the antique societies. A text passage in the Digesta of Justinian (D 21.1.1.8), written by the post classical jurist Ulpian (approx. 170-223 A.D.), illuminates selectively in region and period the malaria situation of the social underclass in and around Rome, a city with a population over a million at that time. The quotation indicates, shortened, "that an old Quartana, about which one does not have to worry any longer, is not an argument for a warranty for defects in case of slaves bought at the market". From this annotation one can deduce that at the turn of the second to the third century A.D. Quartana recrudescence represented the medical normality for people from the social underclass in Rome and the surrounding area. Thus, while at that time Plasmodium malariae seemed to be a common part of the human parasite fauna in Latium, Malaria tropica and Malaria tertiana did not yet unfold their depopulating, economically and socially devastating effects; this happened several centuries later, although the existence of at least one effective vector is proven.

  19. How Should Long-Term Tunneled Central Venous Catheters Be Managed in Microbiology Laboratories in Order To Provide an Accurate Diagnosis of Colonization?

    PubMed Central

    Martín-Rabadán, P.; Echenagusia, A.; Camúñez, F.; Rodríguez-Rosales, G.; Simó, G.; Echenagusia, M.

    2012-01-01

    Guidelines recommend the roll-plate technique for short-term central venous catheter (CVC) tip cultures. However, the issue of whether the roll-plate technique is better than the sonication method for long-term CVCs remains unresolved. In addition, no data are available for predicting the value of direct Gram staining in anticipating catheter colonization or catheter-related bloodstream infection (CRBSI) in these long-term CVCs. Our objectives were to compare the roll-plate technique and the sonication method and to define the validity values of Gram staining for the prediction of colonization and CRBSI in patients with long-term tunneled CVCs. During the study period, all tunneled CVCs removed at our institution were prospectively and routinely sent to the microbiology laboratory for Gram staining (first) and tip culture (the Maki technique and sonication, in a random order). We received 149 tunneled CVCs, 39 (26.2%) of which were colonized and 11 (7.4%) of which were associated with CRBSI. Overall, the roll-plate method detected 94.9% of the colonized catheters, whereas sonication detected only 43.6% (P < 0.001). The validity values of Gram staining for the detection of colonization and CRBSI were as follows: a sensitivity of 35.9% to 60.0%, a specificity of 100% to 94.2%, a positive predictive value of 100% to 42.9%, and a negative predictive value of 81.5% to 97.0%. The roll-plate technique proved to be better than sonication for the detection of bacteria in long-term tunneled CVCs. Gram staining of the tips of tunneled CVCs can anticipate a positive culture and rule out CRBSI. In our opinion, direct Gram staining should be incorporated into routine microbiological assessments of long-term catheter tips. PMID:22170928

  20. Cultivation and characterization of Cynara Cardunculus for solid biofuels production in the Mediterranean region.

    PubMed

    Grammelis, Panagiotis; Malliopoulou, Anastasia; Basinas, Panagiotis; Danalatos, Nicholas G

    2008-06-01

    Technical specifications of solid biofuels are continuously improved towards the development and promotion of their market. Efforts in the Greek market are limited, mainly due to the climate particularity of the region, which hinders the growth of suitable biofuels. Taking also into account the increased oil prices and the high inputs required to grow most annual crops in Greece, cardoon (Cynara cardunculus L.) is now considered the most important and promising sources for solid biofuel production in Greece in the immediate future. The reason is that cardoon is a perennial crop of Mediterranean origin, well adapted to the xerothermic conditions of southern Europe, which can be utilized particularly for solid biofuel production. This is due to its minimum production cost, as this perennial weed may perform high biomass productivity on most soils with modest or without any inputs of irrigation and agrochemicals. Within this framework, the present research work is focused on the planning and analysis of different land use scenarios involving this specific energy crop and the combustion behaviour characterization for the solid products. Such land use scenarios are based on quantitative estimates of the crop'sproduction potential under specific soil-climatic conditions as well as the inputs required for its realization in comparison to existing conventional crops. Concerning its decomposition behaviour, devolatilisation and char combustion tests were performed in a non-isothermal thermogravimetric analyser (TA Q600). A kinetic analysis was applied and accrued results were compared with data already available for other lignocellulosic materials. The thermogravimetric analysis showed that the decomposition process of cardoon follows the degradation of other lignocellulosic fuels, meeting high burnout rates. This research work concludes that Cynara cardunculus, under certain circumstances, can be used as a solid biofuel of acceptable quality.

  1. Chemical Treatments for Mobilizing Arsenic from Contaminated Aquifer Solids to Accelerate Remediation.

    PubMed

    Wovkulich, Karen; Mailloux, Brian J; Lacko, Allison; Keimowitz, Alison R; Stute, Martin; Simpson, H James; Chillrud, Steven N

    2010-10-01

    Arsenic is a prevalent contaminant at US Superfund sites where remediation by pump and treat systems is often complicated by slow desorption of As from Fe and Al (hydr)oxides in aquifer solids. Chemical amendments that either compete with As for sorption sites or dissolve Fe and Al (hydr)oxides can increase As mobility and improve pump and treat remediation efficiency. The goal of this work was to determine optimal amendments for improving pump and treat at As contaminated sites such as the Vineland Chemical Co. Superfund site in southern New Jersey. Extraction and column experiments were performed using As contaminated aquifer solids (81 ± 1 mg/kg), site groundwater, and either phosphate (NaH(2)PO(4)·H(2)O) or oxalic acid (C(2)H(2)O(4)·2H(2)O). In extraction experiments, phosphate mobilized between 11% and 94% of As from the aquifer solids depending on phosphate concentration and extraction time (1 mM-1 M; 1-24 h) and oxalic acid mobilized between 38 and 102% depending on oxalic acid concentration and extraction time (1-400 mM; 1-24 h). In column experiments, phosphate additions induced more As mobilization in the first few pore volumes but oxalic acid was more effective at mobilizing As overall and at lower amendment concentrations. At the end of the laboratory column experiments, 48% of As had been mobilized from the aquifer sediments with 100 mM phosphate and 88% had been mobilized with 10 mM oxalic acid compared with 5% with ambient groundwater alone. Furthermore, simple extrapolations based on pore volumes suggest that chemical treatments could lower the time necessary for clean up at the Vineland site from 600 a with ambient groundwater alone to potentially as little as 4 a with 10 mM oxalic acid.

  2. Effect of night time-intervals, height of traps and lunar phases on sand fly collection in a highly endemic area for canine leishmaniasis.

    PubMed

    Gaglio, Gabriella; Brianti, Emanuele; Napoli, Ettore; Falsone, Luigi; Dantas-Torres, Filipe; Tarallo, Viviana D; Otranto, Domenico; Giannetto, Salvatore

    2014-05-01

    The activity of phlebotomine sand flies was monitored in a sub-urban area of Sicily in order to acquire data on seasonality and to elucidate the effect of the night time-intervals, height of traps from ground and lunar phases on the abundance of the capture. The study was conducted in the farm of the University of Messina (Italy). Light traps were placed as in the following: biweekly, from dusk to dawn, and from May to November; for three consecutive nights from 18:00 to 6:00, with the net bag being changed every 2h; for 30 days, at different heights from 18:00 to 6:00. A total of five species (i.e., Phlebotomus perniciosus, Phlebotomus neglectus, Phlebotomus sergenti, Phlebotomus perfiliewi, and Sergentomyia minuta), three of which are proven vectors of Leishmania infantum, were captured. The most abundant species was P. perniciosus (73.3%) followed by S. minuta (23.3%). The highest number of phlebotomine sand flies was collected in August and September with a peak of collection recorded in the evening (i.e., from 20:01 to 22.00). The number of phlebotomine sand flies collected at 50cm above the ground was significantly higher (P=0.041) than that captured at 150cm. Results of this study shed light on the ecology of main phlebotomine species in the Mediterranean area, and on the influence of some factors, such as time and height of traps, on the light trap capture efficiency. PMID:24561074

  3. Movements of Wolves at the Northern Extreme of the Species' Range, Including during Four Months of Darkness

    PubMed Central

    Mech, L. David; Cluff, H. Dean

    2011-01-01

    Information about wolf (Canis lupus) movements anywhere near the northern extreme of the species' range in the High Arctic (>75°N latitude) are lacking. There, wolves prey primarily on muskoxen (Ovibos moschatus) and must survive 4 months of 24 hr/day winter darkness and temperatures reaching −53 C. The extent to which wolves remain active and prey on muskoxen during the dark period are unknown, for the closest area where information is available about winter wolf movements is >2,250 km south. We studied a pack of ≥20 wolves on Ellesmere Island, Nunavut, Canada (80°N latitude) from July 2009 through mid-April 2010 by collaring a lead wolf with a Global Positioning System (GPS)/Argos radio collar. The collar recorded the wolf's precise locations at 6:00 a.m. and 6:00 p.m. daily and transmitted the locations by satellite to our email. Straight-line distances between consecutive 12-hr locations varied between 0 and 76 km. Mean (SE) linear distance between consecutive locations (n = 554) was 11 (0.5) km. Total minimum distance traveled was 5,979 km, and total area covered was 6,640 km2, the largest wolf range reported. The wolf and presumably his pack once made a 263-km (straight-line distance) foray to the southeast during 19–28 January 2010, returning 29 January to 1 February at an average of 41 km/day straight-line distances between 12-hr locations. This study produced the first detailed movement information about any large mammal in the High Arctic, and the average movements during the dark period did not differ from those afterwards. Wolf movements during the dark period in the highest latitudes match those of the other seasons and generally those of wolves in lower latitudes, and, at least with the gross movements measurable by our methods, the 4-month period without direct sunlight produced little change in movements. PMID:21991308

  4. Nighttime aqueous-phase secondary organic aerosols in Los Angeles and its implication for fine particulate matter composition and oxidative potential

    NASA Astrophysics Data System (ADS)

    Saffari, Arian; Hasheminassab, Sina; Shafer, Martin M.; Schauer, James J.; Chatila, Talal A.; Sioutas, Constantinos

    2016-05-01

    Recent investigations suggest that aqueous phase oxidation of hydrophilic organic compounds can be a significant source of secondary organic aerosols (SOA) in the atmosphere. Here we investigate the possibility of nighttime aqueous phase formation of SOA in Los Angeles during winter, through examination of trends in fine particulate matter (PM2.5) carbonaceous content during two contrasting seasons. Distinctive winter and summer trends were observed for the diurnal variation of organic carbon (OC) and secondary organic carbon (SOC), with elevated levels during the nighttime in winter, suggesting an enhanced formation of SOA during that period. The nighttime ratio of SOC to OC was positively associated with the relative humidity (RH) at high RH levels (above 70%), which is when the liquid water content of the ambient aerosol would be high and could facilitate dissolution of hydrophilic primary organic compounds into the aqueous phase. Time-integrated collection and analysis of wintertime particles at three time periods of the day (morning, 6:00 a.m.-9:00 a.m.; afternoon, 11:00 a.m.-3:00 p.m.; night, 8:00 p.m.-4:00 a.m.) revealed higher levels of water soluble organic carbon (WSOC) and organic acids during the night and afternoon periods compared to the morning period, indicating that the SOA formation in winter continues throughout the nighttime. Furthermore, diurnal trends in concentrations of semi-volatile organic compounds (SVOCs) from primary emissions showed that partitioning of SVOCs from the gas to the particle phase due to the decreased nighttime temperatures cannot explain the substantial OC and SOC increase at night. The oxidative potential of the collected particles (quantified using a biological macrophage-based reactive oxygen species assay, in addition to the dithiothreitol assay) was comparable during afternoon and nighttime periods, but higher (by at least ∼30%) compared to the morning period, suggesting that SOA formation processes possibly enhance the toxicity of the ambient particles compared to mobile-source dominated primary emissions in the Los Angeles area.

  5. Development of Coated Conductors in Japanese National Project "Development of Fundamental Technologies for HTS Coils"

    NASA Astrophysics Data System (ADS)

    Yoshizumi, Masateru; Izumi, Teruo; Shiohara, Yuh

    RE1Ba2Cu3O7-x (REBCO, RE=rare earth) coated conductors have attracted the attention of many scientists due to the high superconducting properties, etc. Due to the great progress of R&D on coated conductors, the activities have shifted to specific applications. The new Japanese national project, named as "Development of Fundamental Technologies for HTS Coils", started last year aiming for the applications of MRI and medical accelerators. To meet the requirements of those applications, the R&D of REBCO coated conductors (CCs) are being performed with that of coiling technology in parallel. The theme has two sub-themes of "development of long CCs with high in-field performance" and "development of CCs with extremely low heat generation" in this national project. The ambitious goals of these themes are set as intermediate ones due 2016 Mar; the theme of in-field: 100m-500A/cm-w@65K, 3T -850A/cm-w@35K, 10T, the theme of low heat generation: 100m-500 μm of filament width w/ Icfilament inhomogeneity of distribution within 10% and joint resistance below 5nΩ. The final goals of these themes due 2018 Mar. were set as follows; the theme of in-field: 200m-600A/cm-w@65K, 3T -1000A/cm-w@35K, 10T, the theme of low heat generation: 200m-500 μm of filament width w/ Icfilament distribution within 5% and joint resistance below 3nΩ. The objectives, goals and progress of this project will be reviewed in this article. As for the progress, for example, the combination of EuBCO+BHO was found to be effective to improve the in-field performance of PLD derived coated conductors. A 94 m long wire with Icmin of 108A/cm-w@77K, 3T (corresponding to 472A/cm-w @65K, 3T) was successfully fabricated. It is as twice Icmin of the long tape as the highest one in the previous project.

  6. HYFLUX: Satellite Exploration of Natural Hydrocarbon Seeps and Discovery of a Methane Hydrate Mound at GC600

    NASA Astrophysics Data System (ADS)

    Garcia-Pineda, O. G.; MacDonald, I. R.; Shedd, W.; Zimmer, B.

    2009-12-01

    Analysis of natural hydrocarbon seeps is important to improve our understanding of methane flux from deeper sediments to the water column. In order to quantify natural hydrocarbon seep formations in the Northern Gulf of Mexico, a set of 686 Synthetic Aperture Radar (SAR) images was analyzed using the Texture Classifying Neural Network Algorithm (TCNNA), which processes SAR data to delineate oil slicks. This analysis resulted in a characterization of 396 natural seep sites distributed in the northern GOM. Within these sites, a maximum of 1248 individual vents where identified. Oil reaching the sea-surface is deflected from its source during transit through the water column. This presentation describes a method for estimating locations of active oil vents based on repeated slick detection in SAR. One of the most active seep formations was detected in MMS lease block GC600. A total of 82 SAR scenes (collected by RADARSAT-1 from 1995 to 2007) was processed covering this region. Using TCNNA the area covered by each slick was computed and Oil Slicks Origins (OSO) were selected as single points within detected oil slicks. At this site, oil slick signatures had lengths up to 74 km and up to 27 km^2 of area. Using SAR and TCNNA, four active vents were identified in this seep formation. The geostatistical mean centroid among all detections indicated a location along a ridge-line at ~1200m. Sea truth observations with an ROV, confirmed that the estimated location of vents had a maximum offset of ~30 m from their actual locations on the seafloor. At the largest vent, a 3-m high, 12-m long mound of oil-saturated gas hydrate was observed. The outcrop contained thousands of ice worms and numerous semi-rigid chimneys from where oily bubbles were escaping in a continuous stream. Three additional vents were found along the ridge; these had lower apparent flow, but were also plugged with gas hydrate mounds. These results support use of SAR data for precise delineation of active seep

  7. Photoionization of As sub 2 and As sub 4 : Implications for group V clusters

    SciTech Connect

    Yoo, R.K.; Ruscic, B.; Berkowitz, J. )

    1992-05-01

    The vacuum ultraviolet photoionization mass spectrum of As{sub 4} is presented, from the ionization threshold to 600 A. The apparent adiabatic ionization potential is {le}8.49 eV, but the true value may be significantly lower. Three broad autoionization features are observed, probably comprising members of a Rydberg series converging to the {ital {tilde B}} {sup 2}{ital A}{sub 1} state of As{sup +}{sub 4}. The first fragment, As{sup +}{sub 3}, has an appearance potential (0 K) of 11.23{plus minus}0.05 eV, from which we extract {Delta}{ital H}{sup 0}{sub {ital f}{sub 0}}(As{sup +}{sub 3}){le}228.7{plus minus}1.3 kcal/mol. The photoion yield curve of As{sup +}{sub 2}(As{sub 2}) is obtained under conditions where As{sub 2} is dominant in the vapor. The adiabatic ionization potential is 9.69{plus minus}0.02 eV. Two prominent autoionizing Rydberg series are observed, converging to the {ital A} {sup 2}{Sigma}{sup +}{sub {ital g}} state of As{sup +}{sub 2}, with an ionization potential of 10.238{plus minus}0.002 eV. At higher energy, three members of a window resonance series can be seen, converging to the {ital B} {sup 2}{Sigma}{sup +}{sub {ital u}} state of As{sup +}{sub 2}, with an ionization potential of 15.37 eV. From an upper limit to the partial pressure of As{sub 3}, equilibrium conditions, and assuming a triangular As{sub 3}, we deduce {Delta}{ital H}{sup 0}{sub {ital f}{sub 0}}(As{sub 3}){ge}60.0 kcal/mol; other criteria suggest {Delta}{ital H}{sup 0}{sub {ital f}{sub 0}}(As{sub 3}){congruent}63 kcal/mol. Consequently, the adiabatic ionization potential of As{sub 3} is {lt}7.32 eV, and probably {le}7.19 eV. Several implications are drawn, relevant to recent studies of antimony and bismuth clusters.

  8. Movements of wolves at the northern extreme of the species' range, including during four months of darkness

    USGS Publications Warehouse

    Mech, L. David; Cluff, H. Dean

    2011-01-01

    Information about wolf (Canis lupus) movements anywhere near the northern extreme of the species' range in the High Arctic (>75°N latitude) are lacking. There, wolves prey primarily on muskoxen (Ovibos moschatus) and must survive 4 months of 24 hr/day winter darkness and temperatures reaching -53 C. The extent to which wolves remain active and prey on muskoxen during the dark period are unknown, for the closest area where information is available about winter wolf movements is >2,250 km south. We studied a pack of ≥20 wolves on Ellesmere Island, Nunavut, Canada (80°N latitude) from July 2009 through mid-April 2010 by collaring a lead wolf with a Global Positioning System (GPS)/Argos radio collar. The collar recorded the wolf's precise locations at 6:00 a.m. and 6:00 p.m. daily and transmitted the locations by satellite to our email. Straight-line distances between consecutive 12-hr locations varied between 0 and 76 km. Mean (SE) linear distance between consecutive locations (n = 554) was 11 (0.5) km. Total minimum distance traveled was 5,979 km, and total area covered was 6,640 km2, the largest wolf range reported. The wolf and presumably his pack once made a 263-km (straight-line distance) foray to the southeast during 19–28 January 2010, returning 29 January to 1 February at an average of 41 km/day straight-line distances between 12-hr locations. This study produced the first detailed movement information about any large mammal in the High Arctic, and the average movements during the dark period did not differ from those afterwards. Wolf movements during the dark period in the highest latitudes match those of the other seasons and generally those of wolves in lower latitudes, and, at least with the gross movements measurable by our methods, the 4-month period without direct sunlight produced little change in movements.

  9. The emergence of the nuclear family: its effect on women's roles and fertility change in Nigeria.

    PubMed

    Omideyi, A K

    1993-01-01

    A survey of Yoruba women was carried out in 1986 in the urban areas of Ibadan and Ilesa and four villages in Nigeria which focused on the relationships between the status of married women and their fertility. A total of 2176 married women and their husbands were randomly selected and interviewed on marriage, pregnancy and fertility histories, employment histories, wife's purchasing power, social and political participation, and knowledge and practice of family planning (FP). At least 60% of the women had formal education (primary, secondary, or university). About one-fifth had no formal education and the same proportion had only Koranic or vocational education. The proportion that had formal education was higher in urban areas (63.8%) than in rural areas (53.2%) and those with no formal education were more in rural (28%) than in urban areas (15.6%). 69.1% of husbands had formal education vs. 60.5% of wives; and 72.5% of husbands were educated in urban areas vs. 61.4% in rural areas. Nine-tenths of the women worked full-time and one-tenth worked part-time. 85% of the husbands received income below Naira (N) 600 a month. In rural areas 89.5% of husbands had such low income; the percentage was lower in urban areas. A higher proportion of husbands living in urban areas than in rural areas earned an income above this level. Also a higher proportion of women living in urban areas earned higher incomes than women living in rural areas. The median household income ranged between N401 and N600, and it was earned in 29.5% of urban households vs. 25.1% of rural households. About 16% of the rural households earned less than N200 compared with 5.5% of urban households. The mean number of children ever born (CEB) was higher for rural women than for urban women with a household income below N200 and above N800. Households with income between N401 and N800 had higher fertility in urban than in rural areas.

  10. Characterization of Angiotensin-(1-7) effects on the cardiovascular system in an experimental model of type-1 diabetes.

    PubMed

    Yousif, Mariam H M; Dhaunsi, Gursev S; Makki, Batoul M; Qabazard, Bedour A; Akhtar, Saghir; Benter, Ibrahim F

    2012-09-01

    Although exogenous administration of Angiotensin-(1-7) [Ang-(1-7)] can prevent development of diabetes induced end-organ damage, little is known about the role of endogenous Ang-(1-7) in diabetes and requires further characterization. Here, we studied the effects of chronically inhibiting endogenous Ang-(1-7) formation with DX600, a selective angiotensin converting enzyme-2 (ACE2) inhibitor, on renal and cardiac NADPH oxidase (NOX) activity, vascular reactivity and cardiac function in a model of Type-1 diabetes. The contribution of endogenous Ang-(1-7) to the protective effects of Losartan and Captopril and that of prostaglandins to the cardiovascular effects of exogenous Ang-(1-7) were also examined. Cardiac and renal NOX activity, vascular reactivity to endothelin-1 (ET-1) and cardiac recovery from ischemia/reperfusion (I/R) injury were evaluated in streptozotocin-treated rats. Chronic treatment with DX600 exacerbated diabetes-induced increase in cardiac and renal NOX activity. Diabetes-induced abnormal vascular reactivity to ET-1 and cardiac dysfunction were improved by treatment with Ang-(1-7) and worsened by treatment with DX600 or A779, a Mas receptor antagonist. Ang-(1-7)-mediated improvement in cardiac recovery or vascular reactivity was attenuated by Indomethacin. Captopril and Losartan-induced improvement in cardiovascular function was attenuated when these drugs were co-administered with A779. Ang-(1-7)-mediated decrease in renal NOX activity was prevented by indomethacin. Losartan also decreased renal NOX activity that could be attenuated with A779 co-treatment. In conclusion, endogenous Ang-(1-7) inhibits diabetes-induced cardiac/renal NOX activity and end-organ damage, and mediates the actions of Captopril and Losartan. Further, prostaglandins are important intermediaries in the beneficial effects of Ang-(1-7) in diabetes. Combining either Losartan or Captopril with Ang-(1-7) had additional beneficial effects in preventing diabetes-induced cardiac

  11. Effect of an allophanic soil on humification reactions between catechol and glycine: Spectroscopic investigations of reaction products

    NASA Astrophysics Data System (ADS)

    Fukushima, Masami; Miura, Akitaka; Sasaki, Masahide; Izumo, Kenji

    2009-01-01

    Adduction of amino acids to phenols is a possible humification reaction pathway [F.J. Stevenson, Humus Chemistry: Genesis, Composition, Reaction, second ed., Wiley, New York, 1994, pp. 188-211; M.C. Wang, P.M. Huang, Sci. Total Environ. 62 (1987) 435; M.C. Wang, P.M. Huang, Soil Sci. Soc. Am. J. 55 (1991) 1156; M.C. Wang, P.M. Huang, Geoderma 112 (2003) 31; M.C. Wang, P.M. Huang, Geoderma 124 (2005) 415]. To elucidate the reaction kinetics and products of abiotic humification, the effects of an allophanic soil on the adduction of amino acids to phenols were investigated using catechol (CT) and glycine (Gly) as a model phenol and amino acid, respectively. An aqueous solution containing CT and Gly (pH 7.0) in the presence of allophanic soil was incubated for 2 weeks, and the kinetics of the humification reactions were monitored by analysis of absorptivity at 600 nm ( E600). A mixture of CT and Gly in the absence of allophanic soil was used as a control. The E600 value increased markedly in the presence of allophanic soil. In addition, unreacted CT was detected in the control reaction mixture, but not in the allophane-containing reaction mixture. Under the sterilized conditions, absorbance at 600 nm for the control reaction mixture was significantly smaller than that for the allophanic soil-containing reaction mixture, which indicates there was no microbial participation during incubation. These results indicate that the allophanic soil effectively facilitated humification reactions between CT and Gly. The reaction mixtures were acidified and humic-like acid (HLA) was isolated as a precipitate. The elemental composition, acidic functional group contents, molecular weight, FT-IR, solid-state CP-MAS 13C NMR, and 1H NMR spectra of the purified HLAs were analyzed. The results of these analyses indicate that the nitrogen atom of Gly binds to the aromatic carbon of CT in the HLA products.

  12. Movements of wolves at the northern extreme of the species' range, including during four months of darkness.

    PubMed

    Mech, L David; Cluff, H Dean

    2011-01-01

    Information about wolf (Canis lupus) movements anywhere near the northern extreme of the species' range in the High Arctic (>75°N latitude) are lacking. There, wolves prey primarily on muskoxen (Ovibos moschatus) and must survive 4 months of 24 hr/day winter darkness and temperatures reaching -53 C. The extent to which wolves remain active and prey on muskoxen during the dark period are unknown, for the closest area where information is available about winter wolf movements is >2,250 km south. We studied a pack of ≥20 wolves on Ellesmere Island, Nunavut, Canada (80°N latitude) from July 2009 through mid-April 2010 by collaring a lead wolf with a Global Positioning System (GPS)/Argos radio collar. The collar recorded the wolf's precise locations at 6:00 a.m. and 6:00 p.m. daily and transmitted the locations by satellite to our email. Straight-line distances between consecutive 12-hr locations varied between 0 and 76 km. Mean (SE) linear distance between consecutive locations (n = 554) was 11 (0.5) km. Total minimum distance traveled was 5,979 km, and total area covered was 6,640 km(2), the largest wolf range reported. The wolf and presumably his pack once made a 263-km (straight-line distance) foray to the southeast during 19-28 January 2010, returning 29 January to 1 February at an average of 41 km/day straight-line distances between 12-hr locations. This study produced the first detailed movement information about any large mammal in the High Arctic, and the average movements during the dark period did not differ from those afterwards. Wolf movements during the dark period in the highest latitudes match those of the other seasons and generally those of wolves in lower latitudes, and, at least with the gross movements measurable by our methods, the 4-month period without direct sunlight produced little change in movements.

  13. Generation of 24.0 T at 4.2 K and 23.4 T at 27 K with a high-temperature superconductor coil in a 22.54 T background field

    NASA Astrophysics Data System (ADS)

    Ohkura, K.; Sato, K.; Ueyama, M.; Fujikami, Jun; Iwasa, Y.

    1995-09-01

    The 4.2 K and 27 K current-carrying performance of a high-temperature superconducting (HTS) coil was measured in background fields up to 22.54 T generated by a hybrid magnet (Hybrid III) at the MIT Francis Bitter National Magnet Laboratory. The coil, 40 mm winding i.d., 108 mm winding o.d., and 113 mm high, consists of 17 double pancakes, each wound with silver-sheathed BSCCO-2223 tapes. Each pancake is the product of a react-and-wind method. In total, the test coil contains ˜1200 m of BSCCO-2223 conductor weighing ˜7 kg. Prior to the measurements in Hybrid III, the coil was tested in zero background field in the temperature range from 4.2 to 77 K. It was coupled to a Gifford-McMahon type cryocooler and at 15 K generated a peak field of 2.1 T; at 18 K, it generated 1.9 T, operating continuously for ˜50 h. In a 22.54 T background field of Hybrid III, the coil reached critical currents of 116.5 A ([Jc]sc, critical current density based on the BSCCO cross-sectional area only, of 261 A/mm) at 4.2 K and 67 A ([Jc]sc=150 A/mm) at 27 K, establishing record net fields at respective temperatures of 24.0 and 23.4 T for HTS magnets. These currents correspond to overall winding current densities of 47 and 27 A/mm. High-field critical current data for short samples of the tape of the same formulation at 4.2 and 27 K are also presented. Although a [J]sc of 261 A/mm at 24 T and 4.2 K for the test coil is significantly less than ˜600 A/mm for the short samples at the same operating point, if factors such as length, bending, and even differences in defining critical current are considered, the coil and short samples have nearly the same critical current performance. Electromagnetic stresses do not seem to have any negative effects on coil performance. Record fields of 24.0 and 23.4 T were achieved after the test coil had experienced, over a period of 15 months, 20 thermal cycles between room temperature and cryogenic temperatures.

  14. Physical-chemical behavior of dietary and biliary lipids during intestinal digestion and absorption. 2. Phase analysis and aggregation states of luminal lipids during duodenal fat digestion in healthy adult human beings.

    PubMed

    Hernell, O; Staggers, J E; Carey, M C

    1990-02-27

    Following the feeding of a triacylglycerol-rich meal to healthy adult human beings, duodenal contents were aspirated for ex vivo chemical and physical-chemical analyses. The aspirates were collected during established lipid digestion and absorption into a "cocktail" of chemical inhibitors that rapidly inhibited ex vivo lipolysis. Following ultracentrifugation, the lipids separated into a floating oil layer, several interfacial layers, a "clear" or turbid "subphase", and a precipitated "pellet". By chemical and phase analyses, the floating layer was composed of oil-in-water emulsion particles with cores of triacylglycerol (TG), diacylglycerols (DG), and cholesteryl esters (CE) emulsified with a surface coat of partially ionized fatty acids (FA), monoacylglycerols (MG), diacylphosphatidylcholine (PL), and bile salts (BS). The interfacial layers contained similar emulsion particles dispersed among excess emulsifier which adopted a lamellar liquid-crystalline structure. Precipitated pellets were composed principally of emulsifying lipids, with smaller amounts of crystalline calcium soaps and BS. Relative lipid compositions of all but three subphases fell within a two-phase region of the condensed ternary phase diagram (Staggers et al., 1990, companion paper) where saturated mixed micelles composed of BS, FA "acid-soaps", MG, PL, cholesterol (Ch), and traces of DG (and TG) coexisted with unilamellar liquid-crystalline vesicles composed of the same lipids. Attempts to achieve clean separation of vesicles from micelles by repeat ultracentrifugation failed. Compared with the structure and sizes of lipid particles in equilibrated model systems (Staggers et al., 1990), quasielastic light scattering (QLS) analysis revealed that ex vivo micellar sizes (mean hydrodynamic radii, Rh) were similar (less than or equal to 40 A), whereas unilamellar vesicle sizes (Rh = 200-600 A) were appreciably smaller. Two-component QLS analysis of the subphases showed that much larger proportions

  15. Studies of beam dynamics in relativistic klystron two- beam accelerators

    NASA Astrophysics Data System (ADS)

    Lidia, Steven Michael

    , and output rf cavities over a 10 m distance. The simulations show that beam current losses are acceptable, and that longitudinal and transverse focusing techniques are sufficiently capable of maintaining a high degree of beam quality along the entire beamline. Additional experimental efforts are described. The first is the commissioning of the RTA injector. This electron gun produces a 1 MV, 600 A beam over a 250 ns pulse length. The post-injector beamline is described, and the battery of diagnostics is presented, with initial results reported. (Abstract shortened by UMI.)

  16. Autonomic innervation of the urogenital system: adrenergic and cholinergic elements.

    PubMed

    McConnell, J; Benson, G S; Wood, J G

    1982-01-01

    The major organs of the male urogenital (UG) system have been examined in various mammals, including man, using light and electron microscopic (EM) histochemical methods. For the light microscopic study, the urinary bladder, the vas deferens and the penis (corpora cavernosa and corpus spongiosum) were studied in the rat, cat, dog, monkey and man using a glyoxylic acid (GA) method modified for peripheral adrenergic nerve fibers, and a thiocholine method for acetylcholinesterase (AChE). Fine structural analysis was done on the vasa of rat, cat, monkey and man, and on the bladder and penis of cat, dog, monkey and man. Tissue was fixed in glutaraldehyde (GMO) as a control or in glutaraldehyde-dichromate (GDC) for the specific localization of norepinephrine (NE). All organs studied demonstrated numerous adrenergic nerve fibers throughout the muscular layers, in the connective tissue, and in the adventitia of most blood vessels. These fibers had a brilliant fluorescence when visualized with the GA method, and demonstrated many varicosities with small (400-600 A) and/or large (800-1200 A) granular vesicles in both control and GDC-fixed tissue examined with the EM. Evaluation of the vesicles with the analytical electron microscope (AEM) verified that those in the GDC-fixed tissue were chrome-positive, and, therefore, NE-containing. In the vas and penis, acetylcholinesterase(AChE)-positive nerve fibers were encountered less frequently at the light microscopic level than adrenergic fibers, and few typical cholinergic varicosities were seen in these organs with the EM. In the bladder, cholinergic nerves were seen with about the same frequency as adrenergic fibers in both light microscopic and EM preparations. Also observed frequently in each of the viscera were varicosities with large to very large (800-2000 A) granular vesicles of the kind presently hypothesized to be peptidergic or purinergic. Few varicosities of the type considered sensory, with large (800-1200 A) clear

  17. Lava Flow Ages and Geologic Mapping on Mid-ocean Ridges

    NASA Astrophysics Data System (ADS)

    Clague, D. A.; Paduan, J. B.; Dreyer, B. M.; Caress, D. W.

    2010-12-01

    of nearby samples commonly yield statistically identical ages, and a few cores where multiple layers were dated show increasing age with depth. Estimated flow ages are 550-7100 aBP for 10 samples from flows within ~1 km of historic flows at CoAxial, and 475-4600 aBP for 11 samples from flows within ~0.5 km of the 1986 North Cleft pillow mounds. Seven flows from the floor of Axial caldera range from 600 to 1160 aBP, whereas two flows from the southeast rim are 905 and 2005 aBP. These dated flows are plagioclase phyric with glass MgO>7.5%. Other flows on the caldera floor are aphyric, have glass MgO<7.3%, and have sediment too thin to sample. They are inferred to be <600 years BP. A significant change in the Axial Volcano magma reservoir apparently occurred ~600 aBP. A sample from 15 cm depth within a 2-m volcaniclastic unit on the eastern rim of the caldera is 6910 aBP and suggests formation of the caldera several tens of thousands aBP. A cone near a deep lava pond on the south rift of Axial Seamount is ~16,580 aBP. Five samples from the lava pond and nearby flows are 950-1510 aBP. Geologic maps of the ridge system can now be constructed in much the same way they have been done on land for many years.

  18. The Type IIb SN 2011dh: Two years of observations and modelling of the lightcurves

    NASA Astrophysics Data System (ADS)

    Ergon, M.; Jerkstrand, A.; Sollerman, J.; Elias-Rosa, N.; Fransson, C.; Fraser, M.; Pastorello, A.; Kotak, R.; Taubenberger, S.; Tomasella, L.; Valenti, S.; Benetti, S.; Helou, G.; Kasliwal, M. M.; Maund, J.; Smartt, S. J.; Spyromilio, J.

    2015-08-01

    We present optical and near-infrared (NIR) photometry and spectroscopy as well as modelling of the lightcurves of the Type IIb supernova (SN) 2011dh. Our extensive dataset, for which we present the observations obtained after day 100, spans two years, and complemented with Spitzer mid-infrared (MIR) data, we use it to build an optical-to-MIR bolometric lightcurve between days 3 and 732. To model the bolometric lightcurve before day 400 we use a grid of hydrodynamical SN models, which allows us to determine the errors in the derived quantities, and a bolometric correction determined with steady-state non-local thermodynamic equilibrium (NLTE) modelling. Using this method we find a helium core mass of 3.1+0.7-0.4 M⊙ for SN 2011dh, consistent within error bars with previous results obtained using the bolometric lightcurve before day 80. We compute bolometric and broad-band lightcurves between days 100 and 500 from spectral steady-state NLTE models, presented and discussed in a companion paper. The preferred 12 M⊙ (initial mass) model, previously found to agree well with the observed spectra, shows a good overall agreement with the observed lightcurves, although some discrepancies exist. Time-dependent NLTE modelling shows that after day ~600 a steady-state assumption is no longer valid. The radioactive energy deposition in this phase is likely dominated by the positrons emitted in the decay of 56Co, but seems insufficient to reproduce the lightcurves, and what energy source is dominating the emitted flux is unclear. We find an excess in the K and the MIR bands developing between days 100 and 250, during which an increase in the optical decline rate is also observed. A local origin of the excess is suggested by the depth of the He i 20 581 Å absorption. Steady-state NLTE models with a modest dust opacity in the core (τ = 0.44), turned on during this period, reproduce the observed behaviour, but an additional excess in the Spitzer 4.5 μm band remains. Carbon

  19. Basaltic Lava Channels

    NASA Astrophysics Data System (ADS)

    Cashman, K. V.; Griffiths, R. W.; Kerr, R. C.

    2004-12-01

    In Hawaii, the mode of lava transport - through open channels or through insulating lava tubes - determines the thermal, rheological, and emplacement history of a lava flow. Most Hawaiian lavas are erupted at near-liquidus temperatures and are therefore crystal-poor; lava transport through open channels allows rapid cooling and consequent rapid increases in lava crystallinity. Solidified aa flows resulting from channelized flow are typically fine-grained throughout their thickness, indicating cooling of the entire flow thickness during transport. In contrast, transport of lava through insulating tubes permits flow over long distances with little cooling. Flows emerging from such tubes typically have pahoehoe flow surfaces with glassy crusts. Groundmass textures that coarsen from the flow rind to the interior reflect rates of post-emplacement, rather than syn-emplacement, cooling. To distinguish eruption conditions that result in lava channels from those that allow formation of lava tubes, we have performed a series of laboratory experiments involving injection of PEG 600 (a wax with a Newtonian rheology and freezing temperature of 19ºC) into cold water through both uniform and non-uniform sloping channels. In uniform channels, tube formation can be distinguished from open channel flow using a dimensionless parameter based on a solidification time scale, an advection time scale, and a Rayleigh number that describes convection by heat loss from crust-free shear zones. Theoretical analysis predicts that in the open channel regime, the width of the crust (dc) will vary with the channel width (W) as dc = W5/3. Crustal coverage of non-uniform channels in both laboratory experiments and field examples from Kilauea Volcano, Hawaii, is consistent with this prediction. However, experiments in non-uniform channels illustrate additional controls on the surface coverage of lava channels. Most important is crustal extension resulting from flow acceleration through constrictions

  20. Electromagnetic earthquake triggering phenomena: State-of-the-art research and future developments

    NASA Astrophysics Data System (ADS)

    Zeigarnik, Vladimir; Novikov, Victor

    2014-05-01

    Developed in the 70s of the last century in Russia unique pulsed power systems based on solid propellant magneto-hydrodynamic (MHD) generators with an output of 10-500 MW and operation duration of 10 to 15 s were applied for an active electromagnetic monitoring of the Earth's crust to explore its deep structure, oil and gas electrical prospecting, and geophysical studies for earthquake prediction due to their high specific power parameters, portability, and a capability of operation under harsh climatic conditions. The most interesting and promising results were obtained during geophysical experiments at the test sites located at Pamir and Northern Tien Shan mountains, when after 1.5-2.5 kA electric current injection into the Earth crust through an 4 km-length emitting dipole the regional seismicity variations were observed (increase of number of weak earthquakes within a week). Laboratory experiments performed by different teams of the Institute of Physics of the Earth, Joint Institute for High Temperatures, and Research Station of Russian Academy of Sciences on observation of acoustic emission behavior of stressed rock samples during their processing by electric pulses demonstrated similar patterns - a burst of acoustic emission (formation of cracks) after application of current pulse to the sample. Based on the field and laboratory studies it was supposed that a new kind of earthquake triggering - electromagnetic initiation of weak seismic events has been observed, which may be used for the man-made electromagnetic safe release of accumulated tectonic stresses and, consequently, for earthquake hazard mitigation. For verification of this hypothesis some additional field experiments were carried out at the Bishkek geodynamic proving ground with application of pulsed ERGU-600 facility, which provides 600 A electric current in the emitting dipole. An analysis of spatio-temporal redistribution of weak regional seismicity after ERGU-600 pulses, as well as a response

  1. PROTOPLANETARY DISK MASSES FROM STARS TO BROWN DWARFS

    SciTech Connect

    Mohanty, Subhanjoy; Mortlock, Daniel; Greaves, Jane; Pascucci, Ilaria; Apai, Daniel; Scholz, Aleks; Thompson, Mark; Lodato, Giuseppe; Looper, Dagny

    2013-08-20

    We present SCUBA-2 850 {mu}m observations of seven very low mass stars (VLMS) and brown dwarfs (BDs). Three are in Taurus and four in the TW Hydrae Association (TWA), and all are classical T Tauri (cTT) analogs. We detect two of the three Taurus disks (one only marginally), but none of the TWA ones. For standard grains in cTT disks, our 3{sigma} limits correspond to a dust mass of 1.2 M{sub Circled-Plus} in Taurus and a mere 0.2 M{sub Circled-Plus} in the TWA (3-10 Multiplication-Sign deeper than previous work). We combine our data with other submillimeter/millimeter (sub-mm/mm) surveys of Taurus, {rho} Oph, and the TWA to investigate the trends in disk mass and grain growth during the cTT phase. Assuming a gas-to-dust mass ratio of 100:1 and fiducial surface density and temperature profiles guided by current data, we find the following. (1) The minimum disk outer radius required to explain the upper envelope of sub-mm/mm fluxes is {approx}100 AU for intermediate-mass stars, solar types, and VLMS, and {approx}20 AU for BDs. (2) While the upper envelope of apparent disk masses increases with M{sub *} from BDs to VLMS to solar-type stars, no such increase is observed from solar-type to intermediate-mass stars. We propose this is due to enhanced photoevaporation around intermediate stellar masses. (3) Many of the disks around Taurus and {rho} Oph intermediate-mass and solar-type stars evince an opacity index of {beta} {approx} 0-1, indicating significant grain growth. Of the only four VLMS/BDs in these regions with multi-wavelength measurements, three are consistent with considerable grain growth, though optically thick disks are not ruled out. (4) For the TWA VLMS (TWA 30A and B), combining our 850 {mu}m fluxes with the known accretion rates and ages suggests substantial grain growth by 10 Myr, comparable to that in the previously studied TWA cTTs Hen 3-600A and TW Hya. The degree of grain growth in the TWA BDs (2M1207A and SSPM1102) remains largely unknown. (5) A

  2. Correcting for initial Th in speleothems to obtain the age of calcite nucleation after a growth hiatus

    NASA Astrophysics Data System (ADS)

    Richards, D. A.; Nita, D. C.; Moseley, G. E.; Hoffmann, D. L.; Standish, C. D.; Smart, P. L.; Edwards, R.

    2013-12-01

    contiguous layers sub-sampled from the first 2-3 mm of flowstone growth after the MIS 5 hiatus, using a sub-sample milling strategy that matches spatial resolution with maximum achievable precision (ThermoFinnigan Neptune MC-ICPMS methodology; 20-30 mg calcite, U = ~ 300 ng.g-1, 2σ age uncertainty is × 600 a at ~80 ka). Isochron methods are used to estimate the range of initial 230Th/232Th ratio and are compared with elevated values obtained from stalagmites from the same cave (Beck et al, 2001; Hoffmann et al, 2010). A similar strategy is presented for a stalagmite with much faster axial growth data, and the data are combined with additional sea level information from the same region to estimate the rate and uncertainty of sea level regression at the MIS stage 5/4 boundary. Elevated initial 230Th/232Th values have also been observed in a stalagmite from 6 m below present sea level in a cenote from the Yucatan, Mexico, where 5 phases of calcite between 10 and 5.5 ka are separated by serpulid worm tubes formed during periods of submergence. The transition between each phase provides constraints on age and elevation of relative sea level, but the former is hampered by the uncertainty of the high initial 230Th/232Th correction. We consider the possible sources of elevated Th ratios: hydrogenous, colloidal and carbonate or other detrital components.

  3. Processing and characterization of superconducting solenoids made of Bi-2212/Ag-alloy multifilament round wire for high field magnet applications

    NASA Astrophysics Data System (ADS)

    Chen, Peng

    As the only high temperature superconductor with round wire (RW) geometry, Bi2Sr2CaCu2O8+x (Bi-2212) superconducting wire has the advantages of being multi-filamentary, macroscopically isotropic and twistable. With overpressure (OP) processing techniques recently developed by our group at the National High Magnetic Field Laboratory (NHMFL), the engineering current density (Je) of Bi-2212 RW can be dramatically increased. For example, Je of more than 600 A/mm 2 (4.2 K and 20 T) is achieved after 100 bar OP processing. With these intrinsically beneficial properties and recent processing progress, Bi-2212 RW has become very attractive for high field magnet applications, especially for nuclear magnetic resonance (NMR) magnets and accelerator magnets etc. This thesis summarizes my graduate study on Bi-2212 solenoids for high field and high homogeneity NMR magnet applications, which mainly includes performance study of Bi-2212 RW insulations, 1 bar and OP processing study of Bi-2212 solenoids, and development of superconducting joints between Bi-2212 RW conductors. Electrical insulation is one of the key components of Bi-2212 coils to provide sufficient electrical standoff within coil winding pack. A TiO 2/polymer insulation offered by nGimat LLC was systematically investigated by differential thermal analysis (DTA), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), dielectric property measurements, and transport critical current (Ic) property measurements. About 29% of the insulation by weight is polymer. When the Bi-2212 wire is fully heat treated, this decomposes with slow heating to 400 °C in flowing O2. After the full reaction, we found that the TiO2 did not degrade the critical current properties, adhered well to the conductor, and provided a breakdown voltage of more than 100 V. A Bi-2212 RW wound solenoid coil was built using this insulation being offered by nGimat LLC. The coil resistance was constant through coil winding, polymer burn

  4. Farmyard Manure and Fertilizer Effects on Seed Potato (Solanum tuberosum L.) Yield in Green House Production

    NASA Astrophysics Data System (ADS)

    László, M.

    2009-04-01

    alta potencialidade (boa textura e adequada retenção de agua). Efeito do nitrogênio No Brazíl em todas regiões onde se cultiva batata é raro encontrar solos com elevado teor de nitrogênio e que não precisam de quantidades desta elemento. É o elemento que governa o padrão de desenvolvimento da planta, estimulando principalmente o crescimento da parte aérea (Kádár et all. 2000., László 2000.). Para se obter rendimento de tubérculos é necessário um rápido e curto periodo de desenvolvimento da parte aérea e uma fase de acúmulo maior possível. Para tanto, devem ser evitadas doses muito altas de nitrogênio e, principalmente, se aplicadas tardiamente, pois haverá demasiado desenvolvimento de folhas que demorarão mais a finalizar seu crescimento e maturação. Isto implicará na redução do periodo de intenso desenvolvimento dos tubérculos e armazenagem do amido, resultando em menor produção. Há risco para a saúde na ingestão de alimentos com altos teores de nitrato e nitrito, havendo preocupação com o efeito de doses mais altas de nitrogênio sobre os teores dos mesmos nos tuberculos. Embora haja diferenças entre cultivares, localidades e períodos de armazenamento, há estudos mostrando que a fertilização com até 150 kg ha-1 de nitrogênio não foi suficiente para propiciar niveis preocupantes de nitrato nos tuberculos colhidos. Efeito do fósforo A grande maioria dos solos brasileiros cultivados com batata apresentam limitações ao bom desenvolvimento e produção da cultura em função dos baixos níveis de fósforo. Isto significa que aumentos de produção quase sempre ocorrem quando o solo recebe adubação fosfatada (László 2001a.). Estes aumentos são mais marcantes em solos nunca antes adubados ou com baixo teor de fósforo. Nestes, dificilmente alcanca- se a produção máxima com níveis reduzidos de fósforo. Não seria exagerado supor níveis de 600 a 800 kg ha-1 de P2O5, como sendo aqueles que iriam proporcionar produ

  5. UVES Analyses the Universe: A First Portfolio of Most Promising Results

    NASA Astrophysics Data System (ADS)

    2000-04-01

    type of observation. ESO PR Photo 09b/00 ESO PR Photo 09b/00 [Preview - JPEG: 400 x 337 pix - 39k] [Normal - JPEG: 800 x 673 pix - 84k] Caption : ESO PR Photo 09b/00 shows a spectrum of the metal-poor star G271-162 in the red spectral region around the Li-line at 671 nm that is used to derive the lithium isotopic ratio. The wavelengths of the doublet components of the two isotopes are indicated. The total exposure time was 3 hours and the S/N-ratio in the continuum region is above 600 - a most satisfactory result considering that the CCD fringing amplitude is more than 20% at these wavelengths. The open circles correspond to the observed data and the fully drawn line to a model atmosphere synthesis with isotopic ratio 6 Li/ 7 Li = 0.02; see the text. The inserted profile of a nearby thorium line from the calibration lamp represents the instrumental profile of UVES ; it has Full-Width-Half-Maximum (FWHM) of 0.056 mÅ, corresponding to a resolution of R = 112,000. The stellar line broadening function needed for such a study is determined from several other lines available in the recorded UVES spectrum. An important byproduct of this spectrum is detailed knowledge about the turbulent motions in the atmosphere of the star. The UVES observation of the metal-poor ([Fe/H] = -2.2) halo star G271-162 (V = 10.35) at a spectral resolution ~ 110,000 was included in the commissioning programme to prove this instrumental capability. This star is representative of a group of about 50 halo turn-off stars that are too faint to be studied with high-resolution spectrographs at 4-m class telescopes. A total of around 3 hours of integration was obtained in excellent seeing through a slit opened to 0.3 arcsec. The S/N of the summed, reduced spectrum, cf. PR Photo 09b/00 , is higher than 600. It is obvious that the profile of the Li line in G271-162 is considerably broader than the instrumental profile. This is due to Doppler-broadening in the stellar atmosphere, caused by thermal and gas